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MikeJohns
01-31-2007, 08:11 PM
Randy

I’m sorry I never meant to offend you in this way. It was not intentional. I do not think you a fool, your posts show that you are intelligent. I would have been more careful not to offend you but from your own style I am surprised you are so fragile.

We are apparently going about this discussion the wrong way and I am not making myself clear enough.

Hidden in some fairly long posts is the crux of the issue that I was debating; that of heavier rigs adding stability through increased roll inertia but we quickly get off the subject as I want to illustrate:

[Randy]Heavy rigs also reduce static stability

[] Heavy rigs reduce stability, from what condition? ………..Do you understand design metacentric height and all that entails wrt motion and stability?

[Randy] I think that a higher centre of gravity is less stable than a low centre of gravity.

[] You are confusing matacentric height and COG. We all know about COG, this wasn’t what I asked you.

[Randy] Metacentric height is not relevant when discussing angles greater than about 10 degrees.

Then you get stuck on GM. This is not what I wanted to discuss with you but simply the fact that a heavier rig is one way of adding roll inertia and consequently reducing the chance of knockdown. In fact the roll inertia is significantly more effective at resisting violent knockdown than the position of the COG. We’ve ended up with you on a limb way off the original subject.

Then PI joins the fray (and now Crag) jumping on GM.

[PI] GM is only an indication of initial (small angle) stability.

Now PI is an Engineer too and wanted to explain that I knew I was popularizing a complex system. I still think that considering what happens to the GM of a vessel if you changed from a heavier to a lighter rig to be a good illustration.

[me to PI] I wanted to know if he [Randy] really understands what happens if you remove a heavy mast and replace it with a light mast on the basis that it will improve stability. The easiest way of illustrating this is to consider what happens to GM. Anyone aware of the issues is immediately aware of the ramifications. ……. I shudder to think…..

Injury and death is what I am “shuddering” about, and I should have explained that in my head I saw a carbon-fiber pole being installed in a more extreme heavy displacement boat and I perhaps I should have illustrated the example, but I was addressing PI and this issue is taught to NA’s.
The resulting (horrible to contemplate) is people literally flung about due to a combination of lower gyradius and a lowered COG.

There is a classic in the shipping industry usually taught to all the budding NA’s, the Ore Carriers where the designers did not consider what would happen to the boat motion when in the loaded condition, the COG was fantastic when loaded but GM went through the roof (literally) many injuries resulted.

Frankly as I have said before I don’t want to get drawn into comparing existing boats because the comparisons are so subjective even the published data can be amiss unless it is a properly vetted scientific study. We have just seen Vega and Guillermo trying to do this.

I hope you have a hangover (from the drunken Rigger). Please come back, it shouldn’t end like this. Perhaps if I promise to capitalize Rigger. Mea Culpa.

RHough
02-01-2007, 02:22 AM
Hey folks. No apologies needed.

I think that it is a measure of the posters in this thread that they were offered.

Not as excuse (since I sometimes winch at the tone of my own posts), but as explanation; my job requires that I bite my tongue when a customer wants to do something clearly idiotic to their boat. I'm afraid I allow my stress level from work to colour my posts here. Mike has been my target too often.

It is hard to make sure we are using terms in the same way. And for some of the posters English is not their primary language, thus adding to the difficulty.

In all honesty, I should try not to spend any more time on this thread for the next two weeks or so. I need to concentrate on a boat show. I cannot allow my frustrations with this thread effect my work, and I should not allow frustrations at work to effect my thinking and posts here.

One thing is abundantly clear to me. Sailing craft are beautifully simple and very complex at the same time. It seems the more I learn, the less I know. My ego is large enough to think that most (if not all) people that try to understand sailboats from a scientific standpoint must share that view to some extent. A better understanding of "why things work that way" has been my motivation for every pastime I've enjoyed over the years. I have taken breaks from sailing, but always return. Sailboats are an endless puzzle to me. Trying to reach a level of understanding that I am comfortable with continues to elude me. Racing motorcycles and cars, building successful racing engines, learning to build, fly and design successful R/C sailplanes all seem like trivial pursuits compared to the complexity of sailboats. :(

Not on topic in this thread, but one of the puzzles of sailboats is trying to evaluate overlapping sail area.

Another is the relationship between lateral hull area and sail plan and how that relationship effects helm balance.

Stability and motion could provide another decade of interesting research.

I'm running out of decades and it bothers me. I apologize for taking my frustrations out in this thread.

Walt Kelly's Pogo:

Guillermo
02-01-2007, 03:11 AM
I would like now to do some analyzing for the Valiant. The presented numbers for its STIX are only a gross estimative, the same way the MOC's STIX for the Pogo a few posts ago were. Maybe both are wrong, but as I have worked them down both the same way, I expect them to be comparable. Let's see:
(Figures in brackets are from the Pogo 40, to compare)

VALIANT 40

Lh = 12,16 m
Lwl = 10,36 m
Bmax = 3,76 m
Bwl = 3,38 m
Draught T = 1,83 m
Body draught Tc = 1,17 m
Disp = 10206 kg
Ballast, fix = 3500 kg
Sail area = 71,7 m2
Heeling Arm = 7,50 m
Angle of vanishing stability = 125 deg
Downflooding angle 110 = deg
GZ at downflooding angle = 0,21 m
GZ at 90 degrees = 0,53 m
Area to flooding (Agz) = 42 m.deg
Area to AVS = 47 m.deg

From those I get:

Length/Beam Ratio L/B = 2,9 (2,74)
Ballast/Disp Ratio W/Disp = 0,34 (0,34)
Displacement/Length Ratio D/L = 256,01 (84,91)
Sail Area/Disp. Ratio SA/D = 15,49 (30,09)
Velocity Ratio VR = 1,05 (1,33)
Capsize Safety Factor CSF = 1,75 (2,55)
Motion Comfort Ratio MCR = 33,99 (12,92)
Roll Period T = 3,36 Sec (1,66)
Roll Acceleration Acc = 0,09 G's (0,44)
Stability Index SI = 0,89 (0,38)

STIX:

Base Length Factor (LBS) = 10,960 (12,080)
Displacement Length Factor (FDL) = 1,036 (0,891)
Beam Displacement Factor (FBD) = 1,061 (0,744)
Knockdown Recovery Factor (FKR) = 1,367 (1,075)
Inversion Recovery Factor (FIR) = 1,054 (1,044)
Dynamic Stability Factor (FDS) = 0,762 (1,500)
Wind Moment Factor (FWM) = 1,000 (1,000)
Downflooding Factor (FDF) = 1,222 (1,222)
Delta 0

STIX = 38,440

So, although being the 'Old ratios' much more appealing (to me) from a cruising point of view, Valiant 40's STIX (Something like 38) is lower than POGO's one (Something like 40) in spite Valiant's factors being better than Pogo's except for two: The Dynamic Stability Factor (FDS) and the Base Length Factor (LBS).

So we can realize here the huge effect of the bulbed keel (Influencing FDS) and the waterline length (Influencing LBS) of the Pogo 40, allowing her to reach STIX values higher than the Valiant 40 ones, being the Valiant a proved oceangoing boat with probably hundreds of thousands of successful miles under her keel. This is one of the reasons I do not like how STIX works.

Crag Cay
02-01-2007, 04:54 AM
Injury and death is what I am “shuddering” about, and I should have explained that in my head I saw a carbon-fiber pole being installed in a more extreme heavy displacement boat ................ The resulting (horrible to contemplate) is people literally flung about due to a combination of lower gyradius and a lowered COG.
That does sound horrific. As carbon replacement masts are not uncommon, you must have links to accounts where this has happened. And what about where a manufacturer offers a carbon mast option - surely those choosing the more expensive 'upgrade' must be beating a path to the law courts if it results in 'death and injury'? Do you have any case studies?

We're all aware of the research done after the Fasnet on rig inertia preventing rolling, and rig loss' contribution to being rolled repeatedly, but do you have any more contemporary studies on these problems with light weight rigs? What values of GM do you use when designing a 40ft sail cruising boat? What trade offs do you make to achieve this? Do you prioritise achieving your ideal GM over, say, righting moment or AVS?

If you have the time, I would also appreciate more information about the limitations Australians have about STIX and "it's wave height of 7m for offshore being considered too low". Any feedback is useful.

Man Overboard
02-01-2007, 06:23 PM
Crag Cay
Here is a link to a document titled

'Submission to Modify the Australian Yachting Federation Special Regulations Part 1, Appendix D Resistance to Capsize’


Prepared by Richard Slater
PO Box 800, Mona Vale NSW 1660
Phone: +61 2 9973 4111
Mobile: +61 (0) 414 752 837

http://www.yachting.org.au/site/yachting/ayf/downloads/Technical/Agendas/Stability%20Submission%20Paper.pdf

I don’t know if this document will help, but it references STIX as it is viewed in Australian racing circles. The document was prepared in 2003; it is primarily about the effects of the AYF 10 degree rule regarding movable ballast, and its insufficiency on determining and /or increasing capsize resistance.

An excerpt:
It is the Static Angle of Heel requirements that this submission questions. This submission also attempts to suggest suitable alternative arrangements to deal with the range of new designs appearing in the sport. The appearance of yachts with canting keels has stirred debate in Australian yachting
circles; with many people misunderstanding the rules and issues that currently govern boats with moveable ballast. Yachts with canting keels are legal in Australia when raced under IRC. There is no safety rule that specifically prohibits canting keel yachts. It is the fixed limit of 10 degrees of static angle of heel that many of the canting keel yachts fail to satisfy and it is the static angle of heel requirement that is being questioned in this submission.


The section that deals with STIX reads as follows: (2003):

The use of STIX in Australia is limited at this time. Mainly because the highest level STIX (Design category A) has the following parameters:
Wave height: up to approx 7 m significant (highest 1/3rd of waves)
Typical Beaufort wind force up to 10
Calculation wind speed (m/s) 28
When considering many Ocean Races include sailing in Southern Australia / Bass Straight these parameters seem low. One option that we have canvassed to RORC is the possibility that a design category can be set with the above variables increased. However this discussion is separate to this submission.

You may be able to contact Mr. Slater and get more info.

Crag Cay
02-01-2007, 07:07 PM
Thanks for that, however I was hoping someone had some information that updated the situation since that was written.

I was wondering if Appendix K to the ISAF OSR 2006 had addressed any of their concerns with regards to screening vessels with movable ballast.

As to the general reservations expressed concerning STIX, I'm still unclear exactly where the problem lies. The STIX requirement for ISO Cat A is pretty much irrelevant to racing (and certainly beyond the control of the RORC), except that there is the option of allowing ISO (CE) Catorgarised vessels to use that as their proof of STIX. (Para 3.04.4) However this is only 'allowable' if the race organisers consent.

The RORC is emphatic that " ... Organising Authorities may incorporate a minimum qualifying STIX for entry to a race. Responsibility for selection of the minimum qualifying value(s), and for any AVS requirement(s), lies with the Organising Authority for a race. It is not possible for the RORC Rating Office, nor any other body remote from the organisation of a race, to lay down firm recommendations or guidance. Only the organisers of a race can be fully aware of the circumstances of a particular race. The RORC does not accept responsibility for the consequences of the mis-use of these systems ( SSSN, STIX or RORC STIX), which are a guide and not a guarantee."

Surely the Australians can set their minimum STIX requirement at whatever level they feel appropriate for racing in their area?

MikeJohns
02-01-2007, 08:14 PM
Crag
Sorry for the delay , I have some work to finish and what you are asking requires some effort.

The STIX consideration is knocking around along with a discussion document not for racing but for non-commercial craft. I will try to find it. As with the US we currently have no such labeling but so far there is no inclination to adopt the EU STIX we may be far better to make full stability info mandatory. My own concerns are similar to Guillermo's on this issue. In that it is a rule that can be manipulated.
(I have decades of papers poorly filed and I have a cleaner who punishes me when she tries to find the floor in my office by stacking documents anywhere ) or it may be a pdf I will look later.

As for metacentric height (both trans. and longnl.) we have used this a lot particulalrly redesigning vessels, in new designs it is always a considered although the general equations are reasonably accurate there is a more involved method, and I'm sure it is presented in one of the common yacht engineering books proably Marchaj's earo-hydro?.

We have some fairly sophisticated sreadsheets and though the numbers are used the underlying maths is sufficiently complex to require some explanation and some re-understanding on my part.

I'll try and write something for you or find a synopsis. Generally you want around 900 to 1000 (trans) for a sailboat. Before I go any farther do you specifically want this? There is quite a complexity in this relationship of motion, stability, mass distribution and hullform.




cheers

MikeJohns
02-02-2007, 06:38 AM
Crag
If you have "Design of sailing yachts" PGutelle 2nd ed revised
Have a look at page 199. This should give you a good primer.

Cheers

Crag Cay
02-02-2007, 07:11 AM
Hi Mike, Don't go digging out any references as I probably have most of them here. (Edit: I wrote this before seeing your reply above) However as you came across as a very passionate advocate of GM as a basic design tool that prevents death and serious injury, I was really after an insight into how you use GM in practice when designing a cruising sailboat (of say 40ft as that is the sort of size that has caused so much debate).

What priority do you place on achieving your ideal figure (900-1000mm) and what other parameters do you compromise to achieve this? Is it roll period and comfort levels you are trying to achieve? How do you differentiate between a boat like a Contessa 32 and Grimalkin which had identical GM's but very different desirable and undesirable characteristics?

Over the years I've noticed a shift in the emphasis that GM gets in text books. Gutelle had us constructing 'metacentric curves' although suggested that 'the real stability is best shown by a righting moment curve' and Marchaj made extensive reference to it, but more recently, there's mention of it in Larsson & Eliasson and even less in Claughton, Wellicome & Shenoi.

So I would appreciate your insight as an active practitioner of its use. I must confess that in all my designs I have not given it much consideration beyond using the steepness of the 0-10/20 degree portion of the RM curve to indicated initial stiffness. It kept me awake last night worrying that perhaps the reason I have not had any complaints from clients is perhaps they have all perished in those accidents you foresee! The only solace I could muster was to think that there no combination of monohull and lightweight rig that could achieve the GM of a Wharram cat and the last time I saw James and Hanneke, they seemed okay.

The only example of a sailing yacht design being driven by a target GM that I could think of, was the two editions of the Chay Blyth Challenge yachts. I know his design brief included a stiffness limitation so Lewmar 65's could be used as the primaries. This was his way of ensuring loads (and accelerations) did not get above a 'safe level' for his paying crew clients.

As to the other matter, I appreciate the RCD does not extend to Australia or the US. Using more detailed stability information may indeed serve the boat buying public better, but the quote was from someone concerned about the screening of race entries. In this context STIX should be seen as the current manifestation of the old SSSN system or IMS Stability Index, and has precious little to do with ISO, CE, Cat A, 7m waves or the like. As I have quoted earlier, local organisers are encouraged to set a level of STIX and AVS that they feel is commensurate with the conditions in their race area. If people (Guillermo ) feel that some parameters inputed into STIX are unduly weighted, then I'm sure these will be considered in either revising ISO STIX (unlikely) or its variant RORC STIX. A lot of work has been done since Richard Slater voiced his concerns in 2003 with both a revision of the ISAF OSR and IMOCA regulations. I'm not sure quoted him really moves the debate about seaworthiness forward in any meaningful way.

hiracer
02-02-2007, 08:33 PM
A boat that hits something and then sinks is not a seaworthy boat. IMO.

There is more to crossing oceans than stability, steerage, and speed. The ocean is getting more littered every day. People say the ocean doesn't change. Well, it does and in this case not for the better.

Speed and light weight don't work too well for impact resistance. Never has, and never will. Either gain weight and go slower, or ignore the risk. As I see it, those are the only two options.

As soon as you design for impact resistance, unless your client's wallet is like the department of defense, at LOA 40 feet you are going to end up with either a medium or heavy displacment sailboat. That displacement restricts a lot of design options. Cruising sailboat design takes on a center of gravity, so to speak.

IMO, you can deviate from this center of gravity only by ignoring impact resistance, which is exactly is what is done as best as I can see it. That's what liferafts, EBRIPs, and helicopters are all about.

Note: There are cruisers who sail the oceans without liferafts (Lynn and Larry Pardey come to mind) and to the best of my knowledge not one of them do it in a light go-fast boat.

Which brings to mind a line out of one of the HANK THE COWDOG series of books that my kids used to like so much: "Junior, how many times have I got to tell you, speed kills. And the speedier you go, the killier you get. If you're not careful, one of these days you're liable to wake up dead."

There, I've done it. Quoted Hank the Cow Dog in sailboat forum. I'm pretty sure that's a first. :)

Man Overboard
02-02-2007, 09:32 PM
Hiracer:
Speed and light weight don't work too well for impact resistance.

There are more ways to design for impact resistance than traditional heavy hulls. In my preliminary design concept for my own cruiser, all of my tankage is low profile integral tanks built below the waterline. (as part of the hull). In addition, integral water ballast tanks allow me to adjust moments of inertia for various conditions, to alter pitching and rolling; and of course to reduce heel angle. If properly designed and built, this concept provides a double hull below the waterline to help protect in the event of a hull breach. Although I don’t think it could be considered ULDB, the overall design can be considerably lighter than, other traditional methods of construction, especially when coupled with water ballast. The dual purpose use of tanks helps defray the cost (in terms of dollars, and weight) through the efficient use of materials. This isn’t a new concept of course, but more precisely an extension of an old idea to include water ballast and double hull construction below the waterline for extra protection, and flexibility in design.

RHough
02-02-2007, 11:38 PM
A boat that hits something and then sinks is not a seaworthy boat. IMO.

There is more to crossing oceans than stability, steerage, and speed. The ocean is getting more littered every day. People say the ocean doesn't change. Well, it does and in this case not for the better.

Speed and light weight don't work too well for impact resistance. Never has, and never will. Either gain weight and go slower, or ignore the risk. As I see it, those are the only two options.

As soon as you design for impact resistance, unless your client's wallet is like the department of defense, at LOA 40 feet you are going to end up with either a medium or heavy displacment sailboat. That displacement restricts a lot of design options...


Here is what the designer of the Pogo has to say:

The work achieved by skippers, builders and designers makes it possible today to cross the Atlantic single-handed in just over 8 days. Everyone can now dream of playing with the wind, the sea and the waves.

Still, we are worried about imponderables :
Lexibook, Hervé Papin’s Pogo 40, hit a container at 10 knots, causing the boat to halt suddenly. The outcome was limited to a big scare and a dent at the front of the bulb, and both boat and skipper were able to carry on with the race.

In the same vicinity, just a few hours earlier, in a strong, gusty wind, TMI Technologies, Joe Seeten’s boat, was sailing an average 17-20 knots, when it stopped extremely violently at the bottom of a wave. « Something extraordinary » even for Joe’s extensive experience. Did he hit a floating object, an animal or a rogue wave ?
Joe, thrown by the shock to the opposite side of the cabin, broke his shoulder and cut his forehead. The water was rushing inside the boat when Joe noticed that the bond between the keel and the boat’s structure had been damaged. A few hours later, he was rescued by a cargo ship.

Passive security systems performed perfectly, especially the buoyancy volumes, with the boat floating even with 50 cm of water inside.
The builder, and us designers, permanently wary about the strength of our boats, apply safety factors twice superior to those usually recommended by standards and norms. Nevertheless, we are still left to wonder if these precautions are sufficient enough considering the high speed these boats can reach nowadays.

It is necessary for everyone to consider that no one is safe from risks at sea (floating objects, waves too large for the boat past a certain speed)
It would surely prove an excellent idea that skippers, race promoters, builders and designers get together to give this a constructive thought…"

Groupe Finot (http://www.finot.com/nouvelles/actucourse/1206rhum_class40_ang.htm)

(bold mine)

10 knots and 17-20 knots ... One continues the race, the other didn't sink and the injured skipper was taken off.

Seems that the designer has some concerns and tries to design extra strength into the boats "just in case". It also appears that they have made a good job of it ... and they did it in a 4800 KG 40 foot boat. Maybe the designer knows just a bit more that the people that say a boat must be heavy to be strong? They also managed to build and sell it for 125,000 Euro, the defense budget of a very small contry. :D

Guillermo
02-03-2007, 02:13 AM
...Seems that the designer has some concerns and tries to design extra strength into the boats "just in case".
Randy,
I would like to know how they manage to get that D/L ratio under 85. It is usually asumed in the industry that for usual construction materials and techniques, for an all around cruising design, is difficult to get a figure under 200. We can go somewhat lower than that, certainly, but....85?

Let's have a look at some intimacies of her basic specs:
(taken from: http://www.pogostructures.com/files/Pogo_15-9-2006_16:43:58.pdf)

Hull in GRP made by infusion with multiaxial glass tissues
Deck in PVC foam sandwich, glass, polyester made by infusion
Structure in GRP/PVC foam made by infusion
Buoyancy, 3m3 in close cells foam.

Carbon mast autoclave cured prepreg , 2 aluminium spreaders levels
aluminium boom, carbon bow sprit
monotoron stainless steel riggings, textil backstay and babystay,
vane, spectra halyards, deck sheets and ropes spectra and polyester

Deck hardware Harken, Wichard, Frederiksen (including spinaker items)
Spécific stainless steel ironware
Pullpit, pushpits, stanchions, all chain plates
Goiot portlights and hatches, GRP hood, lifelines, deck cleats

Keel, 2 draft choices : 2,20m or 3m
High strenght iron fin with GRP outline shape
lead bulb
Rudders blades in GRP with high strenght stainless steel rudder shaft
Spheric bearings with needles in the bottom one
Carbon tillers

Water ballast system 2x750L, filling pump, transfert knife valve

Inside fitting
Central charts tables / kitchen with cooker and sink
3x20L water tank, WC, tissue doors, cushions

Engine 30 hp VOLVO Sail Drive,
battery 55 Ah

No info on fuel storage

From my point of view this spec is a very scarce one. Accomodation looks very spartan (as per images and spec) and provided water tanks and battery capacity seem clearly insufficient for serious cruising. So it keeps looking to me what it always has: A boat conceived for exilarating short term coastal cruising, with no much more personal equipment that your swimsuit. A nice boat for that. Occasional quick, light crossings with short crew are possible, indeed, but, again in my opinion, that's its most.

What happens if you load it with all water, fuel, stores and personal items needed for a 6 people crew for, let's say, an atlantic circuit (europe, canaries, caribbean, bermuda, açores, europe)? Not to talk about those hundreds of kilos a cruiser accumulates of books and souvenirs from visited ports, or either high latitudes cruising equipment. An this not only from the point of view of performance and seakeeping abilities, but also from the point of view of possible structural overloads.

And, what about materials fatigue? Properly cruising purpose built and reasonably maintained 'slow' heavy/medium-weighters have been around here for decades in a healthy condition, even if severely punished. Are these fancy extra-light designs going to be there in, let's say, a 30 years time of globetrotting? or, at what cost? I would like to know.

On its price: Total EX-WORKS price excluding taxes is 145876 euros, for this very, very basic spec. Even CE mandatory items such as the holding tank or bilge pumps are optional. So, what's the final price for cruising mode? Adding items from their option list I come to a figure of 186.973 euros with the medium priced electronic package, but some items' prices seem not to include installation. Knowing what I know after having purchased several boats myself, having had several responsibilities at pleasure boat yards, and after quite some surveying and appraising activity, my opinion is that Pogo's cruising 'go sailing' price may very well be around 200.000 euros, ex-taxes (+/- 250.000 USD). And this without sails. Nor personalized caprices.

Has somebody asked for a quotation?

More:
"Lexibook, Hervé Papin’s Pogo 40, hit a container at 10 knots, causing the boat to halt suddenly. The outcome was limited to a big scare and a dent at the front of the bulb..."

I would like to have had the opportunity of performing a thoroughful inspection to the hull and structure at the aft end of the keel-hull joint. I have my doubts.

Cheers.

Guillermo
02-03-2007, 04:00 AM
If properly designed and built, this concept provides a double hull below the waterline to help protect in the event of a hull breach.....
What's the size of your design?
Cheers.

rayk
02-03-2007, 05:28 AM
...water was rushing inside the boat when Joe noticed that the bond between the keel and the boat’s structure had been damaged. A few hours later, he was rescued by a cargo ship.

Good grief.

Man Overboard
02-03-2007, 05:42 AM
Guillermo,
If the budget pans out, between 70 and 80 feet(21 to 24 meters)I'm a ways out before I can start construction. In the mean time I have much studying to do.

CT 249
02-03-2007, 07:12 AM
Even the Dashews have reported the benefits of water ballast tanks fwd in their speedy cruisers.

Off the top of my head regarding studies, have you seen the Stevens Institute 12 meter studies on this? As the pitch Inertia increased the spectra response was studied.
Looking up a synopsis.... Resistance caused by wavelengths of between 6 and 15 metres decreased, from 15 to 25m the resistance was higher. The conclusion is that Cutting through a wave can be better than pitching over it and the forward energy absorbed depends on the resulting flow field against the energy loss of pitching effects.

These changes are significant enough for a racing boat to take this seriously, and significant enough for people not to generalize about it being detrimental.

As for Sydney:p
I have been more sea-sick sailing out of Sydney on small vessels than any other port in the world! Something to do with two predominant swell directions and those cliffs. I’ve only had light breezes on every departure I've made there. Sailing out of small Southern Pacific islands ( like the southern Cooks) the sea is incredibly boisterous with a large underlying swell (and you are in deep ocean blue water conditions 10 minutes after clearing the reef) but you have over 20 knots of wind constant, the difference is significantly more comfortable. Even there, whether you want the weight in the ends depends on your course relative to the sea, and the length of the boat.

Usually you cannot be bothered shifting the weight around particulalry at sea, you just sail a more comfortable course, but the racers are stuck on the fastest route and would benefit more from this alteration of pitch inertia.

I'm not up with the big racing boats but surely they would do this with water if allowed?

It's an interesting study, but it deals with a very unusual style of boat that has a very unusual motion in any case. Australia II was well known to have had poor motion due to excess weight in the ends (ie the end of the keel) compared to other 12s. This was noted before the boat even arrived in the USA.

And I think we can safely say that none of the other 12 Metre design/test teams, who would almost certainly have spent vastly more time and effort in testing their designs than the Stevens Institute, ever tried to increase the weight in the ends. The "Glassgate" incident in Perth 1987 was mainly about the fear that other syndicates had that the Kiwi GRP boats had superior weight concentration. This is spelled out in the Farr/Bowler bio and Conner's "Comeback" as well as contemporary sources.

If the Stevens Institute study is right, then just about every other designer and study team, and everyone who has written a book on sailing, is wrong. Connor and the Kiwis and the USA II team and Blackaller's designers like Mull, and the other 12 or so teams, would all surely have spent multiple times as much in tank testing as the Stevens team. It would be surely highly unlikely for the Stevens team to be right and everyone else to be wrong.

Wasn't Mariner the result of a Stevens testing programme?

In some conditions, yes the higher gyradius can be faster as is generally agreed.


GUILLERMO

I agree that the tankage of the Pogo is extremely light. However, not everyone cruises in the way that most people do. Some people DO cruise on extremely light boats, like the French couple who have been sailing around the Pacific for a decade on Accanitto, a lightweight almost flush-decked stripped-out IOR machine with tall fractional rig, in-line spreader and runners.

I have spoken to them about the boat and they love it. It suits them. Surely the Pogo style could suit similar people.

PS I regularly hear about the way lightweights lose performance radically when overloaded. I don't actually see this very often. One recent example was the last Mooloolaba race here, where some boats continued on for about 900 miles more after crossing the finish line for a 430 mile race. The guys on boats as light as Farr 40 ODs reported no major loss in performance from the extra food and water for 900 extra miles for about 10 men. Similarly, I have yet to hear of anyone using lower target speeds at the start of a Sydney-Hobart, when boats as light as 2,500kg are carrying supplies for 6 men for 7 days.

Sure, cruisers carry more than this in overload. But having done things like live ab aboard (and race) a 2,200kg 8.5m boat and raced a few boats of similar weight on long races, I wonder whether the lightweights really do lose much pace when loaded up.

Pic is the lightweight Sayer designed- and built- 11m "Belle" coming over a bar in Queensland. No damage, I believe. Not all lightweights are fragile.

Vega
02-03-2007, 07:22 AM
From my point of view this spec is a very scarce one. ...What happens if you load it with all water, fuel, stores and personal items needed for a 6 people crew for, let's say, an atlantic circuit (europe, canaries, caribbean, bermuda, açores, europe)?.... An this not only from the point of view of performance and seakeeping abilities, but also from the point of view of possible structural overloads.
.

Behind ISO 12217, (the one that certifies EU boats on the different categories) is ISO 12215. This is the one that certifies that the boat pass the structural demands to be approved by ISO 12217. Among many specific demands the ISO 12215 demands on scantlings a safety factor of 2.3.

ISO 12215 follows ABS another Classification Society Code. Prof. Paul Miller considers that a boat that is made under the ABS code is fit for offshore work.

In the keel area the safety factor of Pogo is 6. This factor is only found in some racing boats, and not many.

They are going to improve on that safety factor, making it even bigger, in what should be a record in the industry.

Why?
I believe that the description made by Rhoug, quoting, I believe, the manufacturer is not entirely correct. I had read the description made by the skypper and he had said that after being suddenly stooped at the bottom of the wave, the boat was caught by a huge breaking wave and dragged violently sideways (a situation that would have rolled a traditional boat).

It is believed that it is this fast sideways movement that can jeopardize the keel integrity (unless the boat had hit something). This is a situation that is new (other kind of boats roll) and the keel is theoretical good to stand a sideways movement of 25K. But we know that sometimes things don’t go as predicted and they are improving the safety factor.

None of the 25 boats have been capsized on those big storms on the “Route du Rhum”, but several had been caught by big breaking waves and experienced a big lateral slide.

About cruising, in what structures concern, the demands for racing in extreme conditions are much bigger than the ones needed for cruising, even with a loaded boat. Safety factors in boat structure of a racing boat are incomparable bigger than the ones you use in a cruising boat.

About the seakeeping abilities while loaded (cruising) you have seen that the boat has a bigger STIX when loaded, and we have seen that the boat has a very good load capacity. So if the boat is not loaded over its Max load capacity, regarding seaworthiness, it would be more seaworthy than in Light condition, but probably, not as fast.

Guillermo
02-03-2007, 09:57 AM
Guillermo,
If the budget pans out, between 70 and 80 feet(21 to 24 meters)...
I thought so. You need big lengths to arrange DWL level 'double bottom' tanks and then a decent room height.


However, not everyone cruises in the way that most people do.... For sure, but I'm talking about 'average' cruising people.

In my opinion, what could be a first approach to a modern nice '40 ft trotter cruiser' for the average people and all around cruising, is a boat more or less like the following:

Loa (Lh) = 12,00 m
Lwl = 10,71 m
Bmax = 3,24 m
Bwl = 2,90 m
Draught T = 2,06 m
Body draught Tc = 0,60 m
Disp (light) = 8000 kg
Disp (loaded) = 10142 kg
Ballast, fix = 3600 kg
Sail area = 75 m2
Engine Power = 30 KW
Heeling Arm = 6,90 m
Wetted Surface = around 30,00 m2
Angle of vanishing stability = around 130 deg
Downflooding angle = not less than 105 deg
STIX = 39 - 40
Negative GZ area/Positive GZ area = not bigger than 20%
LCB around 0,38 m aft of mid section.
Cp = 0,59

Cutter rigged.
Bulbed keel (not extreme).

How about that?

Vega
02-03-2007, 11:57 AM
This one seems to meet your criteria. A little bit lighter (200kg) a little bit narrower (6cm). It is a luxury Danish cruiser, bought mostly by Swedes and Germans. It has 140 AVS, very small inverted stability and a Negative GZ area/Positive GZ area smaller than 20%.


I find it a very nice oceangoing cruiser. What is your opinion about it? (I like other kind of boats, beside beamy boats:D ).

http://www.nordborg-baadbyg.dk/da/index.php?B%E5dtyper:Nordborg_40:Tekniske_data

Guillermo
02-03-2007, 12:25 PM
Very nice boat, Paulo, much in the line of what I'm talking about. Thanks.
A cutter top masted rig would be more appealing (safer) to me, from an all around cruising point of view.
Cheers.

RHough
02-03-2007, 12:47 PM
Randy,
I would like to know how they manage to get that D/L ratio under 85. It is usually asumed in the industry that for usual construction materials and techniques, for an all around cruising design, is difficult to get a figure under 200. We can go somewhat lower than that, certainly, but....85?

From my point of view this spec is a very scarce one. Accomodation looks very spartan (as per images and spec) and provided water tanks and battery capacity seem clearly insufficient for serious cruising. So it keeps looking to me what it always has: A boat conceived for exilarating short term coastal cruising, with no much more personal equipment that your swimsuit. A nice boat for that. Occasional quick, light crossings with short crew are possible, indeed, but, again in my opinion, that's its most.

What happens if you load it with all water, fuel, stores and personal items needed for a 6 people crew for, let's say, an atlantic circuit (europe, canaries, caribbean, bermuda, açores, europe)? Not to talk about those hundreds of kilos a cruiser accumulates of books and souvenirs from visited ports, or either high latitudes cruising equipment. An this not only from the point of view of performance and seakeeping abilities, but also from the point of view of possible structural overloads.

Has somebody asked for a quotation?



All valid points Guillermo.

Rather than compare the Tankage etc. to other 40 foot boats. Compare it to my 30 foot of about the same displacement.

The Pogo carries almost exactly the same amount of water and fuel as my Catalina 30.

The C30 empty is about 4800 kg with D/L 300.

The C30 would be very hard pressed to accommodate 6 crew for an Atlantic crossing also. Both boats are equally able as far as stores capacity.

The big difference comes with cruising speed. 3000M at 5 knots means the C30 must have stores for 25 days. 3000M at 8 knots means the Pogo must have stores for 16 days. 9 days of Water, Food, and Fuel is ??? pounds per person? 10 pounds per person per day?

If, the C30 has the ability to make crossings (it does), then the Pogo can support the same number of crew, since it's capacities are similar to other boats of the same displacement.

I know that a 5000kg boat has room for more than more than just a swimsuit, but I may save this post and use it as an excuse to limit the gear that female crew can bring on-board ... :D

I will be visiting the yard in July. If I like what I see, I will most likely take an option for 2009 delivery. If I have misgivings about the build quality or scantlings, I'll pass.

As far as the interior goes, I like the look. I'm not in love with high maintenance wood interiors. The cruising version has just enough wood (cabin sole and nav station) to make it look almost perfect to me. I agree that the canvas "door" in the head and no door for the other cabins is a bit spartan. However, I place a higher priority on sailing performance than on luxury interiors. Those that buy Shannon's (at $600,000+) have different priorities. The one glaring omission in the interior is a lack of a hanging locker. Hanging lockers are of little value under sail (the boat's motion chafes the clothes), but are wonderful when living aboard in port. The head is well placed (close to the companionway) and is the logical place to hang wet gear at sea. In port, I don't care to live out of a sea bag, so some portion of the load budget might go for storage.

I'll agree that if you are planning to spend years cruising (that means 80% of the time in port and 20% of the time at sea for many), your boat must look more like a house. My idea of cruising is 80% sailing and 20% in port. Coastal cruising here is mostly 25-50 mile day sails, anchoring out sometimes and making it into a harbour with laundry and showers every few days. You might spend a week in one place, but not often. As Guillermo says, the Pogo would be great at that.

Wench won't be making long passages with me, or living aboard for extended periods, so we don't need a boat that fits the 80% in port living aboard, 20% sailing that I agree make a good traditional cruiser. I think the Pogo will be a very good fit for our cruising plans.

I don't think that boats like the Pogo are a good choice for traditional cruisers. I think that there is little doubt about their seaworthiness.

Guillermo
02-04-2007, 06:53 PM
Our fellow Pericles passed me an info on another keel lost related accident, this time in the UK. Thanks a lot Perry.

"A man in his 20's died and four other crew members were rescued from a life raft after the Hooligan Five sank on Saturday at Prawle Point near Salcombe.
The Marine Accident Investigation Branch will look into reports that the boat capsized after losing its keel...."

See: http://news.bbc.co.uk/2/hi/uk_news/england/devon/6329071.stm

Once again. Too many accidents related to keel loses, lately. Why?

Guillermo
02-04-2007, 07:01 PM
Randy,
Let me quote you from another thread:

"Another interesting data set is:
1851 America, 0.70 S/L average
1866 Henrietta, 1.00 S/L average
1931 Dorade, 1.14 S/L average
1955 Carina, 1.18 S/L average

Compare these boats and numbers to the numbers posted in the S-H this year:

Ichi Ban, 1.23 S/L
Wild Oats, 1.11 S/L
Love & War, 1.07 S/L
Skandia, 1.04 S/L

Anyone care to try to put this in a light that shows great progress since 1931? Are the new boats more or less seaworthy than Dorade and Carina? Are they more or less seakindly?"

I would like to know your own answer.
Cheers. ;)

CT 249
02-04-2007, 08:51 PM
It's statistically wrong to use one race, or a limited number of figures, to try to prove that old boats are fast. It's about as statistically valid as saying that because the plumber who just came to my place had a blue shirt, every plumber in the world has a blue shirt.

This year's Hobart was a notoriously slow race. To compare an upwind bash to largely downwind races is not valid. "Great progress" is not defined, however many advocates of heavy displacement complain bitterly when the rating rules supposedly disadvantage their favoured craft a minor amount, so "great" is obviously in the eye of the beholder.

The latest Sydney-Hobart provided ideal conditions for the 47 foot Love and War. Despite that, she was 1 knot slower than the state-of-the-art (non radical) IRC boats a foot or two shorter. She was beaten across the line by 9 hours by a Swan 45, a luxury racer/cruiser. She was 1/2 knot slower (7.3 v 6.8) than the first Sydney 38, a cheap one design racer/cruiser. She was beaten by cheap cruiser/racers like Beneteau 44.7s, by 40 footers, 42 footers, 43 footers, and 38 footers.

Love and War succeeded not because she is faster than modern boats; she is not. She succeeded because the rating rule recognises that she is a heavy old boat and therefore gives her a much lower rating than new boats get. Given normal conditions she is much more than 1 knot slower.

As has been pointed out here several times, new boats ARE faster than old ones. Even in the most advanced of sailcraft, speed advances are not always spectacular. The foiler Moth has advanced about 35% (approx) in speed since 1930, in the change from planked scows to carbon foilers. Merlins and National 12s (development class dinghies) have advanced something like 1% per decade since the '30s and '40s. WIndsurfers have doubled in top speed but the modern speed boards cannot actually sail properly in light winds. In light winds the original Windsurfer is faster than many modern boards. In small cats, the Tornado was the fastest boat (apart from the rare C and D Class) in the '60s, in 2007 it's still just about the fastest thing.

The other forms of sailing aren't being transformed with speeds 50% or 200% greater. Why people expect displacement-style rating yachts to improve their speed at a rate that is faster than any other craft is something I cannot fathom. Since about 1973, rating monohulls have increased in speed about 13%. That's respectable compared to typical beach cats, restricted development dinghies, windsurfers in average winds, etc.

Re Dorade. Easiest way to look at her real performance is to look at Stormy Weather which was a faster update. She has raced in Fastnets recently, went faster than she did when she was young, and was well beaten by much shorter modern yachts. Put Dorade up against a modern raceboat (rather than comparing her decades and thousands of miles apart) and she will be beaten handsomely.

I'm not sure if the '55 Rhodes Carina is still racing. Similar vintage Rhodes designs are still sailing; for example an Offshore 40 put out a Mayday in the NZ-Tonga rally (one of those events where heavy cruising boats rolled and put out maydays en masse) and a sister won the 2000 Bermuda race. She rates about as fast as a modern 25 footer. Once again, NOT a fast boat by today's standards but successful due to her low rating.

America and Henrietta are no longer racing, of course. Big boats like the J Class and the 140' schooner Adela are rated IRC and rate slower than modern boats 50% as long. If the rating was innacurate, the big old boats would beat the small boats on IRC. They don't. The IRC rating is fairly close to reality, and the big boats are as fast as modern 70s.

I've raced 12 Metres; great old boats, but slow by today's standards and struggling to keep pace with boats 20 feet shorter.

I know people, extremely experienced people, who maintain that newer boats ARE as seaworthy and more seakindly than earlier boats like their 1950s Arthur Robb long keelers; their steel double-ended Halvorsens from the '60s; their timber S&S classics from the '60s and '70s; or their Frers boats from the '70s. I for example hate the motion of Finnisterre types, Malabar yawls, Swanson double enders, etc. They have greater amplitude and go slower and take lots of water over the deck in my experience. That does not suit my own taste.

Years ago I did an article on sailing techniques for older boats like '70s S&S designs. The top sailors I spoke to emphasised how important it was to keep weight out of the ends, because those old boats (with their fine sterns) bounced more (albiet slower) than new boats and that slowed them down notably. That may not be everyone's version of seakindly.

RHough
02-04-2007, 11:54 PM
Randy,
Let me quote you from another thread:

"Another interesting data set is:
1851 America, 0.70 S/L average
1866 Henrietta, 1.00 S/L average
1931 Dorade, 1.14 S/L average
1955 Carina, 1.18 S/L average

Compare these boats and numbers to the numbers posted in the S-H this year:

Ichi Ban, 1.23 S/L
Wild Oats, 1.11 S/L
Love & War, 1.07 S/L
Skandia, 1.04 S/L

Anyone care to try to put this in a light that shows great progress since 1931? Are the new boats more or less seaworthy than Dorade and Carina? Are they more or less seakindly?"

I would like to know your own answer.
Cheers. ;)

Since it is my thread and I collected the data ... :)

If you look at boats that are limited to displacement speeds, you will find that passage speeds have not changed very much over the last 100 years. That is what you would expect, since the physics of oceans has not changed either. This years S-H was predominately upwind, and even the most modern canting keeled, rube goldberg designs were basically limited to displacement speed (as shown in the result that an old S&S design won the race on corrected time). IMO when boats that sail a course at lower S/L ratios beat boats that sail at higher S/L ratios, it is the fault of the rating rule. In the S-H I think that Ichi-Ban, Wild Oats, Love & War, and Skandia should have corrected out in that order.

The only reason that newer boats are "faster" than older boats of the same LWL is because they are able to exceed S/L = 1.34 a greater percentage of the time. The rating rule must try to account for this, but when conditions prevent the boats from sailing at angles that allow high S/L ratios, the "wrong" boat wins. Not on topic, but upwind speed for ocean racing boats has not changed very much over the last 100 years. S/L .9-1.3 is about where they sail. Ocean racing mono's just don't have the power to sail upwind much faster.

What they do have is enough power to sail in semi-displacement mode at S/L 1.5+ on some courses and truly plane on other courses. This shows in the higher average BDR and Downwind passage speeds that modern boats achieve.

If you look at the Trans-Pac (Southern California to Hawaii) it is a predominately downwind route as would be chosen by a cruiser. In 1936 Dorade was 1st to finish, 1st in class, and 1st overall on corrected time. Her S/L average was 1.14. In 1939 Dorade only managed a 0.90 S/L average for the Trans-Pac. The design did not change, conditions did.

If you look at best days run and downwind passages (the kind I would choose as a cruiser) you will see that mono hulls have been stuck under S/L 1.5 until the 1980's. The pre-WWII "wooden boats" averaged about 1.25 S/L for BDR, Plastic boats (post WWII) averaged 1.41 S/L. Dorade (50 ft LOA on LWL 38) managed a BDR at 1.44 in 1931.

As soon as you get into the ULDB era (post 1988 or so), the monohull average jumps to 2.44 from the 1.32 S/L that all the mono data points I looked at averaged.

The reason is quite obvious. Increased power to weight ratios. It only takes power equal to 3-4% of the boat's displacement to drive it at displacement speeds. It requires 10%+ power to weight for the boat to plane.

I most certainly agree that unless a boat has the power to plane in cruising wind speeds (Force 4-6?) there is no point in adopting planing hull forms. As you rightly state, they are fashion. If the boat will operate in displacement mode for 90% of it's sailing, it would be more seaworthy and seakindly to use a traditional hull form. If, however, the boat has enough power to exceed S/L 1.5 in moderate breeze it makes sense to me to adopt a planing hull shape.

One way to get high power/weight ratios is with high SA/D ratios. For a 10000 pound boat to plane you need 1000 pounds of drive force. If we design the boat to plane in 12 knots true wind we need about 1100 sq ft of sail area. (assumes Cl=1.9 for sail force = .912 pounds/sq ft). It is very hard to pack 1100 sq ft of sail on a 25 foot waterline. :D

When boats have high RM they can make 10% + drive force over a wider range of angles and spend more of the time at speeds above S/L 1.5. The Pogo does this at some angles in only 12 knots true (lower end of Force 4), In Force 5 she can sail faster than S/L 1.5 at all angles greater than 70 deg. At 130 deg off the bow the S/L ratio is 2.0+ in Force 5. when you get to Force 8 (35 knots) the Pogo can sail at S/L 1.5 + at all angles over 60 deg, and tops out at S/L over 3.0!

What does this mean to a cruiser?

Compare a typical cruise in a C30 and a Pogo40:
Victoria BC - San Francisco in October:___C30 7-8 days_____Pogo40 3-4 days
San Francisco - San Diego in October:____C30 4-5 days_____Pogo40 2-3 days
San Diego - Cabo San Lucas in November:_C30 8-9 days_____Pogo40 4-5 days
Cabo San Lucas - Maui in April:__________C30 23-25 days___Pogo40 12-13 days
Maui - Victoria in May:_________________C30 19-22 days___Pogo40 11-12 days

The obvious pattern is that the Pogo has more freedom to chose her weather. 3-5 day forecasts are much more reliable than 7-14 day forecasts. It is also obvious that the Pogo will need to carry a smaller load for each of the legs, so her performance and seaworthiness will not be compromised with extra "cruising stuff". :)

The greatest chance of gale conditions on the cruise is less than 3% on the Victoria - SF leg. The Pogo needs a 3-4 day window, the C30 needs 7-8 days. Expected conditions are 15.5 knots of breeze and 5-6 foot waves. I doubt that the Pogo would have a less seakindly motion under those conditions than the C30, they are not extreme.

As long as you cruise in boats with SA/D ratios less than 15:1 and D/L ratios of 200+ you might as well copy Dorade. :D

Just my opinions.

CT 249
02-05-2007, 12:25 AM
"If you look at boats that are limited to displacement speeds, you will find that passage speeds have not changed very much over the last 100 years."

I certainly don't agree with that. I don't think you can just pick a few few figures and use them to apply to the wider world. Sydney-Hobart S/Ls are definitely dropping. So is that of just about every race. If boats weren't getting faster why don't boats from the 1900s still hold the records? Why has the Transpac and Transat record dropped despite the boats being over 100' shorter these days?

The performance of boats limited to displacement speed, even boats that were quite heavy like an S&S IOR boat like Love and War, a Ganbare type Peterson or an early Farr type (which only surfed occasionally) was considerably higher than that of older boats. Take Caprice of Huon. In 1965 she was top-scoring boat in the Admiral's Cup and about as fast as any 45 footer. By 1973 she was 10% slower than the Lexcen and S&S heavyweights of similar length. She's been restored and is back racing, and she's about 10% slower than a modern 30 footer. A Beneteau 31.7 would be quicker. The old boats are not as fast in any conditions.

There is a reason that Dorade, Malabar, Caprice gave up ocean racing - they were outmoded in speed by later boats. Dorade just wasn't as fast as later yachts and she was beaten by them.

Look at great designs like the Reimers "Bachante" from the Great Lakes and the similar 62' Fidelis from Sydney (formerly NZ). In the mid '60s Fidelis took line honours in the Hobart. Last year she was 52nd across the line, behind old production 38 foot racer/cruisers. She was 2.5 knots slower than the top modern 60 footer. If a boat drops from 1st to 52nd over the line there is room to indicate that maybe, just maybe, boats are getting faster. When former champs average 2.5 to 1 knot slower than modern champs it is hard to see how they are not faster.

When Love and War won the '78 Hobart, she was 6th or 7th over the line. When she won the 2006 Hobart, she was 32nd over the line in a much smaller fleet.

Age allowance here in IOR days was about 0.5% per year, on top of other rating features like DLR and MkIIIA which gave older boats a big break. If boats were not advancing, even under that restricted rule, at more than 0.5% per year new boats would have been beaten. They weren't beaten, they normally won.

I have sailed an IMS nationals on arguably the most successful older boat in the ocean racing world today - 4 times UK Yacht of the Year; 4 times Fastnet class winner. Commodore's Cup victor. Sydney Hobart class winner.

This 1965 boat gets eaten alive by a Beneteau 40.7 in all conditions. It can't see which way a Farr 40 (IOR or OD) went. It gets hammered at about a minute a mile by a fast IMS 30 racer/cruiser.

Love and War was a knot slower even in her favoured conditions than a modern boat. That's a fact and it indicates the improvement in design since 1973.

In light winds, when no one is close to 1.34, the modern boats give the old boats a real caning generally. When you go a knot faster upwind in a breeze AND go much faster in light winds AND exceed hull speed and surf away downwind, that's good performance.

Personally, I can't see why a boat with a high S/D ratio should necessarily win. That will typeform design with all boats with very short length, massive rigs and RM for their length, and minimum displacement. Old boats may as well not turn up. Cruiser-racers may as well just not turn up. Boats with smaller rigs (more seaworthy, cheaper, arguably more efficient) may as well not turn up. And the boats that win (assuming enough turn up for a race) will still be slower than a multi.

Interestingly, there is a very strong correlation between having a system that means that development boats do NOT become totally obsolete quickly, and having a strong development class culture. The US gives very little care to outmoded development class boats, and it has a terribly weak development-class culture and most people sail ancient designs. The UK and Australia devote a lot of care to ensuring development boats stay worth something so owners can afford to sell them and then use that money to buy a new boat, and they have strong development class cultures.



That is what you would expect, since the physics of oceans has not changed either. This years S-H was predominately upwind, and even the most modern canting keeled, rube goldberg designs were basically limited to displacement speed (as shown in the result that an old S&S design won the race on corrected time). IMO when boats that sail a course at lower S/L ratios beat boats that sail at higher S/L ratios, it is the fault of the rating rule. In the S-H I think that Ichi-Ban, Wild Oats, Love & War, and Skandia should have corrected out in that order.

The only reason that newer boats are "faster" than older boats of the same LWL is because they are able to exceed S/L = 1.34 a greater percentage of the time. The rating rule must try to account for this, but when conditions prevent the boats from sailing at angles that allow high S/L ratios, the "wrong" boat wins. Not on topic, but upwind speed for ocean racing boats has not changed very much over the last 100 years. S/L .9-1.3 is about where they sail. Ocean racing mono's just don't have the power to sail upwind much faster.

Guillermo
02-05-2007, 02:50 AM
Very nice posts, Chris and Randy.

Randy, I agree that for coastal cruisers intended for weekend sailings and occasional 2/4 days crossings, in an area where you have available good 3-5 days forecasts and where you need not to carry heavy loads because you have available 'land support' easily, it makes sense to go for light and fast boats. You may take advantage of their speed by covering a greater area in the same amount of time or the same one in an shorter time. The only draw back I see is that coastal waters may be or become very tricky, in spite of weather predictions, and you may get caught into trouble, suddenly struggling against strong head winds and confused seas, which can make life very interesting for an excesively light and beamy boat not able to quickly go through or run off. And to find those conditions in coastal waters is not so rare. In fact it may prove relatively common, at least in my experience. And let's put, over this, the possibility of a dicimated crew (seasickness, injuries or whatever other reason) leaving the helmsman alone to take the hardest of the punishment for several hours or even whole days.

For longer passages the risk of encountering this kind of limit situations is higher and you may be forced either to quickly run off, losing a lot of hard earned miles, run under drogues, lay at sea anchor or heave to. Running quickly off is better done with a lighter and shorted (chord) keeled boat, but for the other three options I think heavier boats with longer keels are better suited, generally speaking. And we have to take into account that when you go cruising for extended periods, specially in not so well 'land supported' areas, a light boat may have her running ability impaired because of heavy loading.

As I think a cruiser boat has to look after you in whatever the circumstances, even if the probability of being caught in life threatening situations is very low (For me a 0,01% is enough, if I sail other than alone), I would like my boat to be able to defend herself precisely at those moments. That's why advocate the use of boats relatively heavy (230-300 when loaded?), prudently beamed and freeboarded, with manegeable sail areas, a sheltered helming position, and a nice iron genny, for all around cruising use. Precisely because the sea is what it always has been.

Cheers.

RHough
02-05-2007, 02:51 AM
"If you look at boats that are limited to displacement speeds, you will find that passage speeds have not changed very much over the last 100 years."

I certainly don't agree with that. I don't think you can just pick a few few figures and use them to apply to the wider world. Sydney-Hobart S/Ls are definitely dropping. So is that of just about every race. If boats weren't getting faster why don't boats from the 1900s still hold the records? Why has the Transpac and Transat record dropped despite the boats being over 100' shorter these days?



I didn't say that boats aren't getting faster, I said displacement monohulls are not getting faster.

Look at the numbers:
Dorade: 52' LOA, 37.25' LWL, D/L 326
Cal 40: 40' LOA, 30' LWL, D/L 248
Farr 40: 40' LOA, 35.27' LWL, D/L 110
Mumm 30: 30' LOA, 27.56' LWL, D/L 97
Pogo40 (Cruise): 40' LOA, 40' LWL, D/L 82

In 1967 the Cal 40 was a lightweight skimming dish, fit only for surfing downwind ... at D/L 248!

It is not news that ULDB's like the Farr 40 and Mumm 30 can pull a horizon job on a boat that has D/L 300+

You cannot consider a boat with D/L under 125 to be sailing in displacement mode in breeze over Force 4. The reason that these boats rate so much faster than older boats of the same length is because they are not confined by displacement. The crew is also a larger percentage of total weight on the new racers, this increases their ability to carry sail.

I think I said that it was not until ULDB's that records started to fall.

If you compare cruising boats of like D/L, I think you will find that passage speeds have not changed very much in the last 50 years. Around the cans speeds have improved, due to better VMG up and down and the ratings reflect this more than any advancement in hull shape.

A 300 D/L boat in 20 knots @ 130deg might sail at S/L 1.60
A 110 D/L boat in 20 knots @ 130deg might sail at S/L 1.95
A 82 D/L boat in 20 knots @ 130deg might sail at S/L 2.05

The increase in race and passage speed is a result of boats with lower D/L being designed to cross oceans.

Higher rated speed is a function of both lower D/L and better windward VMG.
300 D/L best VMG .8 S/L
110 D/L best VMG .93 S/L
82 D/L best VMG 1.0 S/L

Since the rating rule tries to handicap 300 D/L boats and sub 90 D/L boats with one number, there will always be conditions that cause odd results. Love & War winning the S-H is one such result. If the race was a heavy air reach, there is no way she would have kept her time against boats that can sail at S/L ratios over 3.0

I think it is fair to say that new cruising designs of any D/L are not much faster than older boats of the same D/L. I think the newer boats are stronger and more seaworthy (for equal D/L) than the old ones were. Now that Cruising D/L's are under 200 in many cases, a semi-displacement hull with good power should be a joy to sail on a trade winds route. Since these boat also tend to have fin keels and more modern underbodies, they should also be better able to work off a lee shore and maintain control in conditions that would overwhelm the older heavier boats (forcing them to heave to).

PI Design
02-05-2007, 04:40 AM
But displacement boats, by their very definition, are boats that can not readily exceed S/L = 1.34, so of course, if you look at BDR, they don't appear to be getting faster. But modern boats can sail at S/L = 1.34 in lighter winds.
Also, as you state, modern boats can sail closer to the wind, so have a better upwind VMG.

CT 249
02-05-2007, 06:15 AM
Even before boats with DLRs under 125, design developments were leading to improved speeds. To take just one example, the Imp (Holland) / Dida (Peterson) shift to wider sterns in IOR boats, 78/79, created an increase in overall performance of about 0.75-1.5% in a single generation. Imp was sailing around in the 1977 AC and SORC with boats 2' longer.

Ganbare, at 35', was about 1.5-2% quicker than the 37-39' batch of S&S and Carter one tons of a year or two before.

These are displacement monos. They were getting faster, and significantly faster. PHRF, IRC, IMS, LYS and every rating or measurement system under the sun, as well as thousands of examples of boats out there sailing, proves that boats WERE improving in their speed well before they became semi-planing. It was in fact one of the great criticisms that designs were developing TOO fast, so that boats were outmoded too quickly.

A classic case would be the 1976-78 era. In half tonners, for example, the world crown went from a Holland 30 (narrow stern, masthead, heavy displacement, PHRF 144 approx) to a Davidson 31 (wide stern, fractional, light, centreboard) with the heavy-ish Holland custom SIlver Shamrock III almost winning the worlds in between.

This pattern continued. Farr's 1981 40 (The Roperunner) was uncompetitive by 1983 (apart from age allowance) and the 1983 vintage design 136 was outmoded by 1987 unless it was a heavy beat.

Records did start to fall before ULDBs. Kialoa (an S&S design) took the Hobart record in 1975; she was no ULDB. The heavy Frers Flyer took 10 days off the Round the World record in the second Whitbread; she was no ULDB. A Fastnet record was set in 1939 by the 85 ft Nordwind; broken in 1965 by the 90ft Gitana; smashed again (I think) by the 77 foot Condor (1) in 1979; then again by the 80ft Nirvana, a luxurious racer/cruiser. Nirvana, very much a displacement boat, also held the Bermuda record. The record cannot be denied; later displacement boats are very much faster than older displacement boats.

As I said, age allowance ran at abouyt 0.5% p.a. through the '70s and '80s. It had to, because boats were getting quicker at that pace. Try putting (say) Windward Passage II, Matador II or Sovereign up against Tempest, Kialoa III, Bolero or Baruna and you'll see how much speeds have improved. Even in the days of bad old IOR the old maxis like Kialoa II and Ondine III were well and truly out the back door against modern displacement maxis; they rated 10%+ lower and still finished well behind on corrected time.

This is looking mainly at passages, not round-the-cans.

Crag Cay
02-05-2007, 07:42 AM
Posted by Guillermo:
Our fellow Pericles passed me an info on another keel lost related accident, this time in the UK. Thanks a lot Perry.

"A man in his 20's died and four other crew members were rescued from a life raft after the Hooligan Five sank on Saturday at Prawle Point near Salcombe.
The Marine Accident Investigation Branch will look into reports that the boat capsized after losing its keel...."

See: http://news.bbc.co.uk/2/hi/uk_news/e...on/6329071.stm

Once again. Too many accidents related to keel loses, lately. Why?
I can't help with why but 'Hooligan V' (Ed Broadway, Royal Southampton Yacht Club) was a Max Fun 35.
http://www.simonis.com/gallery.php?did=9

Conditions: Wind F5, Sea 1 mtr.

She was corrected time winner of the 2 handed RB&I Race 2006:
http://www.simonis.com/news.php?pos=0&nid=32

And RORC Boat of the Year 2006, IRM Class 1.
http://www.maxfunboats.nl/news.php?pos=0&nid=47

And finally
http://www.hooligan-v.org.uk/

http://www.boatdesign.net/forums/attachment.php?attachmentid=11422&stc=1&d=1170682113
http://www.boatdesign.net/forums/attachment.php?attachmentid=11423&stc=1&d=1170682113

Vega
02-05-2007, 05:52 PM
Very nice boat, Paulo, much in the line of what I'm talking about. Thanks.


Yes Guillermo, it is a very nice boat (post 520), but even with a very small inverted stability and a 140ºAVS it is not necessarily more seaworthy than a beamy boat;) .
The Nordborg 40 has a STIX of 34.5, in MOC and LDC.

http://www.nordborg-baadbyg.dk/da/index.php?B%E5dtyper:Nordborg_40

By the way, I have got the Pogo 40(cruising version) STIX in MOC condition: 41.3.

Vega
02-05-2007, 06:11 PM
Our fellow Pericles passed me an info on another keel lost related accident, this time in the UK. Thanks a lot Perry.

...
Once again. Too many accidents related to keel loses, lately. Why?

I agree that in modern boats special care should be taken regarding the keel and the spade ruder. Some manufacturers have greatly improved safety in these areas. Cantieri del Prado, the manufacturer of Grand Soleil is one of them. Look at the Steel structure that holds the keel and the shrouds:cool: .

DanishBagger
02-05-2007, 08:37 PM
Nice, Vega.

Guillermo
02-06-2007, 02:46 AM
Yes Guillermo, it is a very nice boat (post 520), but even with a very small inverted stability and a 140ºAVS it is not necessarily more seaworthy than a beamy boat;) .
The Nordborg 40 has a STIX of 34.5, in MOC and LDC.

http://www.nordborg-baadbyg.dk/da/index.php?B%E5dtyper:Nordborg_40

By the way, I have got the Pogo 40(cruising version) STIX in MOC condition: 41.3.
You know I do not agree (And I'm not the only one around here) on how STIX works, because it can be very tricky. Beginning by the waterline length issue....

Vega
02-06-2007, 11:12 AM
Quote:

Originally Posted by Vega
Yes Guillermo, it is a very nice boat (post 520), but even with a very small inverted stability and a 140ºAVS it is not necessarily more seaworthy than a beamy boat .
The Nordborg 40 has a STIX of 34.5, in MOC and LDC.

http://www.nordborg-baadbyg.dk/da/in...er:Nordborg_40

By the way, I have got the Pogo 40(cruising version) STIX in MOC condition: 41.3.


You know I do not agree (And I'm not the only one around here) on how STIX works, because it can be very tricky. Beginning by the waterline length issue....


I believe that when you say, "I do not agree" you are talking about the STIX.
About it, you know that I have said that I believe there are better ways, for knowledgeable people, to analyze a boat’s seaworthiness. The STIX is designed as a general tool to give the max information on a boat’s stability with just one number. And looking at it this way, it is the best tool available.
Saying that, I would say that I agree with you about the waterline issue.

But the important issue is this one:

” even with a very small inverted stability and a 140ºAVS (a narrow boat) it is not necessarily more seaworthy than a beamy boat”.
About this I have said in previous posts:



..The better or worst ability to recover from a capsize is an important factor, but by no means inferior to the better or worst ability to RESIST to a capsize.
......
Of course, a bigger AVS is better for returning to the “normal” position...., if bigger, then the positive area under the RM curve (and the initial stability) will be smaller, and that means not only a slower boat, but an easier boat to capsize.

Some compromise is needed here. If you know what you are buying, then you can chose the type of compromise that suits you better.

there are some very fast cruiser-racers, like the Swan 45 that have a huge initial stability with a small inverted stability and a good AVS. You have to look at each case. Bulbed keels make a lot of difference in what regards fast boats with high initial stability, relatively high AVS and relatively small inverted stability. For relatively I mean that they can have a better stability curve than many good cruising boats, normally considered more seaworthy.

Please look at the compared RM curves, in the slide taken from a presentation by Professor Miller about “Stability and Structure” for a 2003 Seminar on “Safety at Sea”.

Typically a beamier boat will have a bigger positive area under the RM curve and also a bigger area under the negative part of the RM curve, with a smaller AVS.

Comparing the Miller curves, the narrow boat is clearly more seaworthy, or at least its static stability curve is a lot better regarding Safety. Not only its Positive area is not much smaller than the one of the beamier boat, but also its RM moment at 90º of heel is more than 2 times bigger than the one of the beamier boat.
There is also a huge difference in the AVS of the Narrow boat (150) to the AVS of the beamy boat (105) and that corresponds to a huge difference between the inverted stability of both boats, as it is shown in the curve.

Now, if we compare the Pogo stability curve with the one from the Nordborg, we will see that, considering the Rightening arm, at 90º of heel, actually the Pogo’s arm is 2 times bigger than the one from the Nordborg and that the area behind the positive part of the GZ curve is more than 2 times bigger than the one on the narrow boat. And also that the difference in the AVSs (127 to 140) and in the negative part of the GZ curve is much smaller than the relative difference in the comparative areas of the positive part of both curves.

This will make the Pogo a more difficult boat to capsize and the Nordborg an easier boat to recover from a capsize. And I am referring to a totally inverted position, because the Pogo, with it’s bigger RM at 90º of heel, would recover from a capsize without rolling, faster than the Nordborg.

Of course I am not taking weight into consideration (to transform GZ in RM) nor am I trying to say that a narrow boat is less seaworthy than a beamy boat. I even consider that special care should be taken on the evaluation of the boat’s stability, with what you call a beamy boat, and that the stability curve should be carefully examined by every buyer.

I am only saying that a narrow boat is not necessarily more seaworthy than a “beamy” boat and that each case is a case. Every boat should be looked individually, avoiding generalization. If well designed, what you call “Beamy boats” can have advantages, different advantages than the ones you get on narrow boats.

What makes a good and seaworthy cruising boat it is not being narrow or “beamy” but the way those balances and advantages are put together, in a good or bad design. With an adequate balance between speed and seaworthiness, between the energy needed to capsize the boat and the energy to re-right it , and of course, a lot of other factors. In the end I believe that personal taste, regarding sea motion, interior space and aesthetics would be the factors that lead to a choice, providing the average sailor knows what he is buying.

Guillermo
02-06-2007, 03:07 PM
I am only saying that a narrow boat is not necessarily more seaworthy than a “beamy” boat and that each case is a case...
I totally agree.
Doing a very quick and rough calculation the righting moment at 90º of the Nordbog (for 7700 kg) is around 4000 kgm and Pogos' (for 5300 kg) is around 4500 kgm, so not that big difference, and the Nordborg probably behaves in a more seakindly way, which is important for cruising mode, from my point of view.
My only concern with the Nordborg (from the point of view of stability) it that it seems to have a quite high Dellenbaugh's angle, so being quite tender. This may force to reef too soon....

By the way, do you have a profile or photo of Pogo cruising version's underwater hull and keel?

Cheers.

charmc
02-06-2007, 10:12 PM
Our fellow Pericles passed me an info on another keel lost related accident, this time in the UK. Thanks a lot Perry.

"A man in his 20's died and four other crew members were rescued from a life raft after the Hooligan Five sank on Saturday at Prawle Point near Salcombe.
The Marine Accident Investigation Branch will look into reports that the boat capsized after losing its keel...."

See: http://news.bbc.co.uk/2/hi/uk_news/england/devon/6329071.stm

Once again. Too many accidents related to keel loses, lately. Why?

The photos appear to show an undamaged hull exterior. So mechanical failure of either the bolts or the backing plate? I'd be interested in hearing from the professionals about this.

Vega
02-07-2007, 11:39 AM
The photos appear to show an undamaged hull exterior. So mechanical failure of either the bolts or the backing plate?

Or the keel itself.

charmc
02-07-2007, 01:53 PM
Or the keel itself.

Quite right, Vega, thanks.

Vega
02-07-2007, 06:30 PM
By the way, do you have a profile or photo of Pogo cruising version's underwater hull and keel?


No, maybe this photo helps. It is not the cruising version, but Ibelieve the hull is the same, the keel is shorter (80cm) and the bulb heavier. the boat will weight more and it will seat a little bit more on the water.

Vega
02-07-2007, 07:02 PM
There it is;)

Vega
02-07-2007, 08:38 PM
Not all modern narrow boats have a high AVS, and that doesn’t mean that they are worse than the Nordborg.
Take a look at a favorite of mine, the Faurby 424, also a Danish boat.

It is a beautiful boat a little bit longer, but also a little bit lighter.

If we compare the GZ curves, we will see that the Faurby has a much bigger max rightening arm (0.77 to 0.55), that at 90 of heel the Faurby has 0.52 and the Nordborg 0.46 and that regarding initial stability there is a huge difference favorable to the Faurby:
At 10º of heel, 0.15 to 0.2, at 15º, 0.2 to 0.3.

In what regards AVS and negative stability, there is also a big difference, this time favorable to the Nordborg (AVS, 119 to 140).

This makes the Norborg a better or worse boat than the Faubry?

I think that depends of what you want, certainly the Faurby is a lot faster and the big question would be: Is the Faurby an oceangoing seaworthy boat?

I would say yes. The negative stability is acceptable and the AVS, if not great, is also inside the average and probably, even compensating for the difference in weight, it will be probably needed more energy to capsize the Faurby than the Nordborg and both boats will be making about the same force to re-right themselves at 90º of heel.

http://www.faurby.dk/gb/faurby424_teknik.html

Mikey
02-09-2007, 01:39 AM
Vega, thanks for the side view of Pogo cruising version, I have been looking for that. The bulb would influence LP slightly (bulb numbers included within brackets). I get (approx. figures);
LP/SA: 7.9% (9.4%)
KA/SA: 3.7% (5.1%)
RA/SA: 0.9%

It's a skimming dish all right, HA/LP is a low 42.7% (36.2%), RA/LP is 11.1% (9.4%)

The Faurby on the other hand shows (assuming no fractional rig and genoa 1);
LP/SA: 13.9% (14.6%)
KA/SA: 5.7% (6.3%)
RA/SA: 1.0%
HA/LP: 52.1% (49.7%)
RA/LP: 7.2% (6.9%)

Pogo has twin rudders, I have just doubled the area disregarding angle, I simply don't like the configuration and haven't bothered spending time on it.

I was looking for the LWL figure on the Pogo 40 website until I remembered that it doesn't need one, I find that funny :) Good to see that the bulb of the cruising version doesn't extend in front of the keel, get's a bit boring to drag the Sargasso Sea along around the world :)

I see a low LP/SA for Pogo, too low in my opinion and I am surprised that both boats show low RA/SA. I consider 1% not enough, but on the other hand, Faurby's LP/SA and KA/SA is rather high. May I have your thoughts on this please

Mikey

Mikey
02-09-2007, 04:40 AM
OK, Norborg figures (with genoa);
LP/SA: 16.4% (16.8%)
KA/SA: 6% (6.4%)
RA/SA: 1.4%
HA/LP: 54.7% (53.4%)
RA/LP: 8.4% (8.2%)

Faurby Norborg
LWL/Bmax 3.3 3.2 (don't have Bwl)
SA/Disp 20.7 20.3 (don't know how much overlap)
Disp/LWL 137 210
Ballast ratio 39.9 37
LP/SA 14 16 (bulb not included)
KA/SA 5.7 6
RA/SA 1 1.4
AVS 119 140

Faurby relies more on form stability and is stiffer, it also has higher accelerations so Norberg will have more comfortable motion, SA/WSA is much higher for Faurby, it will be much faster all around but especially in light winds. Norberg's larger rudder area (and skeg) is a plus IMO. Storage in Norberg is better.

Is the Faurby an oceangoing seaworthy boat? Well, the question - Is the Faurby a good oceangoing cruiser for your round-the-world trip is easy to answer. No, the compromise is a bit on the extreme side.

Oceangoing seaworthy boat then? Yes, but clearly at the lower end of the scale. Its relatively high LP/SA and KA/SA saved it from a No (took me an hour to decide which :) )

Mikey

CT 249
02-09-2007, 05:45 PM
"Is the Faurby a good oceangoing cruiser for your round-the-world trip" surely depends on what YOU want to make of YOUR trip.

For the people who cruise around the world (with a baby born on the way) in 25 footers, the Faurby would surely be "good". For the couple who have been cruising for about 14 years+ on an old stripped-out flush-deck IOR lightweight with runners, the Faurby would surely be "good". For the family of four who live on a fairly spartan cat, it would be "good" in some ways.

Surely in the same way that we can choose to drive a Ferrari or a 4wd or a sedan or a people mover, or the way we can choose to live on a farm or an inner-city unit, we can choose what is "best" for US, our way of sailing and our way of life.

RHough
02-10-2007, 12:01 AM
Here is an interesting data point to add to the discussion ...

I spent some time talking to a gentleman that circumnavigated in a 34 foot boat. I asked about how the boat was rigged and found that it is a sloop with an inner forestay added to make a cutter rig. They have a roller furling Genoa on the headstay, the heavy air and storm jibs hank on to the inner stay.

I asked him how often they had to roll the Genoa up and use the storm sails ... his reply was "Never".

He did admit that they got caught in one squall and saw 55 knot winds for about 2 hours. During the squall, they just dropped the sails and waited it out.

13 years sailing, including a circumnavigation (they spent 6 years in the Med), and they NEVER had to use the storm sails. Kind of makes me question how much weight to place on ultimate stability and storm survival when choosing a boat. The way some people talk it sounds like having to deal with storm conditions is likely and unavoidable, yet the people that I talk to that have actually sailed oceans and circumnavigated tell a different tale.

Raggi_Thor
02-10-2007, 07:03 AM
That depends on where and when you sail. If you are in the north Atlantic in the winter you will probably meet a storm :-)

Guillermo
02-10-2007, 07:12 AM
There it is;)
Thanks, Paulo.
Working on that image to estimate measurements, I get an STIX of 38,475 for Pogo 40 Cruiser in MOC condition. You posted before her real STIX is around 41 for this condition. May I see the complete calculation sheet you have (Even if it is the one for the loaded condition) to check out my estimated numbers and find out where is the difference, please?
Thanks in advance.
Cheers.

Guillermo
02-10-2007, 07:26 AM
Not all modern narrow boats have a high AVS, and that doesn’t mean that they are worse than the Nordborg.
Take a look at a favorite of mine, the Faurby 424, also a Danish boat.

It is a beautiful boat a little bit longer, but also a little bit lighter.

If we compare the GZ curves, we will see that the Faurby has a much bigger max rightening arm (0.77 to 0.55), that at 90 of heel the Faurby has 0.52 and the Nordborg 0.46 and that regarding initial stability there is a huge difference favorable to the Faurby:
At 10º of heel, 0.15 to 0.2, at 15º, 0.2 to 0.3.

In what regards AVS and negative stability, there is also a big difference, this time favorable to the Nordborg (AVS, 119 to 140).

This makes the Norborg a better or worse boat than the Faubry?

I think that depends of what you want, certainly the Faurby is a lot faster and the big question would be: Is the Faurby an oceangoing seaworthy boat?

I would say yes. The negative stability is acceptable and the AVS, if not great, is also inside the average and probably, even compensating for the difference in weight, it will be probably needed more energy to capsize the Faurby than the Nordborg and both boats will be making about the same force to re-right themselves at 90º of heel.

http://www.faurby.dk/gb/faurby424_teknik.html

Paulo,
On top of what Mikey has posted:
As per a quick estimative RMs at 90º are 3600 kgm for the Nordborg (better figure than the 4000kgm posted before) and 3500 kgm for the Faurby. Faurby's negative/positive GZ curve's areas ratio is around 0,19 and Nordborg's around 0,10. Also, max GZ happens at around 55º for the Faurby and descends from that on, but although happening at 50º for the Nordborg, it remains in high values for a bigger range of heel angles, due to the flatter upper end of the curve.
I find more seaworthy the Nordborg than the Faurby (from the point of view of stability).

Vega
02-10-2007, 09:07 AM
I spent some time talking to a gentleman that circumnavigated in a 34 foot boat. I asked about how the boat was rigged and found that it is a sloop with an inner forestay added to make a cutter rig. They have a roller furling Genoa on the headstay, the heavy air and storm jibs hank on to the inner stay.
.

If you really want to cross oceans, what European big production builders propose to you is a removable inner forestay. You don't say if it is the case (removable), but if it is not, that would make a genoa a very difficult sail to tack.

There is also another option and that is a special storm sail that you rig over the furled genoa, utilizing the spinnaker halyard.

Vega
02-10-2007, 09:34 AM
Hey Mikey, about boats and seaworthiness, let me tell you the story of Diogo Botelho Pereira. He was a Portuguese, born in India around 1507, probably a product of miscegenation of Portuguese with beautiful native ladies. This guy was smart and brave; he learned maths, was a good sailor, a good pilot and a cartographer.

In 1533 he sailed to Portugal, to offer the king a world map made by him and asked him to be a captain of the Kingdom and to be Governor of a small Indian fortress (Chaul). The king said NO and later he found out that Diogo had said that, no matter the king decision’s, he would manage to be a Captain by his own means.

The King did not allow that kind of disrespect and arrester and deported poor Diogo back to India (Diu).

Well, Diogo was stubborn, and after having built by himself a small Fusta (a sailing boat) with 5.5m length and 2.4m beam, secretly set sail for Portugal in 1535. The Fortress of Diu was finished and he wanted to be the first one to tell the king the good news.

After making a scale in Azores, for water and fresh food, Diogo made it to Lisbon.

This time the King was impressed and after having ordered the small boat to be burned (he did not want to be known that it was possible to travel to India in such a small boat) he made Diogo a captain, making him first the Governor of S Tomé, a small Island on the equator and later the governor of Cananor, an Indian Fortress town, much bigger than Chaul. He stayed as Cananor Governor till his death..

So, an 18ft home made wooden sailboat, 500 years ago, was seaworthy enough to make it from India to Portugal, with a small detour to Azores and you think the Faurby 424 is barely fit for oceangoing travel ?

I know, Diogo has taken some chances, but remember he was not crazy, he was an expert, a excellent sailor and a prime navigator, and I am sure he knew a lot about boats and seaworthiness. If he had thought that he had not a decent chance to succeed he would not have tried.

As CT has pointed out, seaworthiness is a relative concept. Some will not put their feet on any boat smaller than a Cruising Ship, others have circumnavigated in 25ft light displacement boats with the family, including a small child.

For me, all the boats we are talking about are seaworthy enough to circumnavigate with an adequate safety margin, but I have nothing against other people’s criteria unless someone tries to impose their standards on me or tries to prove, against all evidence, that only certain types of boats are seaworthy, I mean heavy displacement, slow and narrow boats;) .

Vega
02-10-2007, 09:55 AM
to check out my estimated numbers and find out where is the difference?
.

Try to change the downflooding angle that you have estimated. The downflooding agle on the Pogo is bigger than the AVS, so I believe you have to enter the AVS angle (127º).

Guillermo
02-10-2007, 02:31 PM
Done, but it only reaches 38,910. In fact STIX does not grow over this figure for downflooding angles over 113º, due to FDF reaching its maximum value of 1,25 at that angle.
I'm really curious to analize the document you have....
Cheers.

Guillermo
02-10-2007, 02:42 PM
....So, an 18ft home made wooden sailboat, 500 years ago, was seaworthy enough to make it from India to Portugal, with a small detour to Azores...
Paulo,
I think that's not a valid argument.
Fishermen have been dying by the thousands through the centuries by going fishing in small open boats well into the ocean. As you know, they are not allowed to do that anymore (at least in Europe), in spite 'Dornas', 'Traineiras' and many other traditional designs being wonderful seaworthy small boats. Safety is always first nowadays.

Fascinating guy, that Diogo Botelho Pereira (he was a cartographer, wasn't he?). Here what Wikipedia says about him:

"Diogo Botelho Pereira é uma das mais obscuras e fascinantes personagens da gesta dos descobrimentos portugueses. Homem de temperamento exacerbado como no-lo dizem as crónicas que o referenciam, por causa desse temperamento fortes dissabores sofreu.

É feito absolutamente fantástico o seu de ter vindo da Índia ao Reino numa singela fusta, navio de todo improvável para realizar tão longa e tormentosa viagem, razão pela qual Dom João III a mandou queimar para " que não se vulgarizasse a ideia de que era possível fazer a viagem em tão modesto meio". São escassas as informações sobre a sua vida e as existentes muitas vezes levantam dúvidas..."

"Absolutamente fantástico" (italics are mine) could be considered as totally fantastic? (from the term 'fantasy'). It seems the guy had an exacerbated temper and his life is not totally clear. Mmmm....

By the way: Sensible man, Dom João III, burning the boat to avoid other crazy people trying to emulate that kind of adventures. Maybe he sent him to São Tomé and then to Cananor not to see him anymore.... ;) ("D. João III nunca confiou inteiramente na boa fé de Diogo Botelho Pereira e acabou por lhe confiar a capitania de S.Tomé, onde adoeceu, acabando os seus dias na Índia como capitão de Cananor....") http://indispensaveis.blogspot.com/2004_07_01_indispensaveis_archive.html

Cheers.

Guillermo
02-10-2007, 03:35 PM
Paulo,
More on Diogo Botelho Pereira:
"Mulheres em trajos masculinos acompanharam uma vez ou outra os seus homens até à Índia e em 1505 Iria Pereira seguiu António Real e foi mãe de Diogo Botelho Pereira, piloto e comandante da fortaleza de Cananor, onde faleceu em 1554." (http://www.historiadamedicina.ubi.pt/cadernos_medicina/vol10.pdf)
So it seems his parents were both portuguese.

And here what Dom João III wrote about him in a letter to dom Antonio d’Atayde, Count of the Castanheira:
"Vy a carta que me escrevestes sobre Diogo Botelho Pereira. Muyto vos agardeço os avysos que de suas cousas me daes. Eu escrevo ao governador que o mãde poer a Recado." :D
Translation: I saw the letter you sent to me on Diego Botelho Pereira. I thank you very much for the advise you give me on the things he does. I will write to the Governor for him to put him (Diogo) in jail" (It's OK, Paulo?)

As said: a fascinating but conflictive guy.
Cheers.

Vega
02-10-2007, 04:05 PM
Done, but it only reaches 38,910. .

Have you taken in consideration that the boat is unsubmergible?

The STIX paper I have is from the long keel version. The calculated ML STIX is 44.7 and that is the STIX of the long keel version. The ML STIX of the short keel version is 44.9 (the MOCSTIX of the short keel is 41.3 and the MOCSTIX of long keel is 41.9).

The first time they had sent stability data to me they have said the stability of the two versions was the same. Not really true, but close enough to be negligible.

Edited: MOC and ML STIXs were swapped.

Guillermo
02-10-2007, 04:12 PM
Have you taken in consideration that the boat is unsubmergible?
Nope, thanks!
That adds another 5 points, so bringing my numbers up to 43,91 for the MOC, which is closer to the numbers you post.
(by the way: are you sure about MOCs and MLCs in your last posts? Aren't they swapped? I understood 44.7 was for the loaded condition)

Now, if we take off the effect of the unsinkability, Valiant seems to have a better STIX (around 38) than Pogo (36.3 = 41.3 - 5). Now this is making more sense. Thanks again.

Cheers.

Guillermo
02-10-2007, 04:45 PM
The nowadays somewhat compulsive pursuit of higher speeds (shorter time passages) for cruising boats has not only chosen the way of extreme lightness and big sail areas. The other way is also lightness and big horsepowers. Have a look at the Mandarin 52 (http://www.mandarin52.com/) or Powersail 15 & 20 (http://www.powersail.co.nz/index.html). In this last case big sail areas, too.
I confess I do not like this solution either.

Vega
02-10-2007, 05:48 PM
Paulo,
I think that's not a valid argument.
...Safety is always first nowadays.

"Absolutamente fantástico" (italics are mine) could be considered as totally fantastic? (from the term 'fantasy'). It seems the guy had an exacerbated temper and his life is not totally clear. Mmmm....


About the argument, I don't agree. There is no absolute safety at sea, at least in what regards small boats. If it is not absolute it is a relative concept and therefore subject to personal judgment. On Diogo's opinion, the seaworthiness of his 18ft boat was enough for the job and he proved to be right.

About your interpretation of the Portuguese language, it is good, but not precise on this case. Absolutely fantastic was used here colloquially and in this context it does not relate to its etymology; Does not mean a Fantasy story, but means: An incredible feat, a real feat that is so great that is hard to believe in it.

We know that he has made that trip on that little boat, because when he stopped in Azores he had the bad luck to choose Faial for going ashore for supplies. He was trying to evade the Governor because he had been deported. He has chosen Faial, because normally the Governor was in Angra, but he was visiting the town and Diogo was brought to him. He managed to elude him, saying that he had a secret and very important information, to deliver only to the king and the Governor let him continue his voyage (I guess we was impressed too).

This encounter is a well documented one, and the only reason why in the end, the king believed that he had made that travel in that little boat.

About his origins (both father and mother were Portuguese), you are right. And with a mother like that it is not a surprise that the guy was courageous (his mother went to India as a sailor, disguised as a man:P , because she didn’t want to abandon her lover, the future father of Diogo).

Vega
02-10-2007, 05:52 PM
Nope, thanks! [/B]
are you sure about MOCs and MLCs in your last posts? Aren't they swapped? I understood 44.7 was for the loaded condition)

.

Of course, you are right. I am going to edit that post.

Guillermo
02-10-2007, 06:59 PM
There is no absolute safety at sea, at least in what regards small boats. If it is not absolute it is a relative concept and therefore subject to personal judgment...
Safety at sea is not absolute, evidently. As living is not either safe: we're condemned to death :) ....Seriously: The pursuit of safer boats and ships has been a constant trend since the first human being went sailing on a log, and has lead to numerous norms and regulations in all maritime activities, as you know. And those rules and regulations tend to be not subjective. On top of that, when you are obligued to comply with a norm, that becomes not subjective at all. Even on seaworthiness, an elusive matter, many efforts to quantify it on a as scientific as possible base have been done, as well as to enforce certain minimum levels. STIX is one example (As are structural norms, another important component of safety).

If you agree STIX is a good tool to measure seaworthiness (the best available, in your words), you have to admit it implies there is somekind of an objective approach to seaworthiness evaluation, and thus to safety. Talking on category A boats, a boat with an STIX of 50 should be intrinsecally safer than a boat with a 32 one, shouldn't it?

Cheers.

(P.S. See the correction of my post #599 on Valiant's and Pogo's STIXs)

Guillermo
02-10-2007, 08:09 PM
Have you taken in consideration that the boat is unsubmergible?
Well, if it is unsinkable the delta factor is 5 and if we take out that from Pogo's MOC STIX of 41.3, we get an STIX of 36.3. That's not so high (In line with Beneteau 373) and not so far away from my estimated 38.475 (I confess I'm more confused now: which one is the mistake I make that leads me to estimate Pogo's STIX as being higher than the oficial one? :( Please, Paulo, scan and post the whole thing, even if it is for the MLC! I need to have a look at the thing to try find out clues!)

So, if we admit STIX is the best available tool to evaluate seaworthiness (or at least a nice one), may we say the qualified people that developed that nice tool think Pogo like boats are not that seaworthy/safe from a cruising point of view....? Are they wrong....? And if, on top of this, Eliasson, one of the four fathers of the STIX, thought category A should begin in 40 rather than in 32, may we (at least) be allowed to honestly have reasonable doubts on this boat as an open ocean cruiser...? And with that wide deck beam carried all the way aft, are we justified to think it may be even dangerous in certain circumstances....?

Cheers.

Vega
02-10-2007, 10:37 PM
Safety at sea is not absolute, evidently...

.Even on seaworthiness, an elusive matter, many efforts to quantify it on as scientific as possible base have been done, as well as to enforce certain minimum levels. STIX is one example (As are structural norms, another important component of safety).

If you agree STIX is a good tool to measure seaworthiness (the best available, in your words), you have to admit it implies there is somekind of an objective approach to seaworthiness evaluation, and thus to safety. Talking on category A boats, a boat with an STIX of 50 should be intrinsecally safer than a boat with a 32 one, shouldn't it?



Of course, and a boat with a 92 STIX should be safer than a boat with a 50STIX. And what do this means? That we should stay safely on dry land unless we can afford a 140ft boat?

The disagreement seems to be about the minimums. For me the minimums are just that, minimums. If you want a maximum, you can go and buy a boat with a 100STIX, providing you can afford it and like to sail with a crew.

Do you really think that a boat like the Norborg 40 (STIX 34.5) should not be classified as a Class A boat? That it is not an oceangoing boat?

That seems odd to me. Of course, I understand that you personally demand for you a higher standard, but saying that boat has not the minimum requirements to be a class A boat, is a bit to much, at least in my opinion.

Guillermo
02-11-2007, 04:08 AM
Do you really think that a boat like the Norborg 40 (STIX 34.5) should not be classified as a Class A boat? That it is not an oceangoing boat?
It is not me who suggests category A should begin at 40, but Eliasson, don't misunderstand me. I have repeatedely said relatively light, slender and bulbed boats (Like the Nordborg and others within the concept but somewhat heavier) may very well be the modern paradigma of cruising boats (without forgetting some other older paradigmas, still perfectly valid).

I agree with you that problems arise when judging the oceangoing ability of yachts with STIX in the lower figures of category A. It is very difficult to determine it when a yacht's STIX is in the 32 - 40 range, just judging by the STIX alone; and on the other hand it happens that some boats of proved oceangoing ability but with STIX figures under 32, are not A categorized. All this has been already thoroughly discussed at the STIX thread. It is such a difficult matter that there have even been knowledgeable people's opinions in these threads saying STIX is producing lethal boats.

It seems like we still need a better criteria to regulate seaworthiness than the STIX in it's actual form. We need (as I have been defending since the very begining of these debates) either to make STIX more accurate, taking into account other factors, like speed, inertia, dumping, negative/positive GZ curve areas ratio, etc, etc, as well as broadening the accidents/events database by a worldwide (huge) effort in acquiring more accurate data from real life, or then abandon and leave things to everyone's subjectiviness. (Or struggle for a new criteria system, but look what happens when we ask for ideas: See the several 'dead short' threads on the matter within this same Stability forum)

Cheers.

P.S: If you do not want to post Pogo's STIX calculation sheet in these forums, would you be so kind to scan it and send it to me by e-mail? I will greatly appreciate that, as I'm writing a conference on these matters. Address: g.gefaell<at>mundo-r<dot>com

marshmat
02-11-2007, 11:12 AM
as well as broadening the accidents/events database by a worldwide (huge) effort in acquiring more accurate data from real life
And in a way that's the crux of the matter- for all the talk of seaworthiness and STIX, the fact remains that boats in general are pretty darn safe. When things go wrong it's usually the result of a multitude of factors coinciding, the crew are usually too busy trying to survive to collect useful data on the cause of the failure, and in the event of a catastrophic failure there's usually nothing left floating to study later on.
A car designer in the USA has access to a wealth of data regarding vehicle performance in fatal collisions- some 37,000 a year in his home country alone. And the wrecked cars can still be inspected to see what failed and why. A naval architect in the same country can draw on statistics from only 700 boating fatalities a year, most of which are the result of operator error or booze. With any given make and model of yacht, there will rarely be more than one or two incidents in total from which sound conclusions can be drawn. In the US at least, the boater is some 52 times less likely to be killed on the boat than to be killed in the car.
The result is that it's very, very hard to get a good statistical basis for a seaworthiness comparison. There are so many factors that must coincide for a boat to fail, failures are rare, and major failures often leave nothing left to analyse.
(Stats from the US DOT, Office of Hazardous Materials Safety, http://hazmat.dot.gov/riskmgmt/riskcompare.htm )

Vega
02-11-2007, 11:27 AM
Well, if it is unsinkable the delta factor is 5 and if we take out that from Pogo's MOC STIX of 41.3, we get an STIX of 36.3. That's not so high (In line with Beneteau 373) ...

So, if we admit STIX is the best available tool to evaluate seaworthiness ..., may we say the qualified people that developed that nice tool think Pogo like boats are not that seaworthy/safe from a cruising point of view....? Are they wrong....? And if, on top of this, Ericsson, one of the four fathers of the STIX, thought category A should begin in 40 rather than in 32, may we (at least) be allowed to honestly have reasonable doubts on this boat as an open ocean cruiser...? … are we justified to think it may be even dangerous in certain circumstances....?


There you go again. Honestly, sometimes I don't understand you.

Guillermo, the Pogo cruising STIX is :MOC 41.3, ML 44.9.

Saying that the POGO STIX is 36.3 is just not right.

The STIX is the result of the integration of a lot of things relevant to the boat’s seaworthiness being one of them the unsinkability of the boat (or not). Even if you consider that a boat’s unsubmergibility it is not important for a boat's seaworthiness (and if you think so, I find it odd) you can not take that away from the STIX calculation, the same way you can not, at your will, not consider or modify any of the other criteria, even if you find that you don’t agree with those criteria.

If you do that we are not talking about the ISO STIX anymore (and you can not talk about STIX), we will be talking about a Guillermo’s proposal to alter the STIX calculation. When we talk about STIX, we talk about ISO certified STIX and that one is for the POGO (cruising version) MOC 41.3, ML 44.9., and that’s it. You have no right to say otherwise unless, as a citizen, you want to accuse Jean Marie Finot of having miscalculated those numbers and the certification body of wrongly have aproved the calculations.

About Ericsson (do you mean Rolf Eliasson?) he is only one of the many fathers of the STIX and it is obvious that the majority did not agree with him. I have to say that I have thought once along the same lines (about the minimum 40STIX for the Class A certification), but I have changed opinion. It makes no sense that boats like the Nordborg 40, with a STIX of 34.5 should not pass the certification for a Class A boat.

Saying that : “ STIX is producing lethal boats” seems to me absurd. Today boats are more seaworthy than 15 year old boats. If you compare Swans, Bavarias, Beneteaus actual Stability curves with the ones from 15 years ago, you are going to find a better AVS and an overall better stability curve.

Guillermo
02-11-2007, 12:15 PM
Paulo,
Being unsinkability an important safety feature, of course, we still can take its effect out of the equation (it is as easy as imagining a Pogo with no watertight divisions), just to compare the influence of the geometry and weight related factors in the STIXs of two given boats. For analyzing purposes we may consider a non-delta STIX. Why not....? This kind of comparisons are absolutely fair and easily understandable, and widespreadily used in NA and other many fields. I do not see a reason for you to become aggressive again. I'm curious: is it a weakness in your personality? Are you the 'STIX's High Priest' or something...? :)

Guillermo
02-11-2007, 12:57 PM
And in a way that's the crux of the matter-
Matt,
I'm not talking just about statistical accidents reports, but also about getting data from a representative number of actual cruising boats, by installing aboard adequate sensors and a 'black box' for a period of time enough to collect data for the different types of boats (and crews!) in a variety of sailing conditions. Tank tests and CFD simulations have been thoroughly done, but a real life check would be great. The idea is not so collecting data from extreme situations like 180º capsizings or the facing of rogue waves (I do not wish that kind of situations for the collaborating crews in the program!) but rather the response and behaviour of boats under very variable conditions. I'm inclined to think there are a lot of B1 knock downs and losses of control out there (from all kind of yachts) that are never reported as long as they do not imply life losses or major breakdowns. It has to be, because of the laws of probabilities.

Technology is fully available nowadays and this has been done at least once by a japanese university, to my knowledge (I have to find the paper on the matter I posted somewhere before in these threads).

Cheers.

Mikey
02-11-2007, 09:37 PM
Vega, I think most of us agree that STIX is currently is the best tool available to assess stability of a sailing boat. Most of us would also agree that STIX is a compromise that does not take all factors in consideration.

Maybe the best way of illustrating that is that Pogo 40 has a much higher STIX than the Norborg.

Guillermo, I would agree with you that not including delta in a seaworthiness assessment is a valid path to go - As seaworthiness mainly should be assessed as a "pre-event". "Post-event" is of course also important when it comes to sailing boats but it should be secondary to "pre-event", IMO.

Mikey

Frosty
02-11-2007, 10:06 PM
This thread has shattered any confidence I had in boat deigners.

It would appear that should any one designer build a boat the other designers will shake there head in disgust and say "no no no" Thats not the way.

You have convinced me never to buy a new designed boat and I shall continue to buy boats from there reputation.

International boat shows will seem different to me fom now on.

Man Overboard
02-11-2007, 10:36 PM
Originally posted by Mikey
"Guillermo, I would agree with you that not including delta in a seaworthiness assessment is a valid path to go - As seaworthiness mainly should be assessed as a "pre-event". "Post-event" is of course also important when it comes to sailing boats but it should be secondary to "pre-event", IMO."

I don't think that eliminating "pre-event” and "post-event" circumstances is a proper methodology for evaluating seaworthiness. As Guillermo has pointed out, it has merit when comparing two boats, to evaluate other parameters, but the fact that the Pogo 40 has watertight compartments is a significant safety feature that can not go overlooked. It is indeed in keeping with safety features already implemented in the open 60 class boats, and is an example of how safety features that compliment a more extreme design can, and should go hand in hand. Just less than a month ago Mr. Greenwood out of New York has made the following comment:

Originally posted by DGreenwood:
Imagine a cruiser having to meet the buoyancy rules for example (water tight bulkheads). That right there would make them way too expensive.

Source, post # 29:
http://www.boatdesign.net/forums/showthread.php?t=15206&page=2

and now here we have an example of just that.

May I also call your attention to the fact that a boat rolling over is partly pre-event, and partially post-event; yet we don’t discount the post-event inversion as trite. No, indeed we attribute a greater necessity for the boat to self right. So if there is some other catastrophic event, say downloading, or a breach in the hull, I would think that not sinking should rank pretty high up on the seaworthiness scale; especially since it is one of the big complaints of the multihull proponents.

It might be advisable to consider the Pogo 40 as a transitional boat that bridges the gap between coastal cruising boats, and offshore cruising boats. A vessel that is great for coastal cruising, but yet one doesn’t have to fear for their life if they decide to make a passage once in a while… just a thought.

Guillermo
02-11-2007, 11:46 PM
Tom and Mikey,
Answers at the STIX thread.
Cheers.

Mikey
02-12-2007, 01:25 AM
Hi Jack, what's up? Don't you agree with evaluating seaworthiness post-event? :D

Mikey

Frosty
02-12-2007, 02:55 AM
Hi Mikey,--well you know its a bit worrying seeing all you clever guys tossing ideas back and forth not agreeing with each other. I have bought new boats in my life and its possible that I shall buy another.

But if I do Mickey it will be with different approach than before I saw all this.

I was kinda relying you guys knowing what you were doing.

From the man in the streets point of veiw this is frightening stuff. Who is right and who is wrong maybe some of you is right and some of you is wrong and may be all of you is--well you know the rest.

There does not seem to be any evaluating its going nowhere, on and on. NO-- agreements on seemingly anything.

Mikey
02-12-2007, 03:09 AM
Jack, yacht design has always been and will always continue to be a compromise - regardless of how much science moves forward. That is just about the only factor that will NOT change :)

Buying a boat based on its reputation sounds like a very good idea to me

Mikey

Frosty
02-12-2007, 07:46 AM
Yes Mikey when we are talking about where the head is who cares really that much,-- but you guys are talking about the dangerous stuff--Seaworthiness-- If you clever guys cant agree on what it should be, how do I know who is right. Or if any of you is right.

The point is none of you seem to agree about anything, and that scary.

So is that the end of the thread? the conclusion! , Buy a boat on its reputation? and never mind the stix stuff?

I doubt it very much!!

DanishBagger
02-12-2007, 11:55 AM
Jack,

They are disagreeing as good engineers should.

To me, it seems like you have just lost your "virginity" when it comes to believing NA's as authorities that have _the_ answer. THere are many answers, many ways to acheive seaworthyness.

It's the same with a house, there are many ways to acheive as little heatloss as possible. there is no _best_ way, but there are many good ways.

In a house, you can use even more insulation, you can reduce the percentage of the windows, use quadrouple-glazed windows, have windows with special gasses, minimize "cold bridges"(don't know what they're called in english), use certain colours on the roofs and outer walls, use speciel heat-regenerators (don't know what they're called either), and make the house smaller, so the heat of the people living there means more. Heck, you can even change the shape, make it a dome, and it'll be more efficient.

All those things are parameters you can adjust. Give me ten engineers, and you will have ten different opinions on how those parametres should be adjusted. And you, as a buyer, will propably have your own opinion too. Do you want to live in a dome? How much of a percentage do you want the windows to have? The colour should be? How large should it be?

Where will your compromise land?

Guillermo
02-12-2007, 03:59 PM
Yes Mikey when we are talking about where the head is who cares really that much,-- but you guys are talking about the dangerous stuff--Seaworthiness-- If you clever guys cant agree on what it should be, how do I know who is right. Or if any of you is right.

The point is none of you seem to agree about anything, and that scary.

So is that the end of the thread? the conclusion! , Buy a boat on its reputation? and never mind the stix stuff?

I doubt it very much!!

Jack,
I think NAs and Engineers around here more or less agree, each one with his own view of things, as it is normal. Interestingly the bigger (and more radical) difference in opinions seems to me to be between the (kind of) group of NAs/Engineers on one side and the (kind of) group of boat-owners/amateurs/would-be-NAs (this said with all respect) on the other. Not bad if debate is creative and respetuous, which many times (not always) has been. Please realize I do not pre-judge which group is right.

And buying a boat on its reputation has never been (and never will be) a bad recipe....

Cheers.

Frosty
02-12-2007, 08:45 PM
Jack,

It's the same with a house, there are many ways to acheive as little heatloss as possible. there is no _best_ way, but there are many good ways.
?


I thank you for your explanation, but a house will not roll over and drown you.

Its ok --not a problem please forgive me for my interuption of your argument which I dont understand any way. I wanted to let you know that I am a little surprised at this thread. It will, and has changed my veiws of designers who I thought were sooo smart and could build a boat and all the other designers would say "oh great job" and pat him on the back. Mmm dont think so, not now.

For instance I have never asked who designed a boat, never knew ,did'nt care. But now I might just ask and do some research. I would never have done that before.

I always assumed that when I bought a factory boat it had perfectly matched ballast with sail area etc etc. Now I will be not so sure, and skeptical of what I am told.

You know just stuff like this, Its all different now.

DanishBagger
02-12-2007, 09:01 PM
Jack, I'm a layman, just like you, so it's not "my" argument as such.

I do know that a house doesn't roll over and drown you, so to speak, but it's the same approach none the less. I could have mentioned how to make a house safe from fires, for that matter, but since I know rather much more about insulation, that was my example.

As always, reputation is not a bad indicator at all.

RHough
02-12-2007, 10:43 PM
Jack,
I think NAs and Engineers around here more or less agree, each one with his own view of things, as it is normal. Interestingly the bigger (and more radical) difference in opinions seems to me to be between the (kind of) group of NAs/Engineers on one side and the (kind of) (this said with all respect) on the other. Not bad if debate is creative and respetuous, which many times (not always) has been. Please realize I do not pre-judge which group is right.

And buying a boat on its reputation has never been (and never will be) a bad recipe....

Cheers.

I would add to "group of boat-owners/amateurs/would-be-NAs" Finot, Lombard, Farr, Dix, and many others that design boats for offshore use. There are a great number of designers that don't seem to think that there is a problem with seaworthiness. The fact their boats don't meet your definition of seaworthy only proves that "seaworthiness" is not well defined.

When the Pogo's STIX was posted as being higher than boats of the type you favor, you decide to remove one of the factors that make up the STIX number and ignore it to show the Pogo in a different light. This only shows that we all find ways to rate boats so the ones we like (subjectively) turn out the best by the objective measures we choose.

It was assumed that beamy boats are less seaworthy, yet when the beam of the Pogo 40 was compared to other boats of equal LWL, the Pogo is not very much wider.

It was assumed that the Pogo's stability curve would show that it was likely to have long inversion times. Yet it's 6:1 ratio of positive area to negative area is better than 90% of the boats raced offshore.

Unlike most of the "seaworthy" cruisers the "group of NAs/Engineers" favour, the Pogo is unsinkable.

That leaves what?

That the "group of NAs/Engineers" that are posting here don't like the Pogo is obvious. Proving in any objective way that the boat is not seaworthy has proven to be a problem.

What I have learned is that there is no one objective measure of seaworthiness. All the objective measurements are very valuable to compare a few similar boats. They don't do so well comparing dissimilar boats. This must drive engineers crazy. :) It leads them to modify formulas to suit the desired outcome ... i.e. ignoring unsinkability so the Pogo does look so good.

Like each person's definition of beauty probably gives a good idea of what their partner looks likes, their definition of seaworthy (and how to measure it) comes from the boats they like. Guilllermo and the "group of NAs/Engineers" that post here will always be able to find some measure by which they can call their dislike of the Pogo rational, after all engineers and scientists think of themselves as rational people. They may be able to convince themselves, but they have not been able to make a convincing case to the group of boat-owners/amateurs/would-be-NAs, Finot, Lombard, Farr, Dix, et al.

Every time new forms are introduced, there are naysayers and well qualified engineers that predict doom and gloom. History has proved them right sometimes and wrong many times. One of the reasons is that marine engineers started from boats that were built with little science and great practical knowledge born of experience working with the boat building material of the day (wood). From the forms that worked with wood, rules and science were created, mainly in order to reduce the number of bad boats that got built. When the design is freed from the constraints of wood and cargo capacity, the old rules don't work so well. A boat does not need a D/L of 200 or 300 to have sound scantlings. Boats that have D/L well under 200 are not limited to the speeds of the traditional hulls. Greater speeds and lighter boats with the same strength and cargo carrying capacity can make use of different hull shapes. It is certainly possible to build a near zero maintenance boat using GRP using the same shapes and weights as 100 year old wooden boats, but what's the point?

If the position is that you don't want a boat that makes use of years of experience and refined methods to reduce weight and increase sailing performance, fine ... say so. If you don't think a modern boat like the Pogo can sail oceans and use her speed to avoid being in survival conditions, you need to spend some time looking at the available resources that make such passage planning possible. If you are talking about a boat that must sail a route on schedule in any season, you are not talking about cruising pleasure craft, you should be talking to a doctor to have your sanity checked. :)

There are people that buy cars that they think are safe based on their "crash protection" rating. They don't think about steering, suspension, brakes and driver ability that might avoid the crash in the first place. I think the conservative engineers here are doing the same with boats. The idea of pre-event and post-event stability factors as a reason to exclude "unsinkable" from the formula is a sign of this sort of thinking. I say that the capsize is a post-event. Boats don't capsize on their own, they capsize when they are operated in conditions and in a manner that might capsize them. The "pre-event" could be taking a boat that could not avoid extreme conditions to sea not knowing the forecast. The "pre-event" might be making a passage in a slow boat and not having the ability or knowledge to update your course based on changing weather conditions.

As Paulo has pointed out on more than one occasion, the energy required to capsize the Pogo is much higher than for many so-called "seaworthy" cruisers. That means in the same conditions that would be threatening to the "seaworthy" boat, the Pogo is far from being rolled. Add to that, the Pogo's ability to cover miles and the chance of sailing in those conditions is further reduced. This should be no great surprise, unlike the "seaworthy" cruiser, the Pogo was designed to race in those conditions, not heave to and pray ... and after it all the Pogo will be floating. :D

As far as buying a boat on it's reputation, it is hard to do much better than Finot and the Pogo 40. They both enjoy a very good reputation. :)

Mikey
02-12-2007, 11:40 PM
Jack, I welcome you to the discussion, as an ocean cruising sailor your input is invaluable. I ask you to put on your “common sense hat” and comment on my view on this;

There is now (in the EU) a mandatory standard that assesses stability and seaworthiness. It is called STIX. It is not yet world-wide but in time, it will be. Many potential buyers will use this tool as a measurement of how safe a boat is. The higher the number, the safer the boat.

STIX adds 5 to the STIX – the “how safe a boat is number” – if it is unsinkable, that would give say the boat that you are looking at buying 41.3 – because it gets a hidden bonus of 5 because it is unsinkable. The “how safe a boat is number” would have been 36.3 had it not been unsinkable.

Two of the main business rules I work with every day are "keep things simple" and "don't spread important information around". The simpler, the clearer, the closer together important information is, the easier it is to pass on the whole message.

Now, it is possible to assess stability and seaworthiness – how safe a boat is – as pre-event or post-event. As a potential buyer assessing how safe your next boat is, would you like to see pre-event or post-event as the primary piece of information? Which piece of information should be high-lighted? Or should maybe only pre-event, or post-event for that matter, be displayed?

I find pre-event more important and would like to see the “how safe a boat is number” as 36.3U. The U is more than enough to communicate to the guy up-side-down that - OK, it won't sink anyway :)

Jack, if you were Joe Blog, the boat buyer :) how would you like to see this very important information communicated?

Mikey

RHough
02-13-2007, 12:08 AM
Jack, I welcome you to the discussion, as an ocean cruising sailor your input is invaluable. I ask you to put on your “common sense hat” and comment on my view on this;

There is now (in the EU) a mandatory standard that assesses stability and seaworthiness. It is called STIX. It is not yet world-wide but in time, it will be. Many potential buyers will use this tool as a measurement of how safe a boat is. The higher the number, the safer the boat.

STIX adds 5 to the STIX – the “how safe a boat is number” – if it is unsinkable, that would give say the boat that you are looking at buying 41.3 – because it gets a hidden bonus of 5 because it is unsinkable. The “how safe a boat is number” would have been 36.3 had it not been unsinkable.

Two of the main business rules I work with every day are "keep things simple" and "don't spread important information around". The simpler, the clearer, the closer together important information is, the easier it is to pass on the whole message.

Now, it is possible to assess stability and seaworthiness – how safe a boat is – as pre-event or post-event. As a potential buyer assessing how safe your next boat is, would you like to see pre-event or post-event as the primary piece of information? Which piece of information should be high-lighted? Or should maybe only pre-event, or post-event for that matter, be displayed?

I find pre-event more important and would like to see the “how safe a boat is number” as 36.3U. The U is more than enough to communicate to the guy up-side-down that - OK, it won't sink anyway :)

Jack, if you were Joe Blog, the boat buyer :) how would you like to see this very important information communicated?

Mikey

If "common sense" equates STIX with how safe the boat is, it become common nonsense.

STIX is a STability IndeX, stability is not the only thing that makes a boat "safe".

There are far more situations where a boat might be in danger of sinking than will find it in danger of capsize or downflooding. If you use "common sense" in rating the overall safety of a boat Unsinkability should far outweigh resistance to capsize.

STIX is only one part of what makes a boat "safe".

Real common sense tells us that NO boat is "safe". No matter what the STIX number might be. As soon as you can divorce yourself from the idea that a small boat can be made "safe", you can begin to see how any narrow-minded focus on one aspect of design will lead to false conclusions.

The only people that would support a "U" suffix are those that wish to ignore how un-safe boats that sink are. :D

Mikey
02-13-2007, 12:12 AM
STIX is only one part of what makes a boat "safe".


Of course, but that is not the point. The point is that there are many people out there who actually see the STIX number as a quantitative measure of how safe a boat is :!:

Mikey

RHough
02-13-2007, 12:42 AM
Of course, but that is not the point. The point is that there are many people out there who actually see the STIX number as a quantitative measure of how safe a boat is :!:

Mikey

And that is why boats that don't sink should have higher STIX ... because they are safer. :p

Man Overboard
02-13-2007, 01:22 AM
Originally posted by RHough
"Real common sense tells us that NO boat is "safe". No matter what the STIX number might be. As soon as you can divorce yourself from the idea that a small boat can be made "safe", you can begin to see how any narrow-minded focus on one aspect of design will lead to false conclusions."

I think this statement by Randy should be given some thought. I see all too often an oversimplification of known facts, with a disregard to unknown facts in order that a conclusion may be derived that supports ones own arguments. The fact that there is no set standard, no agreed upon measure of seaworthiness makes it impossible to verify that a conclusion is false. It may be instructive to not draw conclusions, but to take a look at facts, and pounder the breadth and depth of their meaning, or their influence, and correlate them with other known variables. In a way STYX does this, but to rely on one system of measure as a be all end all formula is nonsense.

Mikey
02-13-2007, 01:29 AM
And that is why boats that don't sink should have higher STIX ... because they are safer. :p

I agree, and adding an U after the quantitative measure of safety number, as many potential boat buyers see STIX, does exactly that :)

By the way, thanks for educating Jack, the potential boat buyer, that STIX stands for STability IndeX, now You only have 99,999,999 people left to educate :)

I want to show both pieces of information, in order of importance as I see them. I and Randy have aired our view, now it is others turn to do the same.

Mikey

RHough
02-13-2007, 01:37 AM
Originally posted by RHough
"Real common sense tells us that NO boat is "safe". No matter what the STIX number might be. As soon as you can divorce yourself from the idea that a small boat can be made "safe", you can begin to see how any narrow-minded focus on one aspect of design will lead to false conclusions."

I think this statement by Randy should be given some thought. I see all too often an oversimplification of known facts, with a disregard to unknown facts in order that a conclusion may be derived that supports ones own arguments. The fact that there is no set standard, no agreed upon measure of seaworthiness makes it impossible to verify that a conclusion is false. It may be instructive to not draw conclusions, but to take a look at facts, and pounder the breadth and depth of their meaning, or their influence, and correlate them with other known variables. In a way STYX does this, but to rely on one system of measure as a be all end all formula is nonsense.

Thanks Tom,

As a sailor of an "unsafe" boat that has never failed to bring me home, I find it quite amusing that engineers think that they can somehow make the sea safe for fools in small boats. :D

How about requiring all CE "Ocean" rated boats to be unsinkable? I wonder how many poster's pet boats would be eliminated? :P

Randy

PI Design
02-13-2007, 06:44 AM
I must admit, as the thread progressed, I thought we would all agree on what the charecteristics of a POGO type boat are, compared to a more traditional cruiser. Surprisingly, however, there has even been some disagreement about this. This is what I see as fact: The pogo is faster, has higher initial stability, higher AVS and requires more energy to capsize. It is also unsinkable, but this is not a function of its hull form, so similar designs would not necessarily be so. On the downside it has faster roll accelerations (which studies show leads to motion sickness), will re-right less easily and will probably be noisier and generally less comfy. The difference of opinion mostly seems to come down to how to interpret that information, which is because personal priorities differ. Some see quick passage making and a large area under the GZ curve as most important, others believe a small negative GZ area is the most critical thing. To an extent, the order of priorities changes with the type of sailing involved (coastal, blue water, racing etc), but within one genre of sailing, say blue water live aboard cruising, it ought to be possible to agree a set of criteria and priority order. It is an interesting question whether pre-event or post-event attributes are more important. Certainly prevention is better than cure, but we all get poorly sometimes...
I have some sympathy with RHough's point that crew skill (or lack thereof) is vitally important. However, it is the responsibility of the designer to minimise the impact of crew error (on a cruising boat).
As I have said before, I think it is important that boats meet some minimum standard of seaworthiness for the intended use. However, designing a boat which significantly exceeds that minimum standard is not really worth it. I for one, would trade excess safety for more speed, more space, better looks, cheaper construction etc, and I don't think I'm alone.
The fact that the pogo is unsinkable is great, but sinkability is a seperate issue to stability and therefore I think seperating it from STIX (STYX seems very Freudian!) is a good idea. I like the 'U' idea.
So don't be disheartened Jack, most of us agree on the physics - just not how to make best use of it! But that's the fun of boat design.
ALL design is a compromise. The Pogo is better at some things and worse at others. It is up to the buyer to decide whether the good outweighs the bad.

Guillermo
02-13-2007, 09:53 AM
I would add to "group of boat-owners/amateurs/would-be-NAs" Finot, Lombard, Farr, Dix, and many others that design boats for offshore use. There are a great number of designers that don't seem to think that there is a problem with seaworthiness. The fact their boats don't meet your definition of seaworthy only proves that "seaworthiness" is not well defined.
Well, to the other group we could add many hundres of NA's, engineers and designers thinking in a similar way we do. Among them probably we could include the working group who developed STIX, formed by most reputed professionals from well stablished organizations such as RORC, etc. Those people developed a system that penalize excessive beams and light weights for the recreational market. And they did the thing after analyzing a huge database of boats as it has already be explained (see post 205 (http://boatdesign.net/forums/showpost.php?p=125135&postcount=205) at the STIX thread, i.e.)

When the Pogo's STIX was posted as being higher than boats of the type you favor, you decide to remove one of the factors that make up the STIX number and ignore it to show the Pogo in a different light. This only shows that we all find ways to rate boats so the ones we like (subjectively) turn out the best by the objective measures we choose.
Excuse me, but the thing is not like that. I deduced the delta value, just to be able to compare geometry and weight related stability issues between Pogo and other boats not having unsinkability properties. That's all, and I think it's fair. Nobody is denying here unsinkability as a safety bonus. For sure it is.

What I have learned is that there is no one objective measure of seaworthiness.
The development of the STIX is precisely a big effort to try to assess some important aspects of seaworthiness. Everything is measurable and quantificable, including seaworthiness. STIX is a magnificent intent and my only worrying is it, in my opinion, still has dark aspects that need to be improved, precisely to make it more accurate. Aspects as transverse inertia, loss of stability due to speed, roll damping ability, negative/positive ratio of areas under the GZ curve, course keeping ability, etc., still have to be incorporated, from my point of view.


Every time new forms are introduced, there are naysayers and well qualified engineers that predict doom and gloom. History has proved them right sometimes and wrong many times. One of the reasons is that marine engineers started from boats that were built with little science and great practical knowledge born of experience working with the boat building material of the day (wood)...
Excuse me, but you seem to have little knowledge of what NAs, designers and engineers formation at schools and universities is nowadays. People like the NAs and designers you mention have also been formed in such places.

If the position is that you don't want a boat that makes use of years of experience and refined methods to reduce weight and increase sailing performance, fine ... say so. If you don't think a modern boat like the Pogo can sail oceans and use her speed to avoid being in survival conditions, you need to spend some time looking at the available resources that make such passage planning possible. If you are talking about a boat that must sail a route on schedule in any season, you are not talking about cruising pleasure craft, you should be talking to a doctor to have your sanity checked. :)
And if you are convinced that when cruising you cannot get into tight situations where speed is not possible, then you'd better check yours...:)

As far as buying a boat on it's reputation, it is hard to do much better than Finot and the Pogo 40. They both enjoy a very good reputation. :)
Absolutely on the side of Finot. About Pogo 40, I still would like to wait some years and a couple of hundreds of Pogos cruising around there to say so.

By the way: It seems Pogo 40 is somekind of my "bestia negra" (I don't know how to translate this into english) but it is not. It's only an excellent example to be brought to discussion and analysis, precisely because of its most interesting radicality. That's all. If I were the designer or builder of this boat I would be quite happy and proud of seeing how she is able to give foot for such a long and passionate discussion. ;)

Cheers.

RHough
02-13-2007, 11:18 AM
Well, to the other group we could add many hundres of NA's, engineers and designers thinking in a similar way we do. Among them probably we could include the working group who developed STIX, formed by most reputed professionals from well stablished organizations such as RORC, etc. Those people developed a system that penalize excessive beams and light weights for the recreational market. And they did the thing after analyzing a huge database of boats as it has already be explained (see post 205 (http://boatdesign.net/forums/showpost.php?p=125135&postcount=205) at the STIX thread, i.e.)

Yet their system gives the Pogo a high value. :)



Excuse me, but you seem to have little knowledge of what NAs, designers and engineers formation at schools and universities is nowadays. People like the NAs and designers you mention have also been formed in such places.

The science of boats was developed from the study of practical boats that worked, just as the science of flight was developed from things that fly. Much of the early scientific "facts" of flight have proved wrong. The theories and formulas were developed from empirical testing. The engineers and designers using data from towing tanks made some monumental errors, Brit Chance's Mariner is a prime example. I think it is more than likely that when any group starts from an existing sample of boats and creates a set of evaluation criteria, it can be very valid for the sample. When used to evaluate designs that are far from the norm, the evaluation becomes suspect. This is shown by the failure of every rating rule to date. IOR did a dandy job of rating existing designs when the rule was written. It does not do such a great job when applied to modern boats. Like racing rules, STIX is type forming. If a clever engineer/designer had a need, they could probably design a boat that was very unsafe but would have a high STIX number. This is a basic flaw in rules based on existing boats.


And if you are convinced that when cruising you cannot get into tight situations where speed is not possible, then you'd better check yours...:)


Getting into that tight situation is the pre-event. Have you noticed that the more experienced a sailor is the fewer times they find themselves in such situations?

If we can agree that all voyages include some risk, then we have to discuss what level of risk is acceptable. Each person should do all they can to keep risk within the limits they are comfortable with. I think the probability of an event that would lead to sinking is more likely than an event that would lead to capsize. My evaluation formula would place unsinkable boats with collision bulkheads higher on the scale of relative seaworthiness than boats with high AVS. Empirical evidence shows that small boats can make safe passages. 1,000's of voyages in boats that do not have high STIX values tells me that using STIX as the sole criteria for determining "seaworthiness" does not fit well with experience.


The development of the STIX is precisely a big effort to try to assess some important aspects of seaworthiness. Everything is measurable and quantificable, including seaworthiness.

This is the attitude of many engineers. While I would like to agree, and do agree in theory, the fact is at this point in time seaworthiness is NOT measurable and quantifiable. We cannot even agree on the definition! The need of engineers to measure and quantify things is shown very well in the cars we drive. Rather than concentrating on reducing crashes, they concentrate on reducing injury after the event. IMO STIX or any other evaluation that does not consider the skill of the operator is of limited value. Relying on a boat or car to protect you after you crash or capsize and not considering the vehicles ability to avoid the situation in the first place is not logical. It pleases engineers, because post-event engineering is indeed measurable and quantifiable. :)

Take care,

Randy

Crag Cay
02-13-2007, 11:27 AM
"bestia negra" (I don't know how to translate this into english)
In English, we say it is your 'bête noir'.

Perhaps 'FcFc' can let us know the French equivalent.

Guillermo
02-13-2007, 12:45 PM
Yet their system gives the Pogo a high value.
Not so high. A non-delta STIX of 36.3 (if it is so) for the geometry and weight related factors (pre-event) for a 40 footer is not that high. I'd even dare to say it is quite dissapointing, generally speaking.

If we could add more factors to the STIX, as the ones I talked about at post 592, it could be very well possible for Pogo 40 to reach a higher non-delta value. How about that?

Empirical evidence shows that small boats can make safe passages. 1,000's of voyages in boats that do not have high STIX values tells me that using STIX as the sole criteria for determining "seaworthiness" does not fit well with experience.
I agree and I have said that several times at the STIX thread. That's one of the reasons I think it's necessary to improve STIX (Crag is more inclined to make the thing simply dissapear, which could be the other way of doing things if we do not arrive to a more accurate and satisfactory STIX definition).

Relying on a boat... to protect you after you...capsize and not considering the vehicle(s) ability to avoid the situation in the first place is not logical.
I think you're contradicting yourself here.

Cheers.

Guillermo
02-13-2007, 12:52 PM
In English, we say it is your 'bête noir'.
Thanks, Crag

Cheers.

Crag Cay
02-13-2007, 01:09 PM
Given the degree of input of the RORC into the formulation of STIX, I am suprised that the adjustment made for having fully integrated buoyance is '5', as they only ever allowed '2' when computing its forerunner, the SSSN.

Guillermo
02-13-2007, 02:23 PM
Just read at Yachting World: "Berrimilla", a Brolga 33 launched in 1977 to a Peter Joubert design, and crewed by veterans Alex Whitworth and Pete Crozier, suffered a 180º capsize and dismasted when sailing under bare poles in a 50+ (gusts) knots gale. Last year Berrimilla competed in both Fastnet and Sidney-Hobart races. They were coming back from Hobart. Boat was receiving waves from the port quarter, when a big beam wave hit the boat on that side, knocking her down. Crew is injured but safe and made it to Eden, firstly motoring and then towed.
Anyone has more info?

http://www.berrimilla.com/
From there: "Joubert’s boats have a reputation for extreme toughness and seaworthiness and Berrimilla is very strong, heavily built and seaworthy and we have sailed her through some atrocious weather. Her stability index is 141.6 (IMS) and her calculated limit of positive stability is 135.4 degrees. Both of these are very much higher than most modern boats and quite reassuring in big breaking waves."

Guillermo
02-13-2007, 03:02 PM
Another one rolled and dismasted, "Privateer" crewed by solo sailor Ken Barnes:
http://www.msnbc.msn.com/id/16457498/

Guillermo
02-13-2007, 07:11 PM
Matt,
I'm not talking just about statistical accidents reports, but also about getting data from a representative number of actual cruising boats...... I'm inclined to think there are a lot of B1 knock downs and losses of control out there (from all kind of yachts) that are never reported as long as they do not imply life losses or major breakdowns. It has to be, because of the laws of probabilities.
Like this one:
http://www.youtube.com/watch?v=zk1o6MgfzrE

The boat: Swedenyacht 390 http://www.swedenyachts.se/

RHough
02-13-2007, 11:21 PM
Not so high. A non-delta STIX of 36.3 (if it is so) for the geometry and weight related factors (pre-event) for a 40 footer is not that high. I'd even dare to say it is quite dissapointing, generally speaking.

But, the STIX includes the delta. If you remove that component it is no longer STIX. You can say that a boat has a STIX of 40 or you can say it has a GVIX (Guillermo Version IndeX) of 35. It is not correct to remove components of a rating system and then call the resulting number by the same name. You are altering the formula by removing one of the components that it is based on so boats you don't like have lower numbers.


I think you're contradicting yourself here.

Not at all, I have always maintained that the ability of the sailor and the boat to avoid extreme conditions is a greater risk reducer than increasing the boat's stability. Now if you can increase the stability without reducing sailing performance, I would choose the more stable boat. If increasing stability means I have to choose between a 125 mile a day boat and a 200 mile a day boat, I would chose the 200 mile a day boat. For my comfort limit of 15,000 pounds, getting 200+ miles a day means a 38ft+ LWL and thus a D/L of under 115. Given those selection criteria, there are probably NO boats that you would find seaworthy.

In countless trial passages using pilot chart data, the faster boat always enjoys better conditions. Shorter passage times reduce risk farther.

The biggest unknown seems to be the location of containers lost from cargo ships. I am not aware of a system that is designed to help a small boat avoid hitting containers. Thus an unsinkable boat with a crash bulkhead makes good sense to me.

If we are to come up with a system to rate the safety of small boats at sea, it seems to me that risk reduction in design should address the most common causes of loss of life and property. Design elements that reduce the chance of going overboard, or sinking, should have greater weight than those that deal with lower probability events like capsize.

RHough
02-13-2007, 11:23 PM
... crewed by veterans Alex Whitworth and Pete Crozier, suffered a 180º capsize and dismasted when sailing under bare poles in a 50+ (gusts) knots gale...

Compare to the Class40 boats that are still racing in 50+ breeze (as they are designed to do)... :D

RHough
02-13-2007, 11:28 PM
Another one rolled and dismasted, "Privateer" crewed by solo sailor Ken Barnes:
http://www.msnbc.msn.com/id/16457498/

Yes the pool maintenance guy altered the boat and was asleep while the boat sailed into the storm ... while less that 200 miles away a 28foot boat sailed merrily on.

This photo rather makes my point. When a novice goes to sea, NO boat is safe. When a good sailor is faced with the same weather information, she managed to avoid the storm in a 150 mile a day boat ... think how much father away and safer she would have been in a boat that could make 200+ miles a day. :)

Guillermo
02-14-2007, 02:18 AM
But, the STIX includes the delta. If you remove that component it is no longer STIX. You can say that a boat has a STIX of 40 or you can say it has a GVIX (Guillermo Version IndeX) of 35. It is not correct to remove components of a rating system and then call the resulting number by the same name. You are altering the formula by removing one of the components that it is based on so boats you don't like have lower numbers.
Whatever you say: STIX, SMYX, GVIX or ASTERIX...It's low!


Compare to the Class40 boats that are still racing in 50+ breeze (as they are designed to do)...

Exactly.

...For my comfort limit of 15,000 pounds, getting 200+ miles a day means a 38ft+ LWL and thus a D/L of under 115. Given those selection criteria, there are probably NO boats that you would find seaworthy.
Probably not, I agree.

I see you're an speedy guy ;) Let me quote for you a funny old spanish song (A 'Chotis', the typical Madrid songs style, from 1920 or so, I think):
"Lo que antes te tardabas de 'La Bombi' al centro de Madrid en un simón, te lleva a Nueva York un aeroplano y...¿Qué haces tan temprano en Nueva York....?"

App. translation: What before took you to come from 'La Bombi' (a park in the outskirts of Madrid by then) to the center of Madrid on a 'simón' (horse cart), an airplane takes you to New York, and...what the hell do you do so early in New York...? :D

Cheers.

Guillermo
02-14-2007, 03:54 PM
Some interesting excerpts from the log of Sir Robin Knox-Johnston at the first leg of the Velux 5-Oceans race. Yachting World, march 07 issue.

"...There was an enormous lurch at about 0120 and the boat was knocked down on her side by a wave. I expected to fall backwards but it was no more than about 90º..."

"...You would not want to be around this boat at the moment. During a sqall we did a Chinese gybe. The mainsail had swung back and hit the runners and broken every single batten..."

"...we have become dependant of electronic aids. We all have been shamed into thinking we must have this stuff, but it is like the Emperor's new clothes -we need to turn back on the producers and say enough is enough, let's have some quality, please, before you sell us your product..."

"...What is not easy is the motion these rather flat-bottomed and wide hulls have. An small angle of heel seems a lot more and when she's thrown by a wave you do need to be holding onto something or you can go flying..."

"...The waves have not gone down; a batten, one of the new repairs, has broken; this computer has gone over-sensitive. The MaxSea programme has lost my polars and the gennaker sheet broke loose and went over side, scientifically wrapping itself around the starboard rudder...."

"It was much easier 38 years ago -no messing around with technology. They said I was missing for four-and-a-half months and prepared my obituary, but I always knew where I was. It was different in Suhaili -I remember we once hit seven knots! With these Open 60 yachts you hit 28 knots- I'm very impressed. They are remarkable boats, very exciting to sail, although you have to work hard to get on top of them."


Something for the thinking when bringing this kind of designs and technologies into cruising boats.

Crag Cay
02-14-2007, 04:38 PM
Ah Suhaili ! If only all boats were like that, eh?

Oh hang on. Wasn't that the one in 1989 that was knocked down four times and lost its mast in the North Atlantic because its crew of four couldn't manage to take the proactive measures necessary to stabilise the boat (towing warps), and left to its own devices, it didn't have the qualities to look after them without their direct intervention?

And wasn't the skipper a fully qualified master mariner who didn't know how to deploy warps in a survival situation without making a cat's cradle of it?

So, are the lessons here that only boats slower and chunkier than Suhaili should be Cat A and an Unlimited Commercial Master Mariner is below the threshold of qualification needed before you can be allowed to go to sea?

Or are there other lessons we can draw from this? Perhaps one of personal choice? RKJ is quite an old bloke. He wanted to do the Vellux as a life affirming experience. He went into it with his eyes wide open. He's obviously finding it a struggle, as most of us would. But that's the nature of the beast. If you don't like it, don't do it.

But if he was cruising he could have taken the mainsail down weeks ago. I bet he would still make adequate progress, and even under bare poles would still be a better sailing boat than Suhaili.

Guillermo
02-14-2007, 06:22 PM
Does that smell to resentment....?


(RKJ capsized twice aboard Suhaili when rounding the world at the Golden Globe, and he radioed: "I am beginning to wonder how much of the original boat I am going to be left with by the time I reach home. So far I have written off the self-steering gear, two tillers, a jib, a spinnaker, half the cooking stove, and the water tank. The cabin has shifted and leaks, and its canvas cover is cracking up.")

Crag Cay
02-14-2007, 07:26 PM
Does that smell to resentment....?
I'm not quite sure what you mean, but believe me, I have absolutely no problem with RKJ, or any of the boats he sails. I just think we need to be careful what lessons we try to draw from isolated comments or examples.

Jester / Suhaili / Gipsy Moth etc alway feature on the list of 'good old boats' that somehow represented an era when boats and their sailors were intrinsically better. However an objective look at their records may not reveal quite such a rose tinted picture. Too often, selective interpretation of incidents are being passed off as fact in support of our own boating preferences.

RHough
02-15-2007, 12:22 AM
Jester / Suhaili / Gipsy Moth etc alway feature on the list of 'good old boats' that somehow represented an era when boats and their sailors were intrinsically better. However an objective look at their records may not reveal quite such a rose tinted picture. Too often, selective interpretation of incidents are being passed off as fact in support of our own boating preferences.

Exactly right! It is human nature to justify ones decisions and choices. Some try to deny their bias and call it science.

fcfc
02-16-2007, 04:24 AM
To understand Guillermo mind, I think you must first understand spanish regulations.

It is THE one that if you want to sail over 60 nm from the coastline, you MUST have a category A (Ocean) boat, carry a sextant aboard, and have the highest spanish sailing license. "Capitan de Yate".

For "Capitan de Yate", you have around 10 hours of theorical exams, and 20 hours of practical exams to pass.

The category A is labelled "Designed for extended voyages where conditions may exceed wind force 8 (Beaufort scale) and significant wave heights of 4 m and above but excluding abnormal conditions, and vessels largely self-sufficient." in the 2006 RCD.

This is where has been educated Guillermo. No wonder he has been trained to think that anything smaller than a 10 000 T rescue tug is unsafe.

I do not think also that UK regulation, much lighter, have a worst score in term of safety.

MikeJohns
02-16-2007, 07:53 AM
Hello all


You may be interested: Papers are invited for RINA’s conference in October at Southampton, The subject is “The Modern Yacht” The closing date for submissions is April 6 2007

Relevant to this thread is a call for papers on such topics as; Performance, Stability, Sea-keeping, Hull motions, Structural design, Hulls, Keels, Rudders , Masts, Rigging, Classification society rules and Materials.

Should be interesting

Cheers

Crag Cay
02-16-2007, 08:53 AM
Maybe, but they're also looking for speakers with experience of helicopter operations, design of helipads, and integrating hangerage into a yacht with consideration of fire hazards and classification society compliance.

I think I'll wait for the program to be published before getting too excited. I'm not sure whether too much time will be spent on the issues that have been concerning people here! I was also intrigued by a conference notification I got from RINA entitled "The Affordable Warship". Now there's an oxymoron !

Equally interesting is a day next month in Southampton when lots of the issues surrounding offshore shorthanded sailing definitely will be discussed. Although the agenda is crowded, I would like to achieve some clarity on a design rule that produces fun, seaworthy, cheap, attractive, durable, multi use offshore boats that compliment the options offered by Mini 6.5s and the Class 40 / Open 40's. And all done, dusted and agreed before tea!

As a rule option, I have been exploring what happens if you limit LOA (30ft*/9.14m), Draft (6.5ft*/ 2m), construction to Eglass & Polyester and cast iron or steel for fin foil construction, and then let the requirements to meet RCD CAT A and OSR CAT 1 do the rest.

(* 30ft is the smallest acceptable length for the OSTAR and the biggest for the Jester. The 2m draft partly keeps them usable in regular sailing waters but also helps constrain excess is other parameters?

DGreenwood
02-16-2007, 09:36 AM
I would like to achieve some clarity on a design rule that produces fun, seaworthy, cheap, attractive, durable, multi use offshore boats that compliment the options offered by Mini 6.5s and the Class 40 / Open 40's. And all done, dusted and agreed before tea!

As a rule option, I have been exploring what happens if you limit LOA (30ft*/9.14m), Draft (6.5ft*/ 2m), construction to Eglass & Polyester and cast iron or steel for fin foil construction, and then let the requirements to meet RCD CAT A and OSR CAT 1 do the rest.

(* 30ft is the smallest acceptable length for the OSTAR and the biggest for the Jester. The 2m draft partly keeps them usable in regular sailing waters but also helps constrain excess is other parameters?

You mean like this?:

http://www.fox-tech.co.uk/projects.html

www.minitransat650.com/950 rules 2.pdf

I think this class may just happen.

Crag Cay
02-16-2007, 10:17 AM
Yes that's certainly one hat that has been thrown into the ring and has also gathered a bit of momentum. However the range of options for a class at this size is probably represented by the Class 9.50s at the high powered end and the Koopman VQ32 at the other.

Whilst everyone is agreed that the jump in offshore race boats from 6.5's to Class 40 is too big, the debate is about how to fill the gap. Mini 6.5's can be seen as little versions of the Open 60's in their complexity and (relative) cost. The Open 50's, 40's and 30's are also scaled versions of the same thing, but never really took off as the savings they represented were limited. Class 40 then came along and offered something radically different in concept and numbers soared as they met a real need.

My concern with the Class 9,50 is that it is again a scaled down version of, this time, the Class 40 with a few further material restrictions. Is this enough to differentiate it from the Class 40's, or do we need to look at something more than just cost cutting if we are to (hopefully) attract another surge in interest in short handed sailing?

30 footers should be the most popular class by far. We need to learn the lessons from the Whitbread / Mount Gay / Open 30 / Figaro classes, etc and make sure we end up with something that is not only financially attractive to the average sailor, but is one he /she wants to sail.

Guillermo
02-16-2007, 02:29 PM
...This is where has been educated Guillermo. No wonder he has been trained to think that anything smaller than a 10 000 T rescue tug is unsafe.
:D Excuse me, but I've also been educated in dinghy and sailboats racing, as well as cruising. And if you have followed my posts, I've defended proper small sailing boats as category A boats. I do not agree with the RCD not categorizing as A boats that have thoroughly proven their seaworthiness through decades.
Cheers.

Guillermo
02-16-2007, 02:32 PM
Jester / Suhaili / Gipsy Moth etc alway feature on the list of 'good old boats' that somehow represented an era when boats and their sailors were intrinsically better. However an objective look at their records may not reveal quite such a rose tinted picture. Too often, selective interpretation of incidents are being passed off as fact in support of our own boating preferences.
I'm not defending we have to come back to 'Suhaili' type of boats, but some of the posted thinkings of RKJ are worth of some consideration when we talk cruising boats.

Cheers.

Vega
02-16-2007, 09:02 PM
I must admit, as the thread progressed, I thought we would all agree on what the charecteristics of a POGO type boat are, compared to a more traditional cruiser. Surprisingly, however, there has even been some disagreement about this. This is what I see as fact: The pogo is faster, has higher initial stability, higher AVS and requires more energy to capsize. It is also unsinkable..

On the downside it has faster roll accelerations (which studies show leads to motion sickness), will re-right less easily and will probably be noisier and generally less comfy. The difference of opinion mostly seems to come down to how to interpret that information, which is because personal priorities differ. Some see quick passage making and a large area under the GZ curve as most important, others believe a small negative GZ area is the most critical thing. ….

It is an interesting question whether pre-event or post-event attributes are more important. Certainly prevention is better than cure, but we all get poorly sometimes......

ALL design is a compromise. The Pogo is better at some things and worse at others. It is up to the buyer to decide whether the good outweighs the bad.




Well, I have been saying that since the beginning of this thread. I guess that’s why Tad considers (on another thread) that this thread goes around in circles:p .


Seaworthiness (or lack thereof) is a combination of a number of factors including design, crew preparedness, construction, and maintenance.

In another thread there seems to be an endless circular discussion of heavy vs light displacement and the suitability of these factors, mostly boiled down to subjective opinion.

One area where we can be somewhat objective is in the motion (accelerations) of a particular hull form in a given seaway. It would seem to me that the discussion below was figured out 30 years ago by Bruce Farr. Make the bow fine to minimize pitching up when meeting a wave, and make the stern flat and wide to quickly damp any pitching.




Of course, what Tad says about motion also contradicts what has been said by the professional engineers that post on this thread and gives a new perspective about the sea motion of a Pogo on a seaway. The Pogo is just one of those boats with fine bows and flat and wide stern;) .


I think NAs and Engineers around here more or less agree, each one with his own view of things, as it is normal. Interestingly the bigger (and more radical) difference in opinions seems to me to be between the (kind of) group of NAs/Engineers on one side and the (kind of) group of boat-owners/amateurs/would-be-NAs (this said with all respect) on the other. Not bad if debate is creative and respetuous, which many times (not always) has been. Please realize I do not pre-judge which group is right.


Guillermo at is best:rolleyes:

NAs/Engineers against amateurs/would-be-NAs in a debate that has not always been respectuous and of course…. guess who is wrong:idea: . Obviously the ones that have not always been respectuous of the superior knowledge of the Engineers. Amateurs against Engineers, and not simple amaterurs, but unrespegtuous amateurs. Bad, very bad:p .

Well, Guillermo and Mike are not sailboat designers and Sailboat designers of this forum have carefully avoided this thread and even experienced NAs have stayed out. Why?
As we have seen, TAD considers this thread “to be an endless circular discussion … mostly boiled down to subjective opinion.”

The few real Sailboat designers that have posted on this thread have said things like:


... I don't know about Americans being prejudiced against heavy. Seems to me there are plenty of heavy boats around, and I think some are fine vessels. When pushed to travel at hull speed downwind they seem to roll and need constant correction on the helm to travel in a straight line, so I think the truth should be told when it comes to issues of directional stability, and I think comparisons should be made at equal speeds (not comparing a boat going slow to a boat going fast). .... I'm just saying I'm skeptical of formulae that predict heavy displacement boats will always have a more comfortable motion. It runs contrary to my experience.

One can always hold the midsection constant and increase station spacing to create a hull of any length. Therefore what advocates of heavy boats are really advocating is SHORT boats. Boats that are too short for their displacement are difficult to control, being inclined to spin and broach when running down the face of a wave.

I've explained, from my direct experience, why I'm skeptical of "comfort factor"... yet you continue to cite it without supporting evidence or validation. Do you continue to believe that it is a meaningful measure? Why? Of what? You may be right, but show me. … Might the formula have predicted the excessive pitching of the boat I was aboard? I've never been seasick on an unballasted dinghy.... its the slow, pendulum like roll & pitch of a heavy boat that fails to follow the contour of the waves in its motion that makes people nauseous, in my experience.




(Answering to Mikey that says: The definition of sea worthiness includes the ability to take a B2 knock down and righten itself, with the rig reasonably intact.
Now the interesting question of what safety margin you reasonably would have to add to ISO 12215-9 to achieve that, any suggestions?


Alik: But ISO12215-9 already assumes safety margin, doesn't it? :)


Mikey: So does the STIX numbers and we still consider them inadequate.

Alik: I would say they are not inadequate, but 'liberal'. Once regulations are too tight boats become not competitive. Saying 'competitive' I do not mean extreme racing boats, I mean commercially successfull production boats.

Overstrength means extra weight and cost. Finally customer pays his extra for safety margins introduced in rules, so they should be reasonable.



Rhough is only an amateur and of the worst kind:P , I mean a retro Dude and probably disrespectful, but what he have said is plainly evident:



I would add to "group of boat-owners/amateurs/would-be-NAs" Finot, Lombard, Farr, Dix, and many others that design boats for offshore use. There are a great number of designers that don't seem to think that there is a problem with seaworthiness.)

….the energy required to capsize the Pogo is much higher than for many so-called "seaworthy" cruisers. That means in the same conditions that would be threatening to the "seaworthy" boat, the Pogo is far from being rolled.

Relying on a boat … to protect you after you crash or capsize and not considering the vehicles ability to avoid the situation in the first place is not logical.

I would add that almost anybody, in what refers to sail boat designers is following Guillermo’s opinion about what “the modern paradigm of cruising boats” should be.

.. I have repeatedely said relatively light, slender and bulbed boats (Like the Nordborg and others within the concept but somewhat heavier) may very well be the modern paradigma of cruising boats (without forgetting some other older paradigmas, still perfectly valid.


Well, it may be your Paradigm, but if we look at the modern work of all significant sailboat designers, in what concerns small bluewater cruisers, we will see that your notion of what the Paradigm of a small oceangoing boat should be, is really a very lonely and personal one. Almost anybody is going along that road.

I guess, their choice regarding stability and seaworthiness has to do to what PI Design was pointing out:

“ It is an interesting question whether pre-event or post-event attributes are more important. Certainly prevention is better than cure….”

Modern sailboat designers are giving more importance to pre-events, I mean, boats that, compared with Guillermo’s Paradigmatic boat, are a lot more difficult to capsize, and that can be sailed successfully in a storm, than to post-events (recovering from an inverted position), even if their sailboats can recover from an inverted position in a reasonable period of time (just not as fast as the narrow boats that Guillermo prefers).

So it seems that in reality, it is the opinion of amateurs and the vast majority of modern sailboat designers against the opinion of some naval engineers that are not even sailboat designers. That will balance the odds, or maybe not….:rolleyes:

Paulo,
I do not see a reason for you to become aggressive again. I'm curious: is it a weakness in your personality? Are you the 'STIX's High Priest' or something...?

I have said that I would not tolerate any more rudeness of your part. I know that you from time to time apologize from your bad manners, but I have enough. Besides I agree with Tad, this thread goes in circles, it is not analytical, and it is full of unsubstantiated and unfair opinions.

PS. About unfair comments, have one as an example:



Originally Posted by Guillermo

I'm not talking just about statistical accidents reports, but also about getting data from a representative number of actual cruising boats...... I'm inclined to think there are a lot of B1 knock downs and losses of control out there (from all kind of yachts) that are never reported as long as they do not imply life losses or major breakdowns. It has to be, because of the laws of probabilities.

Like this one:
http://www.youtube.com/watch?v=zk1o6MgfzrE

The boat: Swedenyacht 390 http://www.swedenyachts.se/

Guillermo, do you sail? “Accidents” like the one shown on that video happen to everybody that sails and likes to go fast. Last year that “accident” happened to me 3 or 4 times, but not at 9K, mostly at 12K:cool: .

Those “accidents” are completely harmless in a modern boat and on that sea condition. If you don’t know enough or are afraid of having fun, you have just to reduce sail and you avoid that kind of situations.

The only capsizing that I can see in that movie is the one from the movie camera.:p

Guillermo
02-17-2007, 06:13 AM
Dear all,
On March the 1st to the 4th it will take place the Vigo Boat Show (http://www.nauvigo.com/)
The Naval Architects and Marine Engineers Association of Spain (which's Galician chapter I preside) is organizing there a one day conference (saturday) on recreational boating. Program includes 7 lecturers talking about technical and not technical matters, as this is an open to the public conference. I will read a lecture on the STIX. Everybody is invited, including Vega.
Cheers.

MikeJohns
02-17-2007, 07:12 AM
Vega

I'm sure I have mentioned this to you before:

I do design yachts and I have at various times in the last 25 years or so had a sporadic involvement with yacht design, mostly in larger sailing vessels. I have knocked out a few designs myself but I only sell the one niche market stock yacht design, aimed at self builders and smaller yards. I have sold yacht plans through this forum.


I am also concerned over your understanding of Marine Engineers or Naval Architects and what you call “Yacht Designers”. Yacht design is not a mystic and separate calling but is a subset of a broader discipline. Any Marine engineer/NA should be able to get up to speed on the complexities of yacht design in relatively short order, and debate issues with a full and thorough understanding of the complexities therein.

Cheers



Guillermo
Good luck with the lecture.

rayk
02-17-2007, 08:02 AM
Good on you Guillermo!

Take seaworthiness to the podium, and harvest some opinions from this thread to spice things up a little.

Guillermo
02-17-2007, 10:20 AM
Thanks Mike and Rayk.
Although not considering myself a sailboats designer (except for the dozen or so of designs I've done quite some years ago), I'm professionally a certified RCD surveyor and assesser for CE marking, as well as regularly perform other sailboats assessments under the spanish regulations, so I have a daily deal with these matters. I hope the lecture will be interesting to attendants.
Cheers.

RHough
02-17-2007, 12:48 PM
I am also concerned over your understanding of Marine Engineers or Naval Architects and what you call “Yacht Designers”. Yacht design is not a mystic and separate calling but is a subset of a broader discipline. Any Marine engineer/NA should be able to get up to speed on the complexities of yacht design in relatively short order, and debate issues with a full and thorough understanding of the complexities therein.



The ones I know would not agree. They know how much specialized knowledge is needed for their "subset" and don't presume that they would be "up to speed" in another subset in anything like "short order". This applies to engineers and scientists alike, not just those in the marine field. None of them ever assume that a subject is beyond the grasp of others and when asked questions never belittle their audience with statements like those made by some of the Marine Engineers and NA's in this thread.

DGreenwood
02-17-2007, 03:38 PM
Vega



I am also concerned over your understanding of Marine Engineers or Naval Architects and what you call “Yacht Designers”. Yacht design is not a mystic and separate calling but is a subset of a broader discipline. Any Marine engineer/NA should be able to get up to speed on the complexities of yacht design in relatively short order, and debate issues with a full and thorough understanding of the complexities therein.



Wow! That statement is at once, so arrogant and so naive, that I cannot see how I would ever allow your opinion to come under my consideration ever again.

Nothing about this thread, including the initial premise (or lack thereof) and the vague couching of the argument on the very first post has the earmarks of a professional engineer. The use of meaningless words like "seaworthy" and "cruising" were used to try to give more meaning to a single aspect of yacht design than it deserved.
Nothing here is supposed to be under the scrutiny of a professional peer review so it is assumed to be casual. So don't pull out the "I am a professional" unless you are prepared to act like one.
I come here to learn about boats and engineering...not how to be arrogant.

Thanks

Guillermo
02-17-2007, 04:11 PM
....The use of meaningless words like "seaworthy" and "cruising" were used to try to give more meaning to a single aspect of yacht design than it deserved.
Probably that's why this thread has come up to post number 624 and you're still around here... ;)

Guillermo
02-17-2007, 04:19 PM
Randy,
May we turn turtle your words?
"The ones I know would not agree. They know how much specialized knowledge is needed for their "subset" and don't presume that they would be "up to speed" in another subset in anything like "short order". This applies to amateurs and aficionados alike, not just those in the marine field. None of them ever assume that a subject is beyond the grasp of others and when asked questions never belittle their audience with statements like those made by some of the amateurs and aficionados in this thread."
Would it be fair?
Cheers.

DGreenwood
02-17-2007, 04:58 PM
Probably that's why this thread has come up to post number 624 and you're still around here... ;)

I am a patient man, if it takes 624 posts to glean 10 posts worth of information then I will wait and watch. :)

RHough
02-17-2007, 06:41 PM
Randy,
May we turn turtle your words?
"The ones I know would not agree. They know how much specialized knowledge is needed for their "subset" and don't presume that they would be "up to speed" in another subset in anything like "short order". This applies to amateurs and aficionados alike, not just those in the marine field. None of them ever assume that a subject is beyond the grasp of others and when asked questions never belittle their audience with statements like those made by some of the amateurs and aficionados in this thread."
Would it be fair?
Cheers.

I don't know that any of the self proclaimed non-degreed posters in this thread have been guilty of taking a self-important "I know more than you do" stance. I have reacted when someone pushes out their chest, proclaims themselves with a title or a degree and then tells me I'm not educated enough to understand the answer to a question. Holding an engineering degree is not proof against bias and ignorance. Some of the engineers and scientists I know come up with the most far-fetched and impractical ideas when faced with a problem outside their area of expertise. Just holding a certification or degree lends no more weight to one's opinion. We have to remember that 50% of engineers graduated in the bottom half of their class. :) I expect those that have completed formal education in a subject to be able to answer direct questions.

I find it odd that anyone with a combination of formal education and practical experience would equate or try to measure "seaworthiness" in terms of stability. It has been my experience that people define and measure things using systems and methods they are familiar with. I think the length of this thread shows that "seaworthiness" is next to impossible to define, much less measure. The level of frustration of those that wish to "prove" their knowledge is superior and that modern designs are not seaworthy has lead to evasive answers, no answers, or holier than thou statements. When self-proclaimed professionals become evasive and pompous, I ridicule them. In my little corner of reality, respect is earned. Those that expect it for whatever reason are held to a higher standard because they think their opinion should carry more weight. There is nothing more satisfying to me than listening to an ego deflate. :)

MikeJohns
02-17-2007, 09:20 PM
Ok it walks talks and quacks like a troll and it's off topic but it needs addressing.:rolleyes:


Originally Posted by MikeJohns
Vega
I am also concerned over your understanding of Marine Engineers or Naval Architects and what you call “Yacht Designers”. Yacht design is not a mystic and separate calling but is a subset of a broader discipline. Any Marine engineer/NA should be able to get up to speed on the complexities of yacht design in relatively short order, and debate issues with a full and thorough understanding of the complexities therein



Wow! That statement is at once, so arrogant and so naive, that I cannot see how I would ever allow your opinion to come under my consideration ever again.

Nothing about this thread, including the initial premise (or lack thereof) and the vague couching of the argument on the very first post has the earmarks of a professional engineer. The use of meaningless words like "seaworthy" and "cruising" were used to try to give more meaning to a single aspect of yacht design than it deserved.
Nothing here is supposed to be under the scrutiny of a professional peer review so it is assumed to be casual. So don't pull out the "I am a professional" unless you are prepared to act like one.
I come here to learn about boats and engineering...not how to be arrogant. Thanks

Yet you appear to have voiced a very superior judgmental opinion most arrogantly. :rolleyes:


If you had asked me to explain I would have been happy to say the following:

The complexities of hull design and the hydrodynamics therein, will have been mastered by any NA/ME otherwise they would not have graduated. Design factors including control, stability, strength, resistance, and motion would be immediately understood by any hull designer, the difference with a sailboat is keel design and Aero-dynamics of sails , leeway and heel angles.

Any hull designer worth their salt would already be aware of the compromises inherent in the hull-forms adopted for sailing vessels, and the effects and compromises this has on operational characteristics.

By up to speed in short order I mean the reading of books such as "Principles of Yacht Design" a novice would take many months to fully absorb the material in such a tome. A professional in the field would already understand the principles and would need to learn how those principles are applied. This would make it light reading, and I would suggest for most NA/ME a few nights would suffice, but lets give them a fortnight to be on the safe side.:)

DGreenwood
02-17-2007, 10:08 PM
Calling me a troll will not make your point any more believable. Nor can condescending to deal with me as if I were the problem here. I very quietly watched this thread for a long time hoping that it would morphose into some revalations and meeting of two different disciplines to produce useful ideas. There were some good moments, but your comment was not one of them. I would dare to say that your comment was insulting to more than one person that reads this material. Sorry all I will not interupt again.

RHough
02-17-2007, 10:36 PM
Calling me a troll will not make your point any more believable. Nor can condescending to deal with me as if I were the problem here. I very quietly watched this thread for a long time hoping that it would morphose into some revalations and meeting of two different disciplines to produce useful ideas. There were some good moments, but your comment was not one of them. I would dare to say that your comment was insulting to more than one person that reads this material. Sorry all I will not interupt again.

Getting insulted by NA/ME that think they know it all is not really an insult is it? People that think they have all the answers are ignorant of their own limitations. I would dare to say that the posters that get characterized as ignorant or amateur are far from being un-knowing and NE/ME's are far from being all-knowing. If you listen to the "everything is measurable and quantifiable" group then ask them to measure or quantify something, the response you get is hard to measure or quantify as an answer. :D

The biggest danger in letting some of the statements in this thread go unchallenged is that some poor fool will take an engineer at their word, put a 500 kg mast in a boat because "heavier rigs are more stable" and kill their family.

CT 249
02-18-2007, 03:50 AM
So if a qualified NA with no yacht design experience can "get up to speed" on yacht design by reading Larsson et al, surely the cruising yacht designers who say that their cruising experience gives them a superior insight into cruising yachts must be wrong?

After all, if experience and study are needed so little, then an qualified NA from the racing field should be able to rustle up a live-aboard cruiser pretty quickly. Yet when they have created lightweight racers and call then seaworthy, they get taken to task by some here. Surely it cannot be so easy as to need only a few evenings with Larssen by the fireside, and yet be so hard that qualified racing designers can't get it right at all (which is the regular accusation here). I used to have a NA friend who was a senior naval vessel designer; could you guys swap jobs with just a quick read of each other's manuals?

Is it really such a simple field that "any hull designer worth their salt (hmmm, I thought MAs had already mastered their subject so this disclaimer should not be needed!) would already be aware of the compromises inherent in the hull-forms adopted for sailing vessels, and the effects and compromises this has on operational characteristics."

Does it really just take a little bit of reading from a basic text to learn the right prismatic for a boat designed to excel in short-course racing in Long Island Sound? Where in Larsson et al do they give the exact details of the hull flare (forward, midships and aft) that experience has found to be best (for a given type) in Sydney, compared to the flare that works best in the Solent. Is there really all the information that one would need to be able to work out the optimum lateral area for a couple with 2 kids and 4 years' experience on a Cal 40, aiming to cruise to Tonga with "X" kg of supplies? What textbook describes the way of working out the correct waterline beam and cross-section shape for a UK Cherub, and why does an amateur designer in that class beat the engineers?

Surely this ability to obtain specialist knowledge within one's professional field so easily must be unique only to NAs. Could my GP could move into brain surgery just by reading a textbook or two? Then again, people from other disciplines are obviously inferior intellects (despite the fact that ('round here last year, at least) a NA degree was no harder to get into than social science or arts so becoming an NA is not restricted to great minds) since few claim that they have "mastered" subjects in their undergraduate degrees.

Guillermo
02-18-2007, 03:56 AM
Getting insulted by amateurs and aficionados that think they know it all is not really an insult is it? People that think they have all the answers are ignorant of their own limitations. I would dare to say that the posters that get characterized as NA/MEs are far from being un-knowing and amateurs/aficionados are far from being all-knowing.....
:D

...The biggest danger in letting some of the statements in this thread go unchallenged is that some poor fool will take an engineer at their word, put a 500 kg mast in a boat because "heavier rigs are more stable" and kill their family.
You know, what I think is some NA/ME around here feel much exactly like you do:
".....my job requires that I bite my tongue when a customer wants to do something clearly idiotic to their boat."
The good (or bad) thing here is this is only open discussion, so there is not such an strong needing to bite one's tongue. :P

I think that probably what has kept people sticked around here is not the further interest of the debate, which has clearly become circular, but the morbidity of strong discussion. I find many of us are insane or become insane when posting (or even watching!) at these boatdesign.net forums...:D

Cheers.

MikeJohns
02-18-2007, 06:14 AM
D Greenwood

A troll as in fishing .............for an argument. As a few people seem to be doing.

DGreenwood
02-18-2007, 11:05 AM
D Greenwood

A troll as in fishing .............for an argument. As a few people seem to be doing.

That is exactly what they are doing, and the trouble is this is not an argument. An argument, as any real scientist knows (and engineering is based in science), begins with proposing an idea and proposing some assumptions to work from. That proposition is defended or argued from more than one point of view to ascertain its value, if any.
This process (even if it is just for diplomacies sake) should follow the rules of argument which you should have learned in high school. As best you can, points of argument always involve clarity of position (Audiatur et altera parsand) and are best served without being smothered in ego.
As much as possible, ambiguous or vague words and phrases should be avoided, particularly considering the language, location and perspective issues that we are handicapped by to start with. A 747 is not “airworthy” because if the engines stop it will fall out of the sky, is not a proposition. It can’t even be intelligently discussed.
And arguments particularly should never involve ad Hominem arguments or attacks on the character.
So if I would be allowed I would like to reassert Guillermo’s initial argument as best I can with what he wrote initially and in following posts, and with some assumptions of my own.

As best I can tell from his statements, he is saying:
It is dangerous and irresponsible of our industry to market boats such as, and in particular, the Pogo 40 to the public as a “cruising boat” due to dangers in dynamic stability issues that could occur in storm force sea conditions.

This requires:

Establishing whether those dynamic stability dangers are real and possible.

The establishment of what acceptable levels of danger are.

What the typical end user is likely to interpret “cruising” to mean when he purchases the Pogo 40. (Assuming the seller doesn’t tell him)

Establishing whether it is possible or significant to the typical buyer that these dangers can be avoided through the application of learnable sailing skills.

I am not going to go further and state Guillermo’s premises here because that is his domain.
But what I will say is that the core of his initial question is a good one.
Do the damn things become dangerous in a stalled state in agitated seas? Whether it is significant to the average buyer or not I would still like to know because it applies to design in general.

One last note: I am in no way implying that I am not guilty of infractions in the rules of healthy argument.

RHough
02-18-2007, 11:57 AM
I think that probably what has kept people sticked around here is not the further interest of the debate, which has clearly become circular, but the morbidity of strong discussion. I find many of us are insane or become insane when posting (or even watching!) at these boatdesign.net forums...:D

Cheers.

I agree (from post #3):

I think Guillermo has put up a moving target.

Trying to define "Seaworthy" in broad terms will be very difficult.

I should have realized 600 posts ago that my definition of seaworthy is so far from Guillermo's that agreeing on what seaworthy is (much less measuring and quantifying it) had gone from difficult in post 3 to impossible by post 35.


We cannot compare stability in planning conditions, when high hydrodynamic lifts are in charge, with stability when there's no lift at all. Two totally different things. But the question, from my point of view, is that even when in no lift conditions (be it a light or heavy one), a cruising boat said to be oceanic must be intrinsicly safe, no matter what her crew abilities are.

It is my opinion that such a boat does not exist and may never exist. I don't believe small boats are "safe", they may be "safe enough" for you to feel comfortable crossing oceans, but no small boat I'm aware of would be considered "intrinsically safe". Certainly not one that could sink. :)

We are too far apart to ever reach a conclusion. The passion of the debate has helped pass the winter.

RHough
02-18-2007, 01:07 PM
A 747 will is not “airworthy” because if the engines stop it will fall out of the sky, is not a proposition. It can’t even be intelligently discussed.

Agreed, it was used in an attempt to point out that the ability of a boat to stop at sea being a requirement for seaworthiness is equally absurd (IMO) and that seaworthiness discussion, debates, arguments that ignore the skill of the sailor and the dynamic stability of the boat cannot be intelligently discussed either.




This requires:

Establishing whether those dynamic stability dangers are real and possible.

The establishment of what acceptable levels of danger are.

What the typical end user is likely to interpret “cruising” to mean when he purchases the Pogo 40. (Assuming the seller doesn’t tell him)

Establishing whether it is possible or significant to the typical buyer that these dangers can be avoided through the application of learnable sailing skills.

But what I will say is that the core of his initial question is a good one.
Do the damn things become dangerous in a stalled state in agitated seas? Whether it is significant to the average buyer or not I would still like to know because it applies to design in general.


Very well put.

Since the start of this thread I've been looking at the probability of gale conditions on several cruising routes. I am also using the polars from my C30 and real time time weather to see if a 25 foot LWL can avoid sailing into or through heavy weather using routing software and freely available weather forecasts. The Ken Barnes incident is an excellent example. IMO if he had been sailing his boat to a higher percentage of it's performance and had been using weather routing software he would still be at sea. I started running a simulation about a week before his capsize and was alarmed that he was sailing at speeds about 50% of the potential of a Catalina 30 in a 44 foot steel ketch. Even after making that adjustment, my software was still able to choose a route that avoided the conditions that rolled him.

So far my experiments lead me to think that the chance of sailing in gale conditions is very low (less than 1-2%). It follows that if the chance of gales (35+ knots) is 2% the chance of 50+ knots is even more remote.

As I gain confidence in the ability of modern methods to avoid extreme conditions (even in boats that I previously thought were too slow to do so), it makes resistance to capsize an even lower priority for me that it was when this thread started.

I think the idea of an "intrinsically safe" boat will lead to more deaths at sea. If the boat is thought to be "safe" and require a minimum amount of skill and experience to operate, we will see the level of seamanship decline even father than it has in the last 20-30 years. I see a parallel in reduced driving skills with the advent of higher crash protection in motor vehicles.

I think it is a disservice to advocate boats that cannot sail in gale or storm conditions over boats that are designed to do so. At some point, how the boat acts when stalled in agitated seas becomes an academic debate. The probability of the event is too low to make it a high priority.

Early on in this thread, the idea of a boat being seaworthy included the boat being able to handle any expected conditions and bring it's crew safely to port. I have to agree. I do not think that (given good seamanship and modern methods) that "expected conditions" include sailing in or surviving Force 9+ conditions.

rayk
02-20-2007, 03:34 AM
....I am not going to go further and state Guillermo’s premises here because that is his domain.
But what I will say is that the core of his initial question is a good one.
Do the damn things become dangerous in a stalled state in agitated seas? Whether it is significant to the average buyer or not I would still like to know because it applies to design in general.

I just felt like quoting this post.

Any way

......most of the arguments for the Pogo seem to be a cut and paste from a multihull thread.
Speed, capsize resistance, strength of modern materials, light weight.....
And yet a multi hull can go faster than a mono.

How idiotic to try and make a racy mono hull. A really 'fast' boat dragging around tonnes of lead.

That lead is for safety not performance.

Pre event blah blah...
Post event is the worst case scenario.
That is what a mono hull is built for.
Pre eventers should get a multi.
Post is inversion issues.
The area under the curve.
And its minimisation
Not justification.

edit: (cool, it looks like a haiku)

Milan
02-20-2007, 05:45 AM
"...my experiments lead me to think that the chance of sailing in gale conditions is very low (less than 1-2%).

It depends where and when.

port. I have to agree. I do not think that (given good seamanship and modern methods) that "expected conditions" include sailing in or surviving Force 9+ conditions.

:?: I admire your level of confidence in the perfect functioning of the fragile computers and other electronics in a salt-water environment on the small boat offshore.

RHough
02-20-2007, 07:19 AM
It depends where and when.

Yes it does. My idea of recreational cruising does not include high latitude sailing in winter (either hemisphere).


:?: I admire your level of confidence in the perfect functioning of the fragile computers and other electronics in a salt-water environment on the small boat offshore.

If you expect your electronics to work in salt water you might have a problem. :) If you keep them aboard the boat, they work much more reliably.

I can only speak for myself, but I don't work well in a salt water environment either ... that is one of the reasons that I keep the cabin and navigation area of my boat dry. Paper charts and pencils don't work well in salt water either.

Any system you rely on must be made reliable and/or must be backed up by other systems. That includes all systems, not just electronics. :) It has been my experience that I can rely on my systems.

DGreenwood
02-20-2007, 09:24 AM
I just felt like quoting this post.

Any way

......most of the arguments for the Pogo seem to be a cut and paste from a multihull thread.
Speed, capsize resistance, strength of modern materials, light weight.....
And yet a multi hull can go faster than a mono.

How idiotic to try and make a racy mono hull. A really 'fast' boat dragging around tonnes of lead.

That lead is for safety not performance.

Pre event blah blah...
Post event is the worst case scenario.
That is what a mono hull is built for.
Pre eventers should get a multi.
Post is inversion issues.
The area under the curve.
And its minimisation
Not justification.

edit: (cool, it looks like a haiku)

Good points RAYK but it still does not address the original questions
Guillermo used the POgo as an example of a dangerous ballasted monohull.

Guillermo claims he can prove that there are situations that, as a result of the Pogo being marketed as a "cruising boat" could mislead a potential buyer and resulting in dangerous encounters with waves.
Rhough claims this does not matter given the 1) likelyhood of encountering those waves and 2) being able to keep the boat in an aspect that would not allow it to become overwhelmed by such a wave.


A pretty good question to me. One apparently that can't be discussed in a civil manner.

Seems to me this discussion woud have been a lot more fruitful if that ridiculous word "seaworthy" were left out of it, and some typical usage for such a boat were established.

fcfc
02-20-2007, 10:21 AM
Guillermo used the POgo as an example of a dangerous ballasted monohull.

Guillermo claims he can prove that there are situations that, as a result of the Pogo being marketed as a "cruising boat" could mislead a potential buyer and resulting in dangerous encounters with waves.


No. Guillermo claims that YOU CANNOT prove that there are NO situations that , as a result of the Pogo being marketed as a "cruising boat" could mislead a potential buyer and NOT resulting in dangerous encounters with waves.

Guillermo is asserting something without prooving it, and is asking you to proove the contrary. And instead of giving facts on what he argues, he simply demands that your argumentation has reports on ALL boats pogo alike, anywhere, anytime to be valid. Which you cannot do. So then he claims your proove of the contrary is false, so his assertion is true.

You can see it there : http://boatdesign.net/forums/showthread.php?p=118120&#post118120

Milan
02-20-2007, 10:32 AM
My idea of recreational cruising does not include high latitude sailing in winter (either hemisphere)

Well, it's not just in very high latitudes. I always try to make a sailing season as long as possible. Autumn, winter and early spring have their own attractions, but chance to be suprized by unexpected storm are quite high.

If you expect your electronics to work in salt water you might have a problem. If you keep them aboard the boat, they work much more reliably.

:D

I keep the cabin and navigation area of my boat dry.

It's a difficult to guaranty "dryness" on the small boat offshore.

Any system you rely on must be made reliable and/or must be backed up by other systems.

Yes, as reliable as possible and I would add as simple as possible. Electronic systems are just to complex to be considered reliable on the boat. There are so many things that can go wrong with them. I would put them in a nice-to-have-not-to-rely-on category. I work daily with computers at the office, in ideal conditions, they are not tossed around, environment is dry, supply of electricity is constant, proper watts and volts, and yet, otenly enough, they don't work and it takes a loads of time for the experts with all professional equipment to figure out what went wrong. Small boat, in the middle of the ocean, screens on tilt. What to do?

DGreenwood
02-20-2007, 11:07 AM
No. Guillermo claims that YOU CANNOT prove that there are NO situations that , as a result of the Pogo being marketed as a "cruising boat" could mislead a potential buyer and NOT resulting in dangerous encounters with waves.

Guillermo is asserting something without prooving it, and is asking you to proove the contrary. And instead of giving facts on what he argues, he simply demands that your argumentation has reports on ALL boats pogo alike, anywhere, anytime to be valid. Which you cannot do. So then he claims your proove of the contrary is false, so his assertion is true.

You can see it there : http://boatdesign.net/forums/showthread.php?p=118120&#post118120

I will agree that Guillermos methods are confusing at times. You have to keep in mind he is not conversing in his native language. If he is confident enough to lecture a roomful of NAs on the topic he must have more sophistication in the topic than we are able to see. On the other hand I would like to see him defend his original statement without all the dodges and obfuscation. I have tried to center the conversation on his original assertions to give him a FAIR shot at clarification.
In my ideal world, these fora would be a casual atmosphere where one could ask a question or make a statement and expect to be vigorously supported or opposed with responses that intended to progress all of our understanding, without people becoming so invested in their own position that they are willing to break all the rules to "win".

RHough
02-20-2007, 11:07 AM
Seems to me this discussion woud have been a lot more fruitful if that ridiculous word "seaworthy" were left out of it, and some typical usage for such a boat were established.

I would be more than happy to participate. If someone would like to select a passage and a time of year. I would provide routing that shows the expected conditions the boat would face. From that raw data, sea state can be determined and the relative merits of the boats in those conditions discussed.

Alternately, if someone provides an average wave height that would threaten a Class40, but not some other boat (of their choice). I will see if I can route the Class40 on a passage that avoids threatening conditions. If I am successful, we can then compare passage times and debate if either boat has the ability to carry stores for a crew of 4 for that time.

PI Design
02-20-2007, 11:26 AM
One difference that seems obvious is that you (Randy) are talking about cruising in conditions of your choice, whereas Guillermo is talking about a boat that is fairly well permanently at sea and therefore subjject to whatever the weather happens to be that day. I think Guillermo agrees that the Pogo type design is adequate for summer cruising on voyages of a week or so. His argument is that such a design, whilst okay most of the time, will encounter conditions that it struggles in if it is permanently at sea. For a live aboard cruiser there are more suitable designs which require less skill and crew attention, fatigue the sailors less and will recover from a knockdown more quickly (at the expense of being more easily knocked down in the first place). For ultimate survival, it is important to be able to recover yourself, which catamrans can not do and the Pogo can not do so easily. In today's world we are more likely to be able to rely on outside assistance, hence perhaps the trend towards boats that are not totally self-sufficient. For many, this is an acceptable risk. However, some people (e.g. Guillermo) do not want to have to rely on others. Indeed it would be foolish to, if you chose to cruise remote parts of the world.

I think it is this difference in how you perceive cruising that is the fundamental difference in the two camps here.

DGreenwood
02-20-2007, 12:37 PM
But if the use is not specified...ie. who the targeted buyer is, what his experience might be, where he might go and what he might encounter, what the boats use is, then the discussion is moot. Giullermo might as well complain that there is no storage for a wheellbarrow on board the Pogo, so it is not a proper cruising boat. It is not a lake dinghy either but that doesn't qualify it for criticism yet, unless somebody was implying that that is what it is for.
I am sure he has an idea of how the boat may encounter some of the danger he has outlined, but he has not shared that idea with us. Personnally I don't see them encountering this situation enough to put limits on the marketing of them. But it sounds as if Guillermo has studied the effect of a stalled boat in big waves and if he wishes to use the Pogo as a test case I think it is a great idea. Just outline the test case so the results are vaguely valid, or at least solid enough evidence to make me pay closer attention to the potental dangers there.
I am not talking about a scholarly paper here.(I probably wouldn't understand most of that anyway) Just some good clear communication that we can all put to use.

Guillermo
02-20-2007, 03:46 PM
It's fair, DGreenwood. I'm too busy these days, but I'll come back as soon as possible and try to post something more claryfying. By the way, do you know we do not have an 'unique word' translation for 'seaworthiness' in spanish? It can be commonly translated as 'cualidades marineras'. The direct translation of 'aptitud para la mar' is not used. (And yes, it takes a lot of effort and time for me to express my thoughts in english.)

PI Design, you've got my point, thanks.

For the sake of fairness, I'd also appreciate if for the forthcoming debates everybody participating here identifies him/herself with full name, formation, experience and what they do for a living. Also some previous reading of at least some basic divulgative books on everybody's side, as the multi-mentioned 'Seaworthiness, the forgotten factor' and 'Principles of Yacht Design' would be very helpful and time and efforts saving. A good base to begin debating again.

Cheers.

rayk
02-21-2007, 02:46 AM
Pre event blah blah...
Post event is the worst case scenario.
That is what a mono hull is built for.
Pre eventers should get a multi.
Post is inversion issues.
The negative area of the curve.
And its minimisation
Not justification.
That makes a little more sense...

Guillermo
02-23-2007, 03:35 PM
.....most of the arguments for the Pogo seem to be a cut and paste from a multihull thread.
Speed, capsize resistance, strength of modern materials, light weight.....
And yet a multi hull can go faster than a mono.
[/SIZE]
But multis can capsize, don't turn up, and people die...
http://www.dailymail.co.uk/pages/live/articles/news/worldnews.html?in_article_id=437932&in_page_id=1811

Interesting from there, not only to multis:
"...They and their skipper, Steve Hobley, were 200 miles east of Bermuda on Monday evening when the storm hit with 40ft waves and winds of 65mph....

....The trio were delivering the boat from France, via Madeira, to Fort Lauderdale, Florida, and had no idea the storm would be so savage.
'There was one exceptional wave. Just as the boat came up, the crest of the wave broke. It just flipped the boat over,' ....

...Paying tribute to Mr Hobley, who was in his 50s, Mr Klinges said: 'He was an extremely competent sailor..... "

Cheers.

Crag Cay
02-23-2007, 04:49 PM
As a general rule, Guillermo, it's probably best to not quote the Daily Mail if you want to preserve a shred of credibility. There is only a slight chance that any facts in the report are actually true. Their sole mission in life is the make the population of the UK as fearful of just about everything as is possible. Seems like they now want to include multihulls in their repertoire of 'things to worry about'.

However, this report is unusual for a Daily Mail article. Apparently the cause of the catamarans troubles was large waves and high winds. In every other story they cover, the cause of the problem is always either Tony Blair or bogus illegal political asylum seekers.;)

RHough
02-24-2007, 02:10 AM
"...They and their skipper, Steve Hobley, were 200 miles east of Bermuda on Monday evening when the storm hit with 40ft waves and winds of 65mph....

....The trio were delivering the boat from France, via Madeira, to Fort Lauderdale, Florida, and had no idea the storm would be so savage.
'There was one exceptional wave. Just as the boat came up, the crest of the wave broke. It just flipped the boat over,' ....



How many hours does of what sustained wind speed over what fetch does it take to generate 40 ft waves?

Take the answer to that and try to reconcile it with "had no idea ..."

Contrary to what seems to be popular belief, 65 knot winds and 40 foot waves don't appear out of nowhere. Makes a great story for a tabloid though. :rolleyes:

Frosty
02-24-2007, 04:41 AM
Eh? what was that? Tony Blair is the reason for catamaran problems?

I thought that it was that in the norther hemisphere the port side hull always goes down first.

Vega
02-28-2007, 08:03 PM
Well, I was not thinking of posting here anymore, but I have read something that I thought that should be posted here. It is the Editor´s column of Bluewater Sailing Magazine, March 2007. It is about choosing a bluewater boat and it is pure good sense, and good sense is something that hasn't been much around in this thread.

Raggi_Thor
03-01-2007, 09:09 AM
Me neither, and maybe not the right thread, but I started to think about seaworthiness and safety, and what are the risks in boating. I didn't find any statistics for sailing crafts but for the Norwegian local fishing fleet.

From
http://www.teknofisk.no/images/news/Faginformasjon/HMS%20i%20sjarkfl%C3%A5ten_resultater%20fase%20II%20-%20SINTEF%20%20RAPPORT.pdf

In the 20 years from 1985 to 2005:
vessel breakdown, capsize etc (84 dead)
man overboard (64 dead)
drowning in harbour(!) (52 dead)
working accidents, hits/squeezes (21 dead)
fire/gases (4)

I assume that sailing yachts are safer than fishing vessels regarding capsize, break down and working accidents. So falling overboard on sea or in harbour is still the most realistic danger in boating.

Milan
03-01-2007, 10:19 AM
So falling overboard.....in harbour is still the most realistic danger in boating.


Yeah, I think that's highest of all boating related risks, getting back to the boat, (if you can find her), coming from the pub late in the night.:)

Raggi_Thor
03-01-2007, 10:33 AM
Most of the people drowning in Norway are men, age 40+, the zip open, alcohol in the blood...

MikeJohns
03-01-2007, 05:47 PM
Ragnar
That's why we could do with some detailed data harvesting, SOLAS is very efficient and effective at saving life after vessels have foundered but I think it skews the statistics too much to use as an indicator of vessel suitability.


Randy
In areas where the swell is often large, a gale produces almost instantly a very dangerous sea state, particulalry when the wind re-inforces the swell. The wind energy is disproportionate concentrating on the crests and can turn a large benign swell into a breaking system considerably faster than the graphs of sea state and wave height indicate. That is usually where the "instant" storm seas come from.


cheers

KevlarPirate
03-01-2007, 10:51 PM
Hi guys, just what you need a new voice.

I have read the posts from the start and considered them to be valuable. I think this has all been healthy even though there is frustrations here and there. All posting here
have valid positions and make good points. I have made a net gain from reading them, There are probably many others who are benefiting also. I hope you will see my remarks as valuable also.
The most recent posts seem to be bringing this to harvest time and some fruit should be dropping.

I make some points here with NO order of importance:


1. I say Mikejohns comments are quite valid re: NA, ME. I am an engineer with structures and materials background. And I work with very senior physicists and engineers with little sailing experience. I started racing in 1970 SORC, plenty of offshore experience since then. I take my guys sailing, and I am always impressed with their ability to quite easily come to speed on concepts which I consider pretty heady. In moments we are having discussion on higher levels than I ever did with the old crews and most of the new guys alike. Presently, I am a Race Chairman, so I get to talk with lots of very experienced racers including some who will be doing the Transpac this year, which I will start. I get to hear a lot of “less than scientific” talk from people sailing some of the fastest boats built. It can be frustrating. On the other hand, my guys will be talking Navier-Stokes equations within minutes, while I end up trimming jib, which is what they should be doing. I don’t complain, I have learned things from them even with my respectable technical background and experience combined. Smart guys pick up surprisingly fast, surround yourself with them.

2. Someone said we all are biased, and subjective. Right, so am I. I own 2 early 70’s 41 and 46 ft. race boats and love them; beefy hulls, cute butts, Barients everywhere, very high static curves, skeg rudders (upgraded). I like how they sail upwind in well developed sea, and I don’t overpower then off the wind. When I go up, they don’t lift their rudders, or bury their bows. They are displacement hulls and don’t pound, and they look good, (to me). Personally I think these boats are at the top of the curve for safety, speed and comfort combined. I would guess they could handle a container quite easily. My 41 spent 6 hours in the surf in Maui, pulled off by a cutter and was sailed away with a minor kink in the rudder shaft. The new breed is painful for me to look at. If speed is so important that I have to get it with something so hideous looking, then I should just be driving jet skies and play station. You can tell I am lost in the 70’s. That’s me. In the 70’s I would get fever walking down the docks looking at Running Tide, Sorcery, Passage……..Yep, I have my reasons. If the newbies get fever with the tea cups fine, I have no problem. We were talking design seaworthiness to start, and the jury is out I say. There is not enough data in for the really stressing cases.

3. Guillermo’s concerns are quite reasonable and no amount of speculation will replace data, which will accumulate as these boats log miles. However, I can say that any boat which requires the crew or driver especially to be on top of their game to keep the boat from harm is not good. Although I sailed with bulletproof crews in the 70’s, I was on one race where we took 2 knockdowns at 2 AM with sky so black the only illumination of the breaking crests was the lightning overhead. In all of this, none of us feared anything until we realized only 4 of us remaining out of 11 crew were still functional. We were tired and getting punchy. This was on a distance race where everyone starts. Out of 120 entries, I think there were 30 DNF’s, lots of broken gear and at least one helicopter rescue. Boats on passages will get caught and hammered. You can’t think you can avoid it every time. I have been hammered in the tropics by quick 60 knot squalls where rain stings and the falling ice cold air chills you past shivering into quaking where I started to loose mental ability to think. It happens. It is a good thing when you have no question that the boat is tougher than you. To keep complications down we cruise with less people, maybe just one other person, so we are already down on crew. These teacups that are out there now, let someone else give me their report if they survive. If they do and the boat too, then great, I will take the battlewagon approach. Fast enough and very tough. My 41 weighs 18500 lb, my 46 weighs 32000, there is a noticeable difference in motion considering they are similar designs. Smaller boats will have to take more risk with time windows and need more cautions on crossings but they will do fine, most of the time, however they will have their stories to tell, no one is going to sail for years with out taking a few lumps. But if you get injured it’s a different story. I jump around on a boat like mountain goat, but 15 years ago, I slipped after landing square and was in a cast for 6 weeks. To this day I can’t figure how it happened.

4. The new boats out there are nothing new to designers. The new breed are just large ballasted dinghies which people are brave enough to take out to sea. The fine long bows and zero dead rise stern was seen decades ago (in protected waters and then hauled on to trailers behind cars). The design now is all to keep the hull from getting locked into a gravity wave. Overhangs are gone and now you get to pierce the oncoming wave with 2 feet of green water over the deck. Wow, just what a cruiser wants. After enough punishment you then crack off and of course you have to power down with a huge slab reef in a boom almost as long as the boat. Now what about that lee shore? And when you below it sounds like inside a cement mixer, however your crash helmet will attenuate some of that noise. And when you try to get some rest you can be serenaded by pounding from the “pounding section” which starts on a 1-foot chop. When you go to the head to take a leak, don’t aim, won’t matter anyway. And then the galley… These are all things the cruiser will love I’m sure. I can say this, Every time I had to make the painful crossing from the Bahamas back to Florida, (painful meaning the fun was over) I wished the boat was just a little slower, the sight of land was painful. Actually I don’t wish the boat were slower. My point is that reasonable speed which is attainable by most boats is plenty fast to do crossings with reasonable care and preparation. Why cruising people need more speed and more concentration and risk is to me as silly as someone who will work an extra 20 hours a week out of his precious spare time just to own a more expensive car.
A seaworthy design is debatable, but I think the nuggets are what we are after. I have my list, others have theirs If people would like to compose their weighted lists and post, I would like to see that and we could average them.


Thanks


KEV

RHough
03-02-2007, 12:03 AM
Randy
In areas where the swell is often large, a gale produces almost instantly a very dangerous sea state, particulalry when the wind re-inforces the swell. The wind energy is disproportionate concentrating on the crests and can turn a large benign swell into a breaking system considerably faster than the graphs of sea state and wave height indicate. That is usually where the "instant" storm seas come from.


cheers

Mike,

I've gone looking for data to support that idea on more than one occasion, mostly from looking at historical data from weather buoys. I can't remember finding a data set that showed waves very far out of proportion to wind speed that developed anything like "almost instantly". Granted, storm strength surface winds can arise quickly from local "mini systems" like thunderstorms. However, these systems are usually short lived (about 45-60 minutes). They are also relatively easy to identify from cloud formations. Ocean racers seek the squalls, since modern boats can use high wind speeds to advantage. If ocean racers can actively seek these systems, it seems to me that the cruising sailor can also avoid them if they wish.

Kev,

Welcome to the thread.

I've had green water over the bow on a 300+ D/L boat more than once. A 80-90 D/L boat would have been surfing in those conditions and no wetter.

As far as a lee shore goes, the cruising version of the Pogo 40 sails 36.8 deg off the wind @ 8.05 knots in 35 knots true wind for a VMG of 6.44 knots. I'll venture to say that many 40 footers cannot do as well. I was quite surprised to find the boats so weatherly. Until I had more information I assumed they were only fast off the wind. Compare the numbers for a Farr 40 (30 knots True Wind): 43.4 deg, 7.33 knots boat speed, 5.33 knots VMG. I'd rather have the Pogo if I have to claw off a lee shore. :D

Guillermo
03-02-2007, 11:30 AM
In areas where the swell is often large, a gale produces almost instantly a very dangerous sea state....
And waves can even go faster than the wind:
http://oceanworld.tamu.edu/resources/ocng_textbook/chapter16/chapter16_04.htm
Cheers.

KevlarPirate
03-02-2007, 09:40 PM
Retro,

I did the math on the data you gave me and it shows the Pogo with VAW = 41.7 kt BAW = 30.1 deg. The Farr shows VAW = 35.3 and BAW = 35.3 deg.

Questions:

1. Am I to assume the Farr can’t sheet in as far as the Pogo?
2. Was the Farr overpowered with too much heel and had to crack off?
3. Is this real or calculated data
4. If real, What conditions (sea state) was these data taken in?
5. If real, Were both cases in the same conditions?
6. Can you provide the sources.

Interestingly, I recorded 40 kt. VAW, 35.deg BAW and 7.6 kt on my 34 year old
41 foot IOR boat. I was heeled 28-30 deg. and balanced. Which means in a gusty state, I don’t have to go scrambling to keep the boat upright and get worn out or hurt in the process. I can ride a gust out because I don’t have a huge wide butt creating nasty weather helm trying to round me up. I would say the Pogo, Farr have to be sailed quite flat. Do you agree or not? I know a J24 and J35 have to be sailed flat.

A little simple math shows the following:

VB/VAW VB/VTW VMG/VTW

POGO .194 .23 .184
FARR 40 .205 .244 .178
34 yr IOR .190 .223 .151

If the data you gave me is believable, it is obvious little performance gain has been gained in 34 years, that is in a high wind on the nose situation. The new radical designs really come to life off the wind. By the way , the Farr shows greater efficiency VB/VTW,VAW something to do with the BAW opening up? That is why I ask those questions about the data. Considering the numbers you gave me are to the 100th, I ask if they were real world or calculated . Mine are real recorded. Even if they are corrupted either by varying input parameters or calculated best case, they are all probably close enough, although I would still be interested in the sources.

When you look at the tracking diagram I have made here, you see that after an hour these boats are inside a 1 mile circle. You can also see that if I were concerned of a lee shore
I could tack thru 300+ degrees, do 9+ kt and have beam seas and cook food in comfort. (in my old boat). So there is no lee shore concern for any of these boats in this case. They all are pretty much in the same camp going up in big wind.

As for shipping water, yes, everyboat does from time to time, however I think it is more of the rule vs: exception with these new knife bows. My forward section flares and has overvhang. As the bow meets an oncoming wave it’s buoyancy increases exponentially.
as it buries itself. Also, it has lots of sheer. I have a dry bow. The new knife bows have no flare, overhang or sheer. When they meet an oncoming wave their buoyancy per degree of pitch is more a linear relation and in they go. Am I wrong?

As for comments on wave heights I can give an interesting anecdote which has consistent repeatability. I sailed off Florida for 20 years, in what people call the Gulf Stream , which is not correct; It is the Florida Current through the Straights. For short we call it the Gulf Stream anyway. I sail the Miami Palm Beach race (now shortened) as often as I can. That race is held in December and was a warm up for the old SORC.
By that time the fronts come in and you have a good 25% chance of getting 25 kts. on the nose (from the north) from Miami to Palm Beach. What is interesting is that wind bucks the 3 knot North current and makes for square waves many over ten feet with unusually short wavelength. We sailed on a C&C 37R which liked this condition, however we never buried our bow. We sailed against (5) ID-48’s which bore off due to burying their bows too much and we saved our time on them quite handily. What is my point? I forget now, but I type slow and I am not going to erase this. Has something to do with the above.
Will return Monday. I attached pdf. below

Guillermo
03-03-2007, 12:45 AM
As for comments on wave heights I can give an interesting anecdote which has consistent repeatability. I sailed off Florida for 20 years, in what people call the Gulf Stream , which is not correct; It is the Florida Current through the Straights. For short we call it the Gulf Stream anyway. I sail the Miami Palm Beach race (now shortened) as often as I can. That race is held in December and was a warm up for the old SORC.
By that time the fronts come in and you have a good 25% chance of getting 25 kts. on the nose (from the north) from Miami to Palm Beach. What is interesting is that wind bucks the 3 knot North current and makes for square waves many over ten feet with unusually short wavelength.
I've suffered those conditions, between Key West and La Habana, aboard a wing keeled MacGregor 26 (a 1984 version) with 5 crew, for a whole night. I can say it wasn't a pleasant experience at all. We almost lost the rudder, which we realized in the early morning. Repairing the thing in that sea state was neither a pleasant experience, nor easy.
Cheers.

Guillermo
03-03-2007, 12:53 AM
and good sense is something that hasn't been much around in this thread.
Absolutely. As knowledge also hasn't.

There are some people around this kind of forums with no formation on these matters but recent and erratic learning curves, who aggressively and stubbornly dare to pontificate on whatever the subject without having enough knowledge. Don't you agree?

Judge by yourself: "For calculating the maximum rightening moment of a boat you have to multiply the max. GZ (rightening lever) by the meters of the waterlength, and then by the total displacement of the boat." (http://www.sailnet.com/forums/general-discussion/11338-how-heavy-too-heavy-ii.html)

Cheers.

Guillermo
03-03-2007, 12:57 AM
Something interesting, directly from the POGO manufacturers:

"We are building "open" design boats from 1993, with a lot of mini 6.50, the Pogo 1, the Pogo 8.50, the Pogo 2, the Pogo 40 and the coming Pogo 10.50. What we want is to build boats to give fun and real sailing sensation to Pogo owners and be sure that they are enjoying their boats and having fun with them.
...................
I agree that we can build a more safe boat (than the Pogo 40) with huge stability, a narrow boat, heavy, big bulb, small mast and small sail area. The question is do we want to build sailboat or floating object? We are always working with compromise, we can do better but we can also do worst."

Cheers.

(Italics are mine)

RHough
03-03-2007, 05:04 AM
Questions:

1. Am I to assume the Farr can’t sheet in as far as the Pogo?
2. Was the Farr overpowered with too much heel and had to crack off?
3. Is this real or calculated data
4. If real, What conditions (sea state) was these data taken in?
5. If real, Were both cases in the same conditions?
6. Can you provide the sources.



The Farr will point higher, but the numbers I posted are best VMG in 30 knots true from the VPP data provided by Farr (http://farr40.org/pdf/farr40vpp.pdf). The BAW is 32.7 deg, VAW is 34.64, and heel is 24.6 deg (In 30 knots true) Best VMG is in 20 knots and the boat reefs between 14 and 16 true (22-23 deg heel). VB/VAW at best VMG is .285, VB/VTW is .364, and VMG/VTW is .283

The 30 knot true numbers for the Pogo (Cruising Version) are 7.96 VB, 36.0 deg BTW, and 6.44 knots VMG (same as 35 knots true). Data provided by Groupe Finot. I don't have heel angles for the Pogo. The Pogo's best VMG is 6.44 knots at both 30 and 35 knots true.

I agree that improvements in performance to weather has not improved greatly in the last 30 years or so. The IOR war horses tended to be optimized for upwind work, since that is where round the buoys races are won. Off the wind, they are still stuck in displacement mode and many of the boats get cranky when pushed hard.

As far as being sailed flat, 20-25 deg upwind is not so flat compared to 25-30 deg.

I cannot speak about the Farr, but the Pogo is designed to sail upwind at fairly large heel angles. The boat sails on it's leeward chine and the wide transom is out of the water creating a narrow waterplane. The Class 40's are designed to sail at their full potential short-handed. That is what makes them attractive to me. It's been my experience that most Racer/Cruisers of the IOR type need a gang on the rail to reach their target numbers.

When you crack the boats off the wind, say 90 deg true the polars look like this:

Farr 40: VB 11.27 in 30 VTW
Pogo 40 (Cruise): VB 12.92 in 30 VTW
Pogo 40 (Class 40): VB 13.72 in 30 VTW

Downwind VMG in 30 knots VTW;
Farr 40: VB 17.62, VMG 15.16 for VB/VTW = .587; VMG/VTW =.505
Pogo 40 (Cruise): VB 17.24, VMG 15.72 for VB/VTW = .574; VMG/VTW =.524
Pogo Class 40: VB 18.56, VMG 17.06 for VB/VTW =.618; VMG/VTW =.568

The new boats beam reach at S/L over 2.0 and make their best downwind VMG sailing at S/L over 2.5. I've not heard of a 70's IOR boat that can come close to those speeds.

Guillermo posted a study of fine bows on "Open" type hulls that shows (IIRC) that wave piercing (small pitch change) shape are faster. Light rigs and small pitch due to waves is a motion that some people quite enjoy. Through, rather than up and over (and several pitch cycles after) keeps the boat driving, not hobby-horsing to a stop and having to bear off to make forward progress.

I have to admit though, as far as looks go, the late CCA and early IOR boats (late 60's, early 70's) are some of the prettiest boat ever built. The early S&S Swans and the Cal 40 are handsome boats. I don't like most of the plumb bow, bubble cabin boats. Below 40 feet they look odd to me (Hard to love the looks of a Mini), and the Open 50's and 60's don't look "right" to me either. The Class 40 boats are just right to my eye. I like the Pogo and just when I was wondering why it doesn't have a chine aft, Paulo (Vega) pointed out the Akilaria and I fell in love. I hope to see and sail one in July.

The Cruise version even has a almost traditional layout:

CT 249
03-03-2007, 07:00 AM
Apart from the designer's own VPP, is there any evidence that the cruising Pogo is over a knot faster upwind than the Farr 40? That seems to put the cruising Pogo 40 up with Volvo 60s, well ahead of TP 52s, and capable of eating Open 50s.

The Pogo rates 1.27 IRC. The Farr rates 1.174 IRC. If the Pogo, pretty much a downwind-optimised machine, is 121% faster than the Farr 40 and rates only 108% faster, then it must be the ultimate IRC race winner. That really knocks the nail in the coffin of those who hate rating rules! The French PHRF-style handicap must also be out of kilter by something like 20% if that VPP is correct.

I also love IOR, RORC and CCA rule boats. However, this is very much a creation of the times we learn to sail in. The best example I know is the great designers Watson, writing about bow shape in a piece I found in an ancient magazine.

The sailing public, he wrote, found it hard to get used to thinking of clipper bows as attractive, because for much of the 1800s they were used to vertical stems - like a Pogo's.

Watson said that after a few years, yachtsmen had come to accept that the clipper bow was good looking - but, he said, no one would ever be able to think that the bow of his current designs was good looking.

The "ugly" bow he was talking of was the one on the King's yacht Brittania - for decades afterwards, seen as perfection. This is the same bow outline we see on metre boats, Dragons, Bermuda Yawls, and most of the other boats we think of as classic beauties today.

I personally love a sleek overhanging bow. But the fact that yachtsmen thought clipper bows were ugly and vertical stems were pretty; then thought clipper bows were okay but "swan bows" were ugly; and now think IOR bows are beautiful and vertical bows ugly; just underlines how much of aesthetics comes down to fashion and what we are used to.

Still, the Open style doesn't look much good to me, and I grew up in a world of scows, prams and vertical bows.


On another note; the fact that (as Kevlar says) IOR boats go upwind well, underlines that they ARE competitive under racing rules in many conditions, when they are sailed and geared as well as new boats (a rare condition). So the popularity of lighter boats is NOT driven by the fact that older boats are uncompetitive under the rules.

tgwhite
03-03-2007, 09:01 AM
A few months ago a delivery crew lost their cat off the US west coast during some hellacious weather. Although easy to single out cats and seaworthiness, the simpler issue is that good judgement is always a precious commodity. In this day and age of super weather predicting capability and on line access to weather routers, a boat lost at sea due to weather is an avoidable event.

However, some of us take risks, venture out without survival gear, no functioning EPIRB etc. Delivery skippers can be the worst as they are pressed for schedule and too used to tempting fate in an unknown vessel.

RHough
03-03-2007, 12:19 PM
Apart from the designer's own VPP, is there any evidence that the cruising Pogo is over a knot faster upwind than the Farr 40? That seems to put the cruising Pogo 40 up with Volvo 60s, well ahead of TP 52s, and capable of eating Open 50s.

The Pogo rates 1.27 IRC. The Farr rates 1.174 IRC. If the Pogo, pretty much a downwind-optimised machine, is 121% faster than the Farr 40 and rates only 108% faster, then it must be the ultimate IRC race winner. That really knocks the nail in the coffin of those who hate rating rules! The French PHRF-style handicap must also be out of kilter by something like 20% if that VPP is correct.



I agree that single number rating rules are not very good for comparing boats. The numbers I posted are for heavy air, upwind in a blow, the IOR boats should save their time on the lightweights. The S-H results show just that.

VMG Up/Down

4 VTW
Farr 40; 2.82/2.83
Pogo; 2.73/3.04

6 VTW
Farr 40; 4.01/4.17
Pogo; 3.98/4.41

10 VTW
Farr 40; 5.22/6.23
Pogo; 5.39/6.38

14 VTW
Farr 40; 5.56/7.51
Pogo; 5.89/7.82

20 VTW
Farr 40; 5.66/9.20
Pogo; 6.25/10.38

I've said before, I don't think comparing ratings tells us very much about boat speed. Multiple number rating systems or event specific ratings should do a better job. I don't see how a single number system can hope to work around the buoys (windward/leeward), Random leg courses, and predominately downwind (TransPac). In light air all the boats are in displacement mode, in medium to heavy air some boats plane off the wind, in heavy air upwind all the boats are in displacement mode again. How can a single number work? As far as being as fast as an Open 50, in the RdR the Class 40 boats were indeed faster than some of the bigger boats.

I'm taking information from the designers at face value. I'm not aware of Farr 40's struggling to hit their numbers, and I can't think of a motive for either design house to post bad data. If someone decides to try a Class 40 in IRC racing, it will be interesting to see what result they get and how the rating will change over time. Both the Farr 40 and Class 40 boats are designed to race in class, not handicap. Given the history of rating rules making huge errors, sailing OD or under a box rule makes sense to me.

We are WAY off topic. :D

Randy

Vega
03-03-2007, 03:19 PM
Absolutely. As knowledge also hasn't.

There are some people around this kind of forums with no formation on these matters but recent and erratic learning curves, who aggressively and stubbornly dare to pontificate on whatever the subject without having enough knowledge. Don't you agree?



Yes I do agree, but mostly I believe that there are some who learn and know that there is always a lot to learn while others believe that they know everything already.

I am afraid you have confused some people about the GZ (rightening arm) and RM (rightening moment) and its importance to judge a boat stability.

I think a résumé is needed:


In my opinion Avs ...should be used not alone but in conjunction with GZ at 90º value. A high value here is to ensure that the boat is able to right herself from a knockdown to an angle of around 90º. ...Also GM at 180º or GZ max in the inverted position should be considered to have a better clue about the boat's ability to recover from a knockdown.



you don’t get any real conclusions with GZ numbers or curves ...but only with RM curves. ..The RM curve is the only that can give you the real forces that the boat can make to recover from a knock down or the force to resist an inversion.


Don't make me laugh. You should tell this to all NA's, national authorities, IMO, Classification Societies, etc., etc., in the world, who assess stability using the GZ curves, instead of RM. Probably we are all stupid and do not know about our work. Please teach us. :rolleyes:



I don’t have the pretension to teach nobody, I am here to learn, but it seems that you have already learned everything.
I have explained why you should use a RM curve to understand the real stability of the boat (comparing it with others) instead of a GZ curve (and you didn’t explain why we should use a GZ).

A GZ curve is the tool to see if a boat is well designed or not, and it is that the reason that makes it a priority tool in the design of a boat. But for the buyer and to compare different boats regarding stability, it is the RM curve that matters. I have already explained why in a previous post.
GZ values are only the size of ARMS at different heeling positions, and its value is given in Europe, in meters, and in the USA in feet.

A buyer, while comparing boats, will not certainly be interested in the sizes of arms (GZ values), but in the resulting moment (the force) that comes from applying a mass (displacement) to the size of that arm and those are RM values (forces), expressed in force units.

A lever, when multiplied by the force pushing it, becomes a moment. With a boat the lever is the GZ and the force is the boat’s mass. So by multiplying GZ by the boat’s mass gives a righting moment (RM) curve.


The energy of the boat to resist capsize is given by the righting moment, absolutely, and, for two boats with a similar GZ curve, the bigger is able to better resist heeling forces. But as sizes and forms are so variable the only way of stablishing simple all around rules is to make the criteria "dimensionless", so avoiding displacement.




And this statement is not completely correct:

Length or the size of the boat has nothing to do with it. Displacement has.

For two boats with a similar GZ curve, the boat with more displacement is the one with a bigger RM, the one that is able to better resist heeling, or a capsize. That’s why smaller sailboats with a heavy displacement are many times more seaworthy than much bigger lightweight displacement boats.

For a similar GZ, the lightweight boat can have the double of the LOA of the heavyweight, but if the heavy one has more displacement, it will have a bigger RM and the force needed to capsize it will be bigger.

Guillermo
03-04-2007, 02:01 AM
Oh....It was YOU...! :D :D

KevlarPirate
03-05-2007, 09:43 PM
Retro

Thanks for those numbers, I will get to playing with them soon, maybe tonight.
I like to hear that you fell in love with a design. Nothing like ringing your bell. As CT tells the bow stories, I relate. As a kid I was in love with clipper bows because of Adventures in Paradise with Gardner McKay and the schooner Tiki. This aired in the 60’s.
When I got into big boat racing I got into the battle wagons of the day, 1970, and started to develop my own personal standards. In my first post, I told of these leanings, and I think all of us have our camps and reasons to defend. The reason I chime in, is when I think a design is being sold in areas which are better served by other designs. In short, I cannot be convinced without further data as to the seaworthiness of a Pogo or similar boat. No one disputes the speed and excitement capability of these boats. In fact the only reason I mentioned the “going up in big wind” scenario is that it is an area where cruisers will find themselves in often. I do every time we get a late start and cross the San Pedro Channel to Catalina Island. I also did when trying to get in to English Harbor, Antigua, before dark, so we wouldn’t have to stand off all night. The boat I had chartered was a heavy fiberglass ketch and it was a struggle but we made it. I know that on my 41 which is really a 1971 design, I would have hammered in and been able to even be a little sloppy on the helm (like with a rum and coke in hand). In these cases the boat and rig are under a lot of stress. My concerns are ultimate strength in the rig, hull and mass of the boat . I want a comfortable ride. I want to know the boat is tougher than me, and hopefully the sea, and if I really screw up and ground out or hit something I have a bullet proof hull under me. When I come onto a wave I want to go over it, not through it. I don’t want green water and I don’t want to blow out the foot of my headsail. I don’t care if there is a fraction of speed to gain, or if some people think it is fun. I am sure it is fun but I have gone to weather, on the nose, in 5-7 foot seas in 20 kt true and after about three hours, you really want to crack off. and, on my old girl, that’s with hardly any pounding (only on the big ones), which is totally unacceptable to me. I cannot imagine lightweight boats having any advantage in this situation. Pounding makes me and my crew uncomfortable. I would rather go slower. As for hobby horsing, I have felt this on slower boats like that ketch I mentioned, but with a boat that can do 1.25 LWL or better going up in big stuff, it doesn’t happen. Also, I have no one on the rail, as the boat takes care of herself . My 41 has a 46% Ballast ratio and my 46 has 52%. If I am off my targets, that’s fine , I will never notice it.
I have seen boats designed after this early 70’s era get very radical looking and the static curves look scary. Seems even worse today. The IOR was blamed for this but I have seen designs that make the IOR boats look tame. I see the beams on deck very wide and I don’t see that as smart. This thread was on seaworthiness, which involves many issues.
As being seaworthy, I also don’t want any really radical high aspect keels. I saw the keel of Grand Illusion (SC70 )after a collision with a whale, I think on the Cabo race and the blade was twisted 20 degrees or more. I do not know the extent of the boats hull damage as I saw the keel after removal. My 41 has ½ inch Lexan ports,
among many other features of strength and safety and those things add up to weight.
Weight adds comfort, lowers the risk of injury too, and allows the cook to feed the crew and keep them happy and alert through the night. I would be very impressed if I were to hear of a midlife couple having a fun time cruising a Pogo for any length of time, although I would guess 4 or 5 surfer guys to have a ball and never come home.
Well maybe, my old surfer friends liked their R&R too.

As for ultimate static stability I want to see a good curve and a lot of weight at the end of the arm, (mass) but I also want to see a good moment of inertia. (roll). Moment of inertia goes up with distance squared, it’s a velocity thing. No noodle masts allowed in my camp. Fine for coastal or Transpac even. Resistance to heel from a gust, wave impact resistance to capsize, and capsize recovery all have common underpinnings but are also have some uniqueness too.

Kev

(little whorls feed on big whorls and so on to viscosity)

Guillermo
03-08-2007, 07:10 PM
This one's about (lack of) common sense:
http://www.sailingmagazine.net/onthewind_0307.html

I'd add to Chris Cadwell's comments I'd obligue sponsors of such events to pay rescuing expenses. That would put also an end to most of such intents.

Crag Cay
03-09-2007, 05:10 AM
Cheap, unthinking, knee jerk journalism, designed to connect with the smug 'know-alls' in his readership. Complete, palpable nonsense.

Making sponsors liable for all possible rescue costs would also kill any involvement they might have with all sailing events. Who would want to sponsor even a professional, skilled, top flight Vendee entry if they thought they would have to shoulder the entire rescue bill of their boat from the southern ocean? Even inshore events and dinghy regattas have had bad days. (2 simultaneous helicopter rescues this summer from the Contessa 32 fleet at Cowes Week - high STIX perhaps but low booms). Should we hit their class sponsor with the bill? - "Thanks for your 100 euro contribution towards publishing the class newsletter, and oh... and by the way, here's the invoice for half a million quid for the life boats / helicopter we needed at Cowes Week!"

Or are we going to have some 'august body' to arbitrate on what constitutes 'sensible' adventure and what does not. Whilst everyone would agree in the instance referred to in this editorial, what about other hair brained schemes?

"You are aware Mr Vasco da Gama, that your intended trip has been deemed 'silly' by the International Committee for the Promotion of the Nice and Safe', and that if you fall off the edge of the world, your sponsor, will have to pay for all the rescue costs?" "Oh.. perhaps best if I stay at home them."

Or perhaps you think that this is a role for government? Perhaps we need some laws to weed out these people. Laws that regulate the type of boat or qualifications you need before embarking on certain trips? But what sort of draconian nightmare would that be? .... Spain?

If it's okay with you, can I exercise my opt out from your Orwellian world? These guys were clearly bonkers, but if having to pay for that through our taxes or increased contributions to the rescue team collection boxes, then I, for one, think it is a small price to pay for the freedom to do what we want without 'big brother' examining us for signs of 'undue risk'.

hiracer
03-09-2007, 01:55 PM
We simply can't have these fools suffering the delusion that they are free to do whatever they want. Not if somebody else ends up having to pay for it. Stopping irresponsible treasury expenditures is the only 'fair' thing to do and collateral damage from the operation of the 'fairness principle' is not subject to comment because everybody knows it's not fair to attack the fairness principle. If the fairness principle is abandoned, then modern society as we know it would be undermined. And that wouldn't be fair.

Besides, you just don't understand. In the calculus of modern politics, the action is in tax reduction. It trumps everything. And, since paying taxes is a form of slavery, even freedom has been transmuted into the drive for tax reduction. It's not fair to make people pay any more taxes than necessary. You really have to think about what's fair for everybody.

DanishBagger
03-09-2007, 02:58 PM
How about merely making it impossible to get the record officially _unless_ they are insured? Meaning, that they would need to get "approval" by means of the insurance company, and if not, then they are on their own, and they won't get their name on the record's list?

How does that sound?

CT 249
03-09-2007, 05:26 PM
I used to think that the taxes ocean racing yachties paid for their boats and gear could reinforce their right to rescue - okay, they took a disproportionate amount of money from the average taxpayer, but they also paid a disproportionate amount of tax. To me, that seemed to be one factor in this question.

But these days, here in Oz at least, many boats are set up so that they are owned by a company dedicated just to running the boat. The boat is then sponsored. The sponsor claims the sponsorship as a tax deduction; the skipper of the boat makes a loss on the boat and claims that as a tax deduction, offset against his other businesses. For example, one prominent 50 footer was transferred to the skipper's son's name because he had a boating-related business. Stick a couple of stickers on the bow and stern and whacko, suddenly the family gets to claim the running expenses of their grand prix boat as a tax deduction. So no one in this equation pays tax on their sport - in fact while figures are kept quiet, there's word that they make money (not that the tax office finds that out, of course). Of course, charter boats do the same sort of thing.

That means there's rescue money going out of the common wealth, but no tax money going in. Is that moral and ethical?

In this situation, where some boat owners are using the technicalities of tax law to escape paying tax, they seem to have very little moral authority to demand that the ordinary taxpayer should subsidise them.

It's just one factor in the question, of course

rayk
03-09-2007, 05:50 PM
Or what about an insurance levy built into the price of EPIRBs?
$10,000 EPIRBs again?

Personally I like user pays.
Who ever initiates the rescue, pays the bills.

hiracer
03-09-2007, 06:14 PM
Personally I like user pays.
Who ever initiates the rescue, pays the bills.

A good example of what's wrong with this world: Very unclear and selfish thinking.

Obviously, this approach never works. It's quite simply unfair.

Some people are fortunate to find themselves in asset rich circumstances. Some by pure luck. Some by right of birth. Some by dint of hard work followed by disproportionate reward. This is a hard fact of life that we all must learn to accept, and one that affects social and governmental policy at all levels.

What might be merely an expensive lesson in risk management to some would be a a terrible lesson in bankruptcy and receivership. Pegging the cost of rescue to one's financial status would mean that only the very rich would be able to engage in such folly.

We can't have that because that's not fair. Folly should be available to all or to none. That's the only way to go about it. Better folly be available to none, because it saves taxes. We must legislate away folly. It's only fair, and it save taxes.

rayk
03-09-2007, 06:28 PM
Dont call for rescue...die solvent.

hiracer
03-09-2007, 06:34 PM
Dont call for rescue...die solvent.

You've been talking to my kids behind my back again, haven't you?

rayk
03-09-2007, 07:21 PM
hiracer, they must have eyes on a reasonable inheritance, you big ol' fat cat.:p

hiracer
03-09-2007, 07:28 PM
you big ol' fat cat.

The greatest thing about the Internet is you can be who or whatever you want to be. :) Sadly, my kids know the truth.

And that's not fair.

Guillermo
03-11-2007, 05:30 AM
...small price to pay...
Hummm... My point is why some sailing idiots in this planet still think they have the right to unduly spend other people's money and risk other people's life to help them to fulfill their glory dreams/childhood traumas or simply take care of their irresponsibility. Are human lives (rescuers') also an small price? I suggest a visit to the RNLY.
Cheers.

KevlarPirate
03-14-2007, 03:29 PM
This thread started on seaworthiness which included or should include:

Seaworthy design, and a definition of that: Here’s mine:

A seaworthy design is (a design) that will survive in storm conditions without the help of the crew. In other words; if the crew is exhausted, do they have the option to call it quits, after all efforts made fail , go below , protect themselves and ride it out to the end of the storm and remain upright. We talked a lot about this earlier.

Seaworthy construction:

Speaks for itself. The best design can be held hostage by something as little as a pin which holds the washboards in place, or a port blowing out. Undersized standing and running rigging.

Seaworthy crew:

Storm survival equipment and adequate personnel to deploy it.
No sense having storm sails on board if the crew is a few old geezers.

Preparation:

The equipment, knowledge and practice needed for survival in severe conditions which includes active boat handling (still sailing), defensive boat handling (hove to, drogues. parachute anchor)


Isn’t it amazing how many people who call themselves sailors will go offshore without doing their homework. To them I say good luck, If you sink and drown,
you have received the Darwin award. To those who survive after a rescue, you get the bill. If you can’t pay, There are liens, property confiscations, wage garnishments. And prison. The IRS does this everyday. Just like in the big world of business, you stick your foot out there you may get it stepped on. That’s life. If I am a doctor who decides not to get mal practice insurance or a manufacturer who runs bare with no product liability insurance then God help me , I am a fool.


The ocean is the big league in sailing , go out there, you may get burned , folly, my butt!

longliner45
03-15-2007, 12:00 AM
quick story; the fishing vessel kelpie in the 80s ,hurrican juan was on them ,they abandond the boat for the safty of a oil rig off louisianna,,the boat broke free and was found 30 miles inland ,,still afloat,,moral of the story ,,if it aint sunk ,,dont get off of it ,longliner

fcfc
03-15-2007, 05:13 AM
Isn’t it amazing how many people who call themselves sailors will go offshore without doing their homework. To them I say good luck, If you sink and drown,
you have received the Darwin award. To those who survive after a rescue, you get the bill. If you can’t pay, There are liens, property confiscations, wage garnishments. And prison. The IRS does this everyday. Just like in the big world of business, you stick your foot out there you may get it stepped on. That’s life. If I am a doctor who decides not to get mal practice insurance or a manufacturer who runs bare with no product liability insurance then God help me , I am a fool.


The ocean is the big league in sailing , go out there, you may get burned , folly, my butt!


I expect you to hit such a rogue wave, http://www.photolib.noaa.gov/historic/nws/images/big/wea00800.jpg
and to be drown, or pay the bill.

The problem is that there are conditions you are expected to handle , and failure to do so is your responsability, and conditions where you simply have bad luck, because it happens less than one in fifty years and it lasts for less than 2 minutes and on a quarter a mile. And you where at the wrong place, wrong time.

RHough
03-15-2007, 08:06 AM
The problem is that there are conditions you are expected to handle , and failure to do so is your responsability, and conditions where you simply have bad luck, because it happens less than one in fifty years and it lasts for less than 2 minutes and on a quarter a mile. And you where at the wrong place, wrong time.
Do you mean to say that there are conditions that can overwhelm a small boat no matter how well it is built or designed?

A seaworthy design is (a design) that will survive in storm conditions without the help of the crew. In other words; if the crew is exhausted, do they have the option to call it quits, after all efforts made fail , go below , protect themselves and ride it out to the end of the storm and remain upright. We talked a lot about this earlier.
That this boat does not exist?

FWIW:
The Jordan Series Drogue has been at sea for over 15 years. At least 1000 are in use all over the world. The drogue has been deployed through many storms including several hurricanes. No boat has ever been damaged and no crew injured.

It seems to me that no small boat can be designed that can survive any conditions that the sea might conjure up. Conditions can exist that should be avoided. Just what are "storm conditions"? Does a boat that can survive "storm conditions" have to avoid hurricane conditions? If so, the ability to avoid conditions that are too extreme for a boat to handle becomes a large part of "seaworthiness".

I think "folly" descibes placing faith in a boat's ability to survive without help from the crew. "Folly" also describes "crash proof" cars. Neither vehicle exists. IMO, owners of "crash proof" cars place their faith in the car and don't bother to develop driving skills. Do sailor's of "storm proof" boats place their faith in the boat and not concern themselves with learning seamanship?

How many times have you heard the owner of a "Blue Water Cruiser" state something to the effect of, "I'm not concerned with speed, I'm a cruiser"? How many cruisers have you seen with all manner of crap lashed on deck? With blown out sails poorly trimmed? These boats had better be "storm proof", they don't stand a chance of avoiding them.

On the other hand, a fast cruiser, an aware skipper and a series drouge will probably never see "storm conditions". If they do (by some freak event), they have the proven drouge system to fall back on.

PI Design
03-15-2007, 08:35 AM
How about merely making it impossible to get the record officially _unless_ they are insured? Meaning, that they would need to get "approval" by means of the insurance company, and if not, then they are on their own, and they won't get their name on the record's list?

How does that sound?

I'm pretty sure that all ISAF sanctioned events do require the particpants to be insured. So this guy should have been, in which case the insurer should pay up.
can you imagine the insurance premium though, when you explain what you're trying to do! That might put a few people off.

KevlarPirate
03-15-2007, 03:25 PM
“Do you mean to say that there are conditions that can overwhelm a small boat no matter how well it is built or designed?”

Of course there are! Let’s talk about designs that will statistically do better than others when the crew is incapacitated and can no longer function.

“That this boat does not exist?”

As stated above, some much more capable than others.

“I expect you to hit such a rogue wave,
and to be drown, or pay the bill.”

I have the option to not make the voyage, If I do, I will not expect to be bailed out, therefore I will do my best re:
Boat design, construction preparation.

“It seems to me that no small boat can be designed that can survive any conditions that the sea might conjure up.”

Case in point , the Westsail 32 in the perfect storm (the real one, not the movie) washed up on a beach ,upright, with some minor rigging damage and the owners papers in a leather bag still in the cockpit) Compare that to the picture below.

“ I think "folly" descibes placing faith in a boat's ability to survive without help from the crew.”

The folly I am referring to is the delusional concept that it is not fair for the unprepared lesser people to not enjoy the “fun” things in life that the competent, capable (and therefore wealthy) people enjoy.
I say grow up! Is it unfair that I may be smarter than you, and make more money than you in my life. Is it unfair that my gene pool is superior to yours and I live longer and stronger than you? Should I be penalized through taxes to make everything fair?? Hogwash!

“On the other hand, a fast cruiser, an aware skipper and a series drouge will probably never see "storm conditions". If they do (by some freak event), they have the proven drouge system to fall back on.”


Retro, I keep hearing you talk of fast boats competent crew avoiding trouble. This is what we all want, but it doesn’t happen in the real world. The best crews get tired, have slip and falls, get hit, get worn out, get punchy and have trouble reacting quickly when body temp goes down, can’t see when in a pitch black sky in big seas. All of this has happened to me by just being out there. These things cannot be avoided as there are too many of them which occur in daily sailing. I still go, however, and I do it with knowledge and respect for forces much greater than me . The boat needs to be stronger than the crew is my point.

You will do what you want and learn by your own experience. I have read your theory (which I would love to be true and dependable) but there are things which are out of our control.
Of the tough times I have been in, almost all of them have been from bad weather. The other things have been near collisions with vessels, A blue whale, currents and seawalls, groundings. When you chalk up a lot of miles, problems always will occur. These things can not be avoided. On the same token when the weather deteriorates, lots ok things go wrong. I was whipped in the face with a sheetline, I thought had taken my skin off. I lost a few minutes. Luckily, I could tend to myself. I had to look out of only one eye, and luckily I was not alone, because it happened when things had to be done fast.

You talk of freak events? These are by no means freak. When doing the SORC longer races or most any crossing you are almost guaranteed you will get beat up. When you do, you need a boat which has better chances of survival without you doing anything but curling up down below. This means typically what the boats survival chances are when lying ahull
In breaking seas, typically in the 40 foot range which covers most all gales which are frequent events. No one can predict survivability in a hurricane or an asteroid hit. Yes life is full of chances.

If a sailor purchases an EPIRB is he doing it because he sees it as a substitute for incompetence, lack of preparation, guarantee for the need to prove some ego driven thing. What are that persons thoughts leading up to the purchase. Have they had dinner conversation like “well if anything happens and we are no longer having fun , I’ll just flop this little switch and there will be helicopters on the way” Yep, Isn’t life great !

RHough
03-16-2007, 12:00 AM
Of course there are! Let’s talk about designs that will statistically do better than others when the crew is incapacitated and can no longer function.

Then lets start with unsinkable as the barest minimum of seaworthiness. :)


I have the option to not make the voyage, If I do, I will not expect to be bailed out, therefore I will do my best re:
Boat design, construction preparation.

“It seems to me that no small boat can be designed that can survive any conditions that the sea might conjure up.”

Case in point , the Westsail 32 in the perfect storm (the real one, not the movie) washed up on a beach ,upright, with some minor rigging damage and the owners papers in a leather bag still in the cockpit) Compare that to the picture below.

“ I think "folly" describes placing faith in a boat's ability to survive without help from the crew.”

The folly I am referring to is the delusional concept that it is not fair for the unprepared lesser people to not enjoy the “fun” things in life that the competent, capable (and therefore wealthy) people enjoy.
I say grow up! Is it unfair that I may be smarter than you, and make more money than you in my life. Is it unfair that my gene pool is superior to yours and I live longer and stronger than you? Should I be penalized through taxes to make everything fair?? Hogwash!

The other side of that coin is a boat that sails better than a Westsnail would not have been such extreme conditions ... unless it's crew made an error in judgement. To me that is part of being prepared.


“On the other hand, a fast cruiser, an aware skipper and a series drogue will probably never see "storm conditions". If they do (by some freak event), they have the proven drogue system to fall back on.”

Retro, I keep hearing you talk of fast boats competent crew avoiding trouble. This is what we all want, but it doesn’t happen in the real world. The best crews get tired, have slip and falls, get hit, get worn out, get punchy and have trouble reacting quickly when body temp goes down, can’t see when in a pitch black sky in big seas. All of this has happened to me by just being out there. These things cannot be avoided as there are too many of them which occur in daily sailing. I still go, however, and I do it with knowledge and respect for forces much greater than me . The boat needs to be stronger than the crew is my point.

It does not take much for a boat to be sturdier than those that crew her. The boat may have uncomfortable, even frightening motion, but even "killer boats" in the '79 Fastnet were found more or less intact after their crews lost faith in them.


You will do what you want and learn by your own experience. I have read your theory (which I would love to be true and dependable) but there are things which are out of our control.

You talk of freak events? These are by no means freak. When doing the SORC longer races or most any crossing you are almost guaranteed you will get beat up. When you do, you need a boat which has better chances of survival without you doing anything but curling up down below. This means typically what the boats survival chances are when lying ahull
In breaking seas, typically in the 40 foot range which covers most all gales which are frequent events. No one can predict survivability in a hurricane or an asteroid hit. Yes life is full of chances.

If we accept that there are things beyond our control, and that no matter how well designed, built, and prepared the boat and crew are, there may arise an emergency situation. This is what the search and rescue system was designed for. If you had the best boat and the best crew and lost them because you could not assist the rescue effort wouldn't that be negligent? An EPIRB is part of preparation of a well found yacht, it is a tool of last resort after the sea overwhelms your well designed, well crewed boat.

It bothers me that there are people that seem to substitute an EPIRB for experience and seamanship. However, who is to judge what boat and what level of seamanship is required to be worthy of emergency assistance? Should there be a requirement for EPIRB usage that the yacht be CE Ocean certified and the skipper hold a yacht-master license? If an incompetent goes to sea in an open skiff and uses a EPIRB to call for help, should they be fined or penalized after the rescue? Could they appeal (to whom?) and if the conditions would have threatened the qualified boat and skipper also they the free rescue? Should the local Coast Guard prevent any voyage that some civil servant feels is unsafe? Where is the line?

I'll give you the asteroid hit. :) That would be tough to forecast.

I'll also say that the ability to heave-to or lie ahull are not high on the list of what makes a boat seaworthy. The series drogue was specifically developed to protect boats in freak conditions and breaking waves. Boats lying ahull tend to end up beam on to the sea, making them prime candidates for getting rolled. I've not heard any coherent argument against the use of a series drogue or case of boat found dis-masted and abandon with a series drogue deployed. There was a rescue off a boat that was dis-masted after being rolled but the drogue was deployed after the boat was rolled.

I think times have changed, the days of unavoidable bad weather and the need for heavy boats to lie ahull in are gone. There are a growing number of fast cruisers that can choose their weather to a great extent, tools available to aid the sailor with weather routing, and boats with D/L ratios under 100 that are unsinkable. If that 4x6 timber on the hatch of a Westsail makes someone feel warm and safe as they go below to ride out the gale, fine. It will protect them from the sight of a modern boat still sailing in the same conditions. Perhaps the modern fleet will have moved on and the Westsail will find a mooring at the end of their days/weeks longer passage. :)

One thing is for sure, if you plan to support your cruising lifestyle by writing books about your adventures on the high seas, you are better off in a Spray, Westsail, or some such traditional cruiser. Choosing those boats almost guarantees you will have storm survival stories for your book. :D

I'm sure "14 days of Hell ahull" will outsell "12 days to get Lei'd in Hawaii"

Just kidding, every sailor should know their own limits and limits of the boat they sail. Operating inside the envelope makes a great number of boats "seaworthy". I just don't want some government committee of NA's moribund opinions deciding for me. Like you, I will take responsibility for my choices.

Guillermo
03-16-2007, 05:19 AM
With a drogue deployed from the stern, after several wave strikes in a confused sea the towline can have so much slack that the boat can be capsized before the drogue exerts any force. This has been tank tested. There is no equipment 100% safe. Even drogues (Not to talk about electronics...!). Built in 'forgiving' seaworthiness is the first barrier of defence of a proper cruising boat.
Cheers.

RHough
03-16-2007, 10:34 AM
With a drogue deployed from the stern, after several wave strikes in a confused sea the towline can have so much slack that the boat can be capsized before the drogue exerts any force. This has been tank tested. There is no equipment 100% safe. Even drogues (Not to talk about electronics...!). Built in 'forgiving' seaworthiness is the first barrier of defence of a proper cruising boat.
Cheers.

Can you provide the data where this has happened with a Jordan Series Drogue? What you describe is a problem for a single drogue and was one of the reasons the series drogue was developed.

Jordan Series Drogue (http://www.jordanseriesdrogue.com/)

Coast Guard Report CG-D-20-87 (http://www.jordanseriesdrogue.com/pdf/droguecoastguardreport.pdf)

KevlarPirate
03-16-2007, 04:55 PM
“Built in 'forgiving' seaworthiness is the first barrier of defense of a proper cruising boat.”

No single sentence more effectively identifies the message this thread should send.

That is where seaworthiness starts. The design. I am not saying it ends there, however it is the last resort when all else fails.

With respect for your positive and optimistic approach, I believe there are too many commonly experienced problems which get in the way of that theory working regurlarly. Like a rudder post or steering breaking, or anything else underbuilt so as to save weight.
Like a long passage where you can’t outrun a storm because there is not enough wind to go your breakneck speed required and you have to motor. No weather routing will help you then.
Fronts can do 500 + miles a day (like with Fastnet)

How about deploying a drogue and loosing it overboard or the cleat pulling out of your minimalisticly built speedster. Or chafing through when you know for a fact you secured it properly.
I have only had a few times when a bowline has whipped loose
On the lazy sheet, yet my dog demonstrated to me he could defeat a bowline with a half hitch added.

And I suppose you will be the only sailor ever to never get any injury to reduce your effectiveness.

Your theory is complex and requires all cylinders firing all the time to work.
It requires electronics and antennas, crew in functioning status,
boat in functioning condition to maintain speed. defensive devices which work all the time..

simple solutions have less chance of failure. When things including yourself break, you will be sitting there just like everyone else. Better have your EPIRB


Good luck, have fun, but don’t forget the Darwin Award.

hiracer
03-16-2007, 07:38 PM
With a drogue deployed from the stern, after several wave strikes in a confused sea the towline can have so much slack that the boat can be capsized before the drogue exerts any force. This has been tank tested. There is no equipment 100% safe. Even drogues (Not to talk about electronics...!). Built in 'forgiving' seaworthiness is the first barrier of defence of a proper cruising boat.
Cheers.
The Jordan Series drogue is relatively new (20 years?) and does not have as much the real world use as unitary drogues and sea anchors, but thus far its track record is better than either. Except for one example of chafing on self-steering gear, it's success rate has been perfect. No injuries to crew during deployment, and all boats survive the storm.

Sailors who have used both the sea anchor and the series drogue have unanimously favored the series drogue.

Not all boats can use a series drogue, however, because much water can be expected to sweep over the stern in a bad storm. Cockpit drainage and companion way must be built to handle the deluge.

I'm in the middle of the tedious chore of sewing my own right now.

KevlarPirate
03-16-2007, 08:48 PM
“Then lets start with unsinkable as the barest minimum of seaworthiness.”

I agree. Light weight hulls with unproven offshore strength should have positive flotation.

“a boat that sails better than a Westsail would not have been such extreme conditions ... unless it's crew made an error in judgement. To me that is part of being prepared.”

Theoretically valid, but fails with a long passage where all boats are vulnerable as storms develop in open ocean and move faster than any sailboat can travel. A week before hitting the Fastnet fleet, that storm was knocking power poles over in the Midwest

“It does not take much for a boat to be sturdier than those that crew her. The boat may have uncomfortable, even frightening motion, but even "killer boats" in the '79 Fastnet were found more or less intact after their crews lost faith in them.”

Don’t think so. Many boats sank and the others were disabled and then gave minimal protection to the crew, that’s why they abandoned them. I wonder what the Fastnet would have done to that (killer) boat in the picture I attached? hmmm when was that built? maybe 30 years AFTER Fastnet? more?

“should they be fined or penalized after the rescue?”

No, just sent the bill, If someone insured them, then the bill is paid. The owner can rationalize the premiums and the return on investment if any. The premium will then go high enough (if he can get insurance) to equal the liability and then the owner can opt to self insure. On his second screw-up he can pay the expenses from his own pocket and then, if he is still alive, he can think about a better design and better prep, or if he can’t pay, he can loose his boat and see it auctioned off, and think those future thoughts while breaking rocks in the hot sun or make some license plates to make up for the tax dollars he has burned from people like me. After a little sobering he can think of a well designed, sound boat which will reduce the probability of having to be rescued. At this point , the word will get around and maybe others will realize the same before they flip the EPIRB on.

“think times have changed, the days of unavoidable bad weather and the need for heavy boats to lie ahull in are gone”

Your statement requires communications and boat speed to escape (active means). A little to bold a statement for me. I will not be held hostage to a thousand single point failures between the antenna and the batteries or the boat and crew to be on their best game to escape.

“I just don't want some government committee of NA's moribund opinions deciding for me”

The very way to attract that attention if for the user to demonstrate behavior which becomes a public tax burden
and risk to others.
Your government watchdogs love irresponsible people, gives them a paycheck!

Guillermo
03-17-2007, 12:54 AM
It was not only Fastnet. Trouble can build up suddenly, even for the more experienced. Read this most interesting analysys of Queen's Birthday Storm:
http://www.setsail.com/products/pdfs/qbs.pdf

**** happens.

About the Jordan series drogue, I find it an interesting device although for my own use I'd rather go for a mono-drogue like Seabrake or Galerider, as I find they can be useful for a wider variety of situations and uses, i.e. as when in shallower waters. Also I'd rather prefer running 2-3 knots under control than being almost sttopped. But this is only a matter of personal preferences, I'm not discrediting the series drogue at all.

Cheers

PS1: The Queen's Birthday Storm of June 1994 involved a cruising fleet of 35 boats voyaging from Auckland, New Zealand, to Nuku'alofa, Tonga, on an annual cruising pilgrimage. In this storm, one boat was lost with all three crew; only its empty life raft carrying an activated EPIRB was ever located. Seven other boats were eventually abandoned, but the crews stayed with them until rescue vessels arrived, possibly a lesson learned from the Fastnet disaster. One of those seven boats was found afloat six months later and salvaged. Twenty-one crew from the seven boats were rescued directly by surface vessels who responded in a very timely fashion to both EPIRB signals and requests for assistance from New Zealand authorities.

PS2: Also the reading of : http://www.bluesuit.co.nz/1994.htm, http://web.mit.edu/mitoc/www/history/tripreports/57 and http://www.latitude38.com/features/nzstorm.htm is interesting

RHough
03-17-2007, 02:42 AM
“Then lets start with unsinkable as the barest minimum of seaworthiness.”

I agree. Light weight hulls with unproven offshore strength should have positive flotation.

No one has proposed cruising in a boat with unproved offshore strength. What boats are you thinking of? :)

Do you imply that heavier, slower boats are somehow less likely to sink? I don't follow that logic. :)


“a boat that sails better than a Westsail would not have been such extreme conditions ... unless it's crew made an error in judgement. To me that is part of being prepared.”

Theoretically valid, but fails with a long passage where all boats are vulnerable as storms develop in open ocean and move faster than any sailboat can travel. A week before hitting the Fastnet fleet, that storm was knocking power poles over in the Midwest

Everyone knew there was rough weather headed towards the Fastnet fleet. The well prepared boats had few problems. The weekend warrior types that had no business at sea did. The owner of the shop where I work was on an Admiral's Cup boat in that race. He does not describe the storm as being all that bad. If you were cruising you would not have gone to sea until the weather had cleared. (Unless your idea of cruising is starting a passage with a Force 8 forecast).


“It does not take much for a boat to be sturdier than those that crew her. The boat may have uncomfortable, even frightening motion, but even "killer boats" in the '79 Fastnet were found more or less intact after their crews lost faith in them.”

Don’t think so. Many boats sank and the others were disabled and then gave minimal protection to the crew, that’s why they abandoned them. I wonder what the Fastnet would have done to that (killer) boat in the picture I attached? hmmm when was that built? maybe 30 years AFTER Fastnet? more?

15 deaths, 19 boats abandoned, 5 boats sank, 306 boats started. That makes "many" = less than 2%?

The picture you posted, what is the context? Was the boat racing? What happened 30 seconds later? A shot of a boat knocked down out of context proves nothing. Passionate opinion not supported by data is one of the ongoing issues in this thread.


“think times have changed, the days of unavoidable bad weather and the need for heavy boats to lie ahull in are gone”

Your statement requires communications and boat speed to escape (active means). A little to bold a statement for me. I will not be held hostage to a thousand single point failures between the antenna and the batteries or the boat and crew to be on their best game to escape.

If you can't build a reliable system perhaps you shouldn't use them. :D I've found that understanding electronics, proper equipment selection, and proper installation yields reliable systems. These systems are reliable enough for aviation, I take it you refuse to fly and be "held hostage to a thousand single point failures"?

I consider sailing to be an "Active" pastime. I am not a passenger letting the boat sail where she will. If I am to expect my boat to take care of me, I have to take care of her. That means actively seeking passages that are easy on both of us. Passive storm tactics strike me as being in the same class as closing your eyes, stepping on the brakes and trusting the air bags to save you in a car. If your vehicle cannot protect you, you must be an active participant at all times. Almost 40 years of riding motorcycles has conditioned me to never rely on the vehicle to protect me, I must protect the vehicle and myself. Removing the false security of crush zones and air bags forces me to be more aware of changing conditions. The penalty for passivity is extreme. I submit that almost any sailboat provides more protection than my motorcycle does.

I have been route planning to get a feel for the probability of encountering storms at sea. I was surprised to find out how easy it is to plan passages with very low probability of gale conditions, much less storm conditions. I have also run simulations using my boat's polars and real time weather. I have not been caught in storm conditions yet. People here talk as if sailing in storm conditions is to be expected every time the boat leaves port ... hogwash. I personally know cruisers that circumnavigated and NEVER sailed in a storm. 13 years cruising and not a single storm ... not one.

Commercial craft and racers are much more likely to see extreme conditions. Their schedule is dictated by man not nature.

The key here is cruising. You don't have to leave on a certain day. You can pick a favorable 3-7 day forecast. Follow the route suggested by pilot chart information and alter it as needed every 12-24 hours as new weather information is available. IMO people that don't think it is possible, have never tried it. Just as people that are wedded to the idea of heavier = stronger can't grasp the idea that a boat does not have to be heavy to be strong and seaworthy.


The very way to attract that attention if for the user to demonstrate behavior which becomes a public tax burden
and risk to others.
Your government watchdogs love irresponsible people, gives them a paycheck!

Like sailing into storms because you can't figure out how to keep a battery charged? Or not having reliable communication systems so you don't hear the severe weather warning? :D

Have a great weekend!

Guillermo
03-17-2007, 03:13 AM
Roughy,
I admire your faith in weather information and your confidence in your ability for weather routeing! You should be hiring your services to the 'Top Round' racing boys! ;)

I think what makes you so confident is that you've never been caught in storm conditions yet, as you say. Have you been caught at least in gale ones (force 8-9)? Or in a humble force 7 in a tight spot? I'd be a little bit surprised if you haven't. Anyhow, if you keep on sailing, sooner or later you'll be caught in such situations, unless you do only summer time coastal cruising in an area with plenty of refuges. And even then.

Cheers.

RHough
03-17-2007, 03:55 AM
It was not only Fastnet. Trouble can build up suddenly even for the more experienced. Read this most interesting analysys of Queen's Birthday Storm:
http://www.setsail.com/products/pdfs/qbs.pdf

**** happens.


Thanks for posting that link, it supports what I've been saying:

"The difference between a survival situation and an uncomfortable couple of days was probably less than 150 miles in position along the east-west axis. Why, then, did so many people get caught in the wrong part of the storm? I hesitate to be a Monday morning quarterback. I wasn't there, and looking at the fax charts which we've reproduced here, it seems fairly obvious what was happening. Yet Linda and I know all too well how hard it is to think straight when you are getting the tar kicked out of
you by the weather, and are cold, tired, and probably more than a little frightened.

The official forecasts did not pick up the severity of the situation until the low had already deepened. Yet the risk factor-that incipient low on the third of June- was there for everyone see. All of the classic rules for determining the center of the depression and its direction of travel were
operable."

The report pretty much says the signs were there, the gale warning was broadcast. Why the boats ignored the warnings they had available to them and sailed into a disaster is a good question.


About the Jordan series drogue, I find it an interesting device although for my own use I'd rather go for a mono-drogue like Seabrake or Galerider, as I find they can be useful for a wider variety of situations and uses, i.e. as when in shallower waters. Also I'd rather prefer running 2-3 knots under control than being almost sttopped. But this is only a matter of personal preferences, I'm not discrediting the series drogue at all.

:D You amaze me. You cite the failures of the very devices you prefer in one post :
With a drogue deployed from the stern, after several wave strikes in a confused sea the towline can have so much slack that the boat can be capsized before the drogue exerts any force. This has been tank tested.
Now you say your preference is for a device that in your own words has failed in test tanks? What have I missed? You are willfully choosing a device that has a proven failure record over one that has never failed?

... and I thought the NA's were supposed to be the logical ones in this thread ...
:confused:

Guillermo
03-17-2007, 04:05 AM
You should be more reflexive and read calmlier.
Cheers.

RHough
03-17-2007, 04:34 AM
Roughy,
I admire your faith in weather information and your confidence in your ability for weather routeing! You should be hiring your services to the 'Top Round' racing boys! ;)

I think what makes you so confident is that you've never been caught in storm conditions yet, as you say. Have you been caught at least in gale ones (force 8-9)? Or in a humble force 7 in a tight spot? I'd be a little bit surprised if you haven't. Anyhow, if you keep on sailing, sooner or later you'll be caught in such situations, unless you do only summer time coastal cruising in an area with plenty of refuges. And even then.

Cheers.

Care to put it to a test? Pick a reasonable passage of 1500-2500 miles that as a cruiser you might make. I'll do the pre-planning, then run the route using real time weather and lets see what conditions a small boat might have to deal with. I'll use my old, slow, Catalina 30 and post 24 hour updates. If I can't make the virtual passage without avoiding storm conditions in a 25ft LWL boat, I'll concede defeat and post "I'm an idiot", If I can do it, you have to post "I Love Pogo 40's" :D

Ground rules:
I have to arrive before I use up 45 gallons of water or 25 gallons of fuel. I'll post the electrical budget and the number of engine hours/fuel used to support my systems. If I run out of water I loose, if I run out of fuel and the electronics die, I loose. If the boat is caught in wind over 40 knots for more than 6 hours, I loose.

If the sea is so big and bad as people make it out to be, it should not be possible for me to succeed.

The gauntlet is thrown. :D

fcfc
03-17-2007, 05:25 AM
“should they be fined or penalized after the rescue?”

No, just sent the bill, If someone insured them, then the bill is paid. The owner can rationalize the premiums and the return on investment if any. The premium will then go high enough (if he can get insurance) to equal the liability and then the owner can opt to self insure.


I don know about Ken Barnes country, but in france insuring worldwide a sailboat (and owner as crew) between 60 000 - 90 000 euros costs 1/3 to 1/10 of insuring a car (and owner as driver) of the same value.

That would mean that french insurers consider risk is really much lower in a sailboat, even circumnavigating, than in a car of same value.

CT 249
03-17-2007, 09:44 AM
“Then lets start with unsinkable as the barest minimum of seaworthiness.”

I agree. Light weight hulls with unproven offshore strength should have positive flotation.

“a boat that sails better than a Westsail would not have been such extreme conditions ... unless it's crew made an error in judgement. To me that is part of being prepared.”

Theoretically valid, but fails with a long passage where all boats are vulnerable as storms develop in open ocean and move faster than any sailboat can travel. A week before hitting the Fastnet fleet, that storm was knocking power poles over in the Midwest

“It does not take much for a boat to be sturdier than those that crew her. The boat may have uncomfortable, even frightening motion, but even "killer boats" in the '79 Fastnet were found more or less intact after their crews lost faith in them.”

Don’t think so. Many boats sank and the others were disabled and then gave minimal protection to the crew, that’s why they abandoned them. I wonder what the Fastnet would have done to that (killer) boat in the picture I attached? hmmm when was that built? maybe 30 years AFTER Fastnet? more?

“should they be fined or penalized after the rescue?”

No, just sent the bill, If someone insured them, then the bill is paid. The owner can rationalize the premiums and the return on investment if any. The premium will then go high enough (if he can get insurance) to equal the liability and then the owner can opt to self insure. On his second screw-up he can pay the expenses from his own pocket and then, if he is still alive, he can think about a better design and better prep, or if he can’t pay, he can loose his boat and see it auctioned off, and think those future thoughts while breaking rocks in the hot sun or make some license plates to make up for the tax dollars he has burned from people like me. After a little sobering he can think of a well designed, sound boat which will reduce the probability of having to be rescued. At this point , the word will get around and maybe others will realize the same before they flip the EPIRB on.

“think times have changed, the days of unavoidable bad weather and the need for heavy boats to lie ahull in are gone”

Your statement requires communications and boat speed to escape (active means). A little to bold a statement for me. I will not be held hostage to a thousand single point failures between the antenna and the batteries or the boat and crew to be on their best game to escape.

“I just don't want some government committee of NA's moribund opinions deciding for me”

The very way to attract that attention if for the user to demonstrate behavior which becomes a public tax burden
and risk to others.
Your government watchdogs love irresponsible people, gives them a paycheck!

It's probably not worth trying to be logical with someone who brags about the fact that his wealth proves that he comes from a "superior gene pool" than mere "lesser people", but your facts about the Fastnet are incorrect, as R Hough pointed out.

Some of the boats that suffered the greatest loss of life in the Fastnet, like the Carter 33 "Trophy" (3 or 4 dead) and the Ohlson 35 "Flashlight" (two dead) were boats of similar style to the typical S&S design. The Ohlson 35 is actually "cruisier" than the typical S&S 41.

There were (I think) four lightweight fractionals* in the '79 Fastnet fleet - they had no trouble and no capsizes. One of them scored second or third in the AC fleet**. The lightweight fractionals were NOT the source of the problem.

You champion the Westsail 32. We don't get many out here, about the only one I know of was subject to a rescue in the NZ-Tonga cruising rally after multiple capsizes and a dismasting. Her exhausted crew (who had spent many years sailing the boat out from Maine) found her uncontrollable.

Yes, this is merely a single incident. But it is no more misleading than the picture you have posted and referred to here. That pic is not of a boat designed 30 years after the Fastnet, as anyone with the most basic knowledge of modern design would know. The boat in the pic is a Dubois IOR 1 ton from 1986 - just nine years after Fastnet '79. Boats of that design have done many major offshore races - Hobarts, Fastnets etc - without loss of life or inversion.

Ironically, one of the most experienced offshore racing owners in the world moved from an S&S 41 and an S&S 45, to a Dubois 1 ton that was a sister of the boat in the pic. I have asked him about comparative seaworthiness. He said that the Dubois you hold up as an example of a bad boat was as seaworthy as the S&S 41 (a 1970 design, I think). The Dubois was dryer and more controllable downwind. His latest boat, an IMS one design, is in many ways (including some aspects of its comfort) the best ever boat of his to sail offshore, he says.

This is a man who has been skippering Hobart races (and winning) since the days of steel double enders. He did (I think) compete in Fastnet '79. He is almost undoubtably much more experienced than you, and he does NOT think the boat you pictured is a "killer".

His only rival to the title of most experienced owner around here - a man who was on the winning team in the '79 Fastnet, who has won Fastnets and world titles and been racing his own boats since the planked long keelers of the '60s - also says that the IOR lightweight and modern boats are just as seaworthy as the 1968 S&S 49 he used to win the Fastnet. This man is probably wealthier than you and therefore according to your ideas he is a superior being, so his ideas can't be too far out.

There are certainly people of enormous experience who do not agree that all lightweights are unseaworthy compared to boats like your S&Ss. Sparkman and Stephens 45s are certainly "killers", though - one of the best ever, the 1973 Morning Cloud, went down with a couple of crew in the English Channel.


* obviously "lightweight" means different things to different people.

** One of those lightweights, the flush decked fractional 42 "Accanito", has been the cruising home of a couple for about 10-14 years. That is an example of the sort of boat you said couples couldn't cruise, but "Accanito" has been proving you wrong for over a decade.

CT 249
03-17-2007, 09:55 AM
It was not only Fastnet. Trouble can build up suddenly, even for the more experienced. Read this most interesting analysys of Queen's Birthday Storm:
http://www.setsail.com/products/pdfs/qbs.pdf

**** happens.

About the Jordan series drogue, I find it an interesting device although for my own use I'd rather go for a mono-drogue like Seabrake or Galerider, as I find they can be useful for a wider variety of situations and uses, i.e. as when in shallower waters. Also I'd rather prefer running 2-3 knots under control than being almost sttopped. But this is only a matter of personal preferences, I'm not discrediting the series drogue at all.

Cheers

PS1: The Queen's Birthday Storm of June 1994 involved a cruising fleet of 35 boats voyaging from Auckland, New Zealand, to Nuku'alofa, Tonga, on an annual cruising pilgrimage. In this storm, one boat was lost with all three crew; only its empty life raft carrying an activated EPIRB was ever located. Seven other boats were eventually abandoned, but the crews stayed with them until rescue vessels arrived, possibly a lesson learned from the Fastnet disaster. One of those seven boats was found afloat six months later and salvaged. Twenty-one crew from the seven boats were rescued directly by surface vessels who responded in a very timely fashion to both EPIRB signals and requests for assistance from New Zealand authorities.

PS2: Also the reading of : http://www.bluesuit.co.nz/1994.htm, http://web.mit.edu/mitoc/www/history/tripreports/57 and http://www.latitude38.com/features/nzstorm.htm is interesting

It's an interesting little test case.

Among the boats that got into trouble were classic or contemporary heavy cruisers like a Westsail 32, an Atkins 32, and a Norseman 447. As the first link Guillermo posted points out on p 249, both the boats that got into trouble and the boats that had no trouble spanned the full spectrum, from heavyweight cruiser to cruiser-racer.

The first link also states "we feel strongly that cruisers don't pay nearly enough attention to performance under sail" and "there is no substitute for boat speed".

Guillermo
03-17-2007, 10:33 AM
I'll concede defeat and post "I'm an idiot", If I can do it, you have to post "I Love Pogo 40's" :D
I take the bet, without the needing of you saying you are an idiot, because you're certaily not. :) Let me think of a route and I'll tell you.
Cheers.

RHough
03-17-2007, 12:17 PM
I take the bet, without the needing of you saying you are an idiot, because you're certaily not. :) Let me think of a route and I'll tell you.
Cheers.

Thank you. I think this will be a good test ... all in good fun. :)

I know that there are others that will be interested in the results. We both know that any one passage won't be proof of concept either way, but it should serve to showcase the methods available to today's cruiser.

hiracer
03-19-2007, 02:04 PM
About the Jordan series drogue, I find it an interesting device although for my own use I'd rather go for a mono-drogue like Seabrake or Galerider, as I find they can be useful for a wider variety of situations and uses, i.e. as when in shallower waters. Also I'd rather prefer running 2-3 knots under control than being almost sttopped.


Actually I agree. I plan to carry both, and use mainly the unitary drogue. The series drogue will be deployed only when all else fails, I'm injured, or pitchpoling is a serious risk during a survival storm. I agree with the bias in favor of an active response to a storm but also recognize that an active response is not always possible, especially in light of the possibility of being injured or vital equipment breaking.

I suspect that this anticipation of the impossibility of an active response to a storm, and conversely the inability/refusal to anticipate such a development, underpins the bias against and for modern sailboat design. The adherents of modern lightweight sailboat design will go to great lengths to deny the possibility of any situation where the boat must look after captian and crew, because they have to.

I like the analogy of riding a motorcycle, the lack of air bags and inherent instability of only two wheels causing one to be more careful. Where the analogy breaks down, of course, is that one can stop a motorcycle under an underpass when the weather gets really bad and wait it out (a passive approach, BTY) while in a cruising boat you are stuck in it, for better or worse, no getting off on dry land to wait it out. And if you do it right, a motorcycle never sinks. :)

Guillermo
03-19-2007, 04:05 PM
Randy,
I have not forgotten you. I am thinking what could be a fair proposal, not too bizarre or absurd.

Maybe something like a leg from The Solent (UK) to the Canary islands non-stop (1500+ miles), as previous to an Atlantic crossing, or either a Bermuda-Azores (Horta) one (1900 miles), when coming back to Europe.

Let's say you're an UK citizen (university professor?) in a sabbatic year and you plan to do the going and coming back within your available one year time. You're planning to have a once-in-a-lifetime adventure spending several months in the Caribbean, and go with your wife and your 12-14 year old kids, so you have to wait at least to August for the departure, and be back at work by the first days of September next year.

To make the first leg in a row makes little sense, I know, because the usual thing should be to stop somewhere along the Iberian peninsula's west coast (more than once), but then the distances would be too short to our purposes.

You'd have to allow for some slowing down when encountering head winds and waves, as those may significatively affect the speed of the boat. How can we manage that? What could be a not too complicated estimative for that? Perhaps dropping speed in an increasing percentage with increasing head wind forces?

The bad thing is that to check the real weather for such routes we'll have to wait to the corresponding times of the year. If we want to go ahead with the test within the next weeks (not to wait too long), we could also think in another 'role', as the one of a delivery crew of 3 sailing a client's boat from the Canary islands to the UK (that lucky guy found a nice deal for a boat there when visiting the islands last summer! ;) ) and the later time to do such trip should be May-June (As a matter of fact a relative of mine is planning to come from the Canaries to Galicia about that time).

What do you think? Any other idea from you or another fellow poster? Maybe a Pacific crossing from the States?

Cheers.

KevlarPirate
03-19-2007, 05:18 PM
“This man is probably wealthier than you and therefore according to your ideas he is a superior being, so his ideas can't be too far out.”

Sorry to have gotten under your skin , however small statistical samples usually lead to wrong conclusions. You seem to rely on them frequently. This thread has a lot to do with physics, more specifically statics and dynamics.
The picture I posted clearly shows a boat having been very easily overpowered and having most all of it’s hull floating above the water exposing the control surfaces to air not water. A quantum jump of impedance mismatch of over 800 to 1. And resulted in a totally helpless condition.
Any first year physics student can see that; the picture tells a thousand words. The boat was well reefed and probably doing well and then lost control with a gust or wave, either one being a small input which put it into an out of control situation. It is obvious that it is not in storm conditions as the ocean is pretty flat and wind gusts were probably benign.

Storm situations create highly variable inputs (a very high standard deviation) very much unlike what the picture shows. Cruising boats are designed to withstand large variables, not fly out of control with just a little push to put it over the top.
If you see that picture and can somehow argue that is a safe offshore platform, then we have nothing more to say. That boat in a big breaking wave would be a death trap.
My point was that Fastnet showed how NOT to design boats for offshore and that unfortunately has been ignored. The fact is that boat and many more were designed after the lessons were supposedly learned , I don’t care if it was one month, 9 years or 100 years.

The point, which is being clearly missed, is that light weight boats like these are excellent for racing in venues like Key West Race Week and similar, but to convince yourself that they are safe offshore boats is a delusion. A total joke!
If you were to ask me to insure one of them I would charge as the premium the full cost of the boat and then some for profit after I have to pay for the disaster, and for that matter so would you.

Retro , you keep avoiding the issues I bring up

You are half way to Bermuda in 4 knots of wind and your weather router informs you a storm in has developed and approaching from the west, doing 450 miles a day and your weather will be seeing deteriorating conditions within 12 hours. Please tell me how you are going to get out of that.

Most boat losses are a result of groundings on reefs and rocks.
You are grounded. Your perfect electronics was held hostage by the combination of a small cross current which you couldn’t detect and a small inaccuracy in your chart. How is your 5mm thick hull going to survive being pulled off?

The second most frequent loss of boats has to do with collisions in open water. Please tell me how a 5mm skin thickness will do better than ¾ inch of solid glass or 3/8ths of aluminum.? Against the corner of a container floating 6 inches above the water. Your forward looking sonar was working perfectly but you didn’t see it because your attention was reduced from 100% to 98% and that was the 2 %.

How do you survive never getting injured or your capacity to keep the boat going 15 kts (in that 4 knots of wind)?


I have heard your pitch now several times (weather routing) and complicated electronics which never fail. but I would really like to know how you are going to avoid all of the common problems cruisers encounter regularly.
You talk of airplanes but you don’t mention 4x system redundancy to overcome single point failures. You also don’t mention that a platform like a F-16 is an unstable platform therefore can’t glide on it’s own and therefore has an ejection seat. (that is it's safety valve because the design cannot offer a solution)

Clearly Mr. CT is not happy with my statements regarding superiority (which he unfortunately took personally),
However, I think you should be the one he is questioning because you are not going to have to go through the hard knocks that all of us had to. That would truly be superior.
As I said before, I admire your enthusiasm and your theories may create encouragement, but I have a problem with the forces which are beyond your control. You keep selling that there are no situations which cannot be avoided with proper preparation and that as a result , you can reduce safety margins in other areas. That seems very risky for the biggest reason is that it takes all of your solutions to be in place and working properly all the time.
Complex solutions are more failure prone than simple solutions. When any of your proactive or reactive tools fail, you have no safety net you can limp into.
My question above about how you plan to escape voids only one of your necessary ingredients (hull speed), so now you are in plan B which means you are going to have to go through it just like everyone else but you will be in a minimalistic boat way more at the mercy of the elements.
So fine be my guest! Do it and you will also write the stories you claim only the Westsail guys write.

I came into this thread mostly for the benefit of readers other than yourselves; I am not trying to change your minds. Others will decide based on what they read here and then go on to find other data reaching far beyond annecdotes. There is much published about this by people with technical backgrounds. It is out there. My mission here is complete.

KevlarPirate
03-19-2007, 07:15 PM
sorry, I missed this

“It's probably not worth trying to be logical with someone who brags about the fact that his wealth proves that he comes from a "superior gene pool" than mere "lesser people", but your facts about the Fastnet are incorrect, as R Hough pointed out.”


You deliberately misrepresented my statement, but you give me another chance to point a finger at those with the “entitlement disease” so thanks. My statement had NOTHING to do with myself or bragging, but everything to do with people who think that they should be allowed every luxury the wealthy. And yes, it is the rule is that people become wealthy because they ARE smarter and work harder than the rest and they should be able to freely enjoy those luxuries without being punished through taxes to take care of freeloaders. Swallow the pill! It is the exception that you are born sitting on an oil well.

As for my Fastnet statement I agree with you, I was incorrect.
“15 deaths, 19 boats abandoned, 5 boats sank, 306 boats started. That makes "many" = less than 2%?”
I should have said TOO MANY, sorry. And obvously to you, those deaths were all on boats which the owners probably thought were much safer then they had been deluded into thinking in light of your statement that they knew the storm was comming.

Retro that was a really arogant statement about 2 %,
It is also incorrect since pretty much all of the fleet which were on the shelf at the time things got really bad were the small guys and they all got beat up pretty bad.
The friend of yours who said it really wasn't that bad was past the really dangerous area. Hell, Ted Turner won it and said "we are eating steak and others are dying out here". I have sailed against him, but I never liked him for his arrogance either.



Maybe you would like these books..

John Rousmaniere, ed., DESIRABLE & UNDESIRABLE CHARACTERISTICS OF OFFSHORE YACHTS. Chapters on the screening test, stability, rigs, and just about every other aspect of offshore design. Authors include many designers -- Olin and Rod Stephens, Mitch Neff, James McCurdy, Karl Kirkman, Bill Lapworth, Ted Hood, etc.

C.A. Marchaj, SEAWORTHINESS: THE FORGOTTEN FACTOR

CT249
03-19-2007, 07:35 PM
KEvlar Pirate wrote "however small statistical samples usually lead to wrong conclusions. You seem to rely on them frequently."

Actually I have been making exactly the same point (about the tendency of small samples to mislead) at many places in this forum! I looked specifically at the boats you mentioned (Westsail 32, S&S 41, S&S 45, 1 tonner) because you had been using them specific examples.

Fair's fair, if the "pro heavy" crowd can use specific examples to make their point surely we "pro light" brigade can be allowed to use specific examples too!

My point is that we can find a specific example of ANY boat getting into trouble. For some reason, when a light boat gets into trouble it is taken by some people as an indication of a general problem. When a heavy boat gets into trouble, those same people will explain it away as being an isolated incident.

The pic you posted is a classic case in point. You have looked at the single picture and come up with a tale of an unseaworthy boat. If you had looked at the series of photos in detail, you will see that the wind was pretty hairy, actually - Jameson has got a #4 and three reefs in. That's extreme for a short race, not benign.

"Storm situations create highly variable inputs (a very high standard deviation) very much unlike what the picture shows."

Another photo taken at the same time shows the boat heeled maybe 10 degrees, while hard on the wind. It appears that there WERE highly variable input, to get the boat from lightly heeled and under full control, to over on its ear.


"If you see that picture and can somehow argue that is a safe offshore platform, then we have nothing more to say. That boat in a big breaking wave would be a death trap."

Well, it depends. I admit that I was familiar with the fact that this design was off the pace upwind in a breeze. I was familar with the Soton Uni testing after Fastnet '79. So therefore, when I asked one owner about what the boat was like offshore I thought he too would have thought it was a death trap.

However, he said that it was fine. I asked him about the low LPS and he said that in something like 7 Sydney-Hobarts (including some bad ones), a Fastnet, a One Ton Cup and many other races, he'd never got the boat heeled over to anywhere near the point where the low LPS was a factor. In contrast, he said, his first S&S boat had regularly been knocked almost flat because this popular design was notoriously hard to steer in some guises.

Now, when someone who certainly has more experience than me, and almost certainly has more experience than you, comes up with a statement like that there's two ways to take it.

We could say "oh, he's full of crap - the boat is obviously unsafe because we think it is. He must be influenced by this factor, or that factor".

We could say "gee, here is an enormously experienced sailor who has a different point of view. Maybe we should open our minds to what he is saying". I prefer to take this course.

His information is not conclusive, of course. The fact that it has been backed up by many vastly experienced sailors is interesting. What such information surely should do is make us open our minds, at least, and not just say "that boat is a death trap" when it has been proven that the design can do 10 Sydney-Hobarts with no major problems.


1 - there were rules changes after the Fastnet. The lessons were not ignored. I myself was racing offshore in '79. We typical offshore sailors of the time went to lectures from people who sailed through the storm, sailed with people who sailed through the storm, talked to guys who sat in with the committee that investigated it, etc. I have copies of the Fastnet '79 and Hobart '98 reports.

2- Sure, we all know that fat boats have inversion problems as illustrated in Fastnet '79. I don't like fat boats, partly for this reason. However, as I pointed out in earlier posts, there were MORE deaths in the Fastnet on a Carter 33 (quite similar to an earlier version of a '70s S&S) than on ALL the lightweights put together. There were AS MANY deaths in the cruising-style Ohlson 35 Flashlight than on ALL the lightweights put together.

Given that there were many MORE deaths from older or cruising-style boats than on lightweights and other new racers, any "lesson" seems blurred. Oh sure, fat lightweights can invert and that's not good - but the major races that have caused the most studies (Hobart '98, Fastnet '79) do NOT show a statistical trend for light or small boats to kill the most people.

Okay, these are limited statistics are not perfect. However, to isolate one factor in one style of boat (capsize in fat lightweights) as is so often done, seems to be working from prejudice because it was a MINOR factor in the deaths. Yes, I am aware that the races highlighted a certain factor (capsize of fat lightweights) and that factor was worthy of investigation in '79 and '98. However, I submit that this factor has attracted far too much attention than it deserves, because it allows us to create numbers and be cast aspersions at a style of boat. There were many more deaths caused by other reasons that have been almost ignored, in comparison.



"If you were to ask me to insure one of them I would charge as the premium the full cost of the boat and then some for profit after I have to pay for the disaster, and for that matter so would you."

Well I assume you don't make a living as an actuary. Sisterships of the boat in the pic have been racing since 1986. They are still entering major races like the Sydney-Hobart. I think one has done 8 Hobarts as well as the Fastnet and Hawaii's Kenwood Cup. Not one has sunk. There has been no disaster. Statistically they are NOT unsafe boats. If you demanded a 100% premium assuming there'd be a disaster, you would have been 100% wrong over a dozen times.

Interestingly, one similar boat just set the record for Sydney-Hobart races - 26 races (1 retirement with a broken rudder, I think) in 27 years. Another similar boat completed a bunch of Hobarts and then a singlehanded round the world race via the Southern Ocean, with no problems. As I mentioned, one of the few fractional lightweights from the '79 Fastnet has been a beloved cruising home around the Pacific Ocean and Tasman seas for over a decade.

As you said yourself, we cannot take isolated examples, so your criticism of a boat based on a single photo cannot be regarded as having much weight when compared to the fact that such boats have a proven record of completing major ocean races.

Is this a small statistical sample? Yes, it is fairly small. However, I can't find any larger statistical sample that shows that lightweights are unseaworthy.

The boat in the pic is not my ideal boat. However the facts are that the design has a proven safety record. I have photos of S&S designs like yours in situations that look much worse, death rolling their guts out. Just looking at isolated pics or problems in extreme conditions tells us nothing apart from what our own prejudices are.


PS

I cannot see how you claim that saying you come from a superior gene pool is not bragging. The rest of that section is too political for me to reply to in a boat design forum.

Guillermo
03-19-2007, 09:09 PM
Capsize represents a small percentage of official reports of accidents at sea, being usually in the range of 1%, or less, at the known databases from national authorities or entities (like the RNLI and others). But one of the problems to interpret those databases is that some accidents due to stability related problems can remain hidden under other concepts.

As an example, a well known database from the RNLI for a five years period previous to 1997 revealed that almost 5% of lifeboat launches were to leaked or swamped yachts, but the database did not distinguish those suffering from minor leaks below the waterline and those swamped in severe weather. Similarly, the data in the category 'adverse conditions' contain a variety of incidents or threats to the safety of the yacht concerned.

Care must be taken in the interpretation of such statistics.

On the other hand, a database of 115 sets of rigurous yacht and stability data were collected by the Working Group 22 of the ISO TC 188 (who collected them from a variety of sources), and used to develope the several STIX factors' formulae. About 30 sets of data involved yachts and vessels that had suffered a stability-oriented casualty of one kind or another. On top of that, the ORC was asked to carry out a systematic series of stability calculations, among their huge database of yachts, for a number of IMS ones with deck camber, systematically varied deck structures and cockpits, and sealed masts.

During the course of collecting those data it became clear that serious knockdowns and capsizes happen more frequently than often supposed. The Group 22 was able to identify over 100 stability oriented casualties in the previous years to 1995 (They used the word 'recent'). They did'nt use the whole of those known casualties, limiting the study to the before mentioned group of 30 yachts, as it proved to be extremely difficult to obtain the required rigurous stability data from all of them.

KevlarPirate
03-19-2007, 11:05 PM
I am only posting to clear up mis-information, First of all, my first post was 658, page 44, I don’t remember ever stating about S&S
except for my reference to Running Tide.

I made the statement that the early seventies designed boats, I consider to be the peak of the curve for a balance of toughness, speed, and comfort and therefore make very capable seaworthy offshore boats.

This is a general theory I hold which takes in many boats before they got light and fat. And I have sailed my share.

I own 2 boats ,A 41 designed by C&C in 1968 and first sold in 1971. My other boat is Bruce king designed Ericson 46, I don’t know of these references you make to these other boats? Please post them. My boats are heavy by today’s standards with swept back fins and skeg mounted rudders.

Both rudders have been upgraded with better and bigger design. This is the only area of improvement I considered needed, a simple one at that. They are tough, fast and comfortable and have nice sea manners in well developed sea.

The reference you make to death rolls are because of huge sail area up , and small rudders. This is an issue of how these boats were sailed. The boats and many of their era have very high static curves over 130 deg. with over 7 to 1 pos. vs neg. areas.
New fat butted boats have scary looking static curves, low moment of inertia. You will not find me on one of them in the open ocean. They can hold a lot of sail downwind because of their zero dead rise wide sterns but the payment for that is the static curve and bad dynamics in big ocean. When they wipe out it happens fast.
Your problem may be what you consider a big sea. The boat I pictured was in a bathtub, how you can call that hairy is beyond me.
Pulling both the rudder and keel out, obviously the rudder ventilated, no cruising boat would have EVER ended up with its rudder out of water with no control.
My boats would have heeled and then come back up resumed sailing. Going upwind and wiping out like that is an example of everything wrong and no amount of excuses will cover it up . Totally laughable. And you must be drinking Koolaid.

Also, I do not champion the Westsail 32. It is not my kind of boat. I referenced it as a boat that can lie ahull and because of it’s weight and motion, give comfort to the crew if they are incapacitated.

In the storm I referenced the owners bag was found on deck washing up on the beach after obviously enduring hundreds and hundreds of beam on waves. This, then becomes statistically significant.

Just as a product design is tested through many cycles whether it be temperature cycling or a shaker table. It is therefore NOT a single anecdote, but instead a valuable sampling. That is why I used it as an example.

“I cannot see how you claim that saying you come from a superior gene pool is not bragging”

nice try, never said I did, but I guess you still don’t get it.

The USYRU and SNAME proved ,much to your obvious dislike that wide lightweight boats were suspect to capsize and long inversion times. The resultant Capsizing Screening Formula was later used by IMS to penalize designs which were going toward the wrong direction. Smart people know that.

Go have fun in your boats, but if you try to promote these designs as safe offshore boats you will have others with physics backgrounds to deal with.
That picture says a thousand words.
Go read the books.

RHough
03-20-2007, 12:30 AM
Randy,
I have not forgotten you. I am thinking what could be a fair proposal, not too bizarre or absurd.

Maybe something like a leg from The Solent (UK) to the Canary islands non-stop (1500+ miles), as previous to an Atlantic crossing, or either a Bermuda-Azores (Horta) one (1900 miles), when coming back to Europe.

Let's say you're an UK citizen (university professor?) in a sabbatic year and you plan to do the going and coming back within your available one year time. You're planning to have a once-in-a-lifetime adventure spending several months in the Caribbean, and go with your wife and your 12-14 year old kids, so you have to wait at least to August for the departure, and be back at work by the first days of September next year.

To make the first leg in a row makes little sense, I know, because the usual thing should be to stop somewhere along the Iberian peninsula's west coast (more than once), but then the distances would be too short to our purposes.

You'd have to allow for some slowing down when encountering head winds and waves, as those may significatively affect the speed of the boat. How can we manage that? What could be a not too complicated estimative for that? Perhaps dropping speed in an increasing percentage with increasing head wind forces?

The bad thing is that to check the real weather for such routes we'll have to wait to the corresponding times of the year. If we want to go ahead with the test within the next weeks (not to wait too long), we could also think in another 'role', as the one of a delivery crew of 3 sailing a client's boat from the Canary islands to the UK (that lucky guy found a nice deal for a boat there when visiting the islands last summer! ;) ) and the later time to do such trip should be May-June (As a matter of fact a relative of mine is planning to come from the Canaries to Galicia about that time).

What do you think? Any other idea from you or another fellow poster? Maybe a Pacific crossing from the States?

Cheers.

Plymouth to Las Palmas in August:
1422 miles
15 Days
12.8 k Avg Wind Speed
3.9 Avg Boat Speed
4.4 feet Avg Wave Ht
0.6 % Chance of Gales

If we optimize the route to reduce the chance of gales further:
1550 Miles
16 Days
12.2 Avg Wind Speed
4.1 Avg Boat Speed
4.3 feet Avg Wave ht
0.4 % Chance of Gales

The trip from Hamilton to Horta is:
1998 Miles
27 Days
8.6 Avg Wind Speed
3.2 Avg Boat Speed
3.3 Avg Wave Ht
0.0 % Chance of Gales

From the Canarys to the UK in May:
1767 Miles
26 Days
12.8 Avg Wind Speed
2.9 Avg Boat Speed
5.1 Avg Wave Ht
0.7 % Chance of Gales

I used 80% of the polar speed for my Catalina 30 to arrive at these numbers.

I've posted screen shots of the routes that have the lowest probability of gales. As you know the Bay of Biscay can be a problem. :D

The nice thing about the Canary<>UK trip is the lowest chance of gales also puts you close to the coast. In the real world, as you said, a cruiser would not make either trip in one go. If you chose to, the most gale free route puts you close to safe havens to wait for better weather if you catch that 1 day of 100 where there are gale conditions.

The Bermuda > Azores Trip is a light air passage, the route shown has a 0 % chance of gales. This means that in August on that route no ship has ever reported a gale.

I agree that we will have to wait until the right time of year to see how well the pilot chart information predicts "safe" routes. I'm up for the exercise when the time comes. :)

RHough
03-20-2007, 01:22 AM
Retro , you keep avoiding the issues I bring up

You are half way to Bermuda in 4 knots of wind and your weather router informs you a storm in has developed and approaching from the west, doing 450 miles a day and your weather will be seeing deteriorating conditions within 12 hours. Please tell me how you are going to get out of that.

I can't respond to incomplete scenarios.
1. Halfway to Bermuda from where?
2. What month of the year?
3. Can you provide historical data (not scary anecdotes) that suggest that a storm develops in those waters at that time of year in 12 hours? Are you suggesting that there was NO indication 12 hours ago and now there is a storm? That is very hard to believe. :)


Most boat losses are a result of groundings on reefs and rocks.
You are grounded. Your perfect electronics was held hostage by the combination of a small cross current which you couldn’t detect and a small inaccuracy in your chart. How is your 5mm thick hull going to survive being pulled off?

Sorry, where did I imply that electronics are a substitute for piloting skills? If I'm in danger of grounding, I'm sailing in daylight and piloting. Don't even start to say that I have no choice. I consider it foolish to approach an unfamilar coast in darkness or bad weather. Piloting errors that put boats on reefs are just that, piloting errors. My 5mm hull won't be on the reef in the first place.


The second most frequent loss of boats has to do with collisions in open water. Please tell me how a 5mm skin thickness will do better than ¾ inch of solid glass or 3/8ths of aluminum.? Against the corner of a container floating 6 inches above the water. Your forward looking sonar was working perfectly but you didn’t see it because your attention was reduced from 100% to 98% and that was the 2 %.

You drive a Hum-Vee with 142 air bags don't you? :D Since you seem to think that smashing into things is normal. I certainly think that an unsinkable boat with crash bulkheads and water-tight compartments will do better after a collision than a '70's vintage boat that will sink and has no crash bulkheads. :)

Seriously, containers and high speed in low visibility are a very real concern. I've given it some thought. Just because a boat is able to sail at 15-20 knots, there are times where that speed may not be prudent. Solo racers and the pros go flat out day and night, as a prudent cruiser I think there are times to slow it down a bit.


How do you survive never getting injured or your capacity to keep the boat going 15 kts (in that 4 knots of wind)?

Injured? You keep talking about getting injured ... how?


I have heard your pitch now several times (weather routing) and complicated electronics which never fail. but I would really like to know how you are going to avoid all of the common problems cruisers encounter regularly.

"Cruisers are hacks." :) (Bitch at Robert Perry not me.) I work in a rig shop, many cruisers are cheap, ill equipped, ignore or postpone maintenance, and are an almost never ending source of half-baked ideas that don't have a snowballs chance in hell of working. You will find the cruisers that regularly encounter problems at your local sailor's exchange looking for cast-off used rigging and equipment that "looks better than what's on the boat". I'm sure that *you* don't fall into this category, but many "cruisers" do.


You talk of airplanes but you don’t mention 4x system redundancy to overcome single point failures. You also don’t mention that a platform like a F-16 is an unstable platform therefore can’t glide on it’s own and therefore has an ejection seat. (that is it's safety valve because the design cannot offer a solution)

System redundancy, seamanship skills, and planning go without saying.


As I said before, I admire your enthusiasm and your theories may create encouragement, but I have a problem with the forces which are beyond your control. You keep selling that there are no situations which cannot be avoided with proper preparation and that as a result , you can reduce safety margins in other areas. That seems very risky for the biggest reason is that it takes all of your solutions to be in place and working properly all the time.
Complex solutions are more failure prone than simple solutions. When any of your proactive or reactive tools fail, you have no safety net you can limp into.

That's right. I ride motorcycles. No seat belt, no air-bag. My sense of self preservation is very highly honed. :) There are many cases of people getting as nearly bulletproof a boat as they can and then screwing it up. If they don't screw up they don't need a battleship. :) No one is talking about sailing in paper boats. You may prefer grossly overbuilt boats, you seem to sleep better behind 3/4" of solid GRP rather than 3/8". You boat weighs more than double what it needs to. The sails have to be bigger, and the loads higher ... is this how people get injured? :)


I came into this thread mostly for the benefit of readers other than yourselves; I am not trying to change your minds. Others will decide based on what they read here and then go on to find other data reaching far beyond annecdotes. There is much published about this by people with technical backgrounds. It is out there. My mission here is complete.

Never assume that people haven't read technical information. In fact, one of the ongoing themes in this thread is the request for hard data that shows that modern light displacement boats are less safe due to design. Such data has not been forthcoming. You have added more opinion and sea stories, but little substance.

Roly
03-20-2007, 01:40 AM
I know that there are others that will be interested in the results. We both know that any one passage won't be proof of concept either way, but it should serve to showcase the methods available to today's cruiser.
Too right! Me for one.

Randy,I have a couple of questions if you will.......forgive the mundaness of them.

Sounds like a lot of work! For virtual time positioning what program will you use? How often will you download grib maps to convert to boat speed via your 80%
of polar. Will your program do this automatically and does it optimise your course to your polars?
Cheers

charmc
03-20-2007, 03:29 AM
"I've come to believe that we have passed two great turning points relating toYacht Design, in recent years, both of which have been under-recognized and I would like to put in my two cents to correct that omission.

The first is the publication of this book, Seaworthiness, by C.A. Marchaj. Written partly in an attempt to sort out the 1979 Fastnet Race disaster, it is an effort to scientifically determine what constitutes a seaworthy yacht, one that has the maximum chance of surviving an offshore gale. And what do you suppose it says? It says, and in my opinion scientifically proves, that those old fuddy-duddies of decades past were right, and what you want for optimum offshore safety is deep ballast, long keels, attached rudders, V-shaped sections, non-planing hull shapes, and guess what else? A fair amount of weight in the rig. And the lighter you make the displacement, the more careful you have to be to keep the ballast deep, and the beam narrow, like the pre-IOR light displacement boats which first started the light-displacement revolution. I think every yacht designer and every race organizer and every magazine design editor should read this book--This is progress!

In my opinion the other great event of our time is the advent of the IMS handicapping system. From the earliest days of yacht racing, designers have struggled to beat the various handicapping rules. In many cases the success of a design office has been completely based on their ability to beat whatever rule was in place at the time, and sometimes when a loophole they were exploiting was closed, those offices closed. Every rule was an effort toward objectivity, but every rule ended up encouraging a certain type of boat, often an unhealthy one. And to make matters worse, cruising boats have always imitated contemporary racing boats because yachtsmen are victims of style-consciousness like everybody else, and racing boats are assumed to be fast, even when in reality they were only designed to be fast for their rating. But with the IMS we have finally broken the objectivity barrier that has eluded us for the entire prior history of yachting. The rule seems to do an excellent job of rating boats of all types in a fair manner, and this seems to be born out by the race results, in which we see Concordia Yawls and Hinkleys and other boats more typical of traditional offshore yacht types, winning races and doing well. Still I don't think the full implications of the IMS are well understood. When I see a boat billed as "an IMS racer" in the magazines it usually looks like an old IOR racer, smoothed up and moderated perhaps, but still basically expensive, uncomfortable, difficult to sail, and not well suited to offshore storm conditions. To me, an IMS racer would be something quite different. She would be designed to keep sailing in the worst possible conditions with the least strain on her crew, partly because this is inherently desirable and partly because there are races to be won when the competition has retired or ceased to function effectively." Address by Daniel MacNaughton, brother of Tom, MacNaughton Associates

It's possible that this might have been introduced earlier in this thread. If so I apologize for repeating it. But it seems that there is a breach coming up again and again. Those on one side say that lightweight racing type hulls with small modifications for comfort are good for offshore cruising. Those on the other side are, like Daniel MacNaughton, in favor of heavier boats, with larger or even full keels, capable of riding out an extreme storm with the crew disabled, or surviving a collision at sea with minor damage.

As a sailor who would go cruising offshore with a few people I love, I have to weigh in with the second group. For the sake of argument, I think it is essential to eliminate the idiots who go underprepared, but to recognize that there is a major difference between a crack racing crew, which will typically include professionals who do little but race and work out, with their expenses paid for by sponsors, and a cruising crew, which will be much smaller, and composed of people who must live in the real world when they are not sailing. They will be skilled in seamanship, but probably not as physically fit as the pros. On a scale of 10, the average overall rating (seamanship and fitness) of an offshore racing crew will be 8.5 - 9.5. For a cruising crew, it may be 7.5-8.5. That does not make such a crew a bunch of unprepared fools. It means what I said, they are people who live in the real world when they are not cruising offshore. The lighweight racing type cruiser is seaworthy, as demonstrated by its ability to sail in heavy seas, often gaining speed by surfing, but it requires exceptional efforts by a large, highly experienced crew to achieve this performance safely. The heavier hull type described by MacNaughton, on the other hand, is seaworthy, as demonstrated by its ability to sail in heavy seas, somewhat slower but with an easier motion, and able to be sailed safely by a smaller crew. The requirement for more crew input is what makes the racer style boat less seaworthy -- as a cruiser. Randy, you seem to think Kevlar Pirate's mention of injury is not a serious argument. Be assured, it is. Particularly in a heavy storm, injury is an ever-present possibility, with the potential to cut the cruising crew's effectiveness by 30-50%. Final thought: I recognize that discussion tends to sound black and white . There are not 2 types of sailing hulls, heavy and light. There are many good designs which attempt to realize the best of the 2 extremes. My point is that a seaworthy cruiser design must factor in the possibility of being sailed shorthanded. Everyone will have a preference, and there is ample data to support arguments on both sides. I would lean toward a heavier boat with large keel and rudder. Such a design won't plane, but there are many of this type recognized as fast sailors.

charmc
03-20-2007, 03:31 AM
I look forward to the virtual sailing contest. Sounds like a fun way to test some ideas!

CT 249
03-20-2007, 03:42 AM
I am only posting to clear up mis-information, First of all, my first post was 658, page 44, I don’t remember ever stating about S&S
except for my reference to Running Tide.

My apologies for my mistake.

I made the statement that the early seventies designed boats, I consider to be the peak of the curve for a balance of toughness, speed, and comfort and therefore make very capable seaworthy offshore boats.

This is a general theory I hold which takes in many boats before they got light and fat. And I have sailed my share.


Sure, I agree that early '70s boats were fine yachts. In other forums, I regularly defend them.

However some people with enormous experience in such boats and with lighter fatter boats who don't share your opinion that the lightweights are "death traps".There were also people who sailed the generations of boats before yours, who regarded boats like yours are unseaworthy; for example Bob Derektor in an article about 1966 in Seacraft magazine headed "NO DAMN FUN", where he lambasted CCA boats of the time. This was about the time the C&C Red Jacket won SORC.





I own 2 boats ,A 41 designed by C&C in 1968 and first sold in 1971. My other boat is Bruce king designed Ericson 46, I don’t know of these references you make to these other boats? Please post them. My boats are heavy by today’s standards with swept back fins and skeg mounted rudders.


[B]I had somehow got the feeling your 41 was an S&S 41, of the same style as Casse Tete, Vittoria, and the Tartan 41. I apolgise for getting the impression your boat was such a design. I know the Ericson 46 by sight and C&Cs by sight; lovely boats.

Of interest, the Ericson 37 (slightly newer and possibly lighter than the 46 by a fraction) has suffered severe hull damage (see http://www.inthepresentsea.com/capehorn.html) as has an Ericson 39 (http://www.latitude38.com/LectronicLat/2003/0103/Jan20/Jan20.html) and at least one larger Ericson (which was in a book I don't own).

Now, I'm NOT repeat NOT saying the Ericsons are not fine boats. I am merely pointing out that we can find flaws in just about every style of boat, so finding flaws in lightweights does not necessarily damn them.






The reference you make to death rolls are because of huge sail area up , and small rudders. This is an issue of how these boats were sailed. The boats and many of their era have very high static curves over 130 deg. with over 7 to 1 pos. vs neg. areas.



I know the boats of that era death rolled because of the way they were sailed. I have done 2 Sydney-Hobarts in boats of this style. Stretchy old sailcloth didn't help either. However, the boat you pictured on its ear also got into trouble because of the way it was sailed. If we excuse the problems suffered by one style of boat because of the way it was caused by the way it was sailed, why can't we excuse the problems suffered by another style of boat when it is caused by the way it is sailed?

Your problem may be what you consider a big sea. The boat I pictured was in a bathtub, how you can call that hairy is beyond me.

I said "the wind was pretty hairy". I did not say that the WAVES were hairy. I started ocean racing the same decade you did. I have done a bunch of Hobarts and 1000 mile plus ocean races. I have seen bad seas, crossing Bass Strait under storm trysail and nothing else. I never said this was a bad sea. As I specifically said, the pic comes from an INSHORE race.

Pulling both the rudder and keel out, obviously the rudder ventilated, no cruising boat would have EVER ended up with its rudder out of water with no control.
My boats would have heeled and then come back up resumed sailing. Going upwind and wiping out like that is an example of everything wrong and no amount of excuses will cover it up . Totally laughable. And you must be drinking Koolaid.

Also, I do not champion the Westsail 32. It is not my kind of boat. I referenced it as a boat that can lie ahull and because of it’s weight and motion, give comfort to the crew if they are incapacitated.

In the storm I referenced the owners bag was found on deck washing up on the beach after obviously enduring hundreds and hundreds of beam on waves. This, then becomes statistically significant.


Just as a product design is tested through many cycles whether it be temperature cycling or a shaker table. It is therefore NOT a single anecdote, but instead a valuable sampling. That is why I used it as an example.

What then of the Westsail 32 that cruised from Maine to NZ and was then abandoned after being rolled repeatedly, dismasted, and repeatedly broached in the NZ-Tonga cruising rally. That boat suffered hundreds and hundreds of waves. Some of them rolled it, one of them dismasted it, some of them broached it. Why ignore that sample in preference to the one you provided?

I'm NOT saying that the Westsail is a dangerous boat, all I'm saying is that both sides in this argument pick out instances to support their own side and we surely need a proper statistical base for discussion.


“I cannot see how you claim that saying you come from a superior gene pool is not bragging”

nice try, never said I did, but I guess you still don’t get it.

You never said "The folly I am referring to is the delusional concept that it is not fair for the unprepared lesser people to not enjoy the “fun” things in life that the competent, capable (and therefore wealthy) people enjoy.
I say grow up! Is it unfair that I may be smarter than you, and make more money than you in my life. Is it unfair that my gene pool is superior to yours and I live longer and stronger than you? Should I be penalized through taxes to make everything fair?? Hogwash!"

In that case, who put that comment in your post 689 on page 46 of this thread? I realise you may well have been speaking rhetorically, but it doesn't clearly come across as that in the context.

PS my italics.




The USYRU and SNAME proved ,much to your obvious dislike that wide lightweight boats were suspect to capsize and long inversion times. The resultant Capsizing Screening Formula was later used by IMS to penalize designs which were going toward the wrong direction. Smart people know that.


Sure, I agree. I have read the article by Claughton (I think) who did the post-Fastnet Soton Uni study. I have read the stuff by Renilson who did a similar study after the '98 Hobart. I was there at the inquest when the report was discussed. I have a copy of the coroner's report. I have a copy of the RORC Fastnet report.

I have done my homework. I am fully aware of the inversion problems of fat light boats. That is why in my previous post I wrote "Yes, I am aware that the races highlighted a certain factor (capsize of fat lightweights) and that factor was worthy of investigation in '79 and '98" and "Sure, we all know that fat boats have inversion problems as illustrated in Fastnet '79. I don't like fat boats, partly for this reason" AND "fat lightweights can invert and that's not good".

I would have thought that mentioning the inversion problem three times in a single post was evidence that I was one of those smart people who are aware of the problem. That's one of the reasons I chose my own boat.

However, some people - enormously experienced people who are engineers and NAs - believe that the IOR/IMS/IRC lightweight boats are as safe as heavy boats. Surely that is food for thought?

The point is that while there is a problem with inversion time, many NAs and engineers and vastly experienced sailors feel that this extra risk is more than outweighed by other virtues of light boats. Guillermo's reference brought up the fact that only 1% of Coast Guard rescues are listed as being due to stability problems in yachts.

Go have fun in your boats, but if you try to promote these designs as safe offshore boats you will have others with physics backgrounds to deal with.
That picture says a thousand words.
Go read the books.

The picture says 1000 words, yes. Among them could be "this boat, the Dubois one ton Jameson Whisky, recovered from this temporary knockdown without taking water. She popped back up and did the Fastnet. Her sisters have done about 10 Sydney-Hobarts and several Fastnets and have raced in San Fran etc, with no serious problems. They are not death traps because they have done one of the world's tougher races repeatedly with no major problems".

I've read several of the books, I have done an interview with the head of safety for US Sailing and some of the world's most experienced owners, I've spent days at the inquest, I own the reports. The reports for Fastnmet and Hobart point out that there is NO statistical case that lightweigths are more dangerous. And there are people with yacht design and physics backgrounds who DO say that such boats are as safe as modern boats.



Like you, I don't agree with the most radical of light fat boats. Like you, I don't agree with RHough that you can always run away from bad weather. Where I live, the weather forecasts just aren't that accurate. In the 2000 Sydney-Hobart, even the pro Volvo Around the World race crews with all the professional forecasters working for them got the weather badly wrong.

Nor do I feel that the old boats were dangerous. It's just that there is little evidence I can find to indicate that the virtues of lighter boats are outweighed by their problems (which have been studied and are recognised).

It just seems that each type of boat has virtues and faults, and some of the most experienced owners recognise that. Some hold very strong opinions that favours one type of boat, but (to quote someone near and dear to you) I find many highly opinionated people are biased.

Guillermo
03-20-2007, 05:18 AM
Randy,
Let's choose the Canary-UK trip, which is closer in time to check things. I think it would be better if you open a new thread for the follow up, instead of doing it here.
Cheers.

P.S.
Interesting also to read Alain Maignan's round the world non-stop sailing log, aboard his Jeanneau Sun Rise "Schuss".
http://alainmaignan.sportblog.fr/

Crag Cay
03-20-2007, 10:07 AM
Just some random observations:

Quote: "In my opinion the other great event of our time is the advent of the IMS handicapping system".

Related comment from a sailor on an IMS Farr 45 last summer: "Just as we were setting up for the gybe a 38 knot puff hit, and we executed one of the most spectacular crashes I have ever had the pleasure of being involved in. A mast-in-the-water, keel-out-of-the-water, carbon-spinnaker-pole-busting, all standing gybe-crash. So we blew the spinnaker halyard, took the kite down, put the jib up and still managed to win the race, from crash to recovery took no more than 1 ½ minutes."

Anyone who has seen the video of the racing from the 1989 Exuma Regatta will have seen me achieve the same thing in a 1973 vintage S&S thoroughbred. After the event we left in the company of 'Syrena', an Ericsson 37 and beat out into the trade winds on our way to San Salvador. After about 5 hours of crashing to windward, Syrena started to break up just forward of her mast as well and had to be run ashore on Long Island. I believe she's still there as a total loss.

In the same way the Contessa 32 was used to illustrate all the 'desirable' qualities in a small offshore boat in the aftermath of Fastnet '79, so the Doug Peterson OOD34 was used to represent everything that was 'undesirable'. You would have thought that after everything that was written, these boats would now only be found rotting away on their cradles in the back corner of some boatyard, both unloved and unwanted.

But they have done rather well in the last two OSTARS including the incredibly stormy 2005 'demolition derby' edition, where oddly, the boats in the smallest class (V) had the least retirements.

In fact one fellow competitor admitted at the weekend he had kept 'a book' on who would do well and who would be the 'no hopers'. Of those he thought would never get to Newport (RI) he highlighted a women racing a 35ft tri for the first time, an elderly gentleman in an Open 40 (?) and the OOD34 as definites for retirement. To his surprise, they all did well, whilst his 'top tips' all retired. But as he added; "after tens of thousands of offshore miles, all you really learn at sea is that you don't know everything".

*****
Is the Jameson photo really of the One tonner? I'm having trouble working out the scale of the thing. The've been so many "Jamesons' it's hard to keep track. I know Cudmore sunk the Davidson One Tonner. My first thoughts it was the IOR50?

RHough
03-20-2007, 10:55 AM
Randy,
Let's choose the Canary-UK trip, which is closer in time to check things. I think it would be better if you open a new thread for the follow up, instead of doing it here.
Cheers.

P.S.
Interesting also to read Alain Maignan's round the world non-stop sailing log, aboard his Jeanneau Sun Rise "Schuss".
http://alainmaignan.sportblog.fr/

Done :D

Weather Routing and Seaworthiness (http://www.boatdesign.net/forums/showthread.php?t=16440)

I'll be more than happy to discuss the tools and methods that I use.

RHough
03-20-2007, 11:27 AM
Too right! Me for one.

Randy,I have a couple of questions if you will.......forgive the mundaness of them.

Sounds like a lot of work! For virtual time positioning what program will you use? How often will you download grib maps to convert to boat speed via your 80%
of polar. Will your program do this automatically and does it optimise your course to your polars?
Cheers

Reply Here: Link (http://www.boatdesign.net/forums/showthread.php?t=16440)

CT 249
03-20-2007, 06:48 PM
Crag, I'm pretty sure the pic was the one tonner - I'm looking at what I'm sure is a "before" pic at the moment. It was in Seahorse's 1987 Admirals Cup programme. There's also a pic of Turkish Delight/Itzanotherpurla/Red Stripe (big boat of the team) in conditions so similar I'm sure it's at the start of the same race.

Guillermo
03-21-2007, 05:02 AM
Not directly related to seaworthiness in the sense it's being discussed here, but most interesting:

"The Volvo Race allows everything on the boat except for sealed safety equipment to be "stacked," i.e. moved to the windward side after a tack or gybe. That adds dramatically to the brutality of sailing a VOR 70. A routine tack or a gybe becomes a 45-minute endurance event involving the entire crew in preparing for and executing the maneuver, and then restacking the boat so that the thousands of pounds of food, sails, tools, personal gear, and spares are moved to the new windward side.
The boats are unpainted pitch-black carbon below making it hard to see without a flashlight even when it is daylight on deck. The boats are nearly always wet on deck and below, and because the boats don't have a bilge or sump, there is almost always a sheet of water sloshing around. The boats are required to carry a heater but the heaters seldom survive the pervasive water and so in the Southern Ocean or North Atlantic the boats are bone-chillingly cold. The food is a dreary repetition of freeze-dried dinners, one every eight hours.
On ABN Amro One, we had enough food, but the combination of being cold much of the time and not eating enough due to the unappetizing food causes most crewmembers to lose about 20 or more pounds over the course of the race. Thegalley has one insulated bowl with a lid that is set into the countertop, and two gimbaled burners each with a kettle. "Cooking" involves dumping a plastic bag of powder into the bowl and then dumping two kettles of boiling water on top. A quick stir, wait 15 minutes, and the salty-brown slurry is ready to eat."

More at: http://www.sailingscuttlebutt.com/news/07/vor/index1.asp

bobothehobo
03-21-2007, 10:25 PM
Not directly related to seaworthiness in the sense it's being discussed here, but most interesting:

"The Volvo Race allows everything on the boat except for sealed safety equipment to be "stacked," i.e. moved to the windward side after a tack or gybe. That adds dramatically to the brutality of sailing a VOR 70. A routine tack or a gybe becomes a 45-minute endurance event involving the entire crew in preparing for and executing the maneuver, and then restacking the boat so that the thousands of pounds of food, sails, tools, personal gear, and spares are moved to the new windward side.
The boats are unpainted pitch-black carbon below making it hard to see without a flashlight even when it is daylight on deck. The boats are nearly always wet on deck and below, and because the boats don't have a bilge or sump, there is almost always a sheet of water sloshing around. The boats are required to carry a heater but the heaters seldom survive the pervasive water and so in the Southern Ocean or North Atlantic the boats are bone-chillingly cold. The food is a dreary repetition of freeze-dried dinners, one every eight hours.
On ABN Amro One, we had enough food, but the combination of being cold much of the time and not eating enough due to the unappetizing food causes most crewmembers to lose about 20 or more pounds over the course of the race. Thegalley has one insulated bowl with a lid that is set into the countertop, and two gimbaled burners each with a kettle. "Cooking" involves dumping a plastic bag of powder into the bowl and then dumping two kettles of boiling water on top. A quick stir, wait 15 minutes, and the salty-brown slurry is ready to eat."

More at: http://www.sailingscuttlebutt.com/news/07/vor/index1.asp



Ok, Guillermo, they look something like this first one:
And yours, is what, maybe this second picture???

Do you not see that you are comparing diffrerent horses designed for specific courses

Guillermo
03-22-2007, 03:19 AM
Of course I'm not comparing them! :mad: Banjers are much more sexy! :D
Look at her: Isn't she pretty...? Has she not beautiful lines...? Not like that kind of aggressive volvo-penis exploding out of the water....!
Oh my god, that poop, that poop....! ;)

Cheers.

CT 249
03-22-2007, 06:36 AM
"I've come to believe that we have passed two great turning points relating toYacht Design, in recent years, both of which have been under-recognized and I would like to put in my two cents to correct that omission.

The first is the publication of this book, Seaworthiness, by C.A. Marchaj. Written partly in an attempt to sort out the 1979 Fastnet Race disaster, it is an effort to scientifically determine what constitutes a seaworthy yacht, one that has the maximum chance of surviving an offshore gale. And what do you suppose it says? It says, and in my opinion scientifically proves, that those old fuddy-duddies of decades past were right, and what you want for optimum offshore safety is deep ballast, long keels, attached rudders, V-shaped sections, non-planing hull shapes, and guess what else? A fair amount of weight in the rig. And the lighter you make the displacement, the more careful you have to be to keep the ballast deep, and the beam narrow, like the pre-IOR light displacement boats which first started the light-displacement revolution. I think every yacht designer and every race organizer and every magazine design editor should read this book--This is progress!


Number of people killed in the Fastnet and Hobart aboard boats with deep ballast, skeg-hung or keel-hung rudders, vee-shaped sections, heavy rigs and non-planing hull shapes - at least 6.

Number of people killed in the Fastnet and Hobart aboard boats with spade rudders, flat sections, light rigs and surfing/planing sections - about 6.

MOST boats in the Hobart and Fastnet were closer to the light fin keel type than the heavy type, yet they killed fewer people proportionate to their numbers. So why the hell is there this concentration on boats that (in reality) kill a smaller proportion of people?

Whether you can "scientifically prove" something that is not supported by real-world experience seems a bit doubtful. The number of "old style" boats in the Hobart '98 and Fastnet '79 (the two best-studied offshore racing disasters) was very small and yet they contributed a very high proportion of casualties. Given that fact, singling out lightweights for their poor inversion characteristics could possibly seem to be like a witch hunt. Surely a scientific attempt to isolate the problem would NOT have centred on a boat (Nich 303) that caused no more deaths than a classic cruiser (Ohlson 35)?

I know I'm pushed towards extremism on this point........I may be overstating the case. Still, all the concern over boats that didn't kill more people than heavier boats seems to leave room to cast doubt on the motivation of the studies. In hard cold truth, out there in the ocean when we had lots of boats in the same area going the same way, the lightweights didn't kill more people - and having looked at some aspects in detail I cannot see that the usual excuses (like "all the lightweights needed rescuing or retired") apply. In the last bad Hobart, for example, the % of "cruising style" boats that pulled for shelter or retired was about as high, or higher, as with the racing machines.




In my opinion the other great event of our time is the advent of the IMS handicapping system. From the earliest days of yacht racing, designers have struggled to beat the various handicapping rules. In many cases the success of a design office has been completely based on their ability to beat whatever rule was in place at the time, and sometimes when a loophole they were exploiting was closed, those offices closed. Every rule was an effort toward objectivity, but every rule ended up encouraging a certain type of boat, often an unhealthy one. And to make matters worse, cruising boats have always imitated contemporary racing boats because yachtsmen are victims of style-consciousness like everybody else, and racing boats are assumed to be fast, even when in reality they were only designed to be fast for their rating. But with the IMS we have finally broken the objectivity barrier that has eluded us for the entire prior history of yachting. The rule seems to do an excellent job of rating boats of all types in a fair manner, and this seems to be born out by the race results, in which we see Concordia Yawls and Hinkleys and other boats more typical of traditional offshore yacht types, winning races and doing well.


Funny thing was that boats like the Finnisterre type Sunstone and the pre IOR S&S boats like Clarionet and Carina were enormously successful under IOR even late in the day. IOR allowed well-sailed older boats to do well, it's just that most older boats weren't sailed well and their sailors liked to blame the rule rather than look at themselves.



Still I don't think the full implications of the IMS are well understood. When I see a boat billed as "an IMS racer" in the magazines it usually looks like an old IOR racer, smoothed up and moderated perhaps, but still basically expensive, uncomfortable, difficult to sail, and not well suited to offshore storm conditions. To me, an IMS racer would be something quite different. She would be designed to keep sailing in the worst possible conditions with the least strain on her crew, partly because this is inherently desirable and partly because there are races to be won when the competition has retired or ceased to function effectively." Address by Daniel MacNaughton, brother of Tom, MacNaughton Associates


For the sake of argument, I think it is essential to eliminate the idiots who go underprepared, but to recognize that there is a major difference between a crack racing crew, which will typically include professionals who do little but race and work out, with their expenses paid for by sponsors, and a cruising crew, which will be much smaller, and composed of people who must live in the real world when they are not sailing. They will be skilled in seamanship, but probably not as physically fit as the pros. On a scale of 10, the average overall rating (seamanship and fitness) of an offshore racing crew will be 8.5 - 9.5. For a cruising crew, it may be 7.5-8.5. That does not make such a crew a bunch of unprepared fools. It means what I said, they are people who live in the real world when they are not cruising offshore.


Sounds good to me. Some people can handle some boats, and vice versa. To use an analogy - a top class crew on a 49er can sail fast and almost flawlessly in conditions a typical Snipe or Enterprise crew may not be able to handle at all. Why use the same criteria of seaworthiness for both crews?

PS no disrespect to cruising crews but few are used to racing boats at their limit.


Final thought: I recognize that discussion tends to sound black and white . There are not 2 types of sailing hulls, heavy and light. There are many good designs which attempt to realize the best of the 2 extremes. My point is that a seaworthy cruiser design must factor in the possibility of being sailed shorthanded. Everyone will have a preference, and there is ample data to support arguments on both sides.

WELL SAID!!!



IMS certainly was not a cure-all. The last IMS boats were about as bad as the worst IOR boats.

hiracer
03-22-2007, 03:26 PM
"Cruisers are hacks." :) (Bitch at Robert Perry not me.)

Isn't this the crux of the matter?

A chain in only as strong as its weakest link. With a lightweight cruising design, that weakest link is the crew--always.

Designing a boat that responds to storm conditions only if the crew is up to the task is inherently unsafe when you look at the reality of cruisers.

And injury, illness, or broken equipment can reduce the most competent cruising couple to hack status without warning.

The whole concept of lightweight boat design involves taking a concept intended for racing venues and then transfering it into a completely different venue. It works only so long as you ignore the reality of the typical cruising couple.

* * *

Further, analyzing the survivability of boats during racing events should not be used to draw conclusions about cruising designs. The most important factor, captian and crew, is complete different in the cruising context, thereby nullifying any conclusions about boat design uncovered in a racing context.

As a matter of logic, a professional captian and crew may be able to nurse a bad design through a storm, while the typical cruising couple will have a greater propensity to fail miserably.

hiracer
03-22-2007, 03:52 PM
Moreover, a racing event lasts how long and involves a crew number of how many? And a cruise lasts how long and involves a crew number of how few?

As a matter of simple statistics, the odds of an injury, illness, or equipment failure are much higher on a cruise--the point of a near certainty. Not insignificantly, the effects of these problems are magnified greatly by the smaller number on board. The cruising design must reflect this reality or it's not seaworthy.

At rock bottom, lightweight design is premised on a bias in favor of best case scenario, while the better cruising designs are premised on a bias of worst case scenario.

Which is not so say that all heavy designs are good. That simply is not the case. Bad design is bad design, even if its heavy. But skinny fin keel, canoe body, lightweight designs presents larger potential problems to the typical cruising couple precisely at the time when they will need the most help from the boat.

KevlarPirate
03-22-2007, 05:54 PM
CT: My quote “ Is it unfair that I may be smarter than you “
was not to imply me personally, but instead people in general. Retro, being superior, more fits this image, why don’t you go after him instead. I only defended the right of wealthy people to enjoy folly. You admit it was rhetorical, yet you scold me again.

I also said I have guys on board my own boat who (I implied) are smarter than myself and (I implied) more successful. You did not recognize my humility, fine, still I fully stand behind post 689

Funny that people have no problem accepting a superior athlete has the luck of the genes. So why can’t wealthy (likely smarter) people enjoy folly, who is to say that either (brains or brawn) is not fair to the rest.


My statements, which have attracted so much fire, was also in defense of, and to counter the attacks of a post saying; a Naval Architect ,having mastered the physics and supporting math, will come up to speed very quickly on someone else’s problem which he may be NEW to. This is very true and working in high science, I see it regularly.

As for Retro; you have a complex, fragile model of survival, which all data coming in must be either overweighed or discounted or dismissed to support your model, an example of highly opinionated people being biased.

And yes, CT, I made essentially the same statement to someone on another board who also has a lightweight fat boat he champions, yet I find his boat, with the “brilliant engineering” he claims has “known” problems with the keels falling off and people drowning, because the 6 mm hull thickness was not strong enough to keep the keel washers from shearing through.

Good engineering requires safety margins to deal with dynamic systems and the impulsive forces encountered. These margins are DELIBERATELY reduced (not a mistake or a QC thing) when something more important to the builder (speed ie. sales) takes over; consequences are guaranteed to arise.

My positions on what I call a superior offshore boat is based mostly on the physics. Newton’s 2nd law for one. Physics was not something I invented to support my conclusions. Physics put me where I ended.

Mass and moment of inertia will always make a boat more seaworthy (waves vs.: boat) and will prove value when (not if) the boat encounters severe weather. Retro of course doesn’t have to care about this.
The authors of the books I mentioned, although not physicists, are plenty technical and also support this. You may call it bias? Just facts backed by scientific data, not a heap of high sigma anecdotes.
And yes, it gets in the way of the enthusiastic support for many speedy boat designs. Probably just as tough a pill to swallow as my “wealthy people” statement.

This physics thing creates my preference for heavier, not beamy, deep fin keel with not too high aspect or too thin (stall), with a tall, stout rig Moment of inertia). This boat will have a high static curve, good sea motion and upwind performance. Oversized hardware and lots of winches, and a good galley to keep me full of food. The best of all worlds.

As for “how a boat is sailed”, I said these boats (like mine) had small IOR rudders, was one issue easily fixed. Many Cal 40’s, as have other newer boats I know of did rudder upgrades. Express 37’s, SC’s

The “one ton” picture I think has more issues. There maybe no simple fixes there. It looks to me to be a design issue, and it plays into the physics, for one, low moment of inertia. Extremely quick response to input forces (Newtons law + CSF) this case causing rudder and perhaps keel ventilation.

Also because of high buoyancy in the beam, the hull rotated through an axis higher and to leeward “port side (CB) shifted” therefore lifting the lightweight keel up and out.

I did the same thing on my 41 and we kept on sailing; 4 seconds it was over ,hull never lifted out. High wind, big beam on wave, no scrambling to ease sheets.

When you talk of people not liking my boat type; most all those cases lead to small IOR rudders and lots of “down wind” (sail flying) scenarios (too much sail vs. hydrodynamic control)
Leftover racing stories from the past.

My point was with a rudder upgrade (now with the IOR ended), and reasonable SA downwind, these boats make very seaworthy cruisers. The peak of the curve in performance, safety and comfort as a package. Not a teacup that can be kicked like a football.
Any newer boat of this design is fine by me , they are also out there too. And will be way better than a clunker at one end and that picture at the other.
I think any other dislikes relate to the boat being a displacement hull and not being able to plane and therefore not being fun and wild. Not a valid complaint if this thread is about “seaworthiness”.

The boat in the pic. could have been de-powered more and had not crashed and that would have made for better control and more closure to a cruising platform, but still you are held hostage to low mass and low moment of inertia. In a sentence why go out there if you are going to get beat up?

It is constantly proven small statistical samples
are inconclusive. Empirical data from races are high sigma.
This fact is not overcome by all the empirical data you present.
“So why the hell is there this concentration on boats that in reality kill a smaller number of people”

The reason is that there are laws of physics that stand between the low sampling rate conclusion and a different conclusion when more data is added. People suspect this and need more data because the data so far is still lacking in quality and quantity and is suspect. The data can also be very squewed.

Much data involves cruisers which many are hacks as Retro says in the same sampling pool with trained crews on race boats.

A Westsail which got into trouble, or dozens of accounts of other boats in trouble have all been in different situations. Still not enough of those samples share enough controlled parameters to make for valid conclusions.
Each patch of water is different from the next. You may be lucky to be in the good ones. It only takes one bad patch to mess you up.

Data leading to statistical significance to validate theory is developed in a controlled environment where parameters are varied typically one at a time.

When many variables are happening together in a dynamic situation, It then takes huge sampling to draw conclusions. Huge , that is the point!

The Westsail I gave as an example was near enough to show reasonable conclusion because there was a reasonably controlled environment (beam on sea) with the boat’s trim stabilized, not much variation.

If the wave was big enough however to roll the boat, removing the mast, lowering the moment of inertia and subsequent rolls become frequent, then you are in highly dynamic (changing) environment beyond the boats limits to resist.
The boat is very capable of being rolled on a big enough wave. It is only 32 ft.

I am talking of (probability of roll vs: wave size and inversion time) comparing one design to the next.

One conclusion you can make is that small, lightweight craft and their crew get punished way more.
And that wide and lightweight are downright dangerous.

Consistent with my earlier statement. If the boat and crew are broken and the occupants have to retreat, how will the boat act when lying ahull, which is what it will do unattended. That is my first criteria for seaworthiness.
One must establish a first criteria and that is mine. It is a very simple one.

In comparison, look at Retros:


If the computer models that create the routing are accurate
and not conflicting.
If the hopefully accurate model has enough weather data inputs to reliably predict and interpolation and extrapolation
are at an absolute minimum.
If you have infallible electronics, power source ,antenna and reception.
If your boat is in operating condition and nothing breaks to slow you or disable it.
If you remain in fully functioning physical condition.
If you never make judgment mistakes.
if you have good visibility.
If your charts are absolutely accurate. (some are off by 8 miles)
If your compass, engine ,fuel, injectors, water pump, alternator, solar cells etc. are perfect. Need I go on.

Essentially if you and your boat start perfect and absolutely nothing goes wrong, you will be OK.

Retro good luck , I admire your enthusiasm and hope your are blessed to never have to go through a real storm. These weather models being sold may be relying heavily on interpolation and extrapolations, I would not trust them alone. Just the Typhoon run to NZ every year guarantees storms.
Also your faith in your capabilities seems past what experience teaches us. New boats have problems too, that is why they have warranty periods. New rigging breaks, I have been there, including rudder and steering (on new IMS boats)
I am sure you can rationalize this butsave your strength, you will need it.

I have to say (the real truth and confession) that having raced into storms, I am drawn to them. I want a boat which will do well in tough conditions.


BTW, CT, the post you sent, the owner on the 39 ft. had removed structural stuff to open her up forward, I have more on that story. The issue is not the “style” here. Nor was it a deliberate reduction in weight, which would test the strength of materials as in the example I gave with the keel bolts (big difference!). These boats were well built, 200+ copies, many cruising. I don’t know much of the 37, few built. Incredible story you sent!

My 46, at 32000lb dry, over double the 37’s weight, I don’t know what you mean by it “being lighter by a fraction”, Not even in the same solar system! And at 13,000 more than the 39, is very comfortable and very soundly built and surveyed. Not that it is indestructable, you can put one on the rocks, someone did (Miami to Nassau, SORC 1974) Great Issac light Northeast rocks.
One thing I was wrong about with the 46 was that I thought she would be slow in light air, very much the opposite.
Let’s see if a Pogo will be sailing in 34 years?

hiracer
03-22-2007, 06:14 PM
So why can’t wealthy (likely smarter) people enjoy folly, who is to say that either (brains or brawn) is not fair to the rest.


1. Ask anybody in the estate planning field, you will learn that most wealth in the U.S. is inherited, not made. For every Bill Gates, there will ultimately be 20 to 1,000 progeny resting on his coattails.

2. The really smart people I have known have figured out that wealth is a false god, and you almost never see them on TV or in the papers.

Crag Cay
03-22-2007, 06:32 PM
As we are talking statistics and reports of incidents, it's perhaps worth noting that the UK Government 'Information Commissioner' has now published his findings into the Marine Accident Investigation Branch's (MAIB) report in 2005 that was so critical of safety in the leisure sailing world.

He has concluded that the report was entirely flawed as the MIAB keeps no records of leisure accidents, had conducted no detailed analysis of leisure incidents and could not provide any evidence in support of its claims because it did not have any.

Its motivation in publishing a report claiming over 1000 incidents and 24 deaths in one year was in order to portray boating as a dangerous activity that should be more heavily regulated, with the MIAB's parent body (The MCA) being funded to administer that regulation.

It would seem that MIAB moles have infiltrated this forum to advance such an agenda, equipped with equally flimsy statistical evidence of their being a real, measurable problem with boats based on modern lightweight, high ballast ratio, deep keel yachts.

KevlarPirate
03-22-2007, 06:42 PM
Wealth is no false God.
It is made from brains and it moves society forward.
That is why we live vastly better than our ancestors.
Think about it next time you go to the doctor and ask him to make you better.
I thought this post was on Seaworthiness of boats. Is somthing else going on here?

hiracer
03-22-2007, 06:55 PM
It would seem that MIAB moles have infiltrated this forum to advance such an agenda, equipped with equally flimsy statistical evidence of their being a real, measurable problem with boats based on modern lightweight, high ballast ratio, deep keel yachts.

That's a straw argument. The statistics you require are not offered because they don't exist. Nobody is keeping track of sailboat designs involved in cruising mishaps.

KevlarPirate
03-22-2007, 06:55 PM
"It would seem that MIAB moles have infiltrated this forum to advance such an agenda"

Could we try to keep this thread technical about design and not drift off point?

It is not worth reading anymore if we bog down with this prattle

Crag Cay
03-22-2007, 07:19 PM
If these statistics are kept or don't exist, how can we possible guage the real extent of the problem? Or shall we just continue to advance our own preferences as gospel?

hiracer
03-22-2007, 07:29 PM
If these statistics are kept or don't exist, how can we possible guage the real extent of the problem? Or shall we just continue to advance our own preferences as gospel?

Exactly. How else to explain this thread?

hiracer
03-22-2007, 07:38 PM
Seriously. Arguments are the most protracted, loudest, and get the most personal where there is the least amount of empirical evidence to adjudicate.

This is why I try to refocus the call of the question back to a cruising couple. Otherwise, seaworthiness can take on so many multiple meanings that it really is beyond examination.

I personally think that once you include the frailty that a cruising couple entials, the call of the question is narrowed enough that intelligent observations can be made. And I believe it was the cruising couple that served as the backdrop for the initial post in this thread. Correct me if I'm worng.

Crag Cay
03-22-2007, 08:40 PM
I still think the notion of a 'cruising couple' is still far too wide for generalisations to be made. Sometimes a cruising 'couple' is one person and a passenger whilst I'm completely happy to alternate single handed watches with the other half of my 'couple'.

But I don't think anyone is debating that there are factors of size / draft / beam etc which have an impact on the behaviour of boats, but the debate is fundamentally about, to what extent should we force people to incorporate these features in the boats they choose.

And for that we have to have a true measure of the risks involved and an agreement as to what extent we should protect people from themselves. It's the same debate they have in the automotive world, where in the UK we are obviously happy with 10 deaths a day on the roads or else we would require twin air bags, ABS and other features that are available to be incorporated in all new cars. If we were really bothered about safety we would restrict speeds to 30 mph on all roads. But neither the car buying public or the authorities believe such a 'cost' is warranted. People have a choice to accept a trade off between safety and purchase price / convenience / high powered fun etc. To debate safety (or seaworthiness) outside of these contexts is unrealistic.

The same is true of housing. People are allowed to build crappy houses along the coast of Florida because it's where people want to live at the price they are prepared to pay, and the authorities accept that the risk, when you factor in the whole picture including hurricane forecasting, evacuation plans and rescue facilities, is acceptable.

So we return to our favourite measurement of 'seaworthiness' - STIX. In isolation raising it to 40 or 50 or more for Cat A boats would probably make ocean classed boats more wholesome. But where is the risk assessment that proves there is a case for doing so? Where is the proof that a STIX of 32 minimum is leading to deaths on a scale that warrants any change? Do the people advocating such a change have a democratic mandate from the people demanding that something is done?

Cruising by it's very nature is about freedom. But like all freedoms it requires the people who enjoy that right to exercise a degree of responsibility. This includes using their financial resources wisely and buying a boat that suits their preferences, ambitions and skill level.

But it's horses for courses: How should we distinguish between the ex SAS trooper, Tom MacClean, who has made a number of solo Atlantic crossings in smaller and smaller boats including one only 5 ft 11 inches LOA, as opposed to the retired couple in a new Bristol 52 who required lifeboat assistance when they ran aground in benign weather on a lee shore in the Chesapeake Bay, but didn't have the skill or capability to run out an effective kedge. One of those boats was deemed (in isolation) to be highly seaworthy, but the same one is also a rescue statistic, feeding the authorities' urge 'to do something' about recreational boats seaworthiness.

hiracer
03-22-2007, 09:00 PM
but the debate is fundamentally about, to what extent should we force people to incorporate these features in the boats they choose.

That's not my understanding. Nobody, certainly not me, is advocating limitations on the right to cross an ocean in the boat of their choosing. I might disagree with somebody's choice of boat and design, but I will not hesitate to defend their right to choose--as I actively did so in another thread.

We are simply trying to figure out what it means to say a boat is seaworthy.

Part of the problem is that we haven't really defined the hazards that come from a boat that is not seaworthy. This can run the gamut, from pitchpoling in a storm, to sinking on account of hitting a container under clear blue skies, hitting a reef from a navigational error triggered by fatigue, getting burned while working in the galley, broaching during a blow, etc. Seaworthiness can mean very many things. What is the objective here?

Ultimately I think the issue of seaworthiness comes done to the subjective evaluation of how to divide the line of responsibility for safety between sailor and boat. If you place greater and greater responsibility for safety on the sailor, that certainly opens up some design avenues. And it is my opinion that this is the route that modern boat design is taking.

charmc
03-22-2007, 09:40 PM
"Number of people killed in the Fastnet and Hobart aboard boats with deep ballast, skeg-hung or keel-hung rudders, vee-shaped sections, heavy rigs and non-planing hull shapes - at least 6.

Number of people killed in the Fastnet and Hobart aboard boats with spade rudders, flat sections, light rigs and surfing/planing sections - about 6.

MOST boats in the Hobart and Fastnet were closer to the light fin keel type than the heavy type, yet they killed fewer people proportionate to their numbers. So why the hell is there this concentration on boats that (in reality) kill a smaller proportion of people?" (CT 249)


Some people can handle some boats, and vice versa. To use an analogy - a top class crew on a 49er can sail fast and almost flawlessly in conditions a typical Snipe or Enterprise crew may not be able to handle at all. Why use the same criteria of seaworthiness for both crews?
PS no disrespect to cruising crews but few are used to racing boats at their limit. (CT 249)

CT, In general, it seems we agree. Your Fastnet '79/Hobart '98 comments that fewer of the lighter, "full race" style boats suffered fatalities in proportion to their numbers makes my point that these designs are meant for running with full crews of fit and highly experienced racers. Randy's earlier comment that the lighter, faster boats can avoid the worst of the weather is true...sometimes, but such boats can sail at their full potential only with large, experienced crews, who are operating at peak performance for a clearly defined period of time. I believe that for most (not all) cruising applications, such boats are not suitable.

That being said, I agree with those in this thread who decry any government "standards" for cruising boats. Buyers need to be informed. By definition, cruising on the open ocean, out of sight of land for days or weeks, is a potentially dangerous activity. No one should consider doing so without experience and a high level of knowledge, particularly knowledge of one's own and sailing partners' capabilities. There are some who will be capable of sailing a high performance monohull like a Pogo 40; most cruisers should avoid it. The responsibility, however, lies ultimately with the buyer to do the research and make a sound and well informed decision.

charmc
03-22-2007, 10:06 PM
Ultimately I think the issue of seaworthiness comes done to the subjective evaluation of how to divide the line of responsibility for safety between sailor and boat. If you place greater and greater responsibility for safety on the sailor, that certainly opens up some design avenues. And it is my opinion that this is the route that modern boat design is taking.

Well said! That's a good summation, in my opinion. No boat can be designed to be stupid-proof. There is nothing wrong with a lightweight, planing hull being used for offshore cruising.....provided the owner knows the potential dangers of the type and has the skill level and crew size to manage them under heavy weather conditions. On the other hand, I witnessed the grounding and near loss of a traditional style 40' sloop by an imbecile who attempted to enter a pass (Southern US-speak for inlet) well known and described on charts as shallow, sandy, with rapidly shifting shoals, and poorly marked. This with an strong onshore wind and an outgoing tide, at near low water. Stupid-proof is an impossible design quality.

RHough
03-23-2007, 12:24 AM
As for Retro; you have a complex, fragile model of survival, which all data coming in must be either overweighed or discounted or dismissed to support your model, an example of highly opinionated people being biased.

Good engineering requires safety margins to deal with dynamic systems and the impulsive forces encountered. These margins are DELIBERATELY reduced (not a mistake or a QC thing) when something more important to the builder (speed ie. sales) takes over; consequences are guaranteed to arise.

Mass and moment of inertia will always make a boat more seaworthy (waves vs.: boat) and will prove value when (not if) the boat encounters severe weather. Retro of course doesn’t have to care about this.

This physics thing creates my preference for heavier, not beamy, deep fin keel with not too high aspect or too thin (stall), with a tall, stout rig Moment of inertia). This boat will have a high static curve, good sea motion and upwind performance. Oversized hardware and lots of winches, and a good galley to keep me full of food. The best of all worlds.

I think any other dislikes relate to the boat being a displacement hull and not being able to plane and therefore not being fun and wild. Not a valid complaint if this thread is about “seaworthiness”.

One conclusion you can make is that small, lightweight craft and their crew get punished way more.
And that wide and lightweight are downright dangerous.

Consistent with my earlier statement. If the boat and crew are broken and the occupants have to retreat, how will the boat act when lying ahull, which is what it will do unattended. That is my first criteria for seaworthiness.
One must establish a first criteria and that is mine. It is a very simple one.

In comparison, look at Retros:


If the computer models that create the routing are accurate
and not conflicting.
If the hopefully accurate model has enough weather data inputs to reliably predict and interpolation and extrapolation
are at an absolute minimum.
If you have infallible electronics, power source ,antenna and reception.
If your boat is in operating condition and nothing breaks to slow you or disable it.
If you remain in fully functioning physical condition.
If you never make judgment mistakes.
if you have good visibility.
If your charts are absolutely accurate. (some are off by 8 miles)
If your compass, engine ,fuel, injectors, water pump, alternator, solar cells etc. are perfect. Need I go on.

Essentially if you and your boat start perfect and absolutely nothing goes wrong, you will be OK.

Let’s see if a Pogo will be sailing in 34 years?

You make some very good points.

No one is saying heavy displacement boats are not seaworthy, only that a boat does not need heavy displacement to be seaworthy. It may need certain characteristics for you to feel comfortable in it, but that does not make boats you are not comfortable with less seaworthy.

When people talk about eventually being in extreme conditions we have to look at what is extreme and how often those conditions actually exist on the ocean. The fact is that storms are NOT every day events. Yes there are almost always storms somewhere, but not on cruising routes during the best months to sail those routes.

Pilot chart data from 100's of years of sail tells us that gales are more frequent in some areas than others and more frequent in some months than others. It does not require anything fancy to plan passages to reduce the risk of sailing in a gale.

Nor does it take anything fancy to learn enough weather forecasting skills to anticipate changing weather. A little study, a log, and a barometer do quite well. Knowing the path that weather systems are likely to take and reacting early (rather than stubbornly holding course towards your destination) should reduce your exposure.

My survival model includes both storm avoidance (highly likely) and preparedness for storms (highly unlikely).

If you start from the idea "I wonder how often I'll find myself in storm conditions" and then do the research instead of starting from "I need a boat that can safely ride out a storm" and not learning to work with nature, you end up with the Ken Barnes story.

There is a HUGE difference between depending on tools to provide skills you lack and making good use of available systems to increase safety at sea. It would be like running aground because a chart was off by 8 miles instead of trusting your piloting skills. If you go aground because you trusted someone else's data (electronic or paper) you have no one but yourself to blame. Seaworthy should not mean idiot proof, such a boat does not exist. :)

I really have a problem with the idea of heaving-to or lying ahull. Lying ahull almost guarantees that the boat will be beam on to the sea and become very likely to get rolled. I also have a problem with boats that cannot sail in 40-50 knots. 40 knot winds should not bring a boat to her knees and force the crew to think about survival. In that respect there are heavy displacement boats that fail that "seaworthiness" test. In contrast, boats like the Class 40's are designed to sail in 40-50 knot winds ... short or single-handed ... under autopilot. How anyone can think that such a boat is unseaworthy is beyond me.

A boat designed to sail at 20 knots in 35 knots of breeze will have huge safety margins if throttled back to 14 knots. If my physics is correct, dynamic loads go up with the square of speed. If the boat has a safety margin of 2:1 at 20 knots, it has a margin of over 4:1 at 14 knots. At 10 knots the margin is 8:1. I seriously doubt that a boat designed for 9-10 knots will have anything close to scantlings that provide such high margins.

The simple fact is that ... if you choose to ... you can sail the oceans for years and NEVER sail in a storm. Designing boats with lying ahull in a storm as the primary design brief makes no sense to me. Building a boat that is not strong enough to sail safely in the conditions for which it was designed is not likely to happen. If you take a Class 40 design and depower it in a cruising version, you have a hull shape that was designed for open ocean under all conditions and scantlings that are engineered for speeds and conditions that a prudent cruiser will probably never see. Concluding otherwise is to ignore basic physics.

charmc
03-23-2007, 01:44 AM
It may need certain characteristics for you to feel comfortable in it, but that does not make boats you are not comfortable with less seaworthy.

In contrast, boats like the Class 40's are designed to sail in 40-50 knot winds ... short or single-handed ... under autopilot. How anyone can think that such a boat is unseaworthy is beyond me.

A boat designed to sail at 20 knots in 35 knots of breeze will have huge safety margins if throttled back to 14 knots. . If you take a Class 40 design and depower it in a cruising version, you have a hull shape that was designed for open ocean under all conditions and scantlings that are engineered for speeds and conditions that a prudent cruiser will probably never see. Concluding otherwise is to ignore basic physics.

Randy, you're right: the boat, considered in isolation, is certainly seaworthy, but aside from R/C models, boats need crews to operate. Fatigue and the higher risk of injury associated with higher speeds, especially planing speeds, take their toll on the crew. A cruising crew's ability to absorb punishment and still perform at peak levels is significantly lower than a racing crew's for a variety of reasons stated previously. The crew's ability to perform is an integral component of seaworthiness.

But as I've said before, I'm speaking of most cruising crews. There will be cruising crews capable of sailing such a boat. As long as it's recognized that a "cruiserized" Pogo 40 is not for everyone, I'm satisfied.

Guillermo
03-23-2007, 02:35 AM
...So any criticism of the RCD can only be made on the grounds that it is allowing boats that are patently dangerous to come onto the market. Not just indifferent, or undesirable or uncomfortable or misguided, but just down right lethal.

....So we return to our favourite measurement of 'seaworthiness' - STIX. In isolation raising it to 40 or 50 or more for Cat A boats would probably make ocean classed boats more wholesome. But where is the risk assessment that proves there is a case for doing so? Where is the proof that a STIX of 32 minimum is leading to deaths on a scale that warrants any change?

I'm confused....

Cheers.

RHough
03-23-2007, 02:49 AM
Randy, you're right: the boat, considered in isolation, is certainly seaworthy, but aside from R/C models, boats need crews to operate. Fatigue and the higher risk of injury associated with higher speeds, especially planing speeds, take their toll on the crew. A cruising crew's ability to absorb punishment and still perform at peak levels is significantly lower than a racing crew's for a variety of reasons stated previously. The crew's ability to perform is an integral component of seaworthiness.

But as I've said before, I'm speaking of most cruising crews. There will be cruising crews capable of sailing such a boat. As long as it's recognized that a "cruiserized" Pogo 40 is not for everyone, I'm satisfied.

Certainly. The cruisers that proudly state that they don't worry about sail trim because they are "just cruising" will not choose a cruising Class 40 boat. I doubt that anyone (except me) that was considering a Shannon will look seriously at an Akilaria.

I don't get the higher risk of injury and fatigue being a problem. No one says the boat has to be pushed that hard all the time. I see being able to sail fast when you choose to, need to, or want to as a plus. It is an option that many boats don't have. You can always sail a fast boat slower, you cannot sail a slow boat faster.

charmc
03-23-2007, 03:32 AM
I don't get the higher risk of injury and fatigue being a problem. No one says the boat has to be pushed that hard all the time. I see being able to sail fast when you choose to, need to, or want to as a plus. It is an option that many boats don't have. You can always sail a fast boat slower, you cannot sail a slow boat faster.

The motion of a flat bottom, lighter weight hull in any sea state above calm and even at displacement speeds will be typically faster, more violent, jerkier, etc. This contributes to fatigue and a higher possibility of injury.

Guillermo
03-23-2007, 03:59 AM
Yes there are almost always storms somewhere, but not on cruising routes during the best months to sail those routes.
That's not true. To blindly believe in statistics is an act of faith. An unexpected storm may arise wherever and whenever.

...Nor does it take anything fancy to learn enough weather forecasting skills to anticipate changing weather. A little study, a log, and a barometer do quite well. Knowing the path that weather systems are likely to take and reacting early (rather than stubbornly holding course towards your destination) should reduce your exposure.
Absolutely. But a prudent skipper should also allow for equipment failure, tiredeness or the like. Blind faith is risky.

...If you start from the idea "I wonder how often I'll find myself in storm conditions" and then do the research instead of starting from "I need a boat that can safely ride out a storm" and not learning to work with nature, you end up with the Ken Barnes story.
And if you think you'll be always able to speed off an storm, you'll have serious chances of toasting down there with Neptune.

...In that respect there are heavy displacement boats that fail that "seaworthiness" test.
As there are light ones. Inconclusive.

...In contrast, boats like the Class 40's are designed to sail in 40-50 knot winds ... short or single-handed ... under autopilot. How anyone can think that such a boat is unseaworthy is beyond me.
I find your expresion “In contrast”quite tendencious. On the other hand Class 40 boats are pretty difficult to steer under autopilot in those conditions, requiring constant skipper attention. Read again Phil Sharp's statements.

...I seriously doubt that a boat designed for 9-10 knots will have anything close to scantlings that provide such high margins.
Proper 'heavy' cruising boats are scantled with pretty high safety margins. I'm not so sure for the new breed of super light ones.

... you can sail the oceans for years and NEVER sail in a storm.
Generalizing that way only from the tale of a couple who said you so, is not prudent at all.

...Designing boats with lying ahull in a storm as the primary design brief...
Please show me a designer following that design brief, my dear!

...Building a boat that is not strong enough to sail safely in the conditions for which it was designed is not likely to happen.
Maybe that's why some keels have a tendency to live an independent life nowadays...

...If you take a Class 40 design and depower it in a cruising version, you have a hull shape that was designed for open ocean under all conditions and scantlings that are engineered for speeds and conditions that a prudent cruiser will probably never see. Concluding otherwise is to ignore basic physics.
I would like to inspect those forty foot boats with D/L ratios under 100 within some years time. I'm not so sure as you are about their fatigue characteristics. I think you are not being prudent at all about all this. You seem to have an excess of faith in performance of electronic equipment, marketing people and your own abilities. Not very wise, in my opinion.

Cheers.

RHough
03-23-2007, 04:59 AM
I find your expresion “In contrast”quite tendencious. On the other hand Class 40 boats are pretty difficult to steer under autopilot in those conditions, requiring constant skipper attention. Read again Phil Sharp's statements.


I'll wager that a boat that was designed to be steered by an autopilot will be easier to steer than a boat that was not. It does not make sense to think that designers with experience designing successful boats for short-handed ocean racing would come up with boats that are harder to steer than boats that were not designed with that in mind.


Generalizing that way only from the tale of a couple who said you so, is not prudent at all.

I have only my personal experience to guide me. I know several people that have sailed oceans, none of them talk about storms that came from nowhere. I am forced to conclude that there is always some warning of bad weather. Some of my friends have had no choice but to continue into the bad weather (racing or working as a delivery skipper), but they knew it was coming and could have avoided it if they chose to.


Please show me a designer following that design brief, my dear!


:) Well, with the number of people that think crew safety while lying ahull is the prime consideration in determining seaworthiness ... I would assume that it is high on the list of a design brief. :D


Maybe that's why some keels have a tendency to live an independent life nowadays...

Not on any boat I would consider for cruising ... :)


I would like to inspect those forty foot boats with D/L ratios under 100 within some years time. I'm not so sure as you are about their fatigue characteristics. I think you are not being prudent at all about all this. You seem to have an excess of faith in performance of electronic equipment, marketing people and your own abilities. Not very wise, in my opinion.

Cheers.

The reality is that in 40 years I'll not care what condition the hull is in. I have no problem with a boat that is not sound after 20-40 years. Most of the solid GRP boats that still look like they are in one piece are nowhere near as stiff and solid as when they were built. At least the good wooden boats of the 30's and 40's could be rebuilt to "as new" condition. As far as I know there is no repair for a soft solid glass hull. There are hundreds of boats still in use that should not be. It is only the easy usage and limited time they spend sailing that keeps them on the market. That does not make them sound.

At one time all the same concerns were raised over boats with D/L ratios under 300, then under 250, then under 200 ... it will always be so. As long as one is tied to heavy = strong rather than good design = strong one will always mistrust lighter weight replacements.

Yes, I put quite a bit of faith in my ability, I certainly have more faith in my ability to take care of the boat than in the boat's ability to take care of me. I don't think that anyone that does not have faith in their ability should consider ocean sailing at all. I doubt marketing people, and I am familiar enough with marine electronics to have confidence in them as well. Electronics don't fail for no reason any more than storms rise up from nowhere. Components fail either early on or they work just fine until damaged or obsolete. As a prudent sailor, I don't rely on systems that have not been in use past the early failure date, after that I don't abuse them and they seem to work just dandy for me.

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