Historical multihulls

Forward on the amas, just taking a quick glance mind you, it looks like there is adequate buoyancy . The wide deck however could be tripping hazard if the boat went bow down. The sterns however don't have enough buoyancy for diagonal stability. They look like the sharpened pencil ends the Brits were using back then. Less immersed drag I suppose was the thinking but if the boat ever stalled on a wave and went astern there isn't much to help you stay upright. Sort of like when Ettore Bugatti was asked about his mechanical brakes after racers started using hydraulics, "I make my cars to go, not to stop."

 

I see my comments have raised a lot of questions, so I'll try to give some precisions.

About the campaign; I have said already to much...Yes it was used for as first database for extrapolations for bigger boats. Other campaigns were made later with 60 feet tris and gave database for the new generation of maxi tris. All these campaigns were privately funded, so the results are not public. The only thing I can say that race catamarans hate to be overloaded, and become happy sweet puppies with cruising rigs 80 m2 but with more than 20 knots with 5 persons aboard and a 400 kg overload. I won't say the names of the cats as I want to keep courteous relations with at least one of the NA. I do not know if the data was used for the AC monster of Denis Conner againts the Kiwi monohull. For later AC multis they probably used fresher data from the 60 feet.

VPP. VPP began to be used around 1972-1975. Norman Riise was the great pioneer. That was complicated as you had to get measures and it was hard to get good measures, note them, go a mainframe AS400, prepare the perforated cards, make a program often written in Pascal trying to obtain usable results. Most of the time was spent to find the mistake of programming that made the boat going faster backwards than forwards...
The revolution was the apparition of electronic sensors (wind speed and direction, speed and more) of personal computers and interfaces permitting to acquire the data in real time at "affordable" prices. Around 1985 at least two guys in France had working systems in real time on boats. One of these guys worked later a lot in the America Cup. In 1987 at least 2 F40 had real time on board CPP optimization systems, including maps, waves, and currents. In 1990 there was at least one system including tension of sheets, luffs, and rigging, curvature of mast lateral and longitudinal, shape of sails. I can say that was not with a Windows or Apple OS...That served a lot for cutting better sails and to simplify the rigging with the new carbon masts.

About diagonal (and longitudinal) stability. A lot of people, beginning by Mr Woods, have given answers;
1- On the flats decks that are a death trap when submerged with a negative angle. The brake is enormous, the boat is stopped in seconds and the real wind catch the sails. No way to save the situation, it's too fast. Jet Services 5 capsized dramatically with several people injured, the maxi cat Royale suffered of a similar situation and the skipper disappeared in sea, too many accidents occurred. It appeared that rising the bows and flares was not the solution.
Add not enough volumes in the amas and you pass in 2 seconds from an exhilarating run to a capsized boat with a broken mast, and people maybe trapped under the trampolines.
2- Rear diagonal stability. As Mr Woods said with rear pointy amas in a storm if you are stopped and begin to go backwards you are in a very perilous situation. Add not enough general volume of the amas and too much rocker. A good wave coming from behind and breaking on a ama's rear flat deck and you're capsized with no hope.
3- Longitudinal stability. As the pressure of the sails rises, the ama is taking more and more loads both static and dynamic. In statics it's simple the volume of the ama has to be equal to the displacement. That was the big mistake in NA at the beginning of the multis. They did not analyse the dynamic part, a boat moves and the interactions grow exponentially with the speed.
It's the dynamic part which is tricky combined with the hydrodynamics. One goes with the other.
A- acceleration, the apparent wind goes forward and speeds up, the multi sits on the sterns. If you have not enough volumes the sterns sink and drag badly.
B- sudden deceleration. It's the most dangerous phase. The multi goes on the bows, the apparent wind goes backwards and will catch the sails, pushing forward. If you have a gennaker you're in a big trouble.
If the bows cannot clear the water, and act like hydrodynamic brakes you're f....d. It will engage in green water in seconds. It's the classical forward capsize. That's the problem with flat decks and flares; whatever the height of the bows, one day they will go into green solid water...So the purpose of rounded decks is to no create an hydrodynamic brake and that works pretty well.
C- constant speed: you must get an acceptable longitudinal horizontal attitude whatever the direction of the wind, but also you must have a stable system able to counteract automatically the external perturbations (waves and variations of wind) in a very short delay, without over-reacting, and as any "pendulum" system must return to an equilibrium state in a minimal number of cycles, not wobbling half a minute like a 1960 Cadillac.
The Hobie 16 was the perfect illustration of what not to do; low volume, small sterns, flat decks, too much rocker. This cata(strophe) wobbles and capsizes in any direction like a (bad) dream; front, back, side. It's funny on a beach cat, it's unacceptable on a cruising or racing multi. Many historic multis had more or less that defect.
The mathematical analysis is rather difficult as it has to integrate many and many factors. There are simplifications that give good predictions for some narrow ranges of speeds, wind and wave systems.
Happily the French built a lot of racing multis, with a very fast evolution the new generation correcting the defects of the former generation and we can say that since 2000-2005 the obtained results has been excellent. All the records show it; relatively safe, faster in instant speed and far faster in mean speed over long periods. Bursts of speed mean nothing in cruising or racing, the true goal is to get a fast constant speed in a wide range of conditions.
We can note that the shapes have gone to very simple ones, and that the riggings and masts are very similar and rather simple. All look a bit the same...This shows that the engineering and techniques are mature and that the new way are the "flying" multis.

The application of the racing "recipes" on the shapes of cruising boats is a factor of increased security. Like the disk brakes over the drum brakes, or independent suspensions over rigid axles 1850 chariot with spring leafs suspensions.
The IDEC philosophy is one interesting path for a cruising boat. I'm repeating myself but Joyon, 51 years old at the time, crushed to 57 days the record around the world (and the record stands always), with a very simple tri. Big but simple and built of a tight budget. The secret is in the shapes of the hulls and the placement of the rig. That can be used virtually on any tri above 40 feet.
For those who say that all this is useless on a narrow cruising multi, I'll answer why to bother to build a complicated and expensive multi, sacrificing amenities, while you can get a similar result for the same price with a bigger and more spacious monohull? A monohull is simpler to design and build. If we go to multis it's to get speed, fun and if capsized to stay alive in the inverted hulls rather than sinking upright, and trying to survive in a small rubber thing...

A few pics of IDEC to have an idea of what is a modern multi with a good repartition of the volumes and placement of the rig. Further the spectacular side, these pics give tons of information if you have the eye. Note on the second and the last pic the impeccable attitude of the ama while the sea is not so flat, with and without lifting daggerboards. You have even the main section very typical of Irens, while capsized in 2011. Note that the inverted hull is high and "dry", with batteries, radio, water and food...Not the best five stars comfort, but far better than being the *** in the water, sea sick, in a rubber inflatable with 2 litres of water, 500 gr of biscuits, and a dying small battery on a VHS.

I hope that long post will be instructive.

 

Thank you for elaborating Ilan, there are helpful insights here for many trying to understand the dynamics of multihulls.

I don't think anyone said this information was useless on a narrow cruising multihull but rather that beam magnified shortcomings.

In the precomputer era Hedley Nicol actually did full scale dynamic and static buoyancy tests on his trimarans.On his first racer Vagabond (MK1) he attached drogues to stop forward speed and sheeted in full sail beam on to 50 knot wind to observe the static effect then removed the drogues to observe the influence of speed on hull shapes. This lead to longer amas, bows were evolved to keep the boat from stopping as it hit tall waves. Much progress has been made since then but it was a good place to start, sometimes simulations miss the nuances of nature. Of course it wasn't over rigged to max out in 5-10 knots of wind like boats now.

We get enough speed to keep us happy out of our old relic (you wouldn't believe me
) and appreciate the motion and the fact it won't sink.

The gennaker point is one many miss, Skip's posting of Etienne's Walter Greene tri shows a sprit and gennaker it wasn't designed for added on. Here in the PNW boats, often Farriers have gone over on chute runs after hitting the big standing waves caused by tidal currents. Sailors have to know how to use the gas pedal and read the water for sure.

 

Cavalier, Hedley Nichols made a great job in his time, when all in multis was uncharted map. I do deeply admire these pioneers, Shuttleworth included even I have criticized one of his designs, who invented from nihil, particularly Newick I had the pleasure to meet long time ago. Easy to be critic nowadays with all we know and the materials we have.
Remain that most of these designs are obsolete, as obsolete as a beautiful 1935 Bugatti, and may have serious safety flaws like the Shuttleworth. So it seems to me rational to use recent plans that include all that have been learned when you are going to invest one or two 5 gallons buckets filled with 100 and maybe 1000 USD bank notes in a boat.
And for the older boats, if you find a cheap one is OK, but you have to sail it accordingly its age and capacities like an old Beetle, it's cute but it's a death tramp.
I love the old Newick with the big front wing, they are very good boats, very well thought, and marvellous and safe when sailed in the way they must be sailed; with a light foot on the throttle, they can be capricious if pushed. By modern standards they are not fast but pleasure can't be measured and computed.
And you can have a lot of fun with an old Hobie 16...but I wouldn't spend the money to build a replica, or restore totally one.

 

Wise words indeed. To me the secret ingredient is feel. If you can't sense what the boat is telling you, when the car reaches its limits or keep your balance you should play things safe. Take a train, book a flight, use a ship. I have sailed Hobie 16s and found they rewarded a sense of touch and balance, I didn't tip over. If I got to choose between the latest traction control Porshe and the 1935 Bugatti I'd go with the Bugatti. The Porshe would get there faster but the joy of travel is the journey, not the destination. Like many I can't afford either so must use what I find and have fun with what it can do. The trick there is not trying to make it into something it wasn't intended to be but enhance and enjoy what it is.

 

1- Crowther had a very solid engineering background at the difference of a lot of NA of small boats. Not all of the following designs were so good...some cruising cats made in France were frankly...and the shipyard had to cease the operations because of weak sales. Compared to a VPLP design of same size there was no match.
2- The hydro of the main hull was rather good. Some extended it to 28 feet to have less rocker as the tri is not famous in "strong" wind. The weight was good.
3- The amas were very decent. Enormous and very long considering the period of design. Some were modified with bigger amas.
4- It was used by good amateurs in mostly light weather, the strong point of this tri, and probably not pushed to the extreme limit in extreme conditions. With a 24 feet tri you do not affront storms, nor 40 feet waves...
Put on a band of pro Frenchies in a race in front of La Trinité with a 35 knots wind and surely they will at least dismast it. They are as brutish as a 240 pounds Samoan All Black hitting a poor 160 pounds guy who had the bad luck of grasping the ball.
5- There are surely several that flipped, capsized etc. It's a probabilistic certitude. Simply we do not know.
And Crowther was inspired the day he drawn it...But compared to some recent 24-25 feet, it will be maybe honourable in light weather but far from bring a winner. It's a very good vintage boat but I would never build one now. As Mr Woods said the Crowthers have never been considered fast in Europe. The amateur racing level in UK and France is very high with plenty of good designs. Happily the sail clubs have forbidden the use of sabres and grapnels, as the races are intense enough. Arriving to the first buoy in a Solent race of the Cowes Week is an experience that can make you consider that water colour painting is an activity better suited for you.

 

For a research boat I would stay away from a racer with lifting foils. Forget the electric winches, they are nuisances and you'll be surprised how they drain the batteries. Better to use a rig designed for solo handling and good 4 speed winches and hydraulic devices.
60 feet, stretched or not, are beasts and need an experience far beyond the amateurs. The amenities are close to zero, and four feet in the middle will not add much. To modify one is a very expensive task.
Carbon fibre has an inconvenient; noise and its insulating value is zero. I would not use it on cruising boat unless I want tons of insulation...
A bigger to have amenities, cheaper, simpler with no bells and whistles boat would be a better approach.
In reality for a research vessel (a true one not an advertisement operation) a monohull or a catamaran would be more convenient.

 

Oh for goodness sake +1 (because this site won't allow <5 characters.

 

Ilan Voyageur, I think you are being overly harsh with your comments on older designs, like those from Crowther and Newick.
With the latter you are implying that the design cannot handle high winds and seas, has to be sailed according to its "geriatric" vintage.
I disagree. In one Coastal Classic sailing on a Newick 36 (with foils) we had sustained 58 knots North east wind strength yet the "antique" handled the conditions extremely well, leading the whole CC fleet.
And another of your aged and pretty useless 50 year old designs, a stock Crowther B24, we averaged 16 knots for over an hour period in a hard and very cold South east wind reaching across the Firth of Thames. Admitedly we were losing steering at times during strong bursts of wind and speed, had to centre helm and wait until steerage returned. So, agreed, the hull design in the after sections, rocker, made this a problem. However aside from that, the old clunker of a mere 24 feet length, handled the conditions extremely well.

 

knowledge sharing...

Indeed.. I just can follow cavlier's opinion and admit. Applaus for this excursion. Dont worry, I still understand it as "short text". No problem with.

Great insight at least for those folks who just do not want visit boat shows and sign with a warft the contract to build a "ready out of the box" multihull over winter.

Beside sailing itself its the technical part which makes this sport so interesting. - And the complexity of Trimarans/multihulls with all the parameters to be defined for getting a record breaking and safely boat is a real challenge to master successfully.

For now I have to digest what I read. Already lots of questions about the future flying around in my head.

And dont worry, Ian.... no need to feel bad. This is not whistle blowing.

All what you tell in princips is "no copyright protection". I would call it "common ownership of human mankind". - Engineers around the globe learn from each other, and not from the scratch. Otherwise we humans still would sit like apes on the trees and eat bananas. (Yeah, I like banana shakes and banana chocolate bars.)

I am very sure about that the students of naval architecture and computer specialists nowadays learn from their Professors in the universities and oceanic institutes about these historical developments.

E.g. look at the École polytechnique fédérale de Lausanne (EPFL) with it’s Rolex Learning Centre in Switzerland.


I wish we'd have some more institutes in Europe compared to what we see in NewZealand/Australia, e.g. with the Royal Institute of Naval Architects (RINA) NZ and infrastructure of University of Auckland. They have specific wind channels for testing new rigging and sails.


I dont know about such in Europe or USA ?

The world best designers meet every three years to exchange their knowledge and status of development, as happened in March 2015 with the
"HPYD5 – High Performance Yacht Design".

Since more than 20 years now we live in times of Internet... we are in the era of knowledge societies (or at least knowledge based information society). - This is very urgent to avoid wasting resources, to bring the wisdom and experiences together from around the globe for minimizing the huge efforts in "try & error" methods. And to solve all the tremendously problems (e.g. wasting of water resources, climate change, global warming, recycling of worthfully materials etc. etc. etc. ...).

Our planet earth is already tortured too heavily by the misuse of its ressources. We all know this. Within the guilde of sailors I miss this responsabilty. Too many are egoistically to sail around for pleasure ignoring that their boat materials are highly toxic (either during the process of production or during maintenance).

In my understanding, this "private person" you were talking about and who owns all this knowledge - I suppose it can only be some guys like millionairs, e.g. Dennis Conner or Ernesto Bertarelli to finance all this out of own pocket - has the duty against future generations of naval architects/designers/riggers/sailors to overhand all this experience with a fully documentation to a University library or Foundation (NGO). So following generations can learn from...

... and as you say, most important is to reach the level of safetyness + seaworthyness. Nobody want read news or see videos from capsized boats and drowned skippers and injured crew members.

And important: the knowledge transfer into other segments, e.g. how can be used Trimaran hulls because of their efficiency for commercially purpose (e.g. hull shapes in cargo ship building). I have some studies about this item and still work on it before I publish them on my blog.

Okeys... this as a first (hopefully) "postive feedback". As mentioned, I have to digest all this... and then I will come back with some relevant questions about "define the future of multihull sailing/racing".

Chilly weekend !

 

good 4 speed winches...

Tks giving feedback... yeah, you got it... "advertising operation". Kind of Research-Media Vessel RMV

Funny you name it... as couple of days ago I went through the product catalogue of PONTOS winches. They call them "Trimmer" and "Grinder" as model name, a 4 gear automatic winch system.
http://pontos.fr/gb/content/34-grinder

Dammed expensive. If you have a bigger 60-80 Foot boat with 8 winches quickly an investment of 15,000 Euros. For (elder) solo sailors or two handed boats a good investment to keep (senior) skipper + crew healthy.

http://www.youtube.com/watch?v=_Y0X80wBFCM


http://www.youtube.com/watch?v=IapwZPv00zg

 

Early on Crowther designs had a tendency to hobby horse to windward, thereby losing speed. So he added bulbs to the bow, some retrofitted, which made a huge difference to the motion and therefore average speed. But they also induced drag so the knuckle became incorporated and then refined and other designers, like Irens, moved the muscle back and up so that it became barely discernible.

AFAIK on catamarans Crowthers bulbous or flared bulbs did not eventuate in capsize in any condition.

 

I agree here with Gary but everyone has a right to their opinion. The ones from those who have actually sailed the designs they are commenting on carry more weight with me. Ilan, though, has some good insight and knowledge of the development of design and is obviously concerned that sailors don't exceed the safety envelope. His experience is very valuable. Time has given us a great way to measure how boats have stood up to the long haul. In the case of Newick it isn't hard to find racers that haven't capsized in battle such as Rogue Wave and Moxie and ones that have such as some of the Vals. It really comes down to the sailor knowing when to stop in the conditions and when to go all out. Dick's canoe bows on his old designs were very good about not tripping. Most of the inversions I heard about were sail overs where the racer put off reefing, something that happens to any design. We don't have to look too far to find plenty of the current French crop upside down because of the human element. If there is lots of power there will be accidents using it.

Just in cruising we have pushed the Nicol hard as the mountains, islands, fiords and channels of the PNW create some strong downdrafts, venturies and shifts. Learning how it handles when the chips are down hasn't been traumatic but reassuring. Still the best weapon is to try to anticipate conditions and hazards and prepare accordingly. Reefing before you get pasted coming around the lee of an island is always easier than waiting till you're in it.

As to the age of a boat it is the mileage not the years that count. All materials experience cycle fatigue as we know. Carbon fiber has excellent cycle life followed closely by wood of all things. Fiberglass isn't really very good at all. A glass racer that has had a steady track record of competing in ocean races would be pretty far down my list. When I surveyed the Vagabond I researched its history to see what it had been exposed to. It hadn't been in the ocean but had spent most of its time using the outboard to carry researchers around our killer whales, often just drifting in position. Lots of life left in that wood. I could compare this odometer to a Nicol that had sailed with a 50-100% overload twice around the world before encountering problems with the stock construction. History of these boats around the world gave me the data to know where modern reinforcements could help and what to leave alone. This is the kind of detective work one needs to do to really know a boat. Talking with Nicol sailors all over the world about their experiences and to Hedley's son Alan about the testing and development of the designs gave me good insight.

I've been lucky enough to have some long phone calls with Dick Newick over the years as I followed his designs. The beauty and easily driven shapes put them on the top of my list to build. He was the first person to say "Hey, we found a better way of doing this." Or point out when a older design would serve the purpose just as well. If I start building from scratch it will be at the least based on one of his designs. For me speed isn't the only reason to build a boat but then I'm not racing. If we painted the French racers the same could we tell them apart?

We could pick anyone of the 3 mentioned designers, Crowther, Shuttleworth or Newick and find that their designs had won and finished more ocean races than anyone commenting. These boats can still be good for something. They have been tested at sea. When contemplating the cruising or campaign of a older boat keeping within the parameters of its design is a good place to start. The center of gravity, center of effort etc.... should be monitored carefully. Adding a squaretop main to a older design is going to affect many interacting elements for a example. A wise man knows that not every new improvement is actually an improvement when applied to the old. The French are very sensible when it comes to cutting things off to start fresh. For the latest rigs and foils the latest design might be best. Just remember that this too will be an experiment to improve on the past and its history will have to be written to tell the tale of success or failure.

 

Interesting and very good, accurate posts from Ilan - thank you.

I don't know whether people still think the Morris Minor, DC3 and Commodore 64 are still the best cars/planes/computers but it does appear that many people think old boats are better than new ones.

My understanding of the French built Crowther cats of the 1980's was that Lock designed the first one and got paid a royalty. After that the yard decided to modify the design, stop paying him yet still called it a Crowther. Certainly I have seen some nice ones of that era, and some shockers

Incidentally, nearly 30 years ago my wife and I left Cherboug after breakfast when cruising on our stock grp 24ft Strider. We did 16 miles in the first hour and were tied up at Poole Quay in time for lunch. No control problems at all, but we did deliberately slow down after a while - "hey we're not racing"

Nigel Irens has always been very open about how he designs, both in private (to me) and in public (at RINA meetings etc). I don't think JS has actually had many race winners since about 1990

Richard Woods

 

The DC-3 is a winner for sure, nothing sense has been built with that kind of durability, the lower slower flight doesn't leave environment damaging contrails and it doesn't use toxic jet fuel. It's forgiving flight envelope still keeps it in use today, when was it designed, the 1930s?

The new/old label isn't really a good one if you think about it. What to look for are the proven ones. All bad designs were new once so you can expect the same in the future. Some will be better than others.