1977 26' simpson-wild trimaran

simpson-wild trimaran - small floats

Small volume floats are okay IMO if they have foils to add extra lift - as soon as the boat moves, even backwards, the foils provide lift. The buoyancy of my two foil trimarans (6x6 metres and 11x11metres) are very low, but I've never really buried them even when completely overpowered with far too much sail up. And they are fast and very light. Very interested in Randy Smythe's latest design Swamp Thing (but no foils and actually quite deep floats - but it apparently broke in the Everglades race - not an unusual result with spidery looking craft)- which has many similarities to 25 year old Flash Harry - but a better paint job and way flashier sails I bet.

 

Three Fingered Jack

Here is a pic of Three Fingered Jack (from Trimaran Develpment, DH Clarke).

 

low disp floats

Many earlier tris have floats of around 100% disp. Think early Crowthers, Brown Searunners, Trailer Tri's and so on. They work fine but if sailed hard tend to sink the leeward hull and drag the crossbeams, see pic below for a somewhat extreme example.

Most contemporary designs use floats in the vicinity of 130 to 150%, while many pure racing designs are using floats in the vicinity of 180 to 200%, some with stabilising foils as well. High displacement floats and wide beam give more stability allowing a larger rig and a potentially faster boat.

The Hughes 24 in this clip has 140% floats. A lot of light wind stuff but there is some footage in higher winds which shows how the higher disp floats work.
Warning: After watching this you may want to own one

http://www.youtube.com/watch?v=RfSQg4s_LsU

 

Thanks Jamez

 

speaking of foils...how would one go about foiling a tri..and is there a manufacturer or supplier of these items..also i was looking at an f-24...96 model year and the fiberglass beams had cracked i do believe that they are mostly cosmetic...the owner had them(three of four)repaired to the tune of thirteen hundred bucks...and was not happy with the resulting repair cause they recracked and now the fourth is cracked.....these are the main beams that attach the floats to the hull.....do they all do this and could there be an easy fix?

 

Probably gelcoat cracks at a guess, beams flex gelcoat does not. Not sure that you will be able to stop it if the beams are engineered such that they flex. Most fillers will crack if the substrate moves enough --- solution = don't worry about it. If they are more than that approach with great caution and surveyors/engineers advice.

 

Simpson designs

Andrew Simpson is consultant editor of PBO in U.K.

 

Smaller Tri

What a great looking Tri. Anyone know if plans are still available?

 

When you add foils to an F-boat, the cracks may not be all that cosmetic. Take Cheekee Monkee, for example.


I've spoken to the builder that made the replacement beams for Cheekee Monkee. They had the good beams on the other side tested to destruction. They failed at something like three quarters of their design ultimate load. Not that one can generalize from one data point to the rest of the fleet, but it is a data point.

I'm also a part owner of an F24 MKI. I would seriously question its suitability as a foiler. The beams are adequate for its intended purpose, but the foils will add a lot of new, unanticipated loads. The pads on the beam ends would be taking lots of additional compression. And, as you point out, they already have a tendency to crack along the joint between the top and bottom beam moldings. Then there are the struts and their attachment points.

Ian Farrier has done a great job of engineering an integrated system with the F-boat designs. When you add foils to the mix, you really need to go back and re-engineer the whole boat. You would need to have very specific goals in mind for what performance improvements you plan to achieve and what deficiencies in the existing design the foils are intended to address. Just slapping foils on an existing boat is likely to be an expensive and disappointing exercise.

 

Beam failure point

Hello Tom

Do you know what the failure stress was and how the beam was stressed?

cheers

Phil Thompson

 

No, I don't.

 

Suggest you check with Andrew Simpson re. plans
There may have been a design article in AYRS - there are entries showing in the index.

http://www.ayrs.org/Index12D.html

 

Three Fingered Jack

 

simpson wild trimarans

hey terry...

been following this post for a bit...lol,
you kinda hit the jack pot...

i did all the fiberglass work for andy simpson and bruce wild
(11-32' trimirans and 2-45' catamarans) from january of 1975 until june of 1976..

what would you like to know...

mark

 

wow...very cool..!..well mark what do you know about the 26' slipstream..early seventies i think...correct me if i'm wrong but i do believe the hull and deck to be solid glass....not cored correct?..not many were made..i'm thinking five or six perhaps. any ideas on the thinking behind the design and did the design live up to expectations with little to no modification. the main hull rocker is fairly extreme..not quite a banana..(on second thought).. i'm thinking this would make for a more responsive craft, perhaps better in wave action?? the craft is very stout indeed...it was the first thing that stuck me when i first looked at her..nothing flimsy there... as a trailerable tri i think the intent was to fold the amas in the up position for travel..correct..any idea on the procedure. oh and i do believe production was based out of kemah texas.. correct? any other info would be greatly appreciated.