42ft racing trimaran

I am building a 42ft tri primarily for offshore racing in Jamestown, RI. I'm interested in talking with anyone who may be either planning or building a similar size boat. Details of my boat are on my site www.buildatrimaran.com.

The construction is all carbon/epoxy and is infused for the most part. This is career related (I'm a consultant in the composites industry www.bravolab.com). I would welcome any discussion especially related to infusing carbon

 

Project 42

Very interesting design and I like your philosophy as well:
"Although its not intended to launch the boat with foils there will be the provision in the structure to add them later. Although, in the past, I have had some checkered experiences with foils, I believe they are, no doubt, the future of fast efficient sailing. "
I think both Sodebo and Idec were originally built without foils(but with the supporting structure,I think) and have now added them so it sure is a viable way to proceed.
I initially thought your main hull might have been designed to plane but I think I was wrong after looking closer at the sections.
I hope you'll keep the forum advised of your progress. I haven't done any resin infusion and am trying to learn as much about it as possible-been in boat design and boatbuilding a long time but infusion looks like the way to go in a lot of cases.
Good luck!

 

Dear Phil Stegall,

whow, its a fascinating feeling to chat with a sailing legend.

I'am quite not in your range, as I'am building a 30' trimaran, primarily for offshore racing and basic cruising in the difficult conditiones of the North Sea and the Baltic. My boat is built as a low cost- and low tech boat, having tortured ply amas and a cedar strip plank / plywood composite mainhull.

Unfortunatly I'am not able to open your website without beeing redirected automatically to your bravolab main page, unable to see the drawings of your boat. Nevertheless I'am very curious about your new boat. Can you post some drawings and informations here on the forum? Who has designed it?

Grreetings from the North Sea Coast, Michel

 

I e-mailed Mr. Steggall about the problem with the link above.....

 

site issues

No sailing legend! but thanks

I think composite and wood is a great way to build especially cedar. Trying to fix the problem with the site. I'll post when its fixed

 

Sodeb'O and IDEC do have ama mounted lifting foils, which will be on full display in the Route du Rhum, which launches in just a few days. http://www.routedurhum-labanquepostale.com/en/s01_home/s01p01_home.php

It may be imortant to consider that even though Coville and Joyon are both using ama mounted foils, the application is far from universal for all multihulls, for good reasons. Coville has an enormous amount of experience with the form through his racing experience aboard the ORMA 60 tris, as does Joyon. To suggest that a freshly built 40 footer should automatically incorporate ama foils would be hovering on the edge of several major sailing issues. Better to gain some experience in the area of lifting foils on other boats before bringing out the foil solution as an across the board answer.

This has been the way to go for state of the art composite building for some time now. I'm surprised that a guy who looks to push himself to the top of the game with his fresh ideas would not know, or have had any relevant experience, with the process of resin infusion. This raises some very important questions as to overall understanding of the current sailing craft design/build technology.

People have been building less than racing related fly fishing boats with resin infusion for more than five years now. Maybe it's time to get in the game and not just talk about it?

 

Foils

I had foils on Sebago (1988 CSTAR) but not adjustable. I'm a believer but will launch the boat minus foils to get sailing then add at a later date. It's interesting to see them on the G boats as they appear low aspect. Maybe that's because they're on a 100ft boat!does anyone know the efficemcy difference between straight and curved Bruce foils?

 

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Philip, my guess would be that they are about the same. One thing that is important to understand is that curved foils were "invented" so that when retracted they didn't extend past the beam measurement. A T-foil that could be pulled up would probably be more efficient and there is the possiblity that Hugh Wellborne's idea of retracting athwartship foils(they could pivot like a centerboard) and would have to be placed very low on the ama to maintain at least 2.5 chords below the surface when the main hull was flying.
This hasn't been done yet on a multihull but the advantages suggest it is worth a close look. These foils could stick out on both sides of the ama or only on the outboard side(and pivot back like a centerboard to retract) which would increase RM substantially over T foils and curved or angled foils.

Thread on monos using DSS: http://www.boatdesign.net/forums/sailboats/hugh-welbournss-dss-25-a-32138.html post 14-Wally with foil that pivots back like a centerboard; post 20 DSS25 wins its first race. This is the close to the first, if not the first application of "foil assist" to monohull keelboats in history.

http://dynamicstabilitysystems.com/

 

I agree, building with wood is a very satisfying work, even if the amount of fibres ist very high. If my financial situation allows it I will do the stiffeneing laminate of the strip planked bottom up to the S-Chine in unidirectional carbon fibre.

Decks and cabintop will be sandwiches too.

Is there a rule of thumb how to replace the wheight of uni glass with the same strengh of carbon fibre?

I thought of using 180gr/m² carbon instead of 300 gr/m² glass. Is this ok or can I go even lighter?

No sailing legend! but thanks

Ok, no legend, but I appreciate your great experience in racing third in the 1980 Ostar and all that came later.



Grreeetings from the North Sea Coast, Michel

 

It would seem that you assume that the designer of both IDEC and Sodeb'O, one Nigel Irens, hasn't the awareness, or the capability, to decide if another type of foil would be better for these two, extremely high performance boats that operate at the finest of edges in the open ocean.

So, not only have the skippers of IDEC, Sodeb'O and also the well-proven, VPLP designed Groupama boat driven by Franck Cammas, gotten it all wrong, but you seem to think that you have a better idea that is much more appropriate than the conclusions drawn by Irens, as well as the fabulous team of Marc Van Peteghem and Vincent Lauriot Prévost.

That's some pretty heady company, Doug. I had no idea that you were flying about among the elites of the multihull world.

 

Airgun Phil, (when are you coming back to Godzone mate?) I'm waiting impatiently to see your new 42 plans ... because if it is similar to your Thompson 60 Sebago/We, it will be a revolutionary design. The Thompson tri had metal (titanium?) inverted Y foils ... but you damaged (bent) them during OSTAR, is that correct? Anyway carbon will reduce that problem.
I'm fooling around with a single main beam, small floats 25 foot tri with J foils and have tried many variations of foil designs on my other boats, angled straights (both inwards and out facing: outfacing gives you a cheating, wider overall boat beam), inverted T's and Y's ... and now the J's. Like Luckystrike, my stuff is basic handlaid low technology, tensioned ply, strip planked paulownia, Port Orford cedar, glass and unidirectional carbon.
Here's a sketch of the 25.

 

How does the infusion process compare weight wise with other means of adding resin to the surface I recall reading a story by a custom boat building firm in Australia in which they noted that infusion added parasitic weight against their normal squeegee and vacuum bagged process.

From my understanding the resin tracks along channels on the surface of the infusion ready core material is there additional unnecessary resin used on the surface of those panels? I would assume with a carbon fibre layup there would be significant savings in weight so maybe a little extra resin is not an issue?

 

Corley,

Bagging and infusion can yield very similar resin to fiber ratios when done optimally.

Probably the biggest advantage of infusion is the fact that you will not be working with wet laminate in the shop. All the resin work is done in a closed environment and the mess factors are reduced considerably, as is the exposure hazard to open resin surfaces.

With infusion, you get to layup all the laminate schedules as dry cloth. You can take your time, get it right and it can be done by a much smaller crew. Once it's all laid-up, you close the bag, mix the resin, crank the vacuum, introduce the resin and watch the part wet-out before your eyes. Normal work clothes, no respirators and a whole lot less frantic.

A straight vacuum bag job is all about the hustle as you have open resin with a specific time component constantly ticking away in your head. You can't avoid getting the stuff on you unless you are some kind of god, so safety clothing is vital, as are respirators.

 

Thanks for the explanation of the advantages of infusion, after doing the mad rush with epoxy resin that I normally experience I can appreciate the advantages that having everything contained and ready to go would offer.

 

Phil,

You are as close to a legend as we have on this group. Sebago was my favourite boat for a long time. Interesting to think about how the ORMA 60's might have developed if you had won OSTAR. With foils becoming all the rage again, the last 30 years of hull shape developments may be looked back on as a blind side alley one day.

We have just started infusing carbon, no problems with any of the test pieces up to 6mm thick, or glass up to 42mm thick. We have a couple of carbon beams and a bunch of unstayed masts to do, so hopefully it will work on the big bits as well as it did on the little ones.

Most of our infusion is done on a table and then we bend the flat panels. Just putting the finishing touches on a new 16m x 4m table, then we have a 15m harryproa and a bunch of other boats to build. Very interested in your development products, if they are commercially available?

Corley,
I used to be a big fan of cedar strip, but went to one of Derek Kelsall's infusion workshops, and was instantly converted to flat panel infusion.

Infusion is heavier than vac bagging if you use channels in the foam to allow the resin to travel along the job. If 1mm x 1mm at 100mm centres constitutes excess weight, then you can use transfer medium, which is removed afterwards. Otherwise it is near enough the same. You will use a little more resin in the pipes, but none ends up in tools, your hair or on the floor. Infusing in a mould requires a lot more care than infusing on a table, and will weigh more as the kerfs in the core fill with resin rather than with bog. However, they do "fill", so there are less likely to be the quality problems associated with bog filling.

Because of the way we put our boats together, millimetre accuracy is required for the core and laminate layout. This is simple with infusion, a lot more difficult, probably impossible with vacuuming, particularly with carbon as you cannot see any marks on the table.

Where you really gain is with the extra bits and pieces you can install as part of the infusion. We put in bulkhead landings, male and female joins, beam reinforcement, hatch and window surrounds, solids, rebates for joins and some fittings. There is a bit of secondary laminating on the 15m, but the following boat should have almost none. Just a couple of kgs of glue to assemble it. The weight, time and cost savings are enormous. The 15m painted without the rig will weigh about 400 kgs and cost $35,000, pro built.

The drawback of flat table infusion is that compound curves are not easy. Derek has some very tricky techniques for shaping hulls after they are infused, we are working on ways of doing this as part of the infusion. The bow areas of the 15m will be compound curved, off the table.

rob