4.75m Trimaran Project

Thanks forthe pointers ref Ray - I have seen those previously.

It all goes into the mix.

I don't want this to become a battleground so I will probably leave it there until I have some more useful progress to report.

 

4.75

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Gary, it's unfortunate you didn't read the first post! The guy wants to use hydrofoils and specifically says so. I was trying to make suggestions that could help him decide on specific ways to proceed.
A 4.75m(15.6') trimaran foiler, whether full flying or foil assist, can easily be designed to carry two people.

 

Maybe on your average sailing dinghy. as suggested, but not on a 4.75m trimaran; that is, if you want any reasonable performance and don't want the crew (maybe two versions of yourself Doug?) to just float around sitting astride a dead porker. The talk of foils is utterly ridiculous.

 

Have you looked at the W17?
Longer than 4.75M - not too much, but you could have lots of fun fitting it with foils. Weight 410#, and an available (free) wing mast design.



Link: http://www.smalltridesign.com/W17/greybox/W17-Trimaran.html

 

End of thread

Yes looked at the W17 and again unfortunately it doesn't quite fit my size parameters.

Anyway, thanks for pointing out that my idea and interest in this is rdiculous.

I had seen a number of small trimarans that had incorporated hydrofoils such as
https://translate.google.co.uk/tran...ttps://foils.wordpress.com/tag/pk/&edit-text=
or
http://smalltrimarans.com/blog/garage-built-hydrofoil-sailing-trimaran/
and most particularly Doug Halsey's Broomstick
https://vimeo.com/34164014

but as you point out it is plainly ridiculous.

I had looked on this as a learning challenge combining my long standing love of making things and my newly discovered obsessive interest in sailing.

I've never contributed to any sort of blog / community before and I had hoped it could offer me some insight into this new interest but I won't further waste anyone's time and will be closing my account.

I will of course be taking the project to its conclusion regardless but I certainly won't be looking for any further help and support from here you will all be relieved to hear.

 

Kaymaran,

This is a relatively "kind" forum.
But it is open to anyone and you have too accept the good with the bad or even the opinionated.
It would be a pity if you gave up on the good.
The trick is to keep a fairly thick skin, focus on actual factual input - ask questions that center on facts and if necessary use the Ignore function to take out peoples responses/ attitudes you don't like.

There is a tremendous diversity of experience and goals here.
You also haven't seen the years of discussion that have occurred before which cause some of the bickering - some of which is justified, some not.

And we all have bad days - there is little on a forum to cause a person to moderate their statements - and little to cause more than a statement of personal opinion. If you get beyond that with factual questions you may find a very strong justification for the opinions.

Stick around and ask for facts. You will quickly see who just has opinions.

Good luck with your boat.

FYI, I also have not found the boat design I believe I want. That may be because my desires run contrary to physical facts.

PS, I hope you weren't talking to me about calling your ideas ridiculous, but virtually everyone does not get everything they want, even if they design the boat themselves.

 

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Kaymaran, please don't leave! I sent you a PM. Upchurchmr's post is an excellent one-take the good with the bad and don't be shy about expressing your opinion. And ,most of all, good luck with your boat-I think your ideas have great potential!

 

upchurchmr no not you - I'm afraid my reply after the first line was directed elsewhere but not clearly.

This isn't my thing I think - I prefer to deal with people face to face hence why I have never used a forum before.

 

Kaymaran, take it easy.
Everyone here knows Doug Lord is full of weird fantasies derived from his playing around with toy boats (that don't work, yet he writes hectares of repetitive drivel about them) - hence the sniping comments.
Your 4.75m idea is fine for a single handed boat; and if you want to go foiling, check out Doug Halsey's design, the other Doug but one who is truly innovative and actually builds and physically sails his small, singlehanded design.
FWIIW, your restricted 4.75m yacht size for a two handed trimaran is too confining and the only way to achieve this is to go wide with the main hull ... a planing hull shape ... and then you may as well have a sailing dinghy. However stretch your trimaran to 5.5 m (18 feet) and then you have something decent to begin with.
So don't get disheartened with the impoliteness here, especially from the brutal ANZACs, which is our way of being helpful and kind ... and yet we are often misunderstood. Life is hell?

 

Did I seem harsh? I'm sorry if I did. Personally I think somewhere around the 18' - 20' mark a two person trimaran starts to get interesting. I've seen a few small kayak trimarans that are smaller than that and seem to have decent performance but they are a different paradigm to a true trimaran in seaworthiness and power. I've got a couple of beachcat hulls from an 18' racing catamaran in my boat rack I often look at them and ponder a demountable trimaran.

Off the beach demountable trimarans are great and much easier to deal with on a beach than a beach cat as the individual bits are not too heavy even when your alone.

 

Kaymaran,

I understand the issue with not being able to talk face to face.
You can get so much more information that way that doesn't come across in 2 sentence comments on a forum - most people know that others generally don't read a long post.

But here there are no indications there is more to discuss as you can clearly see in face to face.

There also seems to be an art to keeping a thread going so you get interested people offering useful suggestions.

Face to Face has the limit that you personally can't reach as many people of diverse backgrounds. So you also have a limit there.

Stick it out. Talk to those who interest you. Ask for facts - it generally tells people you want to get something from them and they open up a lot.

Gary in particular opens up with lots of information that is not apparent in the normal chit chat. He seems to have stated the information before, but we were not all on the forum to see it all.

For instance you could ask Corley to expand on his cryptic comment about a "true trimaran in seaworthiness and power" - personally I'd like to know what he thinks is a "true trimaran" and what he considers to not be one. That way we would know where the comment comes from and how to evaluate it.

So Corely - is a W17 a true trimaran or why not - in your humble opinion? (or not so humble)

 

Well I guess the W17 qualifies I agree that perhaps I got a bit over excited with seaworthiness and power in the context of a small tri but a higher freeboard design like the W17 is certainly more capable than a converted kayak style trimaran. Lifting foils are all very well but the boat has to be capable of carrying a big enough rig with a high enough power to weight ratio to use them gainfully and you do want some reasonable LoA for longitudinal stability.

 

powerful fast comfortable small trimarans

One of the keys to power in small tri's from 12' on up is an oversquare platform-with lifting foils including a rudder T-foil. Very, very few under 20' trimarans have been designed to take full advantage of the potential there is in this size range.
It's a wide open design space sure to be developed as time goes by......

 

I doubt it. Two people on a short main hull trimaran with foils ... you have to be joking? Don't get me wrong, I'm all for lifting foils .... on sensible length designs but crew weight - I repeat, 2 crew total weight exceeding the platform weight - on a small boat carrying foils ... the weight plus drag would defeat the whole purpose; it is an idiotic suggestion.
There is a reason that there have been very few tris designed which are under 18 feet - the Weta doesn't count, as mentioned, it is a monohull with floats.... because under 18 feet they are near useless when compared to cats and mono dinghies of similar size, no matter how wide you make the overall beam; in fact the wider, heavier beam would be just an extra disadvantage, create even a worse dog in performance terms.

 

small trimaran foiler

Sorry , Gary but in this case you don't know what you're talking about. A small tri from 12' on up would have way more righting moment than any monohull and would be able to carry substantially more sail. In monohulls there is a two person Cherub racing ON FOILS as well as the 2 person 12.75' R Class ON FOILS and in 1999 an I14 used full flying foils!
There is simply no reason whatsoever that a small foiling tri wouldn't work very well and be very fast-faster than any mono except maybe the Moth depending on the design. Using an oversquare platform allows the boat to have tremendous power compared to a monohull and boats in this range can be designed to use downforce from the daggerboard foil to allow a single crew to sail in the same wind as a two person crew. The technology is available now to produce small tris of incredible power with hydrofoil systems that make it practical. Aside from speed, the oversquare platform coupled with well designed hydrofoils can provide an easy to sail, very seaworthy daysailer capable of foiling in light or heavy air starting in about a 5mph wind. Again, there is tremendous room for design innovation in trimarans under 20'-from around 12' on up. The idea that small trimarans are slower than beach cats is simply because of the lack of high powered small tri's-the tri can be faster if it is designed to be! And the tri can do this with a much more comfortable layout and be much easier to sail(fly).


Pictures,L to R- 1) R Class(12.9') racing foiler, 2) Cherub(12') class racing foiler,3) Moth having fun, 4) David Luggs International 14 in 1999 :