Monohull verses Multihull powersailers / motorsailers

[brian eiland]

I've wanted to bring up a subject that seems to be a trend amoung monohull folks lately. I can only think it has to do with the competition they are feeling from the multihull market. I continue to see these inflated claims as to their particular design's performance capabilities, particularly under sail.

Case in point. Have a look at the new PowerSailer (http://www.powersail.co.nz/) from NZ.

Can you really believe that a 28 tonne (I would venture to guess heavier by the time its finished) monohull vessel will 'sail' at 18knts??...even with a 110' mast. The vessel is only 66' long and carries a 21' beam. And I imagine it will be very difficult to keep that underwater, retractable Z-drive housing/sea chest volumn free of sea water (lots more weight). And she's carrying around a 13.6 keel and twin rudders. Granted the small print says in a downwind surfing condition, but they advertise the vessel as though a perspective client should readily expect such performance....wishful thinking I believe.

I've seen some number of other monohull manufactures claiming some 'very optimistic' speeds for their sailing performance lately....can't recall the specifics at the moment, maybe someone else can fill in the blanks.

Now, to get to 'planing speeds' desired of this power sailer she's going to need 800hp....boy, that's not going to be light. Then how do you get the rt-angle gears of a Z-pod unit to stand up to a continuous hp rating of this magnitude??

Plus they're going to have a retractable keel (more weight) to gain entrance into shallow areas. And the vessel is going to be unsinkable??

It seems to me they should just accept the multihull motorsailer planform in the first place, as all of these goals (and their others) are met with this planform.

Boy, I wish I could find a boater such as this gentleman, who would wish to put the money and effort he has committed into a custom catamaran motorsailer design. We could accomplish this sort of performance with a 75' mast, two 200hp engines, and a 3.5' draft.....probably cheaper too.

[Ilan Voyager]

I've wanted to bring up a subject that seems to be a trend amoung monohull folks lately. I can only think it has to do with the competition they are feeling from the multihull market. I continue to see these inflated claims as to their particular design's performance capabilities, particularly under sail.

Case in point. Have a look at the new PowerSailer (http://www.powersail.co.nz/) from NZ.

Can you really believe that a 28 tonne (I would venture to guess heavier by the time its finished) monohull vessel will 'sail' at 18knts??...even with a 110' mast. The vessel is only 66' long and carries a 21' beam. And I imagine it will be very difficult to keep that underwater, retractable Z-drive housing/sea chest volumn free of sea water (lots more weight). And she's carrying around a 13.6 keel and twin rudders. Granted the small print says in a downwind surfing condition, but they advertise the vessel as though a perspective client should readily expect such performance....wishful thinking I believe.

I've seen some number of other monohull manufactures claiming some 'very optimistic' speeds for their sailing performance lately....can't recall the specifics at the moment, maybe someone else can fill in the blanks.

Now, to get to 'planing speeds' desired of this power sailer she's going to need 800hp....boy, that's not going to be light. Then how do you get the rt-angle gears of a Z-pod unit to stand up to a continuous hp rating of this magnitude??

Plus they're going to have a retractable keel (more weight) to gain entrance into shallow areas. And the vessel is going to be unsinkable??

It seems to me they should just accept the multihull motorsailer planform in the first place, as all of these goals (and their others) are met with this planform.

Boy, I wish I could find a boater such as this gentleman, who would wish to put the money and effort he has committed into a custom catamaran motorsailer design. We could accomplish this sort of performance with a 75' mast, two 200hp engines, and a 3.5' draft.....probably cheaper too.


I agree totally with you. I'm fed up of all these impossible claims and "over technology" I see in too many internet sites. Any naval engineer or architect with some experience would laugh of such claims.

And as you said a cheaper, simpler and safer alternative is a catamaran.

[brian eiland]

Yacht Design Competition
Boating International & Camper/Nicholsons
(“the best boat to undertake a world cruise”)
(cover ltr)

Well here’s my submission, a Motor/Sailer.

I was a little disappointed that you didn’t have a separate category for this combination of sail & power, rather than just lumping it in with the sail category....but that seems the way the motorsailer has been treated (neglected) for so long. I tried to get an article on motorsailers into the current very popular American magazine, “Passagemaker”,......no way, the boat has sails on it!...... As though the only true passagemakers were trawlers.

I asked my friends at the Annapolis Boat Shows (were I had participated for years) about bringing in a display model of my gamefishing cat to the PowerBoat Show.....no way, it has sails on it!

I ran into the same situation when I tried to get my motorsailing/gamefishing catamaran design published.....not in the gamefishing mags as this boat has sails on it.....and not in the sailing mags as this boat has a fishing chair and big engines in it.

So I’ve not been able to get this motorsailing design published.....only a 30-year-old article on the sail-plan idea itself. Hopefully I will be considered as unpublished in your definition, as I have not had this design published in any printed publication I’ve had to resort to taking some computer courses, and finally getting a website up to promote this idea. I feel like I’m in the same ‘uphill’ battle with the marketplace that I was for18 years in the sailboat business pushing ‘the multihull concept’. Several times I’ve put this idea into hibernation, particularly the ‘Gamefishing Under Sail’ idea. My comment at the time was something like, “I just spent 18 years in the sailboat business trying to convince sailors of the virtues of multihulls, and now I’m going to try and sell a fishing guy a boat with sails on it. I’ve got to be crazy!”

So now you are the happy recipient of this idea. I hope you take a little time to give this concept some serious consideration as a great vessel concept ‘to cruise the world ’. In the essay I submitted I had to spend quite a few of my allotted words to talk about the motorsailer concept in general, rather than my design in particular. It wasn’t as though I could just say trawler and all would be assumed as understood. The word motorsailer (or motorsailor or.......) just doesn’t translate that easily.

You encouraged innovative ideas. I think I’ve presented a few, and particularly my sail plan. I chose not to expound on the performance potentials of this unique rig, but rather just point out those particular features so applicable to the cruising situation. And those would exist regardless of its potential windward capabilities with tight, straight forestays.

While I have your attention let me bring up another of my observations about cruising sailboats I made long ago. I always felt that the raised saloon/deckhouse arrangement was a particularly good one.... up where you can see the world around you rather than buried down below. Look at the multitude of today’s monohull designs that are incorporating this raised saloon concept, maybe due to the popularity of the catamaran configuration.….and/or some number of the early motorsailers that incorporated this feature. My twin keel monohull incorporated a mini version of this feature, and was introduced back in the early days when there were VERY few cruising specific designs, and the Out-Island series was just coming on (something like 35 years ago).

If I were choosing a monohull vessel as a world cruiser, I would give serious consideration to a vessel such as my twin-keeled monohull perhaps extended to 60-65 feet, with an expanded upper saloon/cockpit, and only two big staterooms at either end. With a good size engine, my ‘ketch’ sailplan, and shallow draft/directional stability of the twin keels it would make an excellent motorsailer.
________________________________
Yacht Design Competition, Contest Essay
(“the best boat to undertake a world cruise”)

I sincerely believe that a well conceived Motor/Sailer is the most practical, capable, comfortable, economical vessel for serious ocean passagemaking......and retaining the ability to explore the most remote coastal areas.

Even Beebe’s book,”Voyaging Under Power”, the bible of the power-only crowd, his vessel, “Passagemaker”, was a motorsailer, albeit smaller rigged than he really wanted. Many of the examples he offers as prime passagemakers are instead prime coastal cruisers, ‘semi-displacement’ hulls not optimized for long passages, but rather coastal cruising, where rapid transit is a primary requirement, while fuel use and surviving ultimate conditions are secondary considerations. ‘Trawlers’ today are gravitating toward planning hull configurations, and twin engines, as buyers become reluctant to accept slow 7-9 knot vessels. And forget wide appeal of primarily sail-powered vessels, particularly with our aging population.

We don’t hear much of motorsailers these days....not a popular subject. The old traditional, stoutly-built vessels, with a hefty engine(s), were necessarily compromised in both their sailing and powering statistics. Let’s modernize the motorsailer. The multihull planform holds great promise to improve this breed. The long slender hulls of the catamaran vessel have proven real efficient to push under both power & sail.....not only efficient, but not limited to the traditional slow displacement/length hull-speeds. Just what the motorsailer needs....far less compromising increases in both sail and power performance, while maintaining economy of operation that truly allows long-range capability.

Let’s explore a 40' example. Take the single 120-140 hp diesel used to push the conventional 40' single-hulled trawler or motorsailer to a maximum 8.3 knots hull speed and divide it into two smaller 60 hp diesels driving two long slender catamaran hulls. Voila!, maximum to 15 knots under power with the reliability of twin engines and the stability of a twin-hulled vessel. Add a modest sailing rig to these easily driven hulls, and you now have a passagemaker capable of cruising 12 knots under sail/ power compared with those older 7-knot boats. With 12 knots of speed at your command, you can really take advantage of 'weather windows' to; 1) make your passage as smooth as possible, 2) make some lengthy passages you might never have considered in a slower boat. This multihulled vessel will likely be slowed less by an obstructive seaway, and will accordingly make a passage at almost twice the average speed of the single-hulled vessel...twice the speed for the same total HP. There is an economy of operation here that cuts fuel requirements and bills, and greatly extends their range. In light airs, running one engine often is all that is needed to bring the apparent wind forward to make the sails work harder, and the combination provides much better results than either motoring or sailing alone……
.sailing synergy/harmony, the motor taking over in the lulls and the rig taking over in the puffs.

The sea-kindliness of multihull craft is being rediscovered every day. Continual experiences with whale watching boats, fast ferries, pleasure, commercial, and military applications are all proving the validity of the multihull form. What many people forget about a good ride in a heavy sea is that it is very much a function of weight in addition to hull shape. More weight, more robust, more form resistance it offers to moving thru the ocean, the more the sea acts to resist the vessel's progress, and thus the more uncomfortable ride, and we must slow down. A big headsea is a particular challenge. Heavy boats carry their momentum into each trough and crest in a battle with the sea, while lighter weight vessels with slender hulls slice through with less battering. Per a sign at the Naval academy, “you can out-think the ocean, but you can’t out-slug the ocean.” Modern materials allow for lighter boats, and we must properly distribute the vessel's weight throughout long slender hulls. Following seas tend to pick up broad sterns and slew a vessel off to either side....broach. The catamaran hull does not require these broad stern shapes.

Storm survivability should be considered at the design stage for any vessel making offshore passages. Loss of power (clogged filters, etc) often occurs at the most inopportune time (during a storm), and this can put the solely powered vessel at peril in short order. A vessel with a modest sailing rig could save your life, and the vessel’s. Add a proper sea anchor installation, and I would challenge a hurricane. The catamaran planform rated ‘best in survivability’ in huge breaking wave tests* carried out by Lock Crowther at the prestigious Univ of Southampton.

Most innovative item on my vessel, the mast-aft sailing rig, also referred to as a ‘single-masted ketch’....a marriage between a cutter and a ketch without the mainsail. I have LOTS of data to support my contentions as to the aerodynamic superiority of this configuration.... But lets leave that theory out of the equation for our motorsailing application. The ketch rig is a good small-crew size rig, particularly where all three sails are roller furling!....even a novice could learn to operate this rig.....and she balances under a variety of sail deployments. Lower force centers add safety. Boats with moderate rig proportions tend to make faster overall passages because they are sailed at a higher level of efficiency than if they carry a lofty hi-performance rig. No big head-bashing booms, and just wing/wing the headsails downwind. The sail rig contributes damping action to the rolling in a beam/quarter sea (no servo-fins needed), contributes to an unlimited range, and ultimately it will get you home if the engines fail. Ahhhh motorsailing!

Optional nacelle-mounted centerboard precludes any extra hull penetrations, and permits maintenance without hauling-out. ‘Pointed’ deckhouse shape conforms to apparent winds, significantly reducing drag. Flying bridge & crows nest. Dedicated engine rooms, isolated from living spaces. Copper-nickel hull material below waterline is impact resistant and naturally antifouling for years.

Accomodations!! How might it appear as a real estate ad?, “Waterfront cottage, 4/5 bedrooms, three baths, large kitchen & dining area, big deck, wonderful views.” Hard to beat a catamaran’s spaciousness and privacy....witness their current popularity in the market. Seamanlike layout... no vast open spaces.

My 65' Motor/Sailing catamaran is the embodiment of a Phil Rhodes’ motorsailer design that has haunted me all these years. Only, this vessel is so much superior. Twin 100hp diesels will cruise her at 12/14knts. Under sail she could make 18/20kts. Range, unlimited. Fuel consumption, extremely low. She could skim over depths as little as 3.5'. Explore those rivers, mangroves, coves, lagoons. Beach the bows. Dive or fish the flats and the reefs from the Bahamas to the Pacific atolls. THIS IS AN EXPEDITION PASSAGEMAKER!! 20-25meters, no crew required.


* reference source: (Lock Crowther Designs Catalogue 1980)

“This work has indicated that the well designed catamaran is remarkably safe in breaking waves up to considerable height, even when beam on, we were unable to capsize a power catamaran yacht in the largest wave which could be generated. This corresponded to a 52' wave for a catamaran of 40' beam. Scaling this down to a typical 24' beam cruising cat means she should be O.K. in a 31' breaking beam sea. An equivalent size mono-hull power boat was easily capsized by a 25' breaking sea, and in tests with conventional yachts after the Fastnet disaster, it was found that a 40' mono-hull yacht could be capsized in a 12' breaking sea.”

[sharpii2]

Dear Brian:

I first want to ask you a few questinons about your design concept. then I want to make a few humble suggestions. First the questions. For the sake arguement, let's stick with the fourty foot version. It can be afforded by your average millionare.

First question. What would its waterline length be? 36ft? 40ft?

Second question. What would its displacement be? 5 tons? 10 tons? 20 tons?
My guess is 10 tons. Am I right?

Third question. What would be its centerline to centerline beam. My guess is 20ft. Am I right?

Fourth question. What would be the wl beam of each hull 5ft? 6ft? 7ft?. My guess is around 6ft. Am I right?

Fith question. How far along the over all length would the wing deck extend. 35%? 50%? 75%? My guess is at least 75%. Am I right?

Final question. Would there be standing headroom in the entire cabin or just in the hulls and the pilot house?

Now for my suggestions.

First. Why not just make it a cutter? Its a rig that has most of the advantages you are looking for, doesn't look bizzare or ugly, and, most important, won't scare potential clients away.

And second. Why not submit a simple profile drawing along with vital stats to a magazine that is a bit off the beaten path such as "National Fisherman", "Boatbuilder" or even "Passagemaker"?

Best wishes. Bob

[fcfc]

Why dont multihull guys give curves or figures like:

http://www.nordhavn.com/40/overview.htm
or
http://www.kadeykrogen.com/krogen44speedandrange.htm
or
http://www.beneteaupower.com/swift/performance.php

And why malcolm tennant in this page
http://www.tennantdesign.co.nz/news.php?story=33
graph : http://www.tennantdesign.co.nz/uploadImages/big1097718450fuelcompmono.jpg

does compare with a monohull who is the shortest and heaviest boat of the tested boats.

Why does not he uses :http://www.classic-boats.com/gamme/fotos-boats/and15-ecran1.jpg or http://www.rodgersyachtsales.com/and.html
who is lighter and longer and does 20 kts with 2* 150 hp ?

The graph scale also are a bit strange. comsuption per displacement without any unit. Why not simply use GPH ?

Another point for power multihull : the average buyer will burn fuel 50-100 hours only per year but will pay marina fees all year long (even with no use).

[yipster]

there is some info...
http://www.tennantdesign.co.nz/pics/viridian2.jpg
on the 15 meter veridian (http://www.tennantdesign.co.nz/boats.php?boat=90) diesel electric i read forexample:
"from the 2 x 350hp Yanmar diesels driving 5 bladed props through a 3:1 vee drive gearbox. The vee drive is used to enable an electric motor to be attached to the back of the gear box for electric propulsion. At a cruising speed of 22 knots the boat has a range of 1400 nautical miles and uses 2.3 litres of fuel per nautical mile [50.6 litres per hour] or 0.6 US gals per nautical mile [13.4 gals per hour]." more info on request i guess...

i do belive malcolm tennant is one of the experts on power cats and enjoyed reading his good maritime articles again...

propulsion, (http://www.tennantdesign.co.nz/articles/65/propulsion.html)
displacement powercats (http://www.tennantdesign.co.nz/articles/66/diplacementpowercats.html)
development in hulls (http://www.tennantdesign.co.nz/articles/67/developmentinhulls.html)

[fcfc]

About the veridian, it uses full power for 28 kts, so 2* 350 = 700 hp.

And only 22 kts, it burns 50.6 liter per hours. this translate in rougthly 250 hp.

Need to nearly triple the power to gain about 27% in speed.

For me, it is strange, since I dont forecast any flow difference for the hulls between 22 and 28 kts.

If I translate to monohull, 125 hp would drive a 9 t very slender 52 ft hull to 22 kts. But it would need 300 hp to drive a 11 t 50 ft monohull 11.5 ft beam to 20 kts. see http://www.rodgersyachtsales.com/and.html

Even Ilan voyager need 140 hp to do 21.5 kts, but it is longer (70 ft) , and I suspect it is really lighter. From N Irens site "The 1568 mile trip was completed in 72 hours at an average of 21.5 knots and required just 2000 litres of fuel." 2000/72 = 27.7 l /h or about 138.8 hp
(From popularmechanics, Ilan voyager should be about 11000 lbs = about 5 T
yanmar endeavour is 5000 lbs = 2T2.)


Unless it is 50.6 l/h *PER* engine.

In that case , we would have 700 hp for 28 kts, 500 hp for 22 kts. 40 % increase in power gives you 27 % increase in speed.
And the 9 t demihull would require 250 hp to go to 22 kts, more or less in par with the 300 hp needed to drive a less slender 11 T hull to 20 kts.

But that would be an enormous mistake from Malcom Tennant.

[fcfc]

For efficiency, I am going to think (powerboats) :

1) the longest waterline possible.
2) the lightest possible.

The remainder is shit.
monohull, catamaran, trimaran, xxxxmaran , slender is worthless from an efficiency point of view.

Now for a given length and building technology, the ligthest boat is the narrower one by ordinary physical constraints. And you need some stability if you want your boat usable.

That s all.

[fcfc]

About the veridian, it uses full power for 28 kts, so 2* 350 = 700 hp.

And only 22 kts, it burns 50.6 liter per hours. this translate in rougthly 250 hp.

Need to nearly triple the power to gain about 27% in speed.

For me, it is strange, since I dont forecast any flow difference for the hulls between 22 and 28 kts.

If I translate to monohull, 125 hp would drive a 9 t very slender 52 ft hull to 22 kts. But it would need 300 hp to drive a 11 t 50 ft monohull 11.5 ft beam to 20 kts. see http://www.rodgersyachtsales.com/and.html

Even Ilan voyager need 140 hp to do 21.5 kts, but it is longer (70 ft) , and I suspect it is really lighter. From N Irens site "The 1568 mile trip was completed in 72 hours at an average of 21.5 knots and required just 2000 litres of fuel." 2000/72 = 27.7 l /h or about 138.8 hp
(From popularmechanics, Ilan voyager should be about 11000 lbs = about 5 T
yanmar endeavour is 5000 lbs = 2T2.)


Unless it is 50.6 l/h *PER* engine.

In that case , we would have 700 hp for 28 kts, 500 hp for 22 kts. 40 % increase in power gives you 27 % increase in speed.
And the 9 t demihull would require 250 hp to go to 22 kts, more or less in par with the 300 hp needed to drive a less slender 11 T hull to 20 kts.

But that would be an enormous mistake from Malcom Tennant.

[Ilan Voyager]

fcfc, Ilan Voyager is heavier than five tons. A good 60 race tri, all carbon nomex has a true weight of about 5.5 to 6 tons ready to sail; claims of far lower weights are originated by the use of illegal substances or incurable optimism.

Ilan is made in a low tech strip plank and glass (no carbon) with confortable scantlings. The boat has now almost 20 years and is in perfect condition (used everyday as small ferry in Cabo Verde islands in strong seas). I do not know the displacement of Ilan Voyager but some rough calculations give a weight fully loaded of a range between 8.5 to 10 metric tons. The best is to ask with european politeness to Nigel Irens who is a very kind and well educated person...

Yanmar Endeavour is made of lighter composite and I think it was handicapped by the diesel outboards (but Yanmar was a main sponsor...). A single diesel with a "big" slow turning propeller would have a better efficiency. The weigth of 2.2 tons is an empty weight. The formula 40 (totally empty race boats) weighted in 1987 at the Grand Prix de Brest from 1755 kg (and needed 45 kg of ballast to get the minimal weight of 1800 kg) for Data General to 2560 kg for the Beneteau built cat used by Randy Smith. Ciphers given by memory.

I agree with you for some of the other assertions: weigth is the enemy. But from the studies made by the english, australian and french the best configuration for 20-30 knots range speed is the trimaran. At least 20% better efficiency for the same lenght/same weight. I agree with you that Ilan was using an average power of 140 HP during the round trip of England, but think the boast was 2000l*0.85= 1700 kg lighter at the arrival. I have to add that most part of the trip has been made in not very gentle seas as the North Sea, and the scottish coast are not known for their soft conditions.

We can make a guess: 140 HP are required for a 7 tons (reasonnably optimistic estimation, I think the empty weight is heavier) empty boat plus 850 kg of fuel, so a total weight around 8 metric tons to get 21.5 knots. That´s very good in open sea.

Studies have been made very seriously as the english one has been founded by the Brittish navy with a very intensive towing tank campaign involving a top cream staff. And the results were good enough to put the money for building the RV Triton, when you know the tight budget and the conservatism of the Brittish Navy... It seems (difficult to get reliable infos while military are involved...) that the theoretical studies are confirmed by the sea trials.

Australian are studying trimaran fast cargos, and the Russians believe strongly in the trimaran formula, but they are more than short of money.

Military navies have comparison means as a lot of warships can be ranged in the slim boats (ratio LWL/BWL > 6) working under hull speed and their design is perfectly known. You can imagine that a navy will not spend a fraction of billion dollars on a boat without making a serious study and good campaign of towing tank trials...

[brian eiland]

Studies have been made very seriously as the english one has been founded by the Brittish navy with a very intensive towing tank campaign involving a top cream staff. And the results were good enough to put the money for building the RV Triton, when you know the tight budget and the conservatism of the Brittish Navy... It seems (difficult to get reliable infos while military are involved...) that the theoretical studies are confirmed by the sea trials.

Australian are studying trimaran fast cargos, and the Russians believe strongly in the trimaran formula, but they are more than short of money.

Military navies have comparison means as a lot of warships can be ranged in the slim boats (ratio LWL/BWL > 6) working under hull speed and their design is perfectly known. You can imagine that a navy will not spend a fraction of billion dollars on a boat without making a serious study and good campaign of towing tank trials...

I thought the Triton project turned out well and that the US Navy would go the next step in development. I have not followed Navy projects for a long time, so I'm not sure where they are with additional studies. I suspect they are NOT proceeding with it as it wasn't technogy developed here. Instead they will spend billions on developing alternatives that may make no sense at all.

As to our Navy not spending monies on projects without making at minimum some 'serious studies' of them in advance, well have a look at this M-Hull project

M-Hull project (http://www.boatdesign.net/forums/showthread.php?t=5687)

[Ilan Voyager]

Mr Eiland, you seem very ironic...-smile-

In fact the M hull project has nothing to compare with the Triton project.

On the english side, you have after theoretical studies made at a university, an expensive towing campaign and the construction of a 90m ship, plus the cost of a 2 years of trials plus further brain work. All that to imagine the next generation of frigates. That involves a long term policy and big financial risks. I'm afraid for the brittish, that the principal defect of the Triton is being english... and the US Navy is more than conservative. It will be the same fate for the power catamaran project as the design is australian (Incat).

All the major navies share this characteristic: no use of foreign designs. If you add the prevalent policy of the White House, the use of a foreign design (even from theoretical allies but the british policy may change in a close futur and the australian are now more bonded to the asiatic countries than to the brittish) becomes very unlikely.

On the other side, you have a 6 million bucks (that is nothing in the US navy budget) contract between the US Navy and a private company for a small boat. Curiously the company is presided by a former Secretary.

It's pure guessing but that smells simple sugaring, and confortables wages for improving the incomes of the former secretary. After building (you do not need 6 M US$ for a small proto unless the workers are paid 250 US$/hour and you're paying 100 US$/pound the aluminium) the boat will be evaluated and maybe (I hope so for Mr Burns, who I think he believes totally in his project) there will be another contract. It's saddly probable that the boat will finish in a junkyard at San Diego or Norfolk after a few trials, as a lot of other boats. Simply because in the past, none boat with the "gull wing" configuration and/or air cushion have worked well enough to remplace the classic boats, and only God may know how many have been tried.

Neverless is a good way to get new designs at low cost, and it's an old policy in the US Navy which gave good results in the past.

[FAST FRED]

"The sea-kindliness of multihull craft (CATAMARANS)is being rediscovered every day."

No problem , but a real offshore boat needs Stability ,

NOT CATAMARAN "stability" which is as good upright as inverted.

Knock downs are inded rare in motor boats , but at under 100 ft not particularly hard to do. At only 40 ft, dont run many inlets , in 40k of breeze.

Multihulling since 1966.

FAST FRED

[Ilan Voyager]

Fast Fred, only monohull sail boats and some special power boats are able to upright themselves after a capsizing if they do not sink being filled by water.
The majority of boats are not able to right up without exterior help. I would add that is a same for a majority of objects as cars, bycicles, motorcycles and others.

If the monohull sail boats have the possibility of self righting, they sink very easily because of the ballast as I almost experimented myself twice: a knocked down monohull sailboat stays half filled of water across the wind and the waves are passing over you...a very unpleasant situation. Do not hope that a power monohull is able to self righting while the superstructure is filled of water rushing by the doors and broken windows.

While being officer in the navy, we have had to rescue too many inverted power monohulls, mainly small yachts anf fishing boats. A good cat or tri is very hard to capsize, with modern meteo you can stay away as far as possible of big storms, so the event of capsizing becomes unlikely on cruising boats. Life is a inverted multihull is far easier and less miserable than in a rubber lifeboat...

The price to pay for a self righting boat is high: heeling, rolling and loss of efficiency as you have a ballast which costs a lot of energy to move. These inconvenients are present 99.999999999999% of the time....

[249]

I once worked out that I've known about 6 people who have capsized multis offshore; two were racing internationally, one was an extremely experienced cruiser, one was a good racer returning from winning (I think) an international event, the other two were on a 380 mile race.

They spent up to three months drifting around upside-down before being rescued at a significant cost to others (in all but one case). There's also the fact that some cats wouldn't actually float all that well- did you see the pics of the Chris White cat that capsized on the Great Lakes recently? It was very low when it was retrieved, not the best of platforms. Others have broken up while capsized, or capsized due to break-up. They were not good surivival platforms.

The only case that didn't involve rescue by ships or rescue services involved the guy I knew being picked up by another racer, who died after a capsize in a later multi race. Another guy I knew lost his brother in a capsize.

This is not knocking multis per se; I advised my mother to get one (she did), I let my 8 year old son go cruising on my brothers', I was recently pestering him to take the boat a few hundred miles out into the Pacific over Christmas.

Because everyone I've known who has capsized a cat or tri has come back eventually. I've known a couple of guys who didn't get back ever, when their monohulls went down. I've been in a situation where we may have been inches away from a sinking, had the keel and not the rudder hit a sunfish (small and fragile racing boat well offshore at high speed, not particularly strong around the keel) and one of my family's similar boats (lightweight half tonner) sunk in similar circumstances after it was sold. This is not knocking lightweights per se I hasten to add, some of them would take it.

I've also never been in a situation like Ilan, where a mono stayed knocked down - what sort of boat was that?

But from one perspective, arguing over whether a sinkable self-righting boat is all that much better than an unsinkable non-righter seems a bit like splitting hairs.

Isn't either alternative much more dangerous than an unsinkable self-righting boat? Look at some monos with positive buoyancy; the space lost is not really significant in terms of the safety benefit is it?

Finally, Ilan, maybe not all places in the world have the reliable forecasts you speak of; I've been at inquests were the reliability of the forecast has been a major point of dispute.

[fcfc]

The TITANIC was unsinkable.

About self righting boats, I have mixed opinions.
Probably on the drawing board, such things exists, but in the real life ?

Having been on *cruise* sailboats in sustained heavy weather, I can speak you of tons of mess you can find on the cabin floor. From sails to toolboxes to nearly everything.

In case of a roll down, every thing would roll on the lowest point : the cabin roof. And I dont think stability have been computed this way.

Of course, I expect an openning drawer, a tool or a winch handle not to fall on a window and break it.

Per my own little experience, up to 45° heel, nothing move in a sailboat. Up to 60°, you become to have some problems with flying objects. over 60° , you will have serious problems inside. I have never gone beyond than spreaders going near the water, but I have seen the mess inside.

Race boats are of different kind, because there are not so much flying objects inside.

[FAST FRED]

The OCEAN is where the difference in "cruiser racers" and honest offshore cruisers is most visable .

Not many Cruiser racers have opening ports that will take much abuse , or in the "New " style, of sailing deck cottages with huge glass windows, that could flood the boat in seconds , just from a heavy wave impact.

Many of the early voyages in small boats were done with simple monohull boats and simple equippment , and not a few survived multiple knockdowns.

The old saw , Cats for Costal (where you can swim home) and Tris for Trans ocean , is still rational.

Having sailed thousands of miles in a 45ft Headly Nichol try , yes the Tropics cruising is great !

But if I were going around the higher latitudes , a "lead slead " would still be first choice if Storm Survival were any concern.


Some oceans and some storms are far too big to hide from ,


FAST FRED

[249]

fcfc;

The books I've read (I may be wrong) said that the Titanic was never said to be unsinkable until a legend grew up after it sank. The waterproof bulkheads were too low.

So she could sink, because she was never designed to be unsinkable.

I used to know a guy, an engineer by profession, who has a 45'ish alloy cruiser, with foam flotation along the hull sides. I can't recall how it's fixed but I certainly can't see it coming undone. There are many videos of Etaps and Sadlers sailing around with the seacocks open.

So surely there can be an unsinkable boat?

That's an interesting point about the mess inside cruisers - I've never got a cruiser down too far.

[fcfc]

There are boats who are boths. I don't think there is a *single* heavy weahter rescue craft who is not.

But that comes at a price.

Unsinkable boats are possible. But that is a complex thing. Flotation is made by foam. The foam must not be too low (say under the floor) because in that case the boat will float inverted. Nor it can be to high (under deck) because the boat will float too low and will barely be liveable. Nor too in front, or too aft (floating like a diving duck may be fun only a few seconds). So maximum of foam have to be where most of the accomodation is if you want your flooded boat floating uprigth, horizontal, with some remaining stability and some liveability.


One interesting device I once saw where inflatable cylinders under the berths (firmly fixed) . In "normal" operation, they took nearly no place. But inflated with an automatic bootle, (about 2 ft diam, 6 ft length, texture equiv to inflatable boats), they would provide buoyancy at the correct heigth. One would provide about 1000 lbs of lift when fully submerged.
I don't think they could make unsinkable a boat not designed for, but they could make more liveable a flooded boat floating too low, or not stable enougth, or with pitch.

Next thing for unsinkable are waterproof bulkeads. Nearly all regulations requires it. (at least one in the forepeak). If water floods your boat, it must not flood ALL. Again, it is not an easy thing to do. How many aft storage can be made waterproof, but are crossed by an exhaust pipe. With of course a big hole in the bulkhead around the pipe to avoid vibrations and heat.

[FAST FRED]

"So surely there can be an unsinkable boat?"

I presently own a conversion of a 50ft Navy Untilty Launch that is claimed by the mfg (Uniflite) to be both fire retardant and unsinkable.

There is a band of foam about 2 ft square that runs all round the boat at gunwhale hight.
The flotation foam takes a huge amount of room , not a problem when an open launch to carry 150 men , but a pain while converting to a costal cruiser.

The hull is Hetron FR fire retardant resin that has a burn rate of under 100 (wood is also 100)

Cheap GRP has a burn rate of 500 , and I wonder how Mfg can sell boats for "offshore" with flame throwing resin.

The difference in resin cost is only 3c a pound , not much on $400,000++++ "Ocean
Cruisers"

FAST FRED

[tarrysailor]

If you want a fast multihull, I hear you can go to Tahiti. There are plenty abandoned there, or up for sale for pennies on the dollar.

You know why? Because after sailing many a snazzy, fast, 21st-century-wonder across an actual ocean for a good while, people got tired of losing the fillings in their teeth from the unending jarring. After going through a storm and finding out for themselves what seaworthiness literally means, they dock, leave their ships behind them, get on a jet and fly home, rather than ever set foot on their awesome wonders again.

There is good reason why traditional designers like Colin Archer put seaworthiness first, comfort second and speed last. Try to tell this to some thrill junkie before he sails, though. Just try. He will tell you in detail all about technology. But after he's come back on a jet, you will never see a person who has so thoroughly turned one-hundred-eighty degrees about-face in his opinions.

Myself, I would not set foot on a multihull. No more so than I would put a heavy lead helmet on my head, wrap life perservers on my shins and go swimming in the surf. If you ask me, it's the same thing. I've had friends in the Navy onboard aircraft carriers who tell me about the man standing on deck getting washed overboard by a wave, and the deck is sixty feet above water. It's true. A definite cause of accidents in multihulls is pitchpoling. In other words, some idiot is sailing so damn fast that he rams a big wave, pushes his hull under it and flips. If he's close to shore, you hear about it, if not . . . . well, it must be hard to speak to a radio microphone when you and it are underwater.

[Ilan Voyager]

I once worked out that I've known about 6 people who have capsized multis offshore; two were racing internationally, one was an extremely experienced cruiser, one was a good racer returning from winning (I think) an international event, the other two were on a 380 mile race.

They spent up to three months drifting around upside-down before being rescued at a significant cost to others (in all but one case). There's also the fact that some cats wouldn't actually float all that well- did you see the pics of the Chris White cat that capsized on the Great Lakes recently? It was very low when it was retrieved, not the best of platforms. Others have broken up while capsized, or capsized due to break-up. They were not good surivival platforms.

The only case that didn't involve rescue by ships or rescue services involved the guy I knew being picked up by another racer, who died after a capsize in a later multi race. Another guy I knew lost his brother in a capsize.

This is not knocking multis per se; I advised my mother to get one (she did), I let my 8 year old son go cruising on my brothers', I was recently pestering him to take the boat a few hundred miles out into the Pacific over Christmas.

Because everyone I've known who has capsized a cat or tri has come back eventually. I've known a couple of guys who didn't get back ever, when their monohulls went down. I've been in a situation where we may have been inches away from a sinking, had the keel and not the rudder hit a sunfish (small and fragile racing boat well offshore at high speed, not particularly strong around the keel) and one of my family's similar boats (lightweight half tonner) sunk in similar circumstances after it was sold. This is not knocking lightweights per se I hasten to add, some of them would take it.

I've also never been in a situation like Ilan, where a mono stayed knocked down - what sort of boat was that?

But from one perspective, arguing over whether a sinkable self-righting boat is all that much better than an unsinkable non-righter seems a bit like splitting hairs.

Isn't either alternative much more dangerous than an unsinkable self-righting boat? Look at some monos with positive buoyancy; the space lost is not really significant in terms of the safety benefit is it?

Finally, Ilan, maybe not all places in the world have the reliable forecasts you speak of; I've been at inquests were the reliability of the forecast has been a major point of dispute.

249, almost all the capsizing of multihulls you show are race accidents or with race boats. The offshore power race boats have also a lot of accidents. All race boat driven hard is subject to a have a big problem. For cruising boats is a different problem.

About the two times I have been in a capsized sailboat there are a lot of similarities:
-strong winds around 40 knots, and very strong sea with breaking waves (arriving to the coast the change of depth of the sea may induce breaking waves, and if you had a tidal current against the wind it becomes worse).
-classic 35 feet monohulls of english design around end of sixties-beginning seventies, heavy displacement, deep keel and suffering of the same defect: instability while going downwind, they can make half-turn at any moment even without main sail. In the two cases we were with swedish main sail and the storm jib.
The two boats were rolled by the waves and went upright very slowly and full of water. After it has been matter of survival and happily in the 2 cases we were young and strong experimented sailors able to cope with such situations.

Following these experiences I looked to this kind of boats with a lot of suspicion, and I do not share the "american" opinion that heavy classic sailboats are safer. Lightness and speed in hard following seas are the best security.

Some years later I and a friend (so only 2 guys) have convoyed a former formula 40 catamaran (design Nigel Irens) very lightly modified (in fact just a kitchen and berths) for fast coastal cruising. With just the mainsail with 3 reefs we crossed at a very fast pace the same place of the second knock down (Raz de Sein) with similar conditions of sea and wind (so 35-40 knots winds and breaking waves around 4-5 meters) ; it has been and exhalariting (and very wet) experience of surfing these waves with a total stability and none fear.

I have recrossed this same place on a 92 meters warship in the same conditions and it was a very shaking experience (but without any danger)... That gives me good comparison points of seaworthiness and I never put the feet again on a monohull sailboat.

Over 30 feet it's very hard to make a boat unsinkable, specially sailboats with their ballast. All the Etap (the first was the 22 designed by Van Stadt around 1975) are small boats and lose a lot of interior space, but are very safe boats.

A multihull must be designed with the event of capsize in mind. All issues must be foreseen (strength of the boat, escape hatches, antiskid surfaces, emergency radios etc...I won't detail all) and I can say after trials we made that in a capzised multihull you can organise quietly your survival.

First it's a relatively stable platform. Second you have plenty of food and water, electrical energy, radio etc... Third you can rise an antena and a radar reflector with a simple kite and send messages of your position. Fourth you can wait in (very) relatively dry and warm place the rescue.

Those who have spent only 12 hours (for trials) and vomited of seasickness during this time while being burnt by the sun, wetted by the rain and chilled by the wind in a small rubber lifeboat have understood...

The most convenient boats in this event are the trimarans as the arms and outriggers keep the boat high on the water. The worst are the cats with the big "saloon" over the hulls as this disgracious appendice is immediatelly flooded.

The self righting powerboat is an horrible roller (it's getting better with the dynamic stabilizig devices) and I've always admired the very strong stomach of the courageous sailors jumping in the rescue boat after a good diner to save lifes in a force nine gale. A self righting power boat for cruising must be a nightmare.

Personnally; power or sail trimaran well thought. These boats have the best combination of seaworthiness and dynamic and static safety.

I agree with you that finally is splitting hairs and the best safety device whatever the boat is a conservative attitude with good marine forecasts. If you have not good forecasts make your best guess.

After it's matter of fate and/or God's will depending of your religion and life's philosophy. We will all face death, and I share the opinion of late Tabarly : drowned is preferable to cancer. He has been lucky. I hope to have the same luck.

[Ilan Voyager]

If you want a fast multihull, I hear you can go to Tahiti. There are plenty abandoned there, or up for sale for pennies on the dollar.

You know why? Because after sailing many a snazzy, fast, 21st-century-wonder across an actual ocean for a good while, people got tired of losing the fillings in their teeth from the unending jarring. After going through a storm and finding out for themselves what seaworthiness literally means, they dock, leave their ships behind them, get on a jet and fly home, rather than ever set foot on their awesome wonders again.

There is good reason why traditional designers like Colin Archer put seaworthiness first, comfort second and speed last. Try to tell this to some thrill junkie before he sails, though. Just try. He will tell you in detail all about technology. But after he's come back on a jet, you will never see a person who has so thoroughly turned one-hundred-eighty degrees about-face in his opinions.

Myself, I would not set foot on a multihull. No more so than I would put a heavy lead helmet on my head, wrap life perservers on my shins and go swimming in the surf. If you ask me, it's the same thing. I've had friends in the Navy onboard aircraft carriers who tell me about the man standing on deck getting washed overboard by a wave, and the deck is sixty feet above water. It's true. A definite cause of accidents in multihulls is pitchpoling. In other words, some idiot is sailing so damn fast that he rams a big wave, pushes his hull under it and flips. If he's close to shore, you hear about it, if not . . . . well, it must be hard to speak to a radio microphone when you and it are underwater.

I know pretty well the Colin Archers as one of my professors was Michel Presles (naval architect who designed a lot of Archers) in the Arts et Metiers school of engineering at Paris.

I've met some people who had Archer type boats similar to the Johua of late Moitessier made by the shipyard Meta. Heavy, slow and often frightening in hard following seas. Read Mrs Smeeton book...

If you reread Moitessier or Vito Dumas (who made around the world by the roaring forties in 1943 on Legh II designed by Manuel Campos, great naval architect of Colin Archer boats) you understand immediately that they were in survival situation (Moitesser with sea anchors etc...) where now guys are racing not surviving on monohulls or multihulls, and a lot cruising to the Antartic.

Archer (circa 1900) work is very respectable but now obsolete, d'Arcier (1763) works on mathematical hulls of warships is extraordinary and totally obsolete. A Ford T is a great piece of engineering but the Ford Ranger is far better. I can give hundreds of examples.

Boat design has evolved a lot in all its domains as I've seen myself as naval engineer and I'm always surprised that for sailing boats a lot of people are stuck to antiquated boats. I understand that someone prefers a Chapelle or Herreshof sailboat because of aesthetics but I do not understand when anyone tries to convince me that are a better boats, safer and so on.

Compare the possibilities of Gypsy Moth IV (16.5m Laurent Giles design for Chichester who had very hard times with this boat) with a modern 50 feet cruiser. No match in speed, strength and seaworthiness.

In reality Tahiti is full of multis and monos for sale simply because is the final destination of a lot of guys running after a dream of paradisiac lazy life in the tropics. And the dream dies...no paradise, no money, no easy job, but boriness followed by alcohol and drugs. We see this kind of guys also here in Mexico, and Belize is full of them.

I've seen a lot of bad sailors who call mommy with a 25 knots wind even with the best boat as some will be always bad drivers even with a Mercedes at 100 km/h. And there are some bad boats of any kind.

About seaworthiness of multihulls ask to Mike Birch how he slept quietly and read books in Third Turtle (trimaran 9.15m, 1000 kg only, design Dick Newick) waiting the end of a force 10 storm during the 1976 OSTAR.

You can go also to Cabo Verde islands to make a passage on Ilan Voyager, or go to Buenos Aire to take the ferry catamaran Juan Patrico for crossing the Rio de Plata at 55 knots with a good pampero of 30 knots blowing.

I'm old enough to have sailed traditionnal and modern boats, monohulls and multis, racing and cruising in a great variety of conditions so I have a first hand opinion by myself. Well designed after 1985 multis are my choice.

Boats, ships, warships, carriers, ferries and others have changed and a lot.

[D'ARTOIS]

Reading the discussion mono/vs multi, it's like everything a matter of taste.
I bought my first 40' sailingboat way back in '80 - a well known Dutch design from Frans Maas, fast & reliable.
I sailed this boat alone, going to the Dutch Island, England, France till Hebrids and Iceland.
The general speed I got was something between 7 and 8 knots. Nothing exiting,
so I became smitten with the designs of Lock Crowther, I bought his book and started dreaming....

I have had some more boats in between, I have been at many shipyards since, Jongert, Huisman, Abeking and Rasmussen, CNB and many others.
I have seen famous names to be built - when Von Karajan, the famous German conductor came to launch his new Helisara V, his dolly for the moment stepped with her high heels through the nomex flooring panels (nobody dared to tell her to take her shoes off)- many years later I saw the boat back and not in the best state, the same thing happened with the ex-Flyer from Conny van Rietschoten, I saw her being built and many years later she came into hand of a Dutch broker, so I had an chance to look at her again. My tastes clearly had changed, since I found nothing exceptional at her, looking after so many years again.
I have now a 100" schooner, an ex-trawler type navyvessel, converted to live aboard floating home annex entirely autonomous pied a terre.
The powerful new rig by Rondal gives this 100 tons Lady a speed of 8 - 11
knots, the latter in a stiff breeze. The engine gives sufficient power for 9/10
knots. Now I don't dream anymore. I can go in reasonable comfort wherever I want to go. With a draft of just 10' I cannot enter too small harbours, but I can always stay outside because, built as a reconaissance vessel, she is strong and can ride out a good swell. I sail her very shorthanded, with just one crew.
I still like fast ships. I try to follow latest design-topics but my dreaming period is definately over......

[Ilan Voyager]

Reading the discussion mono/vs multi, it's like everything a matter of taste.
I bought my first 40' sailingboat way back in '80 - a well known Dutch design from Frans Maas, fast & reliable.
I sailed this boat alone, going to the Dutch Island, England, France till Hebrids and Iceland.
The general speed I got was something between 7 and 8 knots. Nothing exiting,
so I became smitten with the designs of Lock Crowther, I bought his book and started dreaming....

I have had some more boats in between, I have been at many shipyards since, Jongert, Huisman, Abeking and Rasmussen, CNB and many others.
I have seen famous names to be built - when Von Karajan, the famous German conductor came to launch his new Helisara V, his dolly for the moment stepped with her high heels through the nomex flooring panels (nobody dared to tell her to take her shoes off)- many years later I saw the boat back and not in the best state, the same thing happened with the ex-Flyer from Conny van Rietschoten, I saw her being built and many years later she came into hand of a Dutch broker, so I had an chance to look at her again. My tastes clearly had changed, since I found nothing exceptional at her, looking after so many years again.
I have now a 100" schooner, an ex-trawler type navyvessel, converted to live aboard floating home annex entirely autonomous pied a terre.
The powerful new rig by Rondal gives this 100 tons Lady a speed of 8 - 11
knots, the latter in a stiff breeze. The engine gives sufficient power for 9/10
knots. Now I don't dream anymore. I can go in reasonable comfort wherever I want to go. With a draft of just 10' I cannot enter too small harbours, but I can always stay outside because, built as a reconaissance vessel, she is strong and can ride out a good swell. I sail her very shorthanded, with just one crew.
I still like fast ships. I try to follow latest design-topics but my dreaming period is definately over......

Mr d'Artois (are you of french huguenot descendance from those who emigrated to Holland because of the persecutions by Louis XIV in the 17th century?) I agree totally with you: the good boat is the boat you like and which fits to your program and needs. It's a matter of personal taste.

And happily the choice is vaste, so we can (besides money issues) take the kind of boat which incarnates our ideas and dreams.

But the objective facts remain; there is no comparison between of a 1960 and a 2004 cruising sail boat in matter of materials, hardware, comfort, seaworthiness and speed. Simply evolution as it happened in all domains involving technics from washing machines to rockets.

I've seen also the boats you evoke...the drama of these racers is they were built for the jauge of the moment (RORC, SORC, IOR, and so on) so they have not future as good cruising boats; a retrofit is too expensive for no guaranteed results. A hull designed for a jauge is generally very far from being the all around best boat, it's often a "slow" boat as we could see while making amical regatta against IOR boats with out of jauge sailboats.

Also these last 30 years the evolution of naval design has been so improved in all domains that a lot of boats became obsolete and will end in the junkyard if someone does not fall in love with them. And I predict that the evolution will be atonishing. It'll take some time as boats are expensive and long life objects at difference with short life objects as cars.

While reading Slocum it seems that the Spray was a perfect boat for him, and now who would make a circumnavigation with a Spray replica? Nothing is permanent.

[sharpii2]

Hi Everybody

I thought I would just share a little thought experiment that I did a few years ago.

I have been working on this design concept for years. Its called a 'lola boat'. It is supposed to be the simplest and the cheapest thing I would ever go to sea in. Its basicly a cylandric developed double ender with a moderate 1 to 2 dead rise which makes up most of its bottom. It is propelled by a single ballanced lug rig. It was supposed to be 20ft (6.15m) long by 5ft (1.54m) wide. It was supposed to displace around 3000lbs (1364kg), and have a SA of about 180sft (17sm). In my preliminary thinking, I figured one third displacement for the hull and rig, one third for ballast, and one third for me and my stuff. It was not to have an external ballast keel and the ballast was to be cheap and removable. I originally thought of water ballast (whats cheaper than that). It looked realy good on graph paper.
Then I did th math.

I found the water ballast would not work. I would need too much of it (1400lbs). I also found that the rig was too much. It got trimed. first to 160sft (15.2sm) then, finally, to 140sft (13.3sm). For ballast, I ended up with sand (still pretty cheap) and about 800lbs of it. This all started comming together. The boat displacement got trimmed down to around 2800lbs (1273kg) and I ended up with something that could right itself from a 140 deg. knockdown. But it was going to be ...a...slow...boat...
My guess is that it might make 5kts in ideal conditions. Mostly, though, 3kts was what was more to be expected. This would mean 72mile days and more likely 50mile days.

Then one day I got an idea. What if I threw all the sand overboard and replaced it with a set of outrigger floats? This of course, would mean crossbeams as well. I guessed that this entire rig may weigh around 300lbs (136kg). Each float would displace around 1000lbs (455kg) when fully submerged. To keep this from becomming too rediculous, I decided to limit the beam to 10ft (3.08m). Not a very good tri, some may say. But I thought about it. 1000lbs at 4.5ft from the centerline = 4500ft/lbs of max righting moment. About 1600 was the best I could get with the sand bags. I could, perhaps, get my 180sft (17sm) sail back. Maybe even go to 200sft (19sm). And I could carry all this in a pretty good breeze. And the boat would be at least 400lbs (182kg) lighter. Maybe it could get 6, maybe 7kts top speed ( relatively beamy center hull would probably preclude higher speeds). And maybe make it to 100 mile days.

I thought about stability. How hard would this be to capsize?
I thought about it. In order to roll this boat over, you would have to imerse the lee foat, its two crossbeams, and the 18 inch wide side deck and roll them completely under the main hull. These items, in my opinion, would present an awful lot of dampening force so, it would take quite a sustained breaker to do the job. And since this boat won't have any deep keels or deep fins (it will have two long, shallow, bilge fins), it may dissipate much of the energy by moving sidways. Not only that, but because the main hull is wider than usual (twice as wide as typical in pure tri's) much of my stuff, that used to sit on top of the sand, (remember the sand) would find itself sitting lowerer in the bilge. My guess is the VCG would be raised by about 12 inches to end up about 1.5ft above the water line. This is because the 800lbs of sand have been removed (replaced with 320lbs of FW and about 200lbs of batteries) and the heavy crossbeams and floats have been added (all much above the WL).

Still. Rolling it in its new configuration compared to its old one would be like rolling a Mercury Town Car as opposed to a Ford Explorer. It can happen and (with terrible luck) it will happen. But this boat was never designed to live on the edge. Carrying a lot of sail in really strong winds would not be attractive because after reaching about 7kts it probably would go no faster anyway. Also, because the main hull will always bear most of the boats displacement, I see pitchpoling (another favorite method of multi capsize) being far less likely.

An interesting idea, eh? A low performance (and much lower cost) multi.

Its interesting to note that Captain Cooke observed more than two hundred years ago that the native craft (ouriggers and double canoes that he encountered) were half again as fast as western boats of the same size. And its (even with todays astounding technology) still true today. (The monos go nearly as fast as the multis used to but multis go about half again faster still).
Curious.

Bob

[Bob Leask]

A LIVEABOARD CRUISER FOR THE REAL WORLD

I'm working on a design concept that might seem a bit eccentric, but here's how the idea germinated:

I just finished a circumnavigation in a 37' traditional double ender of my own design, but to say that I sailed around the world is to use the word "sailed" a bit loosely. She's a heavy boat, around 30,000 lbs, and when the wind is 15 knots or better she'll make good time, my best 24 hour mileage was a little over 150 and in good sailing conditions I averaged about 125. But when I did a review of my logbook and estimated how many days I had such conditions, I came up with a rough estimate of about 25%. And that's optimistic. I did more or less standard trade wind westabout passages at the right times and latitudes and found that the pilot charts can be very misleading. The pilot charts give average wind strength and direction compiled from observations of deep sea vessels over long periods of time, but the figure they give for probability of calm is way off, from a cruising sailors point of view. If the observer saw any ripple at all on the water, the report would have been Beaufort 1, but anything less than Beaufort 4 for all practical purposes is flat calm, if you're trying to sail in a heavy displacement boat. All full time liveaboard/cruising boats less than 45 feet overall should be considered heavy displacement. If they aren't before you moved aboard, they will be by the time you've moved everything you own onto them, including fuel, water, food, stores, spare parts, tools, books, souvenirs etc. etc.

Having voyaged over 30,000 miles I have come to the conclusion that idyllic trade wind sailing with steady winds of 15 to 25 knots for 24 hours is a dream, or a myth made up by writers of cruising stories. I've never experienced a single day like that, anywhere.

However I found out early on, in the calms that prevail on the west coast of the mid-latitude Americas, that low speed motoring is a very good way to make passages in flat calms. Motorsailing is by far the easiest and safest way to cope with highly variable conditions, when the wind is constantly varying from near calm to 25 knots and back again cyclically, which is common. In my experience trade winds were always variable to some extent.

The days when I had my best passages were not the most pleasant. To make an average speed of near 6 knots meant that some of the time I was overcanvassed and overdriven, which can be exhausting and uncomfortable. It's hard to relax when the boat is heeling and rolling heavily, and at any moment you might have to take in a reef if the wind increases any more. To get into passagemaking and seamanship is too big a subject so I'll leave that now, but just summarize by saying that relying entirely on sail to cross oceans is not as easy as many might think, or hope, or want to believe.

Early in my voyage I found out that my boat would motor at four knots and burn 1 liter of diesel per hour in flat water. That means 96 miles in 24 hours which is quite an acceptable rate for ocean passagemaking and when you can buy fuel in places where it's cheaper, such as latin america or southeast asia, the cost per mile is very reasonable. When I was in Indonesia the price of diesel fuel was less than 15 cents US per liter. Of course I can throttle up and go faster, but fuel consumption goes up exponentially. At my top speed of 7 knots the consumption is about 3.5/hour, roughly 1 US gallon.

Here is some very simple math: to go around the world (about 30,000 miles) divided by 4 knots would have cost me a total fuel consumption of 7,500 liters. At the current high prices today of about 60 cents US per liter the voyage would have cost me a total of $4,500 dollars in fuel. Add to that a guesstimate of $1500 for oil and filters etc. and we have a grand total of $6,000. Think you can set up a sailing rig for that price? And you can spend plenty on all the bells and whistles to gain more sailing efficiency, and add to that the cost of larger battery banks and solar and wind charging systems, to cope with electrical requirements when under pure sail for long periods.

And another hidden cost of offshore sailing: the heavy wear and tear on sails and rigging while trying to sail in very light and variable conditions. One day of flogging your sails in light air and a swell running, quite a normal experience at sea, probably shortens their life more than weeks of hard sailing. When you have lots of wind the sails stay full and are under a constant load, but they aren't wearing much, and the same goes for your standing rigging. When you hear about dismastings at sea they almost always happen in light and variable conditions. When you do the simple math, you can't avoid the conclusion that from a purely economic point of view, it's unlikely that sail propulsion can ever come close to the cost effectiveness of an efficient diesel. Flogging that expensive sailing gear to bits to go very slowly makes no sense at all. The miles I sailed cost me a lot more than the miles I motored, probably by a factor of 3 to 1. By the time I got home all my sails were totally worn out. My engine is still going strong.

Here's a broadside at the sailing purists: those who haven't lived among the offshore cruising community might be amazed at how often they are sailing "dark ships", with no navigation lights at all, to conserve battery power. A totally idiotic practice but it's shocking how often it's done.

The sailing purists have already clicked out, those still interested in where I'm going are now thinking that I haven't considered engine breakdowns and rebuilds. I have a simple answer for that, it's a single word: Sabb. After the thousands of hours I've put on my Sabb 30 horse engine from Norway it's running exactly the same as it did when I got it, secondhand. I'm pretty sure that it'll still be running long after I wear out. It may outlast my boat, too. Low speed diesels like the Sabb are designed to run efficiently at low rpms and you can idle them for long periods without damage, unlike modern high speed engines. The bearing surfaces are so large that at such low speeds the wear on them is practically nil. I'm willing to bet that my Sabb would do another circumnavigation without major trouble, just the way it is.

The high efficiency is for several reasons: One is that I don't have a heat exchanger. I used a Walters keel cooler and dry exhaust which saves much of the energy wasted by running in effect two cooling systems. The low rpm engine design is another, as is the controllable pitch two blade propeller which comes standard with the Sabb 2J. It has a large diameter and is always optimally pitched. And I have no doubt the efficiency could be improved. But it definitely beats any other sailing auxiliary diesel I've heard of so far, by a wide margin.

Another observation of mine was how much fuel cruising sailors actually do use. When I admit that I motored or motorsailed approximately 50% of the way around the world, I'm simply using the records of my log book. What I am quite sure of is that I used less fuel than the average cruising "sailor". Almost every other cruiser I met in harbour after a long passage had used nearly all their fuel, and most of them carried more than I did, my own fuel capacity being only 210 liters. I would say that on average, those claiming to be "sailors" were using more fuel on passage than I was. The reason for that is that the average sailing auxiliary yacht built these days is abysmally inefficient for motoring. Too small propellers, badly designed propeller apertures, high rpm engines that are inefficient at low speeds, and wasteful heat exchanger/wet exhaust systems are to blame. All of those things are done for the sake of incremental improvements in sailing performance. Fuel efficiency is simply not part of the equation in the design of modern crusing boats.

Motorsailing offshore is by far the most pleasant way to make passage, most of the time. With the engine barely above idle and a moderate amount of sail set, there is a synergy created by the apparent wind which generates more forward thrust than either one alone, with the bonus that you don't have to set large areas of canvas, which will have to come down in a hurry if the wind increases. The boat rides better, makes a better average speed and the batteries are always full. The beneft of using a much smaller sailplan can only be appreciated by someone who's been caught offguard in a squall with too much sail up. "Adventures" like that might be fun for weekend sailors and short coastal passagemakers, but on a long ocean passage they're something to avoid, even if it means a slower passage.

Now that I've made my case for the motorsailing offshore cruiser, I'll describe my design which is a work in progress. For a lot of reasons I've chosen a catamaran as the best overall type for long range cruising and living aboard. My main reasons are shallow draft, beachability, visibility from the bridge deck salon and ample deck space. Even the slowest cruising multihulls generally beat monohulls on passage times. However I view that as a bonus, not a primary design objective. With my slow boat I spent about a week in harbour for every day I spent at sea. When you're wandering around the world on a boat, speed is simply not an important issue. Comfort, liveablility, economy and versatility are the things that matter most to a liveaboard/cruiser. If you can have those qualities and go faster too, that's great.

And now I'm finally coming to the point. After much time spent browsing the offerings of boatbuilders and designers around the world, I've found nothing, zero, zipola about achieving maximum fuel efficiency per mile, with mono or multihull boats. Where fuel consumption graphs can be found, most of them start at five or six knots. It seems that there is not a single professional boat designer working today who is interested in designing boats to be used in the real world, the way offshore cruisers actually use them. The main design objectives are speed speed and more speed, and anything less than 3 gallons an hour is touted as "economical".

There are a lot of designs I like, in particular at: http://www.runningtideyachts.com/motorsailing/, but in this case information is lacking as to actual fuel consumption rate, displacement and payload, and fuel capacity. Can such a motorsailing cat carry enough fuel to make a 2000 mile passage? Is the fuel efficiency only relative, compared with other boats at the same speed? In the real world when you might have to motor on one engine at a minimal speed to stretch your fuel out over a long passage, does the efficiency still apply, or is it better/worse than the average cruising monohull?

In terms of optimal fuel economy per mile for monohulls and multihulls of the same displacement, monohulls have a theoretical advantage. Going strictly by experience because so little data seems to be available on the subject, I believe the most economical speed for a yacht is at around 50% of hull speed where wave making resistance is not important and skin friction will be the major factor, but optimal speed will depend on whether or not the propulsion system is designed to operate at a low power output efficiently, and that for me is one of the most crucial things for a good offshore cruiser, but does not seem to be considered at all in the modern world of boat design. Why not? A little more simple math will tell you that even if you don't mind the cost, it just isn't possible to carry enough fuel for long motorsailing passages in a boat of 40 feet or less, especially a multihull, if your consumption is over a liter or two per hour. You simply can't carry enough fuel to go the distance.

Which brings me finall to the concept that I've settled on: a catamaran with three engines. Two will be outboard motors mounted on the sterns of each hull. The third will be a small, low speed diesel, preferably air cooled, on the centerline housed in a pod. I expect to pay a penalty in wetted surface higher than a monohull of the same displacement, offset by the fact that a multihull can be a bigger boat with less displacement, which I hope should work out approximately equal. The outboard motors will be lighter weight and cheaper to install, and will provide higher power when high speed is wanted, albeit at a much higher fuel consumption. The high redundancy factor in this design will add to safety, with enough power to get out of bad situations like dragging anchor in a confined area. Outboard motors won't have the service life of inboard diesels but will probably not be used very often, almost never offshore. They're easily serviced or replaced, and it would be possible to carry spares onboard. New ones are available anywhere.

My most basic question now is what would be the best combination of engine and drive? The belt drive system described on http://www.runningtideyachts.com/motorsailing/ makes a lot of sense, it would virtually eliminate mechanical loss. The best option of all might be a direct drive or longtail system, if the problems of installation on the centerline are solvable. There are some very good gensets on the market that might be easily adaptable to a direct drive with a chain or belt reduction, and voila, you've got an economical auxiliary and a genset all in one, that will work fine while you're beached, too. Yet another option would be installing a genset wherever it pleases you, and using an electric motor for propulsion. That's also a nifty idea, because a fixed magnet electric motor will also serve as a very good water generator while you're sailing. Lots of electric power at all times while underway, eliminating the need for elaborate and expensive solar/wind power systems. And no limit to propeller diameter with either system. Either way it could be made to easily retract out of the water and with the outboards retracted up as well, no propeller drag while sailing at high speeds.

Has anybody here been thinking along the same lines, or know of anybody who's done anything similar, or have any ideas? I know the idea of a multihull that isn't designed to be a seagoing hot rod is a little radical, but after weighing the pros and cons of every other idea I've thought of, it seems the best one. A monohull designed for low speed economy might be the absolute best motorsailer for long passages, but could not have as shallow a draft as a cat. Shallow draft and beachability are my main design criteria, a little time in the third world with a boat that requires a travelift to haul out will teach you why.

Comments?

[Mark Peiffer]

I too have come to many of the same conclusions. In much the same way - though without the experience I just dream alot. In terms of the motors the need to make speed to avoid a blow is a consideration. Multihulls are faster and could make good use of speed if your anchorage is not to far away. I understand that a cat actually can move well on only one engine - But I prefer the tri design as well. I think the electric would be too ineffecient and I would stear clear of a system that is not widely used ( belt) as parts would not be available. I think a pod on a central position that could be withdrawn might be the best option. I think inboards are often made into outboards in the philipines ( there
is a thread in this regard.) Perhaps the Z drive that began this thread might be a reasonable alternative. I would like two have the largest prop spinning in the least disturbed water. But mechanicly the angled drive shaft with a universal terminating joint would be the simplest and most effecient. I wonder if this could be mounted in a housing and rotated with the entire pod, like a large outboard. We often use sliding splined shafts - perhaps one above the water line could be detatched and the entire motor would not have to be tilted.
In addition where would you put the exhaust? Would it make for better motosailing if the exhaust was sent up an elevated stack, perhaps within a mast or radar pylon ?
Thanks for letting me dream along with real sailors - Mark

[sharpii2]

Hi Bob

I really liked your post. This is a problem I've been working on since the late '70's. It was at that time that my dad told me about some guys he knew that liked to canoe on some Northern Michigan lakes. The canoe worked out good except when the lake breazed up (at about 20 kts or more). Then it was a desperate struggle to make any headway at all against the wind.
Their solution, of course, was an out board.It had several problems though. First, the engine wasn't light (for a 1 mile portage). Second, it needed fuel (which also had to be portaged) And third, it got in the way to such an extent that it was just simpler to bolt the damned thing to the transom and motor all the time.
My dad wanted to know if I could come up with an alternative.
When I thought about it for a while, I realized that what was needed was a small sailing rig that could sail up wind in a good breeze. In anything less, the paddles would most certainly be used either in conjunction or instead of the sail.
I thought that a rig of maybe 30sft or less would do the trick. Such a cut down rig would be reasonably light, easy to stow, and very easy to work. All it needed was some sort of leeway preventer. I thought of a leeboard or maybe even one of the paddles. The hope was that the entire rig would could go with the canoe during a portage. That would save these ilustrious adventurers one trip for each portage which would add up quick.
The idea never came to anything. I was too young (still in highschool) and I knew nothing about how to engineer it. Stepping a mast in a boat without a mast step proved to be a bit too much for me at the time (I have since seen how it can be done) and these two men lives took on differnt tacks anyway. However, the idea of a boat with a small but real (capable of going up wind) rig stayed with me. When at THE LANDING SCHOOL OF BOAT BUILDING AND DESIGN, I drew two sailboats. One was what I called my 'Mackinaw Boat'. It's purpose was to be able to make the trip from Port Huron to Mackinaw and back in under a week in all but the very worst conditions. It had an average mast head sail rig, a powerful (36 hp) deisel, and an inefficient folding prop. The 35 footer also had a long fin keel and had a beam of only 9 ft. The hope was to be able to push it at hull speed continueously, so half the average two week vacation could be used for sight seeing and half could be used for the voyaging itself.
The second boat was to be an ocean going craft for a live aboard. It was just as long as the first one, half again as heavy, and with a diesel with one third as much power. It was, however, to have a three bladed feathering prop intended for much greater efficiency. It was supposed to push the 27ft WL boat at about 4kts, but have some reserve for when things got hairy (sails were expected to be used in survival situations such as beating off a lee shore). The hope was to get good fuel economy during those looong periods of calms and to despense with inventories of light air sails (more room for my stuff). Though serviceable, it was not a good design. The raised deck cleared the boom by a mere 18 inches making it necessary to 'work it from below' and the cockpit was a mere foot well. I jokingly called it a 27 footer crammed into 35 feet.
A present project is a 12ft scow with a 48sft rig along with short sweeps to propel it through calms. The lake it is intended to sail on has either dead calm or wind shot out of a cannon.
As for your proposed design, I would suggest that you forget about the outboards and invest their weight ration on better ground tackle. The reason I say this is because it has been my experience that engines don't like long periods of non use (especially in salt water conditons). And you may very well find yourself with one or both of them concked out when you need them most.
At another thread 'Concept Catamaran Project' A man named Duane is working on a boat that is very similar to your ideas. I keep adding my two cents. why don't you join the fun. A man with your experience could be most helpful.

boB

[brian eiland]

Motorsailing offshore is by far the most pleasant way to make passage, most of the time. With the engine barely above idle and a moderate amount of sail set, there is a synergy created by the apparent wind which generates more forward thrust than either one alone, with the bonus that you don't have to set large areas of canvas, which will have to come down in a hurry if the wind increases. The boat rides better, makes a better average speed and the batteries are always full. The beneft of using a much smaller sailplan can only be appreciated by someone who's been caught offguard in a squall with too much sail up. "Adventures" like that might be fun for weekend sailors and short coastal passagemakers, but on a long ocean passage they're something to avoid, even if it means a slower passage.

I was making this same point in my #3 posting above in this thread, "In light airs, running one engine often is all that is needed to bring the apparent wind forward to make the sails work harder, and the combination provides much better results than either motoring or sailing alone…… sailing synergy/harmony, the motor taking over in the lulls and the rig taking over in the puffs"

And take note from that same posting, "Optional nacelle-mounted centerboard precludes any extra hull penetrations, and permits maintenance without hauling-out."






Which brings me finally to the concept that I've settled on: a catamaran with three engines. Two will be outboard motors mounted on the sterns of each hull. The third will be a small, low speed diesel, preferably air cooled, on the centerline housed in a pod. I expect to pay a penalty in wetted surface higher than a monohull of the same displacement, offset by the fact that a multihull can be a bigger boat with less displacement, which I hope should work out approximately equal. The outboard motors will be lighter weight and cheaper to install, and will provide higher power when high speed is wanted, albeit at a much higher fuel consumption. The high redundancy factor in this design will add to safety, with enough power to get out of bad situations like dragging anchor in a confined area. Outboard motors won't have the service life of inboard diesels but will probably not be used very often, almost never offshore. They're easily serviced or replaced, and it would be possible to carry spares onboard. New ones are available anywhere.My most basic question now is what would be the best combination of engine and drive? The belt drive system described on http://www.runningtideyachts.com/motorsailing/ makes a lot of sense, it would virtually eliminate mechanical loss. The best option of all might be a direct drive or longtail system, if the problems of installation on the centerline are solvable.

I'll come back to a few of your other questions a bit later, but meanwhile I'll post this portion of a previous thread (http://www.boatdesign.net/forums/showthread.php?t=2225) I tried starting with no results. It considers a centerboard mounting that is above the waterline (easy maintanence and repairability without hauling), and a single 'cockpit mounted' engine with steerable outdrive....and the relatively small HP you are considering would be easily compatable with the industrial belts I site.
_____________________________
"One item of your thought processes caught my attention in particular; your desire for a single centerboard, and real shallow draft capabilities. I'll certainly second that motion, that shallow draft idea. One of the greatest attributes of multihulls is their capability to really go exploring ALL the water areas including those tributaries, lagoons, reefs, etc. That's why I had kick-up CB's in each hull of my design.

BUT, what you may not have noticed was my alternative to the CB's in each hull. Look at the attached drawing, (or the very bottom profile drwg that denotes "asymmetrical CB's, nacelle mounted". First, imagine a flat plate, on edge, mounted down the centerline on the underside of the bridge deck. This flat plate will act as a rib to strengthen the fore-to-aft rigidity of the vessel, a somewhat weaker characteristic in a catamaran structure vs. a keeled monohull. If a tow bundle (rope, etc) of carbon fiber (kevlar, PBO, etc) was laid along the bottom edge of this flat plate, the rigidity could be even greater (sort of akin to a bottom truss structure, or a flange of an 'I' beam). Now on either side of this flat plate I propose to mount a centerboard, not a single, symmetrical one, but rather two asymmetrical ones; sort of like a single board split in half. The flat sides of these asymmetric boards would fit up against the flat plate nacelle, and rotate on oversize (possibly 1-foot) diameter bearings. The flat fit & big bearings would together supply a great big surface for the large bending moments to bear against. Only one board at a time would be lowered. In fact the two could be linked together such that the act of lifting one automatically lowers (& powers) the other down. And they both could be rigged to 'kick up' upon hitting any solid object and/or for shallow cruising. The control lines (cables) could be routed right up to the cabin top and back to the cockpit.

There are several advantages to an asymmetrical shaped centerboard. First, it requires less total board area to develop a leeway reducing force....so the board size is reduced. Secondly, since it is asymmetrical, it does not require an angle of attack (does not require the boat itself to be sailed at a skewed angle) to develop the 'board's lift' (leeway reducing force). This actually
may result in the vessel making less leeway. Plus the drag forces associated with the CB lift forces are on the centerline of the vessel, rather than off in one hull that produces turning moments about the center of the vessel.

This centerline mounting may also improve the tacking capabilities of the vessel as it allows the 'clean' hulls to slip a little while pivoting about the central board.

The front of this nacelle/plate could be configured to act as a wave splitter to actually attack, up front, the formation of those peaky waves under the tramp areas that eventually slap at our bridge deck underside. We kind of slice those waves down a bit. A lightweight fairing might also be added to this 'flat plate nacelle' so it appears outwardly much more esthetically pleasing, as well as more curvature to shed those peaky waves.

And how about the maintenance factor, particularly in remote cruising areas. No need to haul-out the vessel to repair kick-up CB problems, or even bottom painting problems. Everything, including the cables, bearings, and boards is all above the load waterline. The initial building cost should be less by eliminating the trunks in two hulls, and the watertight integrity is much
better. The twin boards might have to be made a little bit longer as they operate with a 'free-surface' end, but then they are asymmetric so they can be correspondingly shorter. I would further suggest that surplus helicopter blades are prime candidate sources for both CB blades and rudder blades....high tech, extremely strong carbon fiber fabrications that have a
prescribed limited life span aboard aircraft, but are perfectly happy for our use.

For rudder designs I would give a cassette system such as the Vara rudder (http://www.socasailboats.com/) a close look in lieu of a kick-up system. Or maybe even Tony Smith's Gemini cat system. Kick-up rudder systems can get pretty complicated, plus they usually don't steer the boat very well at all when they are kicked up in shallow water. (LOTS of weather helm).

If I were looking to use my auxiliary engine in a strictly aux manner, rather than in a motor/sailing demand, I would seriously consider a single engine installation. This engine would be conveniently mounted in an enclosure on the cockpit deck and would belt drive a steerable out-drive leg that would be incorporated into the rear portion of the central nacelle structure. Maybe this rear nacelle might appear as on "Earthling's pod" (attached photo and/or http://www.earthling.co.nz/boating.htm This saves the cost and weight of the second engine, trans, shafting, prop, etc, and opens up the rears of the hullsfor a nice master bath, or whatever."

[Bob Leask]

I have seen Z type drives mounted on the centreline, one I saw used a hydraulic motor and simply swung up laterally under the bridge deck to stow. My doubts about hydraulic drives are about the power loss in the transfer system. Manufacturers of hydraulic motors claim from 80 to 100% efficiency but the power lost in moving the hydraulic fluid through valves and hoses is another matter, I know from experience that hydraulic systems get very hot while under continuous load, meaning power loss. Also potentially a major problem with failure in third world places. Always something to consider for world cruising, as you rightly point out.

We both seem to be coming to the same conclusion, that the best solution is always the simplest, and diesel gensets are commonly available and easily serivced. In southeast asia they adapt cheap Chinese made diesels for longtail type drives, using a chain reduction (very efficient) and a steel shaft that runs through a pipe with the propeller bearing on the outboard end. Those 30 horse diesels can be bought new in Indonesia for about $300 US and seem to be pretty reliable, but I'm told that they can't be rebuilt because the cylinder liners and valve guides etc. are not replaceable. In Australia mounting an inboard engine on the bridge deck on a hinged bracket to raise and lower it is a common way of poweriing cats, especially Wharrams. I heard from someone who had that arrangement that the biggest problem was protecting the engine from splash and spray, especially if it's air cooled. Air cooling is noisier and providing it with enough air and keeping water out at the same time presents a challenge but is probably the best idea overall, because then the genset is useable while you're on the beach. And whatever the pros and cons of multihulls might be, it's beachability that sells me on the catamaran concept more than anything else.

Water generating could be done by driving an alternator via the shaft, with a mechanical clutch to disengage the engine. Not as elegant as an electric drive but maybe more efficient. Water generating can be a great system if it's done right, the key seems to be a large enough diameter prop. A guy I know has that on a big ketch and it will start working with as little as 2 knots boat speed, so when anchored in a tidal river he gets enough power from that alone. Very nice for a cruiser.

The best way to run the exhaust on a cat seems to be straight down out the bottom of the bridge deck. I've been alongside cats with generators running and the exhaust routed that way, and heard absolutely no noise from alongside. You only hear it when directly forward or aft, but the enclosed space between the hulls seems to act as a big muffler and from on deck you can't even hear it.

One thing for sure, I am mystified why virtually all yachts use heat exchangers and wet exhausts. Apologies for being a bit evangelical on the subject, but I think one of the reasons all the cruising cats I've had experience with performed poorly in terms of fuel efficiency, is that the only thing worse than a heat exchanger on a cruising boat is two of them. If you contact a dealer for Walters keel coolers they'll show you test data on various boats comparing keel coolers with heat exchanger systems and they show that the negligible drag of the keel cooler is more than compensated for by the elimination of cooling system power loss, even on high speed vessels. I've owned two of them and found that they were absolutely install-and-forget. None of the problems of corroded mixers, corroded heat exchangers, plugged impellers, and no risk of salt water backing into the engine, which seems to the most common cause of marine diesel breakdown. Not to mention the danger of fire when the raw water pump fails. Best of all, it's much cheaper. Why are keel coolers virtually unknown in the yachting world?

Bob

[Mark Peiffer]

Bob,

I appreciate your experience, I have wondered how I could best avoid the desiel fumes when running slow with different wind angles. I have never had a placement anywhere but in the stern. And in a light following wind, where I would like the sails set, if I ran the motor I would choke on the fumes. If you place the exahust under the wing does't it get a bit smelly on the aft deck of the bridge.
Also I totaly agree with the keel cooler but I thought that water injected exhust was much quieter. With the motor mounted above the water line there wouldn't seem much danger of contamination to the engine. Is the maitenance of the dry system actually easier when it is exposed to such high temperatures. I've never had a dry system but on tractors, and those systems would never stand up to exposure to salt water at the temperatures they run at.

Mark

[Bob Leask]

I don't have personal experience with catamaran sailing, but have been around quite a few, and I'm working at a catamaran factory right now. I know lots of them vent exhausts out the bridgedeck, the auxiliary gensets at the company I work for are done that way. While sailing downwind I would expect the gases to be blown forward, I think the only time it might be a nuisance is while anchored in a flat calm, and those times when motoring downwind and the wind happens to be on exactly the same speed and heading as your boat. All exhaust systems other than raised stacks or through-the-mizzen type dry exhausts are bound to be a problem at times. I do have that problem on my own boat from time to time, but fortunately not too often. It's not fun when those gases start making their way down the companionway. All you can do then is stop the engine, or change course.

My fondness for keel cooler/dry exhaust systems is in diesel inboard installations. It's clearly a superior way of cooling a water cooled engine. On a scale of 1 to 10 I rate keel cooler 10, heat exchanger 0. For the cenerline mounted engine we've discussed it might be problematic to use a keel cooler, but possible. It would just mean longer hoses to the cooling pipes.

Dry exhausts can be quieter, it's just a matter of how much you want to spend on a muffler. And you won't have those weird regurgitation noises that wet exhausts often make. Mine is just piped through stainless flex pipe through an insulated thru hull in my stern. It's all inboard so there's no problem with corrosion.

The absolute best way to get rid of exhaust gases is to pipe them up a mast, if the rig type allows it. I've seen quite a few ketch rigged motorsailers with that arrangement. Once I saw one on a wooden mizzen, with a copper exhaust pipe fastened onto the forward edge, with a hinged and counterweighted rain cap on top. You couldn't get the noise and gases any farther away than that.

Bob

[Richard Petersen]

Well people, we have all lived long enough to meet the most important person in each boat company. The PUBLIC RELATIONS SALES MANAGER. HE can make improvements we have not even thought of needing, without redesigning the boat. May I please shake his hand? I am so blessed to buy his product.

[Bob Leask]

Thanks for those links, I do enjoy seeing what the innovators are coming up with. That is another appeal of the multihull concept, that it's still so relatively new that there are endless possiblilities for future development. The Vara rudder system looks like a good solution to the problem of steering a shallow draft boat. I think the best thing about that concept is that it could allow a variable depth of rudder. Under different speeds and conditions there is no perfect rudder, most cats have very small rudders which are best for high speeds but ineffective for low speed maneuvering.

Earthling is a real work of art, beautiful. Boat design is more art than science, I feel. A good boat must have a lot of good qualities but one of the most important is that her crew must love her. Greg Young has done a fantastic job. I've seen few boats that "pushed the envelope" and departed from the traditions of boat styling so far, so successfully.

I like your idea of putting a centerboard in a nacelle on the centerline, but I've only seen that done in smaller cats. Quite a few cats use a center nacelle to break up the convergence of the two bow waves and reduce underwing pounding but for some reason I've never seen it done in larger boats. It makes sense to me for several reasons, one big board should be more effective than two smaller ones with less drag and wetted surface. Also it would uncomplicate the hull construction by eliminating the two slots. The only possible problem I can think of is placing it in an area of interaction between the two hulls, could that disrupt the flow past the board and possibly cause oscillation? Your dual assymetric CB design sounds interesting but I'm having trouble visualising it. I'd like to see a sketch if you have one.

Your point about outboard motors tending to be unreliable when out of use for long periods is a good one. I still think that a small diesel auxiliary combined with outboards is the best solution for a versatile propulsion system which could be both fast and fuel efficient for long passages, but the drawback would be higher maintenance.

Bob

[brian eiland]

I like your idea of putting a centerboard in a nacelle on the centerline, but I've only seen that done in smaller cats. Quite a few cats use a center nacelle to break up the convergence of the two bow waves and reduce underwing pounding but for some reason I've never seen it done in larger boats. It makes sense to me for several reasons, one big board should be more effective than two smaller ones with less drag and wetted surface. Also it would uncomplicate the hull construction by eliminating the two slots. The only possible problem I can think of is placing it in an area of interaction between the two hulls, could that disrupt the flow past the board and possibly cause oscillation? Your dual assymetric CB design sounds interesting but I'm having trouble visualising it. I'd like to see a sketch if you have on

Don't have a lot of detail in drawings at this moment, as it is an alternate proposal I am suggesting for consideration, and that may have some resistance to overcome as does my unusual sailing rig.

NOTE: There is a requirement for a transverse bulkhead in the boat structure at this CB location to which diagonal 'wires' can be attached to offset the big side-loads of the CB's

[Bob Leask]

It was too early in the morning when I read your description of the dual assymetric centerboard but now it's clear what you're proposing, and I agree completely. I've thought the same way, a centerline board fits in very well with the concept of the motorsailing cat because keels on the hulls would not be necessary for lateral resistance, reducing draft even further and wetted surface while under power, when the board would not be needed. The use of surplus helicopter blades is exactly the sort of idea I love. Why reinvent technologies that are already perfected and available off-the-shelf?

I've been working on a design of my own which is still a long way from anything I would be brave enough to start building, but I think a centerline board will be going into it in the next draft. The boat I sailed in for eight years was much easier to design because it was so conservative, it was really just a matter of borrowing proven ideas that had evolved for generations in traditional boats, and combining as many of the things I liked into something of my own.

The potential of the concept of a motorsailing cat is exciting, but I'm finding it challenging because there doesn't seem to be very much experience to go on. I have a long list of features I want in my ideal liveaboard/cruiser and can't see any reason why they can't all be achieved. I don't see any reason why a cruising multihull can't be shallow draft and beachable, capable of much higher speeds than a monohull, equally economical under power, and a good sailing performer too. Add to that the rest of my wish list such as a fully enclosed pilothouse with unobstructed 360 degree visibility, ample covered deck space for those hot climates, an efficient but easily handled rig etc. and combine it all into a package that looks good. I know it's possible with the materials available today but I'm finding it's not easy, I'm on about the sixth draft now and I'm still not satisfied, and starting again from scratch.

But I do feel that it's the right direction to go and that if there is such a thing as a perfect cruising boat, it will likely be a motorsailing cat. The first boat I built was a Brown trimaran and I know how resistant the nautical world can be to new ideas. Now that the cruising multihull has gained such wide acceptance I'm sure that the motorsailing cat is the next phase in the evolution of ocean sailing craft, it just makes so much sense.

Bob

[Mark Peiffer]

I know that there are many kinds of outboards. As pointed out in earlier postings, inboard deisels have been converted to outboards. I have also seen designs that shelter the outboard in a hull, and when retracted nearly completly protect the motors. Surely not all outboards are unreliable, what about the new generation of outboard deisel motors ? These should not be any different than a regular inboard. Are there any outboards that utilize a keel cooler ?

[Bob Leask]

Outboards seem to be reliable enough when they're used often, as in the dinghy motor while you're living anchored. It's when they're stowed away for long periods that things seem to go wrong. Also their lifespan is shorter in salt water unless they're flushed out after every use, which is impractical while cruising.

There are quite a few diesel outboards available these days and have been used to drive catamarans, and housing them in a well works nicely. If you have a plug that fits fairly close around the leg the problem of water surging up into the well is solved. I've met quite a few people cruising with outboard auxiliaries and there are some good arguments for that, as well as some negatives. On the plus side the cost of installation is much less than an inboard and unless you're planning to motor a lot of miles, the higher fuel cost of an outboard might add up to less than the higher initial cost of the inboard. On the negative side they don't last as long, and will need more maintenance such as replacing impeller pumps and shaft seals. On the plus side, those maintenance jobs on an outboard are much easier to do than on an inboard. Working in the engine room in the tropics is pretty miserable. Also to consider is the lighter weight of outboards. Another plus is that they're so easily replaced. I feel it's a matter of preference, both ways work.

However I don't think the outboard idea really suits the motorsailer concept except as a "booster" for high speed for short distances. The fact that they have small high speed propellers and a 90 degree bevel gear at the base means that they will never be as efficient as a well designed inboard. The weakest point of outboards and all legs that use a bevel gear are the seals that keep water out of the base, they wear out fairly quickly and when water gets into the bottom end, it causes some very expensive damage. The cost of replacing all those bearings, seals and gears can be more than the cost of replacing the entire motor. Long hours of motoring would mean high maintenance cost, and time.

Converting an inboard to an outboard sounds like it might be a good solution but I don't know how that's done, I assume you would adapt the engine to a sail drive or possibly use the leg from an outboard. Using a keel cooler for an outboard is a novel idea, it wouldn't be practical on a normal outboard because the cooling system is not closed and the water pump is down in the leg below the water. But it could certainly be done with any water cooled engine which has a closed cooling system.

I'd like to know how you convert inboards to outboards. Can anybody help here?

To optimise the motorsailing cat concept what we really need is a populsion system that will work efficiently over a wide speed range. Diesel/electric seems to have a lot of potential. It's been in use in locomotives and big ships for a long time already and lately the technology has been trickling down to us small boaters, it would be very interesting to hear from people who've been using those systems and find out how happy they are with them.

Bob

[Bob Leask]

I have lots of offshore experience in a heavy monohull but planning to do my next cruise in a cat, which hasn't been built yet. I agree with most of what I've heard in this thread but would like to add a little more: the tendency to broach in heavy weather is mainly because of the modern "superior" rigs being used. I used a gaff rig which is the rig meant to go on those traditional types. It got me through lots of heavy weather, including one tropical cyclone.

A "traditional" boat with a high aspect rig on it is an oxymoron. The top hamper of such rigs while reefed down becomes very dangerous in heavy weather. The sailors of the last few centuries all used low aspect rigs not because they weren't as enlightened as modern yachtsmen, it's because they knew better. What kind of rig did Moitessier have? And Chichester? The fact that 99.9% of all modern cruisers are using high aspect rigs only proves to me what Benjamin Franklin once said: there's nothing common about common sense.

Looking at the number of cats cruising the "milk runs" convinces me that they're quite capable of getting you around but I also agree that they're not the right thing for high latitudes. If downwind cruising in the trades is the bunny hill of cruising, the roaring forties is the giant slalom. If you want to ever go places like that (I don't) the probability of being upside down at some point is very high. Moitessier did one thing right, he built Joshua like a submarine.

I think it's a fact that sailing in a multi will be riskier than in my old heavy double ender, but I also think the positive aspects of a multihull make it worth it.

Has anyone seen any design work lately in the area of self righting multihulls? Jim Brown and his devotees did some work on that idea back in the '70s and came up with an idea that works, since most capsises happen pitchpole-wise it also turns out to be the easiest way to right them again. Cats and tris have been built or retrofitted to do that, and it's fairly simple, at least theoretically. Bulkheads and built-in buoyancy are placed so that the boat will float bow down after a capsize, then you have to have a means to pump out the flooded bow compartments. Some experiments were done and the idea seemed to be feasible.

[brian eiland]

..... Diesel/electric seems to have a lot of potential. It's been in use in locomotives and big ships for a long time already and lately the technology has been trickling down to us small boaters, it would be very interesting to hear from people who've been using those systems and find out how happy they are with them. Bob

Bob, do a 'search' for that term using the search function while you are logged into the general forums heading. If you've not utilized this function before you might find it quite useful for other subject matter as well.

That search will search all of the forums. A search under the individual headings will search just in those subheadings

[icetreader]

Monohulls are hydrodynamically disadvantaged.
Unfortunately not everybody is aware of this fact.
This is especially true in my field of paddlesports boats.

[Richard Petersen]

They are the IN boat in all circular power boat racing. 40 years ago. If you want a REAL boat, buy the mono hull. All others, please feel free to pass them anytime.

[sharpii2]

Monohulls are hydrodynamically disadvantaged.
Unfortunately not everybody is aware of this fact.
This is especially true in my field of paddlesports boats.

Hi Ice trader.

I beg to differ. It is in hydrostatics that multihulls have the advantage. The Center of bouyancey shift on a healed multihull can be up to five times as far as that of a monohull with the same beam (the usual number seems to be about three), but the multihull has more wetted area for the same displacement which is usually made up for by a larger press of sail. It is for this reason that we don't see multihull container ships and oil tankers.

I see two major advantages with multis: speed and lack of cumulative rolling.

It is the second advantage that I find most compelling. It has led me to consider heavy multihulls that don't do much better than displacement speed, but don't require you to weigh everything on a gram scale before bringing it aboard.

Indeed, heavy multihulls have been built in the past. Take the catamaran Kamiloa (built in 1936) for example, she wieghed in with a whopping D/L of 310 Rehua Maona, built almost thirty years later came in at 335. And this was when there were plenty of fast, light weight cats running about. The two boats just mentioned were not fast, but they were said to be comfortable and they made long voyages.

I don't envision anything that heavy. I'm thinking more in the area of around 200. I'm thinking a tri can be built heavier than a cat if you don't extpect super displacement speeds and are willing to use low bouyancey floats. (because full bouyancey floats are so dominate in tri design these days, I would call such a craft a double outrigger rather than a trimaran). Such a boat can have a moderate rig of, say, an SD of 15 to 20. (Most modern multi SD's start a 20 and go up from there). The floats would have a combined total voume that would exceed the total loaded displacement by about 25% and thereby keep the boat afloat if the main hull was holed.

Bob

[icetreader]

Hi Bob,
What I meant to say more specifically is that the multihull design effers the possibility to achieve logarithmic reduction in residual resistance through smaller wetted beams.
The more constraints you put on a design (e.g. size, mode of propulsion) the more advantageous the multihull design seems to be in terms of speed.
For example: Since the shape of canoes and kayaks is constrained by the need to have passengers seated inside it is a priori non-optimal as far as wetted surface goes, which makes a good twinhull design not that lossy in terms of wetted surface: http://www.wavewalk.com/COMPARISON.html

Monohull sailboats require to incorporate large keels and heavy bulbs into their design, which affects wetted surface, and consequently speed.

I suppose that big ships would hardly benefit from the multihull design in terms of speed because they are not constrained by small size proportions or by propulsion mode.

Yoav

[Richard Petersen]

When it comes to getting from here to there, as fast as possible, with a maximum of HP, 2 hulls or sponsons ( baby hulls ) are used. Any speed records read otherwise? Read that as efficiency. And I love MONO's.

[FAST FRED]

"I suppose that big ships would hardly benefit from the multihull design in terms of speed because they are not constrained by small size proportions or by propulsion mode."

Transports are constrained by hull speed.

If the vessel gets to fast and looses the midshops wave , most will break in half.

20 to 25K seems to work interms of low power required , delivery times and hull structural constraints.

FAST FRED

[Richard Petersen]

Since I don't understand a word. O K

[icetreader]

I think I understand :-) and it makes sense to me.
I bumped into serious structural problems when designing the world's smallest catamaran: A polyethylene, roto-molded 122 inches long and 25 inches wide paddlesports boat.
The problem was the the passenger(s)'s weight distorting the boat's shape.

Yoav

[ron17571]

I once talked to my neighbor,an ex navy man and told him of my thinking of cruising with a forty foot catamaran(to many years of reading multihulls magazine)he started laughing and said he wouldnt go on the ocean with a ship less than 600 foot long. But i just think of slowly slogging along at an angle in a monohull.I couldnt hang it.I think a catamaran trawler is my latest idea,I like the workmans boat on the trikini site.

[CT 249]

When it comes to getting from here to there, as fast as possible, with a maximum of HP, 2 hulls or sponsons ( baby hulls ) are used. Any speed records read otherwise? Read that as efficiency. And I love MONO's.


What about the world outright sailing speed record, held by a monohull (sailboard)?

I suppose I could also mention that single waterski is faster than a double, but that'd be silly.

[Richard Petersen]

I am a firm beleiver of " the wider the stance the faster we go. ". Look at mono hulled iceboats. They are all tri-hulls or tri-wheels. A delta wing and trike gear is the fastest shape in the air and on the ground. The mono hull has not been seriously attacked by a multi hull yet. :eek:

[B. Hamm]

"I suppose that big ships would hardly benefit from the multihull design in terms of speed because they are not constrained by small size proportions or by propulsion mode."



Ships generally need weight hauling capability, one of the downsides of multi's is the need for them to be light. Conflict of terms.

B. Hamm

[B. Hamm]

A delta wing and trike gear is the fastest shape in the air and on the ground. The mono hull has not been seriously attacked by a multi hull yet. :eek:

The delta wing isn't hardly the fastest in the air, has by far the highest drag vs. lift of any wing platform shape known. It's used only because it's strong owing to it's thickness and it's extreme leading edge angle helps with compressability at the speed of sound.

The trike gear isn't fast either, a conventioal gear (taildragger) has far less drag.

B. Hamm

[Richard Petersen]

How many land speed records have been set with a tail dragger compared to a trike. 1-2 - 4 or more points are all unstable for a table or chair or anything. 333333 is the only stable contact points of support of any object. Stopped or moving. Eventually, we will devote serious effort in the right direction. Ice boats do great in all directions and wind speeds. Why?

[Richard Petersen]

Do you remember the paper airplanes we made in school? Deltas were always the fastest and longest distance in still air. Straight could sometimes stay aloft longer.

[edaydesign]

Please excuse me but I am new here. After reading for the past 15 or so minutes about the constant argument on weather multihulls are efficient or not, I am getting confused.
I am currently finishing up my final year in Transportation design and began working on my senior thesis this past week. I am considering doing a project which will make the boating industry more sustainable(40-50 motor yachts). My previous research has mentioned that catamarans where a truely more efficient boat. Mainly for less drag and fuel efficiency. Is this Info Correct? Should I be looking into monhulls instead or continue with multihulls?

[terhohalme]

As a rule of thumb: At low speed, well under hull speed, monohulls are more efficient than catamarans, from hull speed to near planing catamarans are more efficient and at planing speed monohulls are again more efficient.

So, the catamarans are most usefull at semiplaning (semidisplacemet) mode.

[Richard Petersen]

All the fast powerboats I have seen and tuned were always 3 point hydros or a direct relative. Most boats running at + 200 are a 3 point hydro. 2 sponsons, and a prop are all that touches the water. Some hydos are fast enough to only have the prop in the water down the straightaway. They are for all purposes not a boat. A BOAT has as much of it's hull in the water during a turn, as it has down the straightaway. Any thing else is a FREAK. O K sensitive ones, take your best shot. Richard Petersen

[Richard Petersen]

Sorry we wandered Brian, from your original thought. I thought you were right. Tri-hulls are the equivelant of a 3 point hydro. Just going to take a FORCE 5 breeze to prove it.

[icetreader]

Thousands of races over dozens of years, and here are the statistics:
http://www.sailspeedrecords.com/major.html

[Richard Petersen]

I need a stronger engine in my boat. Or, more hot air in me.

[sharpii2]

Hi edaydesign

The answer to your question depends on what you intend to use the boat for.
Judging by the way you worded your question, I'll assume you are talking about speed. There are three criterias of speed and all are based on the length of the boat at its waterline. These speeds are multiples of the square root of the waterline in feet expressed in knots.
The first is called displacement speed and that is approx. 1 to 1.34 * sqrt WL. For a boat that has a 9ft WL that would be 3 to about 4kts.
The second speed is what I call sub-displacement speed and that is usually significantly less than sqrt WL. With our 9ft WL dinghy that would be, say 1.0 to 2.25 kts.
The third speed is what I call super displacement speed and that is from say
1.5 * sqrt WL on up (usually to 2.0 * sqrt WL). So at this speed our 9ft WL dinghy would be doing 4.5 to 6.0 kts or better.

All these three speeds are based on wave making. With sub displacement speed, very little energy is spent on wave making. That is why rowing dinghys and container ships almost always travel at this speed. It requires the least hp (hourse power) per ton. At this speed the vessel with the least wetted surface area (WSA) wins. And because a monohull has less WSA per ton it is usually the best option for this speed. If you are rowing a few hundred pounds of provisions out to your yacht with this 9ft WL dinghy. This dinghy had best be a Monohull.
At Displacement speed a lot of energy is spent making waves but not so much as to make it prohibitively expensive in energy use. at this speed our rower of provisions would be working his guts out but would be able to do it if the natives were wading in after him. This is the most contentious speed for multihuls vs monohulls. If the boat is heavy for its length, the monohull is better (our provision laden dinghy). But if the boat is modrate weight for its length and is powered by sail or carries a cargo that makes it top heavy (like a multi deck pasenger ferry or our 9ft dinghy with just the sailor and his sweet heart on board day sailing) The multihull is the better choice. Our 9ft WL dinghy would be able to carry more sail and/or carry it longer as a multihull than it would be able to as a monohull even if, as a monohull, it had the same width (Beam). For this reason, it would be able to reach and maintain displacement speed over a wider range of wind conditions without its crew having to go to uncomfortable contortions such as hiking over the side.
At super-displacement speed there is no contest. The multihull, because its hulls are narrow and sharp, make smaller waves than a monhull with the same Beam. Here, light weight is essential. If the multi is light enough, it should be able to easily reach these speeds under sail while being rather easy to mannage. A mono can reach these speeds (only if its light for its length) under sail if it has either a very deep ballast keel or a long hiking board. If its very narrow, it can power through its bow wave just like the multi. If its reasonably wide (to carry the huge rig it would need in even light airs without hiking or a ridiculously deep keel) it would have to plane. That means it would have to climb over its own bow wave and that requires a lot of energy, so it needs either a large rig or a strong wind or both.
When I was comming of age, light Mono sail boats were designed to the IOR rule and had pinched ends. Because of their light weights, they often planed. But when they did, they were squirrely and hard to control. In those days. a cheap multi could easily beat an expensive mono of the same length. Now light monos are designed so they can plane much more safely and they have much bigger rigs and deeper (and sometimes shifting) ballast. Now it takes an expensive multi to beat an expensive mono of the same length under sail.
The reason I spent so much of my explaination with sailboats is because they are always designed to use minimal energy per given performance. In an age of cheap, portable, energy (an age not likely to occure again in our lifetime and is now fading fast) it was economical to build heavy planing power boats (at about 40hp per ton). But now, the times, they are a' changing.
In the near future, I expect to see more and more multis in the top two speed ranges and monos relegated to the slowest speed range and/or the heaviest displacement for length (such as rowboats, tug boats, large cargo ships, and boats needing ultimate stability). (Alas, you multi lovers. Monos, like the poor, will always be with us.)
There is yet another difference between multis and monos which is worthy of considering. Ant that is that a mono has accumulative rolling where a multi dosen't. For this reason, some are considering multis for even slower speeds as motor sailers (see 'The Concept Catamaran Project' thread).

I hope I have answered some of your questions.

Bob

[edaydesign]

Thanks Bob for the reply!

Ill tell you a little more of my project.

So I am trying to bring the marine industry into a more sustainable world. Speed is a major factor in my projected market. A modular interior will be designed to make the vessel more friendly to be refitted down the line instead of wasting alot of materials in this "refitting" process. The overall size of the vessel will be around 55'. Now for the tricky part, detemining the power source. I too believe that the cost of energy is only going up and up. what I am percieving is generating clean alternative responsible fuel sources. What I read from your reply, if the vessel i am creating is lighter and if you want speed, then go with the multi hull. Was this correct???? One possibble solution to this "lightness" could be sail power (as you mentioned) but what if there is no wind? You cant go back to your alternative propulsion, powered by diesel.

*****what if this vessel was powered with the use of electricity. Sortof like a diesel-electric motor to turn your props. Instead of a diesel motor to supply an electric current you used a fuel cell powered by hydrogen. These fuel cells are tremendously smaller(and LIGHTER) than diesel motors and only emmits h20!! the storage tanks for the hydrogen are actually smaller-to the same size as diesel tanks.

Am I still looking at a multihull or a mono??

Getting enough HP should not be a problem, just look a locomotives. These trains pump out HP and torque to pull tons and tons over a mile long.

One might say that the infrastructure is not in place so it may never work. But this is not like the automotive industry and infrastructure, because the marine industry does have to worry about roads. refueling stations can be very easily installed at marinas all over. Hydrogen can also be manufactured at these facilities very cost effectively too.

Sorry for getting off track....

Also among my research I have all the power specs needed to run a 68 Searay. It uses a pair of 1540HP Catapillar diesels a total of 3008HP for propulsion, 27.5KW Generactor for AC and a 500 amp intermittent DC load. I know that i will not need all of this power to run my 55' but hopefully it will get me started.

Thanks,

[sharpii2]

Hi edaydesign.

Thanks for the kind words!

Your right in your last question. A multihull is the superior choice to meet your criteria (light weight + speed).

Your propulsion sytem, using H2, Is, I believe, unrealistic. The problem with H2 is that it comes as a gas, not a liquid. It must be compressed by several hundred pounds to get any range at all. This would mean heavy, expensive, high pressure cylinders for your fuel tanks.

The alternative is biodeisel which is made from recycled frying oil. This way you can use conventional deisels into the forseable future.

The only snake in this paradise is that the fuel will be very expensive, say, 5 times the present price adjusted for future inflation. In view of this likely reality, I think it best to plan on having all the super displacement speed happen under sail, and all the motoring be at sub-displacement speed, say, 5kts in your case. In this case, you would need 1hp per ton. And your vessel would displace about 12 tons. You would need about 12hp per hour/16hp per hour per 1gal. of deisel, or about 0.75 gal. per hour. And you may be able to do much better than that.

By going to a hybrid (deisel electric) system, you may be able to wring out more effeciency. The deisel can be sized for the average power requirement. whereas your electric motors can be sized for your peak requirements. This might get you down to 0.5 gal per hour.

So lets say you want a power range of 1,000 nm. We take 1,000 nm and divide it by 5nm hour (5kts) and that gives you 200 hours. Now multiply that by 0.5 gal. per hour and that gives you a tankage requirment of about 100 gallons. If you wanted enough power to do your sailing speed of, say, 20kts, you would need 20hp per ton or about 10 gallons per hour divded by 20kts (your new speed) times 5kts (your old speed) times 100 gal.(your old tankage) to get 500 gal. (Your new fuel tankage). In short, you would need five times as much fuel. This is , of course, asumming a dead calm for the entire trip (which, I think, is as it should be).

As I hope I have demonstrated, There is a high penalty in fuel usage for trying to go fast under power, even with multihulls.

Bob

[DiverDown]

If you want to look at an interesting powercat,goto yachtworld.com,advanced search for power cats.There is a 65' aluminum Prometa,Santorini.
http://www.yachtworld.com/core/listing/pl_boat_full_detail.jsp?slim=quick&boat_id=1056019&units=Feet&currency=USD&access=Public&listing_id=50230&url=

From memory: 7000 litres, 15 knots top speed,cruise 12 knots(range 4300 nm).I read somewhere,using one engine at 8 knots gave a range of around 7000 nm.

For drives, I've often thought a surface drive would be good.It would have to be propped for lower speeds of course,and would never act as a true surface drive,always driving submerged.There are two types from what I've seen: the steerable type,and the non steering type with a rudder behind, like this:
http://ultradynamics.com/10-26-2004/sections/surfacedrives/drives.asp

The steerable type may seem a little complicated,but yachts have hydraulics anyways,and trawlers go in long straight lines.With easy access,carry a couple spare cylinders,lines, and oil.

The main advantage would be,with a dual engined vessel or cat,the ability to lift one out of the water so as not to drag when running economically on one engine.Another:not having rudder skegs,and prop shafts and all that stuff interrupting flow and possibly leaking, several feet under water.

I'm sure there are other qualities.

Anyone?

[brian eiland]

....
*****what if this vessel was powered with the use of electricity. Sortof like a diesel-electric motor to turn your props. Instead of a diesel motor to supply an electric current you used a fuel cell powered by hydrogen. These fuel cells are tremendously smaller(and LIGHTER) than diesel motors and only emmits h20!! the storage tanks for the hydrogen are actually smaller-to the same size as diesel tanks.

Forget the hydrogen fuel cell for the moment and concentrate on the diesel-electric possibilities....but not in the 1000hp plus units for pleasure boats. Have a look at the real good article in Dec/Jan issue of Professional BoatBuilder on the subject. And pay particular attention to the DC systems coming on line in leu of the AC systems.

If you don't get this magazine apply for a trade subscription....it's well worth it if you deal with boats

[brian eiland]

If you want to look at an interesting powercat,goto yachtworld.com,advanced search for power cats.There is a 65' aluminum Prometa,Santorini. http://www.yachtworld.com/core/list...g_id=50230&url=
From memory: 7000 litres, 15 knots top speed,cruise 12 knots(range 4300 nm).I read somewhere,using one engine at 8 knots gave a range of around 7000 nm.

I looked quickly at this vessel and noted that supposely it is powered by a single diesel engine. It doesn't appear to be so from the looks of the wake and the central hull nacelle. Do you know where there is more detail on this vessel?




For drives, I've often thought a surface drive would be good.It would have to be propped for lower speeds of course,and would never act as a true surface drive,always driving submerged.There are two types from what I've seen: the steerable type,and the non steering type with a rudder behind, like this:
http://ultradynamics.com/10-26-2004/sections/surfacedrives/drives.asp

On a multihull trawler type I think you would have an EXTREMELY difficult time making a surface acting prop work. It would, as a result of the props location and pitching of the vessel, be constantly immersed too much and then not enough which would subject the prop and its shaft to huge short peak loadings.

[DiverDown]

It definitely is twin engined,with two 6 litre 135 hp Perkins Sabres.I have a magazine article from Multihulls World.Not other info online other than yachtworld selling info.
Personally, I wish it was a little wider with an interior helm.

[brian eiland]

It definitely is twin engined,with two 6 litre 135 hp Perkins Sabres.I have a magazine article from Multihulls World.Not other info online other than yachtworld selling info.
Personally, I wish it was a little wider with an interior helm.
What issue of that mag was it in? I will be next to them at the Miami show and will have a closer look.

Don't know why you would want a space eating interior helm in this modern day of hand held controls, and considering her covered helm already, unless its because of your cold Canadian air.

And if you get her too wide you limit your berthing choices. No need for really wide unless you want stability for a sailing rig. Looks to me as they have a slender enough hulls so as to not get a peaking of bowwash in the bridgedeck area, as well as a central nacelle to try to limit wave slap in this area.

Santorini power cat engines:
And six cyl diesels, very good choice. Do you realize that the six cyl configuration is the most inherently balanced configuration for an internal combustion engine

[brian eiland]

I've always appreciated the seaworthy look of trawlers, but often I must remind myself that they are subject to rolling at sea....sometimes precariously. With this in mind I happened on to another thread on this forum that I added a photo and a few comments. Have a look at this photo (http://www.boatdesign.net/forums/showpost.php?p=40251&postcount=17)

And maybe this comment if your interested, http://www.boatdesign.net/forums/showpost.php?p=40383&postcount=21 This reported incident was a serious situation which could have resulted in abandoning the ship for many owners....just another reason I like the concept of motorsailers over trawlers for REAL ocean going boats.

[DiverDown]

After digging for 15 minutes...I found the article,which I had taken out of the magazine,no date or number.Would be from spring or summer 2002,they offer reprints of articles-they'll know.

Some quick info for you: Length 20m.,Beam 7.4 m,Light 20 tons,Loaded 28 tons,11knots at 1500 rpm with 4200 n.m range,7000 l diesel,consumption at cruising speed 1.65 l per n.m(both engines)

So,18.15 l per hour at 11 knots,385 hours to empty is 4250 nm. If one engine is off,would burn 9 l an hour,run 777 hours and go how fast/far? 7 knots=5450 nm, 7.5 knots=5800 nm, 8 knots= 6200 nm. If it will do 8 knots, thats enough to get direct to Australia from L.A with a little reserve. You'd carry extra.And top up in Hawaii anyways.Beats the heck out of sailing,and cheaper too.

Being indoors and climate controlled while enroute is so much easier and less tiring than being buffetted by wind (hot or cold)rain or sweating all day.An indoor helm needn't take up much space. I like the option of choice.And yes, those outflow winds straight off the glaciers,even in August, can put a real willy up your back.

[Guillermo]

I'd like to know how you convert inboards to outboards. Can anybody help here?

Visit: http://www.jetpac.us/default.htm

Regards.

[mattotoole]

Forget the hydrogen fuel cell for the moment and concentrate on the diesel-electric possibilities....but not in the 1000hp plus units for pleasure boats. Have a look at the real good article in Dec/Jan issue of Professional BoatBuilder on the subject. And pay particular attention to the DC systems coming on line in leu of the AC systems.

If you don't get this magazine apply for a trade subscription....it's well worth it if you deal with boats

I'm intrigued with diesel-electric too -- especially for catamarans. There are a few things I wonder about though. What is the duty cycle of the genset, and how does it compare to its equivalents? Also, what about high voltage (144V) DC systems in a marine environment? I'm sure it can be handled with good engineering, but does the insurance industry and Coast Guard agree (esp. if you plan to carry passengers and hired help).

Perhaps this ought to be in a new thread...

[FAST FRED]

"but does the insurance industry and Coast Guard agree (esp. if you plan to carry passengers and hired help)."

The Cruise Ship industry and the Staten Island ferry use electric drives with no CG or insurance co hassles.

Its ALL on the shelf , just the price is a shocker compared to a simple diesel and std shaft setup.

FAST FRED

[brian eiland]

Sorry we wandered Brian, from your original thought.... .
I did feel this tread subject wandered off the path a few times. Now I'll post a letter I recently wrote to the creators of the new 156' MitSeaAh motor sailor. I think this discussion is more closely related to my original posting that started this thread.
________________________
Liebowitz & Pritchard
Washington, NY
www.LParch.com

Pedrick Yacht Designs
Newport, RI
www.PedrickYachts.com

Dear Sirs;

I was just looking thru the latest BOAT USA International mag (Mar/Apr 05 issue), and came upon a sizable article about the new “MITseaAH” motor sailing vessel. This unusual and challenging design is receiving quite a bit of boating press at present, and apparently a lot of interest at this past years’ Ft. Lauderdale boat show. There was also a very good, extensive article & illustrations in the Apr 04 issue of Yachting World.

What I find particularly interesting is the fact that an owner of a power vessel (and 5 previous ones) would commit to a new vessel design with a sailing rig on it!! Usually it’s the other way around, a case of an older sailor finally converting to a power vessel. Sure wish I could find such a progressive individual to consider building my power-sailing, gamefishing/motorsailing design www.RunningTideYachts.com/gamefishing/

I applaud most all attempts to resurrect the motorsailer concept, as I feel it has been a sorely neglected subject in this modern boating world. Witness again my website reference, www.RunningTideYachts.com/motorsailing/, and the attached document I created for this past year’s Miami BoatShow, “Motorsailing Catamaran Concept”. The latest doubling of the crude oil prices might just spur more developments in the motorsailor arena.

Back to the subject of the vessel “MITseaAH”. I really can appreciate the extraordinary efforts on the behalf of the creators of this vessel. They were really challenged to develop solutions to a tough number of requirements by the client. And they managed to come up with some very unique solutions.

But here I would like to offer an alternative solution to satisfy that owner’s requirements. First lets look at some of his major requirements:

1) the sailing rig needs to pass under a 127' high bridge for visits to the Statue of Liberty
2) shallow draft to be able to moor in front of his house on Long Island in water of 7 foot depth
3) shallow draft to visit some of ‘his favorite locations’, and ‘root out those shallow anchorages’
4) top speed under power of at least 25 knots
5) sail well & power well (I think the ‘sail well’ portion was an added challenge of the designers)
6) accommodations for owner and up to ten guest
7) maximize usable deck space for guest
8) luxury of his present yacht

I submit that all of these requirements could have been met by a 100-120 foot catamaran
motorsailing vessel. For an example have a look at “Douce France” <http://www.charterbrochure.com/doucefrance/index.shtml> , <http://www.admirals.com/doucefrance/> . Now this vessel utilizes a two-masted ketch style sailing rig that might seem a little complicated for an owner not accustomed to sails. How about if we replaced that with my ‘single-masted ketch’ rig. <http://www.runningtideyachts.com/sail/> Everything roller-furls, no hoisting of sails, no stowing of sails, nor extensions of the mast height, a much more simple rig to build and operate. At the 127' upper limit it would look ‘in proportion’ (aesthetics) on a catamaran from 100 to 120 feet. And its lower center of effort (than a sloop) could allow for the use of a smaller beam to maintain sailing stability.

With reference to the subject of stability look at the massive efforts and expense on MitSeaAh. A 15 ton lead bulb, suspended on a stainless fin keel (total 24 tons), that pivots up on precision-machined bearing blocks from a 21 foot draft to 7.5 feet. Special hydraulics to raise and lower the keel, as well as special hydraulic vaporizing considerations to account for the ‘accidental grounding’ of this huge assembly. And then a big hole up in the accommodations to accept the retracted keel. All of this is totally unnecessary on the big catamaran, as it gains its stability by a spread-out- form, saving tons of weight, cost, and complication, and damage potential. Plus we don’t need stabilizers at all, nor their complications, particularly those autogyro-controlled flaps on MITseaAH. And our draft could be as little as 4.5 to 5 feet.

There are also a few massive efforts expended to attain a powering speed of 25 knots; two huge 12 cyl 3500 hp diesels, 204,000 gal fuel supply tanks, Servogear, computer-controlled, variable- pitch 5.4' dia props, and a very complicated bottom configuration with recesses to accommodate the big props, plus huge hydraulic rams to control the two vast trim tabs extending across the whole width of the transom, and finally a complicated retracting rudder system to operate in the area of these trim tabs. Sure sounds extremely complicated , expensive, and HEAVY. That much HP, and that much fuel, reminds me of another article I included in the archives of my website, “The Need For Speed” http://www.runningtideyachts.com/articles/needforspeed.html, wherein there is a discussion of the ever spiraling need for bigger engines to carry the ever increasing load of fuel required by the bigger engines. (in this case for some modern game fishing vessels).

I would venture to guess that the alternative big catamaran design might have only required twin engines as small as 600 HP.....or lets go with a big extra margin and chose twin 1000 HP’s. Total, 2000 HP verses 7000 HP!! Quite a difference in fuel needs, weight needs, space needs, and propulsion gear sizing and configuration. And what about all of that extra aux power required to run the hydraulics required for MITseaAH’s trim tabs, auto-gyro flaps, controllable pitch props, keel control, extendable mast, etc, etc I know which vessel I would rather be charged with maintaining in good working order.

Please excuse me just a moment while I digress to consider the fuel needs of these big engines. The owner looks forward to trips from Long Island, NY and Newport, RI to Bermuda. I believe it has been estimated that MITseaAh will burn about 60 % of her fuel load on this 25kt dash out the 630 miles from Newport to Bermuda. That works out to about 122,400 gal or about 200 gal/mile. At an average approaching $3.5 per gal (between here and Bermuda) this trip will run about $428K per one way trip. I’ll bet we could have cut this bill SUBSTANTIALLY with the catamaran hull form. And we might have been capable of maintaining a higher average transit speed in adverse conditions.

Per the requirements for 10 guest (5 staterooms) plus owner, and lots of deck space, I don’t think there is much doubt this can all be achieved in the catamaran; and in very nice privacy manner. Luxury can be provided as well, particularly with attention to light weight construction as desired by the multihull vessel, and utilized on MitSeaAh.

Excessive beam is the one attribute of a catamaran most sighted as a negative aspect, particularly in finding docking space. But in this case I detected an owner willing to ‘moor’ his vessel in front of his home, and I imagine he might be willing to do so in Bermuda, Newport, Nantucket, etc when available dock space is limited, or NA on short term notice. He has the toys onboard, and the nice stern boarding platform to make this connection with shore readily accessible.

As I look back over this letter I almost feel the need to apologize for the negative overtones I’ve conveyed on MITseaAH. On the contrary, I really appreciate the efforts of her creators to solve the problems and produce a very unique new yacht. I can only hope the next time they are presented such a challenge, that they give some consideration to the catamaran vessel form.

Regards,
Brian Eiland

[FAST FRED]

"Excessive beam is the one attribute of a catamaran most sighted as a negative aspect, particularly in finding docking space. "

Sounds like this bucket in Cat form would have to pass up on St Georges , the great spot to stay in Bermuda , as the channel in is quite narrow.

Shame to miss Doubble Diamond Ale , and ICE CREAM, in the same shop , only to have to put up with the commercial port with the great view of the cruise ship sides.

FAST FRED

[cyclops]

When efficency is raised all we need do is to look at the "new" ferries. Cats. When nostalgic times are needed , power and sail. You can not have a past form and modern design in the same boat. Any attempt to such a design relagates the designer to a person who needs the money.

[brian eiland]

Several of my postings on this subject thread had been rather critical of a couple of new motor sailer designs. This posting counters that negativity, and introduces a real good article on monohull motor sailors I ran across as I was researching MITseaAH. This was written by Greg Jones of BlueWater Sailing magazine so I will not copy it to this posting, but rather give a couple of brief excerpts, and then tell you the site address were you can read the full text if the subject interest you. I would recommend it.

The first one is, "Motorsailers, The 50 percent solution"

by Greg Jones
The new generation of motorsailers might be the biggest design evolution since the Bermudan rig. Motor sailing is the dark secret of most cruisers; ask any cruiser how often they run the engine while sailing and the answer may surprise you, given that they are on a sailboat, designed to make way without the use of an engine. But the reality is that regular use of the engine is almost a necessity, even with good and fair winds. Primary among the reasons for this, apart from driving the boat, is the need for electricity. While some cruisers run their genset instead of the engine, it is still nice to get that extra few knots out of the boat, and the engine prefers to have a load on it, so why not engage the prop and get to that palm-lined island a few days quicker?

…big snippet…..

We are not going to go out on any limbs and say which is the best motorsailer. Even more than with sailboats, the design dictates what the boat does best. Sailboats only have to sail, but motor sailors have to perform well with two very different motive forces. When done right the solution results in a boat that is comfortable, relatively fast (or at least consistent) and has more room than a comparably sized sailboat. There aren't any "pocket" motorsailers as the design requirements virtually assure the boat will be big enough to be comfortable in a seaway. With a design that provides an easily driven hull and adequate sail area, the boat will derive maximum efficient speed from each. This will reduce fuel costs, and the smaller sail area will be easier to handle. Today's motor sailers are evolving quickly, driven by more knowledgeable owners and designers who derive inspiration from the best boats of the past and improve them with modern design technology and a sure eye

<http://www.bwsailing.com/01articles/issue/0405/bwb.htm>





The second one is "Motorsailing with Design Honesty"
(BE notes: sort of a sales pitch for Ted Hood’s design)

by Greg Jones
Most cruisers spend a lot of time motorsailing. This is the dark secret of cruisers; with the larger engines now being put in cruising boats, cruisers often fire up the cast iron gennie whenever their speed falls below, say, four knots. This allows them to plan their voyages with greater accuracy as regards arrival times and passage durations.

This evolution of use has resulted in more motor-sailers being designed that are good sailboats to begin with (as opposed to being motorboats with a small rig), and the latest design from Ted Hood's Portsmouth Marine, the No Compromise 54, is exactly this sort of boat……

<http://www.bwsailing.com/01articles/issue/0205/bwb.htm>

[FAST FRED]

There is NO question that a boat with a "multi hull" style hull, light and long and skinney will be the easiest to push thru the water.

But why bother with a Capsizing Cat ?, when the same building costs will get a FASTER monohull boat , although longer.

Sure Cats are great Roomarians and make great dockside cottages , but the VAST wetted surface makes for really slow going in light airs and costs boodles of power at speed.(Tho perhaps less than the current power boxes)

The RV Triton style cruiser would seem to offer the best compromise in an offshore motorsail that is fast , ez in fuel

and COULD RIGHT herself after a CAPSIZE!

Could be YOUR but in those 46- 70 ft waves off FLA!

The Kite rig will alow fast sailing sans big stability requirements ,
and location of the mast where it can be used as cargo boom ect.

"ONLY Fools & Yachtsmen Beat to Windward" not Motorsailors.

How am I wrong?

FAST FRED

[brian eiland]

Several of my postings on this subject thread had been rather critical of a couple of new motor sailer designs. This posting counters that negativity, and introduces a real good article on monohull motor sailors I ran across as I was researching MITseaAH. This was written by Greg Jones of BlueWater Sailing magazine so I will not copy it to this posting, but rather give a couple of brief excerpts, and then tell you the site address were you can read the full text if the subject interest you. I would recommend it.......

This was my answer to Mr Greg Jones:
Hello Greg,
Just finished reading two articles you wrote on motorsailers, and I can tell you are ‘hooked’ (to use a fishing term) on them as much as I am. Right up front I would like to compliment you on your “50% Solution” article. I liked it better than any other I have seen that tried to define this potentially very broad spectrum of vessels…..very comprehensive and fair as far as the monohull versions are concerned. You just left out the most modern versions based upon the multihull form.

I really can appreciate a lot of these new ideas in the ‘motorsailer theme’. I believe that many marketing people are waking up to the reality that the already small sailing population is on a decline and gravitating toward faster cruising forms in power and/or sail. Some of this is a result of the older population deserting sail for a trawler. Some of this is the younger population not content with slow cruising in this fast paced world….they may only have the weekends to work with.. I think some of the renewed interest in the motorsailer concept is the result of these observations…so they say lets add some more OOMPH in our sailboats. But be cautious, that does not a motor sailer make.

Adding a bigger and bigger engine (or twins) is not the most efficient solution, although it does more truly exist as a MOTORsailer. As you said, “A big engine will only mean you will be able to maintain speed in adverse conditions: You won't go any faster” I think you made a very important observation, “Accept that the virtue of a motorsailer is that you can make higher average speeds, which is done by eliminating the slow speeds and continuing to make decent way even in the absence of wind”. In other words bigger engines for faster top end speeds aren’t the answer in defining the monohulled motorsailer, even thought the marketing guys would have you believe so. And the real virtue of twin engines is maneuverability and ‘back up’ propulsion source. But wait a minute, in a motor sailer our back up propulsion source is the sailing rig, so twin engines is overkill in most situations.

I start to see a trend here similar to what is happening in the trawler world. There seems to be an increasing demand by the public for just a little more speed than that offered by the truly efficient displacement trawler. So now we see more and more twin-engined trawlers, with greater and greater HP, that in reality are going beyond the definition of trawler…they are becoming motoryachts in trawler clothing. (wolf in sheep’s clothing)

The crux of the problem is when we try to overcome some basic laws of nature in trying to push the monohull form pass its ‘hull speed’ in an efficient manner, whether power or sail. Sorry, but it just takes more power and some ‘planning surfaces’ to do it. Alternatively we can look at pushing longer slimmer shapes that exhibit less hull speed resistance. In the sail mode we have to space these slimmer hulls apart some considerable distance to get stability to carry the sailplan. In the power mode this wide separation is not required necessarily.

In the ever-continuing effort to define the term motorsailer, I particularly liked your Supreme Court Justice quote, “We know it when we see it”. I think this is particularly applicable to the increase in both sailing and powering performance available with the multihull planform over that of the monohull. There are still many boaters that are unwilling to accept these very compelling attributes. As you said, “today's motorsailers are evolving quickly, driven by more knowledgeable owners and designers who derive inspiration from the best boats of the past and improve them with modern design technology and a sure eye.”

Two of the most innovative monohull vessels I’ve seen that take efficient cruising into mind along with increased performance would have to be Chuck Paine's Steadysailer <http://www.chuckpaine.com/zsteadysailer.html>
and Steve Dashew’s FPB (fast pilot boat) series <http://www.setsail.com/dashew/do_PARADIGM.html>
Dashew’s vessel is not a motor sailer as it has no rig, but it is an honest attempt at efficient cruising under power. Here also in the strictly power category the multihull form will present a formidable challenge to the monohull form….just look at the variety of power cats already unfolding.

I believe I have already referred you to my forum posting, “Monohull verses Multihull powersailers / motorsailers”,http://boatdesign.net/forums/showthread.php?t=4499 that starts with a discussion of the Powersailer 20 from New Zealand. Much further along in this subject tread at posting #76 I introduce my observations on the big new MITseaAH
motor sailer http://boatdesign.net/forums/showpost.php?p=45367&postcount=76 . Within this same tread discussion there is another particular posting you might find interesting, “A Liveaboard Cruiser For The Real World” http://boatdesign.net/forums/showpost.php?p=35945&postcount=27


And then I’ve attached another letter I wrote just recently to a gentleman who built a big monohull Rivolta 90 motorsailer http://www.rivoltamarine.com/rivolta90statement.html
In brevity I submitted to him, “When I review all of the virtues you sought for your Rivolta 90, I find I can accomplish all of these same virtues in my 65' catamaran design…..And with half the sail area, considerably shorter mast, less engine hp, less complicated keel arrangement, etc, etc. Thus the building cost/selling price of this vessel should be considerable less”.

Cheers, Brian

[yokebutt]

Methinketh perhaps Brians' just a bit of an unprincipled, opportunistic slut, but then again, that's just based on a very cursory and not-very-well-researched impression.

Yokebuttocks.

[Bob Leask]

This might be a little off the topic for a multihull motorsailor forum, but I just checked out Dashews new design at http://www.setsail.com/dashew/do_PARADIGM.html
and must say that I think it's the most practical real-world cruising boat design I've ever seen. I'm just a little annoyed that it's not my own design, because he has come to so many of the same conclusions I have, for the same reasons, and much the same solutions. The choice between multi and mono for a motorsailer is a matter of tradeoffs as I see it, each would have it's own merits and would be a matter of preference.

One thing I especially like about the FPB design is the use of two booms for a simple sailing rig (never waiting for swing bridges, no useless windage aloft) and doubling as stabalizer outriggers. Stabalizers, sometimes called paravanes, have much potential for offshore yachting and deserve more attention and development.

A few sailors have used them offshore and loved them. By using only the windward one I'm told that the drag is approximately cancelled out by the increased righting moment, plus the boat heels less and rolls a lot less. When stuck in the heavy seas after a blow with no wind, there were times I would have paid anything to have a set of those aboard. I'm attaching a drawing of a very good type of stabalizer which seems to be unknown outside of the west coast of N America, but has been used successfully on sailboats.

[brian eiland]

This might be a little off the topic for a multihull motorsailor forum.....

I don't consider it off-topic at all. I don't consider this just a multihull thread. I like monohull motorsailers as well. I do feel on occassion they have exaggerated some aspects on the monohull craft. Hey, multihulls get oversold as well.

I just feel the motor sailer concept as a whole has been sorely neglected, and needs some OMMPH added to it.

I know how long many of us preached the multihull concept in the early days only to combat many naysayers. Well now some of us feel the need to preach the motorsailer concept, and particularly the multihull addition to the concept.

Yokebuttocks called me an opportunistic slut. Sorry he had to make it personal. I guess I just spent too much time in the past selling the multihull sailing concept, and now feel a need to push the motorsailer, mono or multi.

[brian eiland]

For anyone interested there is a brand new forum taking up the primary subject of Power Catamarans (http://lists.samurai.com/pipermail/power-catamaran/). Naturally some discussions have arisen as to the power & sail combination.

Malcolm Tennant has recently made a posting on a portion of his view on the motorsailing catamaran subject, http://lists.samurai.com/pipermail/power-catamaran/attachments/20050420/946d507d/MOTORSAILERSforPASSAGEMAKER.doc

[Guillermo]

I don't consider it off-topic at all. I don't consider this just a multihull thread. I like monohull motorsailers as well. I do feel on occassion they have exaggerated some aspects on the monohull craft. Hey, multihulls get oversold as well.

I just feel the motor sailer concept as a whole has been sorely neglected, and needs some OMMPH added to it.

I know how long many of us preached the multihull concept in the early days only to combat many naysayers. Well now some of us feel the need to preach the motorsailer concept, and particularly the multihull addition to the concept.

Yokebuttocks called me an opportunistic slut. Sorry he had to make it personal. I guess I just spent too much time in the past selling the multihull sailing concept, and now feel a need to push the motorsailer, mono or multi.



Brian:
I want to thank you for your devotion to motorsailers and your enthousiasm and efforts to widespread the concept. I have been following you since some years ago, as I'm the commodore of the Banjer 37 Motorsailer Club and keep a site at www.banjer37.net, where we also talk about motorsailers and some links to your pages have been added.
Keep on doing the good work.
Best regards.
Guillermo Gefaell

[Bob Leask]

I considered a reply to Yokebuttocks (his handle says it all) but like his ilk in the amateur radio world the worst thing you can do is acknowledge their presence. I don't doubt he's wanking off on the 2 meter band when he's not here. I do like this forum and appreciate the time you've put into it.

I'm still favouring a catamaran as my ideal boat because I feel a multi beats any mono as a liveaboard. However if I ever got the urge to go wandering around the world again I would probably choose something like Dashews Unsailboat. Dashews design would be a good choice if you planned to do a lot of miles offshore, and wanted to visit places where moorage is scarce. On the other hand for off the beaten path places where beam is not a problem, the cat is the hands down winner.

Some of the qualities I admire in Dashews design which are usually lacking in modern designs are:

flush decks for high structural integrity, a well thought out plan for handling and storing the dinghy (very important), all around unobstructed visibility from the deckhouse, consideration of the seakeeping qualities of the boat, as opposed the the speed-is-everything monomania of most contemporary yacht designers, shallow draft, designing for efficiency at a modest speed as opposed to throw-in-a-bigger-engine

About the only thing missing is a hard canopy over the aft deck. One of the nicest things about motoryachts is that shady aft deck where you can put tables and chairs and sleep there in the tropics when it's too hot to be inside. I always liked mooching a cold beer from people on motoryachts when it was 50 degrees C down below in my keelboat.

[brian eiland]

I've had this one stored on my computer for some time now. She is a beauty

Custom, 52’, pilothouse, twin engine, auxiliary cruising sloop with clipper bow, counter stern, round bilge and full ballast keel with slot for drop keel designed to be lovely and functional. She has best of everything and sails in a manner one would expect of such lovely yacht.

Dimensions
LOA" 51'6" Beam: 13'5" Displacement: 41,000 lbs
Draft: 5'2" / 9'3"
Engines
Engine(s): Volvo Engine(s) HP: 60 Engine Model: MD30A
Cruising Speed: 7.5 kts Max Speed: 9 kts
Tankage
Fuel: 250 g Water: 350 g Holding: 55 g

Accommodations
Below deck, all brightwork is varnished, match grain black walnut. Each locker is fitted with an interior light activated by an automatic door switch. The hanging lockers are lined with aromatic cedar and there are finishing touches such as back-lit etched glass on the china locker doors in the galley and laurel leaf inlays in the saloon and cockpit tables as well as the companionway doors


Mechanical/Electrical
Twin Volvo Penta, MD30A, four cylinder 60 hp marine diesel engines with Walters V-drives (2100 hours). Fuel consumption is approximately 2.3 gallons/hour at 2100 rpm (about 7.5 kts). Two blade bronze self-feathering props by MaxProp on 1 3/8” stainless steel shafts with PSS shaft seals. Wagner hydraulic steering from both steering stations to skeg mounted rudder. Robertson AP100DL autopilot with remote controls for operation from the bow or cockpit.


Sails
Sail area: 1250 sq ft. Sails by Doyle (1997): Main, 105% jib, storm jib which sets on a masthead inner stay, and an 1800 sq ft assymetrical spinnaker in a sock. Rigging: Navtec rod rigging with hydraulic vang and backstay. Hood in-the-mast electric furling, PROFURL electric headsail furling. Winches: 2 – Lewmar #40 ST halyard winches on mast, 2 – Lewmar #30 ST winches and 2 – Lewmar #65 ST electric winches mounted on cockpit coaming

[brian eiland]

Couldn't resist a few more photos

[sharpii2]

Hi everybody.

How about this for an idea.

A design inspired by kayaks.

30ft length.
6ft beam.
5,000lb half load displacement.
200sft of sail carried on two seperate short masts. (Probably gaff rigged)
1000lb ballast on a '70s style fin keel with swept back leading edge.
3hp continuous diesel which would be housed in the center cockpit and would turn a 3 blade feathering propeller.
100gal deisel tankage.
5kt cruising speed goal.
A permanate awning over the center cockpit.
Permanate sleeping for two in the aft cabin and makeshift sleeping for two guests in either the forward cabin or the 7ft long cockpit (depending on the weather).

Who says motor sailers have to be big, bulky, and expensive?

Bob

[brian eiland]

....But why bother with a Capsizing Cat ?, when the same building costs will get a FASTER monohull boat , although longer.

The RV Triton style cruiser would seem to offer the best compromise in an offshore motorsail that is fast , ez in fuel

and COULD RIGHT herself after a CAPSIZE!

Could be YOUR but in those 46- 70 ft waves off FLA!

How am I wrong?

FAST FRED

Fred, from this posting and several others of yours, you seem to preoccupied with the subject of capsize and subsequent recovery. It appears as though you are of the impression that monohull powercraft will readily recover from a capsize.

I would like to refer you to Steve Dashew's analysis as he was looking to build his new power craft, "Stability, Comfort, & Capsize Resistance (http://www.setsail.com/dashew/dashew215.html)" (very interesting discussion and illustrations). One small paragraph from that discussion, "The powerboat industry must assume that there are no capsize risks, because as far as we can see, 99% of all powerboats - right up to 100,000-ton bulk ore carriers - will capsize and not recover, given the right set of circumstances. One of the facts which startled us when doing research for our book Surviving the Storm, was the calm manner in which the professional seamen we interviewed discussed what would happen if the right wave caught them at a vulnerable angle. The norm for most yachts, ships, and military vessels is a maximum heel angle of 65 to 70 degrees, after which the boat keeps going and does not come back. They accepted that their ships would capsize and everyone would die. One of our former clients told us of a 50-knot gale he weathered, hove to behind a parachute anchor, in a heavy displacement 60-foot steel trawler. He said he felt they would not have survived much worse conditions than this modern storm (after which he sold his trawler and went back to sail)."

.... from another forum, "I think that a multi-hull is a fine platform for sailing the oceans of the world, so long as it is not allowed to become entangled in such rough conditions that they become life threatening. I am suspicious that such hulls will become dangerously unstable under conditions that a mono hull would not be endangered. In short the mono hull with a vanishing point of stability of say 110 degrees is more likely to stay upright than a multi-hull where the vanishing point is more like 70 degrees

Hey, Mike, what's the source for that data or is it conjecture?

I'm on the hunt for news of any power catamaran ever capsizing--and so far I've come up empty.

Brian commented:
It's a shame we could not get ahold of that video Derek Kelsall mentioned in his posting, excerpt... "However, imagining lying ahull to those waves did not fit the picture. A couple of clients have described being in a situation where they expected to capsize from the size of the wave and the angle of heel, but then suddenly found the cat was back on its feet again. One of these clients decribed the waves passing while lying ahull and of the most disturbing part being the fall of the windward hull into the trough as the wave passed. The video demonstrated the situation as I understand it. The tank test was done in Southampton comparing a Lock Crowther catamaran ferry with a comparable mono, in large breaking waves and high wind, with the models lying ahull. As the wave hit the cat, which was still in the water, the windward hull was thrown up into the air, looking like an immediate capsize, but before the angle of heel had gone to 30 - 40 degrees, the wave had passed to the lee hull, lifting it just as rapidly to bring the cat level and then fall as the wave passed. The cat never capsized. The mono rolled every time. This situation actually applies whatever the orientation of the catamaran to the waves.

I also find the RV Triton hull interesting, look here (http://www.yachtforums.com/forums/showpost.php?p=8976&postcount=26). But I'll venture to guess she is not self-righting

[DiverDown]

There also is a major difference between fixed keel hulled cats (usually 4.5-5' draft) and shallow draft (<2' daggers up,6' draft or so daggers down) daggerboard cats.Apparently keel hulls won't slide sideways as well and may trip up,but it would still take a hell of a lot.

I spent a lot of time in a large dagger cat in Australia.We were playing around in a cyclone once (daggers up) when everyone else was freaking out and getting extremely beat up.
Very large swells would come from abeam-she would slide sideways down the hill quite a bit.The weather hull would float up and over the crest,and then the crest would drag the lee hull along for a bit and then we would start the ride all over again.

You would have to be trying very hard to flip that thing.

[chandler]

What was the draft of the cat? CB up and down?

[DiverDown]

It's been 13 years...for sure 18" up and I think 6' or so down, 64' by 31' beam.
The cat was very similar in design/dimensions to the Shuttleworth 63.

Fabulous for scooting over the barrier reefs and beaching on a little tropical cay.

[shoulders]

After reading your story I was thinking you might know some lifeboats for sale. Im seriously looking for lifeboats.

Yours sincerely Simon Sluis

sofian@kth.se

[Guillermo]

Here you have my definition for monohull motorsailers:

"Motorsailers should be, in my opinion, hybrids among sailing boats and motor boats, with amplier volumes than those of a pure sailing boat (And to my taste with a nice pilothouse!) to make them more livable and able to carry a generous cargo; have manegeable sails but able to easily develope hull speed under sail alone; have a propeller-engine combination allowing for a fuel efficient motoring and with power enough to reach hull speed, as well as some extra muscle to beat dead to winward in a storm (force 10) in protected waters.
This means, to me, an SA/D ratio from 13 to 15 and a HP/(D/1000) ratio from 2 to 2.5 (Imperial units)
D/Lwl ratio may go from 250 for lighter ones as in many modern designs bred in sailing boats, up to 450 for heavy-weigths long keelers bred in fishing boats"

Now, your criticisms.

[Vega]

Here you have my definition for monohull motorsailers:

"Motorsailers should be, in my opinion, hybrids among sailing boats and motor boats, with amplier volumes than those of a pure sailing boat (And to my taste with a nice pilothouse!) to make them more livable and able to carry a generous cargo; have manegeable sails but able to easily develope hull speed under sail alone; have a propeller-engine combination allowing for a fuel efficient motoring and with power enough to reach hull speed, as well as some extra muscle to beat dead to winward in a storm (force 10) in protected waters.





Regina, Nordship and the new range of Nauticat seem to fit the description. If you want more power than standard they will provide it.

http://www.siltala.fi/
http://www.reginayachts.se/
http://www.nordship.dk/

Regarding motorsailing, for me, the best improvement came from a propeller:
Autoprop, manufactured by Bruntons.

Suppose I have wind to make 3.5 knots and I want to make 6 knots. With the standard propeller I would have to put the motor at 2000rpm. With an Autoprop, to do the same, I only need 1000rpm. There is almost no noise and the autonomy increases almost twice, not to mention costs and motor life.

http://www.bruntons-propellers.com/products/variable/autoprop/

[FAST FRED]

"Fred, from this posting and several others of yours, you seem to preoccupied with the subject of capsize and subsequent recovery. It appears as though you are of the impression that monohull powercraft will readily recover from a capsize."


I was under the assumption that a MOTORSAILOR would have some sails and be as usefull as a std OTS sail boat , where a knockdown is a survivable event.

Some have had the mast submerged and NOT lost the rig , so with the usual smaller rig installed on Motorsailers expect any Knockdown would be survivable .

Sure pure motorboats don't come back up , but a real MOTORSAILOR should easily, and with proper hull and deck constriuction remain watertight integrity and stay afloat.

My concern is many multihulls CANT right themselves and therefore become death traps in the right (perhaps Wrong) conditions.

Having gone offshore in a Headly Nichols Voyager Tri in the mid 60's I know that low aspect ratio keels will allow the hull to sideslip when caught abeam in the small rough stuff 20ft and under. The ride is rough as the vessel assumes the slope of the waveform , but its survivable .

The concern is with the NASA finding that 70ft waves are more common (10X) than previously thought, and that the old 24 ft of beam would be really hard to right after meeting a big one.

Seems silly to me to venture offshore in a vessel that can not take conditions that may be met at times.

Esp when so many simple small monohull boats have met these conditions and survived to continue their voyage . A proper offshore voyaging M/S should be able to SURVIVE even the rough stuff , why endanger folks lives when OTS designs some 100's of years old do so well?

A modern Version of Herrishofs Marco Polo with modern construction and engineering (and a modern interior) should be able to survive any conditions met , even the Southern Ocean . Added stability with modern engineering (roll tanks, gyroscope, bilge keels , powered active foils or RV Triton training wheel style amas ) or just good old fully battened sails should bring the ride up to todays standards.

Anyone got a few tons of Marine Aluminum??

FAST FRED

FAST FRED

[sharpii2]

Here you have my definition for monohull motorsailers:

"Motorsailers should be, in my opinion, hybrids among sailing boats and motor boats, with amplier volumes than those of a pure sailing boat (And to my taste with a nice pilothouse!) to make them more livable and able to carry a generous cargo; have manegeable sails but able to easily develope hull speed under sail alone; have a propeller-engine combination allowing for a fuel efficient motoring and with power enough to reach hull speed, as well as some extra muscle to beat dead to winward in a storm (force 10) in protected waters.
This means, to me, an SA/D ratio from 13 to 15 and a HP/(D/1000) ratio from 2 to 2.5 (Imperial units)
D/Lwl ratio may go from 250 for lighter ones as in many modern designs bred in sailing boats, up to 450 for heavy-weigths long keelers bred in fishing boats"
Now, your criticisms.

Hi Guillermo.

Not a bad definition.

But to say it is all encompassing is to do the type a major disservice.

My definition would be a bit looser.

I would go by what I call "the 25% or over" rule. If a vessel is either sail or motor powered but intends to use the propulsion method not chosen as its main propulsion exclusively for at least 25% of the time, then it is a motorsailer. Thus, if you are on a, say, 3,000nm voyage and you intend to use the engine, if you are a sailboat, or the sails, if you are a motorboat, for at least 750nm of the trip, you are a motorsailer.

This definiton, I think, is inclusive enough to include a vast array of hull types and engine/sail combinations. All the way from a kayak with an unbrella on board to serve as a makeshift down wind sail to take advantge of frequent strong favorable winds to a sailboat with an outboard auxiliary that has extra fuel tanks added in exchange for less light air sails stored in the forepeak.

These two examples are, obviously, at the outer edges of my definition, but I think they definately qualify. And, if that's so, everything else in between qualifies as well.

This, of course, creates new problems, because some vessels are specifically designed to be motor sailors and others just end up that way. Some of the former are primarily sailboats and others are primarily powerboats.

To solve this problem, let me suggest a return to the old "century definiton". That is, if the boat can only sail or power well, its label will add up to 100. So if the boat is primarily a Motor boat but can sail in strong winds and, perhaps, make gruding progress upwind without the motor running, it might be called a "30/70p" motorsailor (or, perhaps, a "25/75p" if it can't go upwind at all without the engine running).

If the vessel can do one really well and the other well enough to consider making an entire voyage (but perhaps a shorter one) using its secondary propulsion system, then its label should add up to more than 100, with the dominate power source having the larger number and the larger number alway being stated last with a single initial signifiying which one it is. So a boat that is primarily a sailboat but can its usual rounds under power alone would be called a: "50/75s motorsailor".

I would further enhance this system by adding a starting initial which would signify the vessel's heft. How about an "L" for light, for vessels with a D/L of less than 100 to 150, "M" for vessels with a D/L of 151 to 270, and an "H" for vessels from a D/L of 271 on up.

With this proposed labeling system, I think one can get a pretty good idea of what a proposed vessel is about by reading just its label. A john C. Hanna "Tahiti Ketch", for example, might be labeled an "h35/65s" motorsailor. The exact numbers in the label would be subject to individual judgement and interpretation and, therefore, should be thought of as only a general indication of the vessel's type and, more importantly, it's design objectives.

Just about every boat I would design would be a "century boat", meaning it's label would only add up to only 100. That being said, I certainly wouldn't fault any one for designing hat I might call a "super-century boat". After all, in the end, it's the client, not the designer, who gets to determine a design a success or failure, or whether its design goals are appropriate or not.

Bob

[chandler]

Is the threat of a rogue wave going to determine design? I can't believe this is a new phenomenon. Every boat should be designed to withstand the seas it can expect to encounter.

[Tennant]

Why dont multihull guys give curves or figures like:
http://www.nordhavn.com/40/overview.htm

And why malcolm tennant in this page
http://www.tennantdesign.co.nz/news.php?story=33
graph : [url]
does compare with a monohull who is the shortest and heaviest boat of the tested boats.

The graph scale also are a bit strange. comsuption per displacement without any unit. Why not simply use GPH ?

Another point for power multihull : the average buyer will burn fuel 50-100 hours only per year but will pay marina fees all year long (even with no use).


This reply is a little belated because I have only just discovered this forum. However I would like to make some comments on the queries by fcfc.

Multihull designers do give performance data. We have data for over 60 of our designs. However it is hard earned proprietary data and we don’t want to make it too easy.

The graph that fcfc refers to was originally drawn for an article comparing different types of catamaran that I wrote for PassageMaker magazine. The monohull , an Ocean Alexander, was an afterthought. We had problems finding a similar type of monohull with with similar performance.

The data was transformed so that the displacement did not make a difference. In absolute terms the differences even are more marked. The Y axis is litres per tonne per nautical mile. I just prefer a measure that tells me how much fuel we are using per nautical mile traveled at a particular speed. We are a metric country. Us gals, Imperial gals? Originally the data on the X axis was given in non-dimensional Froude numbers for our own benefit but as we considered that a lot of the visitors to our web site would not understand Froude numbers we used knots instead. In fact the numbers are relatively unimportant. It is the shape and position of the curves that tells the story.

Fcfc makes a good point concerning marina fees. This difference is probably not as marked in countries outside the USA where fuel costs are much higher. In the USA the relatively low fuel costs mean that outboards and petrol inboard engines are more popular than in many other parts of the world where diesel is much more popular. Regardless of this the cost of a marina berth for a multihull is higher in most places than that for a monohull. So unless you use your boat a lot any fuel advantage the multihull might have is largely negated.

The fuel consumption of 50.6litres per hour is for both motors. The increase in fuel consumption/horsepower very clearly demonstrates the high price you pay for an increase in speed, particularly at the upper end of the speed range. It is very much in line with what you would expect from a displacement hull, even a high speed one. Unless the vessel is longer or lighter, or both, than the Viridian we discourage any attempt to go at more than approx 25 knots, the price is just too high. However the lighter Red Diamond has done a certified 32 knots over the measured mile.

[Milan]

One of the major problems of the motor - sailors are costs. "Traditional" motor - sailors types combine heavy displacement hull with the expensive bermudian rig and strong engine. So, result is slow, expensive boat. It can't sail well especially not to windward (what's the point in wasting money installing bermudian rig on the hull which can't sail against the wind any way). Such a boat isn't very good for motoring either. To be economical she have to motor under the speed 'length ratio of 1, (would be about 6 knots for 36 ft LOA hull). Faster then that just digs deeper hole in water wasting a lot of fuel for marginally faster ride.

Multihulls offer very interesting possibilities but at the high price I'm afraid. If budget isn't limited that's fine, but unfortunately, for most people costs does meters. If one wants economical, (to build, run, and maintain), motor boat or motor sailer, long, narrow nad low mono hull with a minimum windage and wave making resistance, could be the best answer. Such a hull would move with a respectable speed under engine, burning little fuel. There is no need to sail to windward, so no need to use expensive sail rigs of contemporary sailing boats. For the reaching and running, low aspect sail plan actually works better then high aspect. It's also much cheaper. Perfect sail shape is not so critical so you can make your own sails for very little costs. Masts could be solid wood pole, rigging galvanized wire, winches not needed. FIn (fins) could be a lot smaller, enough to give stability against capsize, but with a less drag than sailboat fin. Such a boat of about 15 m LWL and 3 m beam could heave constant cruising speed of about 8 - 10 knots, giving daily mileage of around 200 miles using very litle fuel and being very easy to sail when the wind is wright. That should apeal to the lots of boaters. George Buhler designed his "trollers" more or less along these lines. Sharpii2, for kayak inspired design look at the Wunderberg, for more affordable size Pilgrim.

http://dieselducks.com/Wunderberg.html
http://dieselducks.com/Pilgrim.html

For the people who would like Dashew non - sail boat but can't afford it, have a look at the simpler, traditional similar concept:

http://dieselducks.com/ellemaid.html

Milan

[Guillermo]

Regina, Nordship and the new range of Nauticat seem to fit the description....

Vega:
I find NORDSHIPS and REGINAS could be better classified into something like a "Pilothouse Sailing Cruisers" category, rather than Motorsailers (under my definition), because models I've checked have a D/L under 250 and SA/D well over 15.
On the other hand, NAUTICATS fall better into my definition, although I find some models overpowered.
I agree with you on the autoprop point: That kind of propellers are a great convenience to motorsailers, and not only.
Regards,
Guillermo.

[chandler]

I think most motor sailor owners appreciate the silence of sailing without the rigors of sailing.

[Guillermo]

..... "Traditional" motor - sailors types combine heavy displacement hull with the expensive bermudian rig and strong engine. So, result is slow, expensive boat. It can't sail well especially not to windward (what's the point in wasting money installing bermudian rig on the hull which can't sail against the wind any way)....
Milan


Have a look at the very nice Paul Gartside's Motor Sailors: http://www.gartsideboats.com/catsail6.php

Regards,
Guillermo.

[Guillermo]

....This definiton, I think, is inclusive enough to include a vast array of hull types and engine/sail combinations. All the way from a kayak with an unbrella on board to serve as a makeshift down wind sail to take advantge of frequent strong favorable winds to a sailboat with an outboard auxiliary that has extra fuel tanks added in exchange for less light air sails stored in the forepeak....

....With this proposed labeling system, I think one can get a pretty good idea of what a proposed vessel is about by reading just its label. A john C. Hanna "Tahiti Ketch", for example, might be labeled an "h35/65s" motorsailor. The exact numbers in the label would be subject to individual judgement and interpretation and, therefore, should be thought of as only a general indication of the vessel's type and, more importantly, it's design objectives.

Bob

Bob:
I find your definition of motorsailers quite loose, indeed! In my opinion we should narrow it, as to all of us know what we are talking about when we talk about motorsailers. If you want to find my way of thinking about them, you may visit the page I make just for fun at: http://banjer37msclub.tripod.com/motorsailers.htm

About your proposal for the labeling system I find it interesting and it could be great to quickly indicate the designing concept. But maybe it depends too much on "...subject to individual judgement..." When you navigate internet and boating literature you find a lot of imprecise talking about XX/YY combinations based many times on the feelings and enthousiasm of the author, not facts.

Regards,
Guillermo

[Vega]

well, Guillermo, looks like we share some common points in the definition of what is a MOTORSAILOR, but also some differences.
I think that the concept of Motorsailors has changed. Of the original concept, back from the 60s, based in the Nordic fishing boats, only the Nauticats (the old line) and the Fishermans remain in production (to my knowledge), both boats representing now a marginal branch to both companies. Northshore bets on the Southerlies and Nauticat has gone to a new line of boats, a new line they have called “Pilot house sailing yachts”, by opposition to the other line they call “Traditional”.

They could also have called the new ones “Modern”, because it is what they are. For me that kind of boat is the new Motorsailor:

They are different from Sail boats because the motor they carry is not just for going in and out of port, but have the capacity to drive the boat (in conjunction with the sails) in any situation and for a long time. Of course, for that they have the capacity to carry two or three times more fuel than a sailboat of the same size.

They are different from the old Motorsailors because they carry more sail, are less heavy and not so high. They can sail almost as well as a modern sailboat and a lot better than a lot of older sailboats. They don’t need to carry as much fuel as the older type because they can use wind a lot better and they don’t need to carry so much water and provisions, because they are a lot faster. Oh, I almost forgot, they are also more seaworthy than the vast majority of traditional sailboats. Normally modern ocean going sailboats have a LPS of 125. This new kind of boats goes for a minimum of 135 and can go as high as 160.

They also offer an interior steering post with good visibility all around. With one of these, sailing is always a pleasure even with rain or cold.

I Think that Chandler defines very well the market:

“I think most motor sailor owners appreciate the silence of sailing without the rigors of sailing.”

Well, there are not new “old type motorsailors” arriving at the market (for many years), but, on the other hand, from the new type (according to my definition) there are several new boats arriving.

Take a look at the new 385 from Nauticat and the new 40 from Nordship.

http://www.siltala.fi/385info.html

http://www.nordship.dk/

Bottom line, from your definition I agree with this:

"Motorsailers should be, in my opinion, hybrids among sailing boats and motor boats, with amplier volumes than those of a pure sailing boat (And to my taste with a nice pilothouse!) to make them more livable and able to carry a generous cargo; have manegeable sails but able to easily develope hull speed under sail alone; have a propeller-engine combination allowing for a fuel efficient motoring and with power enough to reach hull speed, as well as some extra muscle to beat dead to winward in a storm (force 10) in protected waters.”

And that is your full definition.

The only difference is that it looks it means different things for you and for me.

[Guillermo]

Vega:
As I stated in the last part of my definition you omited, the clasification of "modern" or "old" motorsailers should be related, from my point of view, with the D/L and SA/D ratios.
Old motorsailers (Banjers, Fishers and the like) went for as high as 450 for D/L and modern ones tend to be more in the 250-350 range, so they are quite lighter. The reason for this evolution are modern materials, engines and equipments. SA/D ratio for modern motorsailers tends to be between 13 and 15, so they are quite sail efficient, while old ones' ratio was more in the 10 to 12 range, or even less, as sails were rather conceived as auxiliary (You couldn't do wonders with D/L's of 400-450!)
Pilothouse Sailing Yachts are, in my opinion, close cousins to Motorsailers, and boundaries are, of course, diffuse. They are even lighter and with more sail area, caracterized by a D/L ratio from around 200 to 300 and an SA/D ratio from around 16 to 18. To see some time advanced designs of this concept, you may have a look at Ted Brewer's Panoceanics: http://www.panoceanic.net/, already designed in the 80's
It has to be noticed that most of the actual manufacturers of Pilothouse Sailing Yatchs do define precisely them as such, not as motorsailers.
Nowadays there is tendency (Paradigmatic in the USA market) to overpower these Pilothouse Sailing Yatchs, probably conceived for short seas - fair weather islands hopping, giving them HP/D ratios well over 3, and providing wide flat sections at the stern. That's why I think this concept is getting apart from the motorsailers one and boats under the PSY category should not be classified as MS.
Regards,
Guillermo.

[FAST FRED]

With wide semi displacement sterns the PSY may not do well in heavy seas ,
and may be impossible to hove to.

Add the light scantlings , large deck house and seaworthyness further diminishes

A motorsailor (to me ) is a capable offshore vessel , not a weekend inshore toy.

Wonder how many of these PSY ever go to Bermuda in December?

Wonder how they handle with 30-60 man days of food & water per seagoing bunk?

FAST FRED

[Vega]

Guillermo:

I agree with you when you say:

”Pilothouse Sailing Yachts are, in my opinion, close cousins to Motorsailers, and boundaries are, of course, diffuse. They are even lighter and with more sail area…”


But when you say:

“Nowadays there is tendency (Paradigmatic in the USA market) to overpower these Pilothouse Sailing Yachts, probably conceived for short seas - fair weather islands hopping, giving them HP/D ratios well over 3, and providing wide flat sections at the stern. That's why I think this concept is getting apart from the motorsailers …”

I think you are putting to many things in the same bag. I am an European and I don’t know the American boats as well as the European, but one of the new Pilothouses in the American Market is the Cabo Rico 42 PH. That is not a flat bottom boat and certainly it is not designed for “short seas and fair weather islands hopping”.
Probably you are referring to the Hunter 426 DS and boats alike. This kind of boat, that has the same flat hull as the “normal cruising” version, has very little in common with the Cabo Rico 42PH. On the other hand the Cabo Rico has a lot of points in common with a modern motor sailor, so many points (seaworthiness, long range passage maker, power and fuel to motor or motorsail for a long time, etc) that for many, the boat is a Motorsailor”.

Around here it is the same, there are some companies that have the same (flat) hull in a Deck Saloon version, like the Sun Odyssey 40 or 43 DS. These boats are so far away from Nauticats, Reginas or Nordships as the Hunter is from the Cabo Rico. They don’t have flat hulls and are all very seaworthy boats, in a word, passagemakers.

You are right, these boats come in the “Panoceanics” tradition and like these are intended for extensive travel. Main difference seems to be on the underbody
That appears to be more modern and faster on these new reformulations.

You say that:

“… most of the actual manufacturers of Pilothouse Sailing Yachts do define precisely them as such, not as motorsailers.”

And you are right but I think that it is just because the word “Motorsailors” has in the sailing community a somewhat negative connotation ( old, slow etc). Fact is that when European sailing magazines test these boats, they call them many times Motorsailors.

One of the few that is not ashamed to call their bopats motorsailors is the “Degero”, a Finnish good quality boat. His boats are advertised as Motorsailors:

http://www.saltyseas.com/boatindex/sailboats.htm

If you take a look at the boat data you are going to see that it is a similar boat to Reginas or Nordship.

http://www.degeroe.com/segelyacht/38ds-home.htm



Fast Fred, all the boats I was talking about are oceangoing boats. They are not planning boats and their hull is not flat. They are all small production, very solid and unfortunately, expensive boats.
Once I have read a test of a Nordship 43 published in “Yacht” the biggest German sail magazine.The wind was blowing between 25 to 30 knots and the boat was making over 7 knots in all sailing positions. The main comment on the boat was: “A boat for all weather” and the German are kind of shy regarding compliments.

Finally, I would like to say that I like almost any kind of boat, including “Traditional Motorsailors”.

Best regards

Vega

[Guillermo]

....I think you are putting to many things in the same bag. I am an European and I don’t know the American boats as well as the European, but one of the new Pilothouses in the American Market is the Cabo Rico 42 PH. That is not a flat bottom boat and certainly it is not designed for “short seas and fair weather islands hopping”....

....One of the few that is not ashamed to call their bopats motorsailors is the “Degero”, a Finnish good quality boat....




Vega:
I'm an European, too, investigating the motorsailers concept world wide, just for thew pleasure of it.
Cabo Rico 42 PH is a very nice ocean going sailing yacht, with a D/L of 361, an SA/D of 16.18, and a HP/D of 2.78
So, from my point of view she has somewhat big sails to be a motorsailer, but modern rigs and gear allow nowadays to handle bigger sails even to a short handed crew, although, of course, for a price. I do not know her hull lines but she looks like being quite effective under sail alone. Maybe that's why the manufacturer does not market her as a motorsailer. I think she is well classified as being an Ocean Going PSY, close to the concept of an Ocean Going MS (The diffuse boundaries I talked about)
On the other hand this manufacturer is the same for the Northeast 400, marketed as a Motorsailer. Northeast 400 has a D/L of 249, an SA/D of 14.02 and an HP/D of 3.74 . So she is proportionally much lighter than Cabo Rico 42, has less sail area and a bigger engine. Stern sections seem to be flatter than those of the Cabo Rico 42. Also this boat has proportionally bigger windows in the pilot house, to my taste, probably noy allowing her to be classified under Design Category "A" under the CE RCD rules. She'd probably qualify as "B" category (60 miles off coast) at its most.
Well, I'm not going to correct Cabo Rico's denomination for their boat, but what I'd say is that she doesn't look to me an ocean going boat. I find she has been designed rather as a fast coastal motorsailer. I would like very much to know her designer opinion.
I've checking DEGERO's yatchs. The manufacturer does not talk about them as being Motorsailers. As a matter of fact they only add the "MS" letters to the 28 feet model. The rest have "S" or an "DS" surnames. Interesting the 28MS seems to have an SA/D of 17 and an HP/D of 3.87 (!!). I find the 36DS and 38DS as coming into to my motorsailers concept.
All of the DEGERO models have somewhat short fuel tankage, so they seem to be conceived also for short seas hopping, (this having a lot of sense for a Finnish boat), although here under the North European style.
Should we talk about two different nowadays approaches to Coastal Motorsailers: Fair Weather (Northeast 400 approach) and Rough Weather (Degero's or Paul Gartside's approaches)?
Of course coastal boats can do passagemaking with fair winds...
And, should we talk also about having two categories for Ocean Going Pilothousers: PSY and PMS? (Both of them for rough weather, of course!)
Nice discussion.
Regards,
Guillermo.

[FAST FRED]

"she has somewhat big sails to be a motorsailer"

Simpler just to call the old very heavy displacement MS with huge engines and tiny sails 50/50s

And the modern light boat and engine with REAL sail ability 90/90.

Of course the add dept of every old slug in the world will claim its a 90/90 !

FAST FRED

[Vega]

Fast Fred, 90/90, that's a good one. That's what I was talking about when I was referring to the new Motorsailors, or should we call them Sailmotors? LoL!

Anyway I am talking about semi-custom boats, and if you want a smaller mast they will mount one, if you want a slightly bigger motor, they will provide one, that's not a problem. Anyway if you don't want to carry all the sail, you can always take a reef.

Guillermo I do agree with Fast Fred in the definition of a different motorsailor, but I don't share his contempt for traditional motorsailors (old slugs?). I have been at your site and was impressed with the quality and the level of participation in the forum dedicated to a boat manufactured in relatively small numbers.
I didn't know the boat and she is a nice boat, a boat that deserves the big amount of care that the typical owner seems to provide in the maintenance and improvement of his boat.

Regarding the pleasure that comes from "investigating the motorsailors concept world wide, just for the pleasure of it", that is also a pleasure for me and not only with motorsailors, but also with sailmotors LOL.

Do you know this one?

http://www.sirius-werft.de/

The real boat looks much better. I have been inside one in the Dusseldorf boat show, and the interior is amazing.
She is also a very fast boat her looks are misleading. They have a big club and they race their boats, can you believe it?

Best regards

Vega

[Guillermo]

Vega,
Thanks for your kind words about our Banjer 37 web pages.

I've found the SIRIUS yatchs very interesting boats, coming exactly into my definition of motorsailers. They have an D/L around 250 (quite light!), SA/D around 13 and HP/D around 2.5 They are designed under Category A, so real oceangoing yachts. The only "..but.." could be I find the fuel tankage only useful for coastal cruising (Same problem with Degeros).

Have you seen the Vancouver 38 Pilot? ( http://www.northshore.co.uk/) Wonderful boat, too. Somewhat heavier (D/L around 350) and with bigger sails (SA/D = 15.7), has an HP/D of 2.5, designed under A Category, but also with a somewhat short tankage (I estimate a range of around 370 miles at it most)

I've found this tankage problem to be quite extended. It seems many modern Motorsailers said as ocean going ones, do not fulfill the expectations because of the tankage. The pursuite for lightness and sailing performance has this penalty.

Interesting to know that Banjers, our old heavyweight ladies, have a fuel tankage of 900 l, so being able of around 900 miles under engine alone at 6 knots. That's really convenient, from my point of view, although you pay the price of the big displacement, of course. And even more interesting is to know that Banjers were not conceived as ocean going motorsailers, but coasters. Maybe to be able to do extended coastal crusing in grounds where there was a lack of fuel supplies? (...Mediterranean 35 years ago?)

I'd like to find one of these modern Motorsailer designs, in the line of Vancouvers and Sirius, but with some more range under engine, what I consider most convenient for globetrotting purposes. Do you know some? ...Or, are we obligued to go heavyweight for that?

Fast Fred: The problem, from my point of view, is that XX/YY talking is too imprecise and whisful thinking influenced (excellent for sales people..!).

Regards to both of you,
Guillermo.

[Vega]

Guillermo:

Yes I know the Vancouver 38 pilot. It is the old 38 Vancouver with a pilot house. It is a good, nice and very seaworthy boat, but also a very expensive one - something like
290 000 euros (standard boat) and it comes only with a 365 l fuel tank. If you want you can mount (and pay) the additional tank.
Almost ( if not all ) oceangoing boats come with a standard diesel tank, but if you want you can mount another, as an extra. Normally this kind of boat comes with a diesel tank of around 300l, with an option to mount another, and that is more than enough for a boat that can sail well.

About the Sirius take a look at this "Ocean" version. As you can see they have mounted another diesel tank.

http://www.sirius-werft.de/Presse/38DS_Ocean_211103_en.pdf

About your quest:

"I'd like to find one of these modern Motorsailer designs, in the line of Vancouvers and Sirius, but with some more range under engine, what I consider most convenient for globetrotting purposes. Do you know some?"

It is also what I am looking for, not only for the pleasure to look at nice boats, but also because I intend to have one of those when I retire (a solid seaworthy boat that can be easily handed solo, with a sheltered place to steer and a long range), some years from know.

The real problem is not finding one, but finding one I can afford. I am looking at a maximum price of 350 000 euros, and that includes taxes, all the extras. Generally this means that the Standard price of the boat should be around 250 000 euros. I am not interested in a used boat. I think that this kind of used boat has a highly inflation price. Typically a used 10 year old boat costs you 30% less and probably you have a lot of expensive things that need replacement and a lot of others that can malfunction at any moment.

There are lots of boats that suit my needs, but not my money, for instance this one:

http://www.victoire.nl/schepen.php?boot=7

I have found that the ideal boat for this kind of program, is between 40 and 43 ft., but I have also found that this kind of boats, in that size range cost more than what I can afford. So, I am looking for the same kind of boats between 38 and 40 ft., and here they become rare (long range ocean going boats). This is the size that matches the 350000 euros :rolleyes: . There are some exceptions though; I mean boats over 40ft that come inside the budget.
What prices are you looking at? Or are you a lucky guy that has no need to worry about that?

I have to go. Nice talk :) .

Vega

[Guillermo]

...I would further enhance this system by adding a starting initial which would signify the vessel's heft. How about an "L" for light, for vessels with a D/L of less than 100 to 150, "M" for vessels with a D/L of 151 to 270, and an "H" for vessels from a D/L of 271 on up....
Bob


Sharpii 2:

Here my proposal for a labeling system for boats with motor and sails:

M35-14/2

Where:

Letter relates to the number of hulls: M: Monohull; C: Catamaran; T: Trimaran

Number after letter is the integer number for (D/L ratio)/10. So 250 would be just 25, 372 would be 37, etc.

First figure in fraction: Integer number of the SA/D ratio, so 14.56 would be just 14.

Second figure in fraction: Integer number for HP*1000/D. So 2.35 would be just 2, 3.15 would be 3, etc.

Maybe this system is somewhat "connoisseurs" oriented, but I think it give us a more accurate idea of the boat's concept than the XX/YY system.


Vega:
Sorry for the delay in answering, but business distracted me from the important things... :)
No I'm not so wealthy as to say money is not a problem. As matter of fact it is the problem. 350.000 are big moneys for me, so no way of spending them in boats. I'm rather planning to invest in them, by (someday) designing, professionally building and commercializing my dreamed motorsailers.

Regards,
G

[Vega]

Guillermo:
Yes, many times money IS the problem. Anyway I don't have that kind of money, I just hope to be able to raise it when the moment comes, and for that I will have to sell a lot of things...but we don't live for ever, and that boat (the retirement boat to travel and live aboard) is a priority for me.

Fortunately, dreaming is for free, so take a look at some nice Pilothouses and Decksaloons that unfortunately are mostly out of my imaginary budget. ;)

http://www.buhlboats.dk/forside.htm
http://www.yacht-design.nl/satellite/designs/northman40.html
http://www.heymanyachtdesign.com/in2_44p.html
http://www.fantasi-yachts.se/yachts.asp?lang_id=1&id=1
http://www.eversail.nl/
http://www.eestimaa.ee/seafinn/index.php?txt_sub=37&kuva=alam&txt_main=16&keel=eng&pg=sisu
http://www.luffe.com/yachts.php?language=eng&site=yachts&range=43_ds&page=draw
http://www.heymanyachtdesign.com/in2_29.html
Best regards

[Guillermo]

Analizing 45 motorsailers from 25 to 54 feet, I have found that dividing the SA/D ratio by 6 times the HP/D ratio, the result should be around one (1.00) for what I understand as proper 50/50 (90/90?) oceangoing motorsailors.

So we may use, to compare things, a new HP/D ratio formulated as:

HP*6000/D

Then we can approximate this number to the closest integer and introduce it in the labeling system I proposed before, so the "fraction" into the label give us a better idea about the relation among power of sails and engine.

So, a monohull with D/L ratio of 356, an SA/D ratio of 14.5 and an HP/D ratio of 2.3, would have a label like:

M35-14/14

If the fraction in label is lower than one, then the boat is motor oriented and if bigger than one, sail oriented.

Another option to simplify the labeling is to eliminate the hull letter and express the D/L ratio as a range, in the line of Sharpii2 proposal (Light, Medium, Heavy, Very Heavy, or similar), so we could label the boat with the ratios upwards mentioned as: H14/14

The benefit of this labeling system, against the century formula is that saying that a boat is a 50/50 says nothing about the real sail and engine power of the boat, and this new label I propose does.

[Ragman]

Hi all
Has anyone heard of the Co. called Sea Horse marine in South of China. They make a motorsailer there, think it's about 45 to 50 ft. Any comments ??

[Guillermo]

Here the link to their pages:

http://www.seahorseyachts.com/

Regards,
Guillermo.

[Ragman]

Tank you Guillermo for your fast reply. I know the website but some how they are very poor in responsing to enquiries so i rather try to get some info on their motorsailer from this forum as i can't seem to get anything from their email contracts as posted.

Cheers
Ragman

[brian eiland]

.....so i rather try to get some info on their motorsailer from this forum as i can't seem to get anything from their email contracts as posted.Cheers Ragman

Take a look back at posting #79 and click on website <http://www.bwsailing.com/01articles/issue/0405/bwb.htm>. There is mention made of Seahorse Marine. I've corresponded with Bill Kimley, the owner, on several occasions a few years back. But he has since built his Mandarin 52, bought a fiberglass production facility, and been pretty busy with his troller vessels. He just might be a little busy to answer all inquiries right away.

[Guillermo]

PROPOSED (ALL BOATS) NEW LABELING SYSTEM:

M 14/14

First figure relates to the SA/D ratio (to the closest integer), so to the sailing power, and
Second figure relates to the 6*HP/D ratio (to the closest integer), so to the motoring power.

Letter is related to the D/L ratio, as follows:
VL = Very low D/L ratio, under 100
L= Low D/L, from 100 to 200
M = Medium D/L, from 200 to 300
H = High D/L, from 300 to 400
VH = Very Heavy D/L, 400+

- If ratio in label is greater than one, the boat is sailing oriented. If less than one, motoring oriented.

- If first figure is 14+ the boat has plenty of power under sails alone. Lower than 10 seems too low sails power to me for a motorsailer: The boat should rather be considered a "sail assisted motor boat". Higher than 16 the boat should probably be better classificated as a pure sailing boat, with more or less engine power.

- Second figure being over 18 usually means quite an excess of engine power, in my opinion. For an efficient motorsailer, it should be around 14, let's say from 12 to 16.

- What are called 50/50 motorsailers by the "century" rule, become 14/14 (more or less) under this labeling system.

For samples with various motorsailers, please visit: http://banjer37msclub.tripod.com/motorsailers.htm

The benefit of this labeling system, against the "century" formula is that saying that a boat is a 50/50 motorsailer says nothing about the real sail and engine power of the boat, nor if she's light or heavy, while this new label I propose really does.

Now we can even add some letters at the end, to better explain the intended design (Or marketing!) concept, as MS for Motorsailers, PH for Pilot House, RS for raised saloon, OC for ocean cruiser, etc, etc (and even a letter for the number of hulls, if necessary). So, if we read something like M16/12 RS-OC, we can understand the boat is a "medium weight, sail oriented, raised saloon ocean cruiser" most probably with a good performance under sail and with an engine allowing for economic motoring passages but having yet enough power reserve to beat to winward in a gale.

Guillermo.

[sharpii2]

PROPOSED (ALL BOATS) NEW LABELING SYSTEM:

M 14/14

First figure relates to the SA/D ratio (to the closest integer), so to the sailing power, and
Second figure relates to the 6*HP/D ratio (to the closest integer), so to the motoring power.

Letter is related to the D/L ratio, as follows:
VL = Very low D/L ratio, under 100
L= Low D/L, from 100 to 200
M = Medium D/L, from 200 to 300
H = High D/L, from 300 to 400
VH = Very Heavy D/L, 400+

- If ratio in label is greater than one, the boat is sailing oriented. If less than one, motoring oriented.

- If first figure is 14+ the boat has plenty of power under sails alone. Lower than 10 seems too low sails power to me for a motorsailer: The boat should rather be considered a "sail assisted motor boat". Higher than 16 the boat should probably be better classificated as a pure sailing boat, with more or less engine power.

- Second figure being over 18 usually means quite an excess of engine power, in my opinion. For an efficient motorsailer, it should be around 14, let's say from 12 to 16.

- What are called 50/50 motorsailers by the "century" rule, become 14/14 (more or less) under this labeling system.

For samples with various motorsailers, please visit: http://banjer37msclub.tripod.com/motorsailers.htm

The benefit of this labeling system, against the "century" formula is that saying that a boat is a 50/50 motorsailer says nothing about the real sail and engine power of the boat, nor if she's light or heavy, while this new label I propose really does.

Now we can even add some letters at the end, to better explain the intended design (Or marketing!) concept, as MS for Motorsailers, PH for Pilot House, RS for raised saloon, OC for ocean cruiser, etc, etc (and even a letter for the number of hulls, if necessary). So, if we read something like M16/12 RS-OC, we can understand the boat is a "medium weight, sail oriented, raised saloon ocean cruiser" most probably with a good performance under sail and with an engine allowing for economic motoring passages but having yet enough power reserve to beat to winward in a gale.

Guillermo.

I Like your new system. It may be better than mine. Under my 'century' system, if a boat has at least '50' in one or the other propulsion category, it would be capable of making an entire voyage under that propulsion category.
That way, if it were an 'P 70/30 H', it would be a heavy sail assisted powerboat. It could only make an entire voyage under power. Beating off a lee shore under sail alone would not likely be in the picture for this boat. But not neccessarily.

That being said, your system is more descriptive because it tells you how much sail or power you have.

When you said hp/D do you mean hp per ton? And if so, do you mean intermitten, peak, or continuious?

It's interesting to note that more than a few 'pure sailboats' have S/D's of considerably less than 14. I know of several that are less than 12. For my money, I would make the cut off point less than 10 even though I know of a few that were less than even that.

Bob

[Guillermo]

Bob,
My system tells nothing about the range under engine, because that depends also on the amount of fuel carried. I've found many actual 36-40 ft+ motorsailers that even having a good HP/D ratio, they carry only around 3-400 lts of diesel, wich is not enough for a long passages scheme nowadays, in my opinion. (Although you always can sail the world without an engine, for sure!)

When considering power for my system, I always consider continuous, although this concept is dissapearing nowadays from the talking of actual engines manufacturers.

Yes, a pure sailboat can have a very low S/D, and for sure have no engine at all. But you know, we are talking about finding a more or less accurate way of simply transmitting a gross idea of the capabilities of a certain boat. And even for sailing boats with low S/D and no engine, they may be labeled let's say as an H 12/0 or so.

Regards,
Guillermo.

[Vega]

PROPOSED (ALL BOATS) NEW LABELING SYSTEM:

M 14/14

First figure relates to the SA/D ratio (to the closest integer), so to the sailing power, and
Second figure relates to the 6*HP/D ratio (to the closest integer), so to the motoring power.

Letter is related to the D/L ratio, as follows:
VL = Very low D/L ratio, under 100
L= Low D/L, from 100 to 200
M = Medium D/L, from 200 to 300
H = High D/L, from 300 to 400
VH = Very Heavy D/L, 400+

.

That makes sense to me, but why not be a little more informative?

Why not put the complete information about D/L ratio in your system?

It would give something like this: 295/14/14 and 305/14/14. These boats, by your system, would be classified diferently, the first as a Medium displacement boat and the second as a high displacement boat, even if they are very close to each other in what concerns D/L.

[sharpii2]

That makes sense to me, but why not be a little more informative?

Why not put the complete information about D/L ratio in your system?

It would give something like this: 295/14/14 and 305/14/14. These boats, by your system, would be classified diferently, the first as a Medium displacement boat and the second as a high displacement boat, even if they are very close to each other in what concerns D/L.

Because the exact D/L is really not that important. What we're looking for is a general idea of the boat's 'size' and likely capabilities. Since the 295 D/L and the 305 D/L are so close together, you might as well call them both 300's.

Besides, the D/L number doesn't tell us as much as it seems to. A 'plank on edge' and a 'skimming dish' can both have the same D/L though they really have little else in common. Not only that, but by having the keelson hovering just above the water for as much as 1/3 or even 1/2 the length of the actual hull has been a rule cheating device used for generations.

When the D/L is quoted, the implicit assumtion is that the boat has rather typical proportions. Such as a Beam that is 3/10 to 1/3 it's Length and a Waterline that is 3/4 to 7/8 its Length as well. And that the 'overhangs' are little more than a raked bow and transom. If these assumtions are true, then the D/L ratio can tell us some real useful though generally vague imformation.

It must be noted that if two boats have the same Length, Beam, and Displacement but relatively small difference (say 10-15%) in waterline lengths, they can have a really drastic difference in D/L numbers.
Take a 3,000lb 20 footer for example. If it has a 20ft WL, its D/L is 169, but if it has an 18ft WL, which is only 10% shorter, it has a D/L of 233.

One would clearly be classified as 'light' where as the other would clearly be classified as 'medium'.

Bob

[Guillermo]

Why not put the complete information about D/L ratio in your system?


Hi, Vega
Bob took off the words from my pen!
I agree D/L is not such a relevant parameter to be in the labeling system as they are SA/D and HP/D. I think we only need to have an idea of what is the kind of displacement the boat we are trying to describe has, in a very simple and illustrative way. In my opinion VL, L, M, H & VH letters illustrate quite well the concept.

[Guillermo]

We can add some letters at the end of my labeling system, to better explain the intended design (Or marketing!) concept, as MS for Motorsailers, PH for Pilot House, RS for raised saloon, OC for ocean cruiser, CC for coastal cruiser, etc, etc (and even a figure for the number of hulls, if necessary).

So, if we read something like M 16/12 RSOC, we can understand the boat is a "medium weight, sail oriented, raised saloon ocean cruiser" most probably with a good performance under sail and with an engine allowing for economic motoring passages but having yet enough power reserve to beat to winward in a gale in protected waters.

Going further, we can try to look for how to better enphasize and define some subtle but most important differences like the ones between boats labeled as M 14/14 CCPH and M 14/14 OCPH. To this end, and using what's already available in the industry, we can add the UE Category Design letter (A, B, C, D) which in a very precise way defines the designed weather-coping ability. So we arrive to the very precise:

Full Labeling System
"A" M 16/12 PHMS

We have labeled here a real ocean going, medium weighted, sails-only oriented, nicely powered, pilothouse motorsailer.
A whole lot of a definition. And a whole lot of a boat.

For those not familiarized with the UE Design Category, here you have the meanings:

- A, applies to boats designed to cope with winds in excess of force 8 and waves over 4 m. Oceanic.
- B, to boats designed to cope with winds up to force 8 and waves up to 4 m. Short open seas passages.
- C, to boats designed to cope with winds up to force 6 and 2 m waves. Coastal sailing.
- D, to boats designed to navigate in protected waters, maximum force 4 and 0,5 m waves.

In most European countries you are allowed to sail only within a zone defined by the local authorities, based on the Design Category and the safety equipment carried aboard. In Spain, with the proper safety equipment, you have no restrictions for a boat labeled "A"; you can go off to 60 miles from a shelter, for category "B"; 25 miles for category "C" and 5 miles, in sheltered waters only, for category D.

For more on this and more Motorsailers & Motorsailing matters, visit the new web pages at: http://www.xente.mundo-r.com/motorsailers

All contributions to those pages will be greatly appreciated.

[brian eiland]

I just happened across this website reference to the Mariner 50 Motorsailer (http://www.caracolyachts.com/cruising/c_various/c_ph7.htm)of which there were an indicated 15 built.

Bill Kimley of Seahorse Yachts in the last years built a brand new motorsailer based on the original mold, making a few improvements. The addition of the integrated swimstep added two feet of length, thus the Mandarin 52 (http://www.mandarin52.com/).

[Guillermo]

I just happened across this website reference to the Mariner 50 Motorsailer (http://www.caracolyachts.com/cruising/c_various/c_ph7.htm)of which there were an indicated 15 built.

Bill Kimley of Seahorse Yachts in the last years built a brand new motorsailer based on the original mold, making a few improvements. The addition of the integrated swimstep added two feet of length, thus the Mandarin 52 (http://www.mandarin52.com/).


Noted.
Brian, would you please send to me some info on main characteristics of your 65' Expedition Cat, to be used for the labeling system study purposes at my web pages on Motorsailers & Motorsailing (http://www.xente.mundo-r.com/motorsailers)?
Thanks in advance.

[KC in OC]

Brian, thanks for your above post and e-mail on the Mariner 50 & Mandarin 52.

I own a Mariner 50 Motorsailer, Hull # 1, and am very interested in discussing the Mariner 50 & Mandarin 52 with other owners. If enough interest is available, I would like to start an owner's group. So if any member or friend is interested, give me a reply.

In the mean time I plan to return to work refitting and modifying my Mariner 50 in January of 2006. I have just had successful carpal tunnel operations on each hand and am looking forward to getting them dirty again.

This forum is interesting and thanks again for bring it to my attention.

[OldYachtie]

My next boat will be a catamaran, but I remember one six month stretch when two Wharram cats went missing off New Zealand in 1977-1978. I knew people on both boats. One was "I Love You 2," and the other was "Tanya". I knew the owner of Tanya rather well. His name was Shawn Blanchford, and he was English. I suspect that they broke up rather than turned turtle, as I have my doubts about their scantlings and about their beam attachment system.

[longliner45]

Ok. Ive read the thread; gotta put my 2cents in ; I worked a 31 ft jc boat- mono hull in the gulf of mexico , been critisized for only going 80 or 120 miles out and staying for a week . at a time. this boat had twin 210 hp turbo charged volvos with duo prop outdrives. she had a 6000lb payload, 13 airtight compartments. she had a semi displacment semi planing hull. in 3 to 5 ft seas we could do 20 knots and burn 1.5 gallons per hr .loaded.in the 80s there was 1 weather satelight which made 1 orbit every 5 days. got caught in many tropical depressions and 4 hurricanes.the last one I was in was hurricane juan 44 hrs at the wheel.I have retrieved sword fish gear in 70 knots gusting to 110knots. this boat had hard chine and was a real good riding boat . you can look up old articals in national fisherman magazine for Broad bill and broad bill2 and touche'.circa 1980s early90s. I rode on 300 ft processing boats -the holland .Ive rode sailboats ,Ive rode cats but not a tramerand, but my vote goes to mono hulls especilly the 31 ft JC boat.also we made 40 trips a year ,one must always respect mother nature and know your limits ,but it was real nice to have a good boat........longliner ; sorry the jcboats were fishing boats...but I wish they had a sailboat

[Guillermo]

Longliner,
Here the link to 31 JC boats: http://www.31jcboat.info/
Although not a motorsailer, she really has to be a nice boat to stand the weather conditions you mention.

[longliner45]

thankyou gilly ,such a treat for me ,brings back really good memores, those are really good boats!

[FAST FRED]

"CC for coastal cruiser, "

Can you honestly concieve of the advertising dept of a 50 ft tub alowing a CC rating to be published?

Most will try for catigory "A" even for a dink.

FAST FRED

[Greenseas2]

I believe that James Wharram has put out some good data on catam,aran sailing efficiency that would be valuable to this forum. The best figures for a cat under sail in the 40 to 65 foot lengths seems to be 3 times the square route of the waterline length in moderate wimds. There have been several claims of 21 knots by cat sailers which is just about right. However, I fully concur that a monohull is best for passagemaking predominently due to it's weight carrying ability. I've motorsailed on long distance passages and find it very comforting to keep the engine running 100% of the time. This precludes the need for a wind charger or generator by simply installing a 100 amp alternator on the engine. The particular engine that I had was a Volvo in the first boat and now have a Yanmar that I find is great at low rpm. I will look up the data on the Saab however. The first long cruise was with a 32 foot schooner (40 LOA). Most of the time the foresail was the only one needed. Chucked the schooner and bought a 30 foot S2 centercockpit that is better, but usually only deploy the genoa. With an 18 gallon diesel tankage, we were able to go from Annapolis, Maryland to south Florida on only 28 gallons of biodiesel at 46 cents a gallon. That's a fuel cost of only $12.88 for the entire trip.

[globaldude]

My next boat will be a catamaran, but I remember one six month stretch when two Wharram cats went missing off New Zealand in 1977-1978. I knew people on both boats. One was "I Love You 2," and the other was "Tanya". I knew the owner of Tanya rather well. His name was Shawn Blanchford, and he was English. I suspect that they broke up rather than turned turtle, as I have my doubts about their scantlings and about their beam attachment system.

Oh dear , my friend has not long purchaced a Wharram cat and wants me to sail with him down the west coast to Wellington from Whangarei !!!.
I was a bit concerned about it being lashed together as it was, now I'm definately concerned !!.

[Greenseas2]

As with any lashings, they have to be checked and tightened rather frequently. Also, before making any hasty decision about the Wharram catamarans, I would check with James Wharram personally to reasolve any issues with the lashings. If you are uncomfortable with lashings, consult with another well known catamaran designer and modify the vessel to the point where you are comfortable with taking it to sea. The most intelligent factor in safe boating is "common sense".

[Lyle Creffield]

Hi

You have raised some very good points:

low RPM diesels make good sense with the cost of increased engine wt
variable pitch/large diameter prop. -3 blade over 12t disp.(my guestimate)
one litre per hour is impressive @ 4kns for 14t disp. 11m LWL

Cats (multis) are cool for protected waters-inside the reef (the great barrier reef) here in eastern Aust. but for me who believes - "boat that sails across ocean bound to roll over sooner or later" adapted from old Confusous tale, it is a mono for my money

I have not crossed oceans but a 3-1 (sail/motor) cost ratio seems about right i would have thought not many sailors appreciate the fact

From memory the 10% power loss factor for energy conversion from rotating shaft/flywheel to generator/electric motor, belt drive, hydraulic drive, with shaft var. pitch prop. the most efficient

tooth belts are better but negates the KISS principle

Have you considered the diesel outboard from your new project?


cheers

lyle

[FAST FRED]

"she had a semi displacment semi planing hull. in 3 to 5 ft seas we could do 20 knots and burn 1.5 gallons per hr .loaded."

20K on only 1 1/2 Gal per hour is difficult to concieve of.

20K on 30-35 hp? Would rank her as the most economical boat in the world !!!

FAST FRED

[brian eiland]

A very interesting new subject thread has recently been posted having to do with a monohull approach to long-range ocean cruising:

Displacement Glider, PowerKeel, etc (http://www.boatdesign.net/forums/showthread.php?p=95771)

One aspect of it I find intriging is the idea of a marriage between the PowerKeel hull concept and Paine's Steadysailer design.

Some of you that have participated in the discussions on this thread might find it rather interesting

[brian eiland]

Thought I might revitalize this subject thread so it doesn't die away.

I am working on a very exciting new catamaran motorsailer design, but I intend to enter it in the Westlawn/Cruising World Design Contest (http://www.boatdesign.net/forums/showthread.php?t=13389) and thus am unable to release any information at this time.

....a teaser...It will have a few attributes mention here:
Offshore Sportfishing Motorsailer, innovations & alternatives
http://boatdesign.net/forums/showthread.php?t=14900

[yipster]

...
so we are not getting a very exiting preview before august eh? :mad:

when i saw about the contest i was thinking of entering my version of here (http://www.boatdesign.net/gallery/showgallery.php/cat/500/ppuser/690) shown and talked about
powercatsailer wavepiercer with bipod aft and folding away sail mast on a more of a powerboat style cat

i asked westlawn if that was within the rules after i allready had shown my sketches and ideas here

frendly answer was that previews on website or this forum was ok long as it was not build or something along those words

getting shorter day now, when finishing a decent freeship drawing i like to put it in that design database too
and hope to be in time with mission statement and asked drawings to content westlawn, wanna enter together? :D

hope we did not borrow to much from eachother as i can only apriciate your inspiration and expertise on paralel and similar ideas

anyway, hope we make it in time and see the new concepts perhaps sail someday...

[FAST FRED]

One of the most interesting versions of the NJ Sea Skiff was done for Motor Boating in the 60's by Atkins.

While the boat was not quite as fast as a flat bottomed skiff , it was said to have excellent weight carrying ability , but more importantly could take the ground AT SPEED with no damage.

The box keel had a simple tunnel aft that kept the prop out of the sand , while sliding over shallow obstructions.

Any one have a more modern design with this ability?

Would happily loose a Knot at top speed to have this , cruisers delight!

FF

[catmando2]

Oh dear , my friend has not long purchaced a Wharram cat and wants me to sail with him down the west coast to Wellington from Whangarei !!!.
I was a bit concerned about it being lashed together as it was, now I'm definately concerned !!.


WIth modern ropes like spectra this is less of an issue

Dave

[brian eiland]

Thought I might revitalize this subject thread so it doesn't die away.

I am working on a very exciting new catamaran motorsailer design, but I intend to enter it in the Westlawn/Cruising World Design Contest (http://www.boatdesign.net/forums/showthread.php?t=13389) and thus am unable to release any information at this time.

....a teaser...It will have a few attributes mention here:
Offshore Sportfishing Motorsailer, innovations & alternatives
http://boatdesign.net/forums/showthread.php?t=14900

...so we are not getting a very exiting preview before august eh?
No Ypister, just had to wait till release info was published on my own site per contest rules.(BTW, I don't think our ideas crossed paths per our private discussions)

So here is a cross-reference to my new design subject thread:
DynaRig MotorSailer, ala Maltese Falcon
http://boatdesign.net/forums/showthread.php?t=16276 (http://boatdesign.net/forums/showthread.php?t=16276)

[yipster]

Brian, good to see you did enter the contest

think i comply'd with the rules but doubt my half a powercat design has much chance here
mailed my concept with discussed design brief in time also but feel this design still needs more thinking
did sections but not fully finished nor did i made tasty renders as my idea is only half finished

at leisure i'm still checking rig handling on boats like Tiketitan with recessed el or hydro drum winches and get a pic of prices

i wonder how many and what other designs entered and hope all get some expert response and exposure

[OldYachtie]

Actually, the Wharram cats I have seen weren't lashed with ropes. They had bolts on either side of a connector beam that held down a plate that extended between them, holding down the connector beams. Under the connector beams was a bunch of pads cut from tires, to give the whole assembly some ability to flex. The assembly didn't look very strong to me, considering the job it had to do.

WIth modern ropes like spectra this is less of an issue

Dave

[brian eiland]

Brian, good to see you did enter the contest

think i comply'd with the rules but doubt my half a powercat design has much chance here

i wonder how many and what other designs entered and hope all get some expert response and exposure
Looks like this will be tough to determine since the magazine and school are doing nothing to notify the other contestants of this forum discussion here:
ALL Contestant's Submissions Aired??
http://boatdesign.net/forums/showpost.php?p=155608&postcount=9

[brian eiland]

This vessel is now for sale...but who can afford these fuel bills :!: in this day and age.

You can find some of my discussions on this vessel back at posting #76 (http://www.boatdesign.net/forums/showpost.php?p=45367&postcount=76)



....some excerpts...
....I was just looking thru the latest BOAT USA International mag (Mar/Apr 05 issue), and came upon a sizable article about the new “MITseaAH” motor sailing vessel. This unusual and challenging design is receiving quite a bit of boating press at present, and apparently a lot of interest at this past years’ Ft. Lauderdale boat show. There was also a very good, extensive article & illustrations in the Apr 04 issue of Yachting World.

I applaud most all attempts to resurrect the motorsailer concept, as I feel it has been a sorely neglected subject in this modern boating world....The latest doubling of the crude oil prices might just spur more developments in the motorsailor arena.

Back to the subject of the vessel “MITseaAH”. I really can appreciate the extraordinary efforts on the behalf of the creators of this vessel. They were really challenged to develop solutions to a tough number of requirements by the client. And they managed to come up with some very unique solutions.

But here I would like to offer an alternative solution to satisfy that owner’s requirements. First lets look at some of his major requirements:....

I submit that all of these requirements could have been met by a 100-120 foot catamaran
motorsailing vessel. For an example have a look at “Douce France” .....

[brian eiland]

copy of letter I recently sent to:
Bill Jacobs, Contributing Editor, PassageMaker magazine

I really appreciated reading your article on “ Power with Wind, The Return of the Motorsailer” in the Dec ‘08 issue of Passagemaker magazine. Back in the early days of this magazine I inquired on several occasions about submitting some material on the same subject of motorsailers, but it was rejected at that time as being outside their scope of subject matter due to it’s inclusion of a vessel “with sails”…no ‘sailing vessels’ allowed. I’m glad the magazine has awakened to the realities of this new world fuel situation, and given recognition to the old concept of the ‘motorsailer’.

I’m judging from the internet sites that you referenced and quoted in the article that you’ve done a fair bit of web browsing on the subject. This being the case, I would also assume that you have likely run across some of the discussions that I’ve contributed on the subject? Here are a few of those forum discussions in case you did not find them:

Motor/Sailer Design, Expedition Yacht
http://www.runningtideyachts.com/motorsailing/

Motor Sailers
http://www.boatdesign.net/forums/motorsailers/motor-sailers-501.html

Displacement Glider, PowerKeel, etc
http://www.boatdesign.net/forums/powerboats/displacement-glider-powerkeel-etc-12512.html#post95771

Motor Sailers by Philip Rhodes & John Alden
http://www.yachtforums.com/forums/general-sailing-discussion/6710-motor-sailers-philip-rhodes-john-alden.html

http://www.boatdesign.net/forums/boat-design/motor-sailers-philip-rhodes-john-alden-16721.html


Obviously I was very taken with the motorsailer concept as well. My early foray (66 years old) into the yachting field was met with most publications of that time making numerous mentions of the term “motorsailer”….very popular term at the time. Sadly the concept has been neglected for so long.

I confess I was a little disappointed that you failed to mention, nor make reference to, the possibilities of multihulled motorsailers, i.e.;

Motor/Sailing Catamaran Concept
http://www.boatdesign.net/forums/motorsailers/motor-sailers-501-2.html#post43251

Monohull verses Multihull powersailers / motorsailers
http://www.boatdesign.net/forums/motorsailers/monohull-verses-multihull-powersailers-motorsailers-4499.html

Gamefishing for Sail Under Sail (and power)
http://www.yachtforums.com/forums/general-sailing-discussion/1548-gamefishing-sail-under-sail-power.html



,,But I commend you on mentioning the kite-power possibilities. I’ve started this particular subject thread on a couple of design forums (and particularly at the urging of Guillermo (http://www.xente.mundo-r.com/motorsailers/)):

New Age Trawler/Motorsailer; Kite assisted PowerYacht
http://www.yachtforums.com/forums/general-yachting-discussion/8127-new-age-trawler-motorsailer-kite-assisted-poweryacht.html
http://www.boatdesign.net/forums/boat-design/new-age-trawler-motorsailer-kite-assisted-poweryacht-20319.html



,,,And I do realize that you couldn’t cover the entire subject matter in only one article.

I want to make reference to your article on both boat forums, and include a link to Passagemaker magazine. It might also be nice that there existed a *permanent web location* where the forum members could go and read a copy of the article . But as happens far to often, many of them may not be able to gain access to the article at some point in the future when a linked-site is taken down. Would you consider placing a PFD article into the forum discussions? ….or is this not allowed in the publishing world?

Thanks again for your article on the subject matter,
Brian Eiland


PS: It was also very interesting that your motorsailer article was followed immediately with an article on Steve Dashew’s exciting new passagemaker, Wind Horse ,…
....a power vessel to contrast with the sailing vessels that he has promoted for years….nice contrast, and a wealth of interesting material.

[FAST FRED]

"but it was rejected at that time as being outside their scope of subject matter due to it’s inclusion of a vessel “with sails”…no ‘sailing vessels’ allowed. I’m glad the magazine has awakened to the realities of this new world fuel situation, and given recognition to the old concept of the ‘motorsailer’."

Interesting as so many of the boats touted there could hardly be of interest as usefull Passagemakers , the majority are dockside condos , happily aground in their own coffee grounds , and many more are high speed big boxes that seldom have 300 miles of range at speed.

The "trawler" blither is simple PC speech code..Lots easier to own a "trawler" than a twin screw diesel yacht in some circles.

The fuel prices have little to do with world voyaging as a guess 95% is done on conventional auxiliary sail boats.

To strut the dock, claiming fantastic seaworthy abilities ,(while "cruising" 25 hours a year) seems the purpose of most of the boats touted there.

FF

[sabahcat]

Let’s explore a 40' example. Take the single 120-140 hp diesel used to push the conventional 40' single-hulled trawler or motorsailer to a maximum 8.3 knots hull speed and divide it into two smaller 60 hp diesels driving two long slender catamaran hulls. Voila!, maximum to 15 knots under power with the reliability of twin engines and the stability of a twin-hulled vessel.

Thats the boat for me and well into one now, with longer hulls


Add a modest sailing rig to these easily driven hulls, and you now have a passagemaker capable of cruising 12 knots under sail/ power compared with those older 7-knot boats.


Yes, but the cost of this sailing rig? How many miles will it buy for those small diesels?

[TeddyDiver]

Yes, but the cost of this sailing rig? How many miles will it buy for those small diesels?

It's more an issue of the range.. I mean how much diesel you can take and how many NM that counts for? If thats enough you ok. Beyond that you got to have sails..

[sabahcat]

It's more an issue of the range.. I mean how much diesel you can take and how many NM that counts for? If thats enough you ok. Beyond that you got to have sails..So, if you build something thats expected to get around 1L/nm and can carry 1500 litres, and longest legs are 800 nm say, then a sail rig would not really be viable

[TeddyDiver]

Right! Thats how I see it anyways.. :)

[sabahcat]

Right! Thats how I see it anyways.. :)

Yep, me to.

Figured I could buy a lot of diesel for the cost of even a cheap rig and sails and associated hardware

[brian eiland]

So, if you build something thats expected to get around 1L/nm and can carry 1500 litres, and longest legs are 800 nm say, then a sail rig would not really be viable
That's true
But then you might consider a 'get home' rig like one of the cheaper kite systems being dreamed up:


http://www.boatdesign.net/forums/boat-design/new-age-trawler-motorsailer-kite-assisted-poweryacht-20319-2.html

http://www.youtube.com/watch?v=qnACybMhPs4&NR=1

http://www.kiteforsail.com/

[sabahcat]

That's true
But then you might consider a 'get home' rig like one of the cheaper kite systems being dreamed up:


http://www.boatdesign.net/forums/boat-design/new-age-trawler-motorsailer-kite-assisted-poweryacht-20319-2.html

http://www.youtube.com/watch?v=qnACybMhPs4&NR=1

http://www.kiteforsail.com/

Thanks Brian, I have looked at and had quotes on these already and they all came in at well over $10,000AUD, which to me at hopefully around 1lm/nm equates to a lot of miles.

Do you have a cheaper source? I had even looked getting a couple of old symmetrical kites and getting them stitched along the foot as they look pretty close to a kite sail. (see pics)

As far as a "get home" device, I figured on the dual engines in a cat being that.
Individual and separate tanks/fuel, battery and engine should provide security as it is unlikely I would have thought that both systems would be out of commission at the same time.

Don't get me wrong, I would love to have a motorsail option, but the numbers, bang for buck, don't appear to stack up as yet

[brian eiland]

Thanks Brian, I have looked at and had quotes on these already and they all came in at well over $10,000AUD, which to me at hopefully around 1lm/nm equates to a lot of miles.

Do you have a cheaper source? I had even looked getting a couple of old symmetrical kites and getting them stitched along the foot as they look pretty close to a kite sail. (see pics)
Maybe try a shot at some surplus military stuff from those performance jumpers. Most military gear has a certain 'life time' that's not necessarily used up?

...and have you looked at the gear these kitesailors are using? There are a fair number of video references on that other subject thread dealing with kite power.

[Guillermo]

Brian,
Thanks for mentioning me in your letter to the Passagemaker editor. I'm honoured.
Best regards.

[sabahcat]

...and have you looked at the gear these kitesailors are using? There are a fair number of video references on that other subject thread dealing with kite power.


Well if youre talking about like on the F24 video, that looks fairly complex and not cheap.

I would like to see what they have on the Mono in my pic above ie: could they launch without the mast?

I do have pics of a 40 odd foot powercat that had a kite up, but never saw how it was launched but the gear you can see (or lack of) is what got me interested, but do you think I can remember where I got the pic?

anyone recognise it?

[sabahcat]

Found it

http://www.kit-cats.com/kite/kite_sail.htm

[brian eiland]

..a bit more simple
http://www.kiteboat.com/kb_videos.html

http://www.skytoys.co.nz/Kite%20videos.htm

http://www.youtube.com/watch?v=tSWfi5AMT2E&amp

[sabahcat]

Just got a reply from Kit cats in regard to their kite sail and even suggested they join the kitesail discussion here.

Reply to the email

Thank you for your inquiry.

We no longer deal in the kite sail. We removed it from our website
many months ago.

Strange, I was just looking at it.

Yep, still there
http://www.kit-cats.com/kite/KiteSailPowerboats.htm

[TeddyDiver]

What the most essential issue when considering btw mono/multi motorsailor is the amount of assets to throw in..
With my few thousands € per year I can invest in about 30-35 mono in a time period of ten years. :)
A multi giving a same internal volume and cargo carrying capabilities just would be about 6 years further away.:( and the propability of a stroke, incontinence and senility severely greater :rolleyes:

[sabahcat]

Other people have saved more and spent less over the years and/or started building early enabling them to have a multi.

So, all depends when the journey started and how badly one wants it

[Fanie]

With a few €k per year you can self build a magnificent boat. It's a lot about how you do it and what's at your disposal. I've seen some very nice methods and it doesn't have to be an arm and a leg.

Look at what Manie did - he made the drawings, took the cad to a laser cutter and they marked the panels on his marine ply. He cuts it out and begins the assembly. Just an example, but not weeks of measuring and working himself to death.

You may have a different method in mind, but you have to work out how you are going to do it so it is easy, less costly and in short enough time.

One is never too old to start either. You may live another 109 years (who knows) and doesn't help waiting till then. If it takes you 5 years to do, you have 104 years left to enjoy it. No use waiting 105 years and have 4 years to enjoy it in. Kinda stupid.

So, start drawing, researching, and most difficult of all, start thinking :D

[TeddyDiver]

So, start drawing, researching, and most difficult of all, start thinking :D

Been doing excactly that :D And I've started already building, some pictures in the gallery..

[Fanie]

Which gallery ? Link ?

[TeddyDiver]

Click my name above and then click view gallery

[Fanie]

Simple Q. Why a mono ?

[TeddyDiver]

Couple of things.. I'm restricted to 3m width due the need for trailering the boat time to time. And like I said earlier couldn't afford a bigger cat. My design has also 1500liters capacity for tankage and to achieve similar quantities with a cat should've required much larger vessel anyway if wanted stick to cats performance characteristcs.
The drawings in the gallery are just sketches to get some insight about the proportions. I'm a bit old fashioned what comes to plans and have done most of drawings on simple "notebook" and in larger scale on the carage wall :D More traditional typically finnish way should have been on cigarette box, but I found it a bit too restricted :P I've done kind of "reversed engineering" and drawn the hull form also with Delfship just to ensure my calcs..
I didn't make too many frames to shape the hull (4). It's a tecnique I don't recommend to anyone unfamiliar with wood, but for someone done before clinker it's much faster way to produce a fair hull.

[Fanie]

Sorry Teddy, I wasn't suggesting there is anything wrong with mono hulls. Some people seem to like them and some of them even stay afloat for a while :D

I was merely wondering why you chose a mono. If that's your liking then so be it.

[TeddyDiver]

If that's your liking then so be it.
No worries.. I actually like cats (and tris) but just find them a bit constricted if not big enough. For cruising maybe some 38' is about where they come more atracting and such cat is somewhat compareable to 45' mono both with the interior space and price. In those sizes the real difference is the cargo carrying capability against speed. So what's the more relevant than mono vs multi likes and dislikes is the intended use of the boat.
What comes to the discussion about capsizing hazards I believe bigger cats are extremely safe in that regard as their

[TeddyDiver]

continued..
size and width make them seaworthy vessels. The biggest danger with them is pitchpoling and thats not an issue for carefull sailor. For a family or for a crew of 4 or more an excellent choice..
Mono's are totally different and I feel, as cruiser, they are better when they are longkeeled, low aspect ratio rig, self rightening etc "old fashioned" boats. There's no other choise better for a single handed cruiser or in the "economy" class..
Chears :)

[sabahcat]

The biggest danger with them is pitchpoling and thats not an issue for carefull sailor.


Have you any examples of that EVER happening with a motorsailer cat?

Racing cat being flogged yes,
Fast cruiser being driven hard yes

Motorsailer ???

[TeddyDiver]

Have you any examples of that EVER happening with a motorsailer cat?
It's hard to say (anyway for me) what's the difference btw motorsailer cat and fast cruiser cat.. And most seem to agree that they are both combined in a modern cruising cat so.. But like I said "not an issue for carefull sailor" as we all over 40years should be.
The most reckless thing to do for an old fart is to marry a girl around 20 but thats an other story:P

[sabahcat]

Motorsailer
http://www.endeavourcats.com/

Fast cruiser
http://www.schionningdesigns.com.au/www/welcome.cfm

[TeddyDiver]

Trawlers aren't motorsailers, anyway not with the standards I've used to.
Schionning on the other hand has a quite nice range of sailing cats, from what's more a racer like to proper ocean cruisers and motorsailers and almost everything btw.

[sabahcat]

Trawlers aren't motorsailers, anyway not with the standards I've used to.
Schionning on the other hand has a quite nice range of sailing cats, from what's more a racer like to proper ocean cruisers and motorsailers and almost everything btw.

Click on sail for endeavourcat, they are motorsailers

First pic endevour motorsaler
2nd pic Pescott whitehaven cruising cat

I wouldnt consider any schionning to be a motor sailer, they can happily sail at windspeed up to about 15 knots+

[Manie B]

This thread has had some very interesting points
and i am rather glad that i read it
i firmly believe that a proper sailing cat still makes for a very efficient motor cat even without mast or sails
same motion and very light on fuel at 10 knots

here are the underbridge shapes from HELL

i didn't know whether i should laugh or cry - so i did both

farkit i cant believe it :mad:

go to schionning - that is proper design :D

[Fanie]

If you're 20 you need one 20 year old.

If you're 40 you need 2 twenty year olds

if you're 60 you should go for 3 twenty year olds.

It's not for what you think.
It's so they can do stuff you're too old to do :D

[TeddyDiver]

i firmly believe that a proper sailing cat still makes for a very efficient motor cat even without mast or sails
same motion and very light on fuel at 10 knots
Couldn't agree more :D
A motorsailer can do it's hull speed with sails or motoring.
A trawler, cat or mono, with some rags hanging on top doesn't make it a motorsailer.