Small trimarans under 20'

Discussion in 'Multihulls' started by Doug Lord, Jun 24, 2012.

  1. Doug Lord
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    Doug Lord Flight Ready

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    Best I can tell there aren't hardly any small(20' and under) high performance tri's. Coming out of the woodwork in cats but not tris.....
     
  2. Jetboy
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    Jetboy Senior Member

    It's a Ray Kendrick design. It's surprisingly efficient to build. While the designer claims 500 hours, I think it can be built by a novice like me in under 1000 pretty easily. And I'll probably have $7-8k in materials building in honeycomb and epoxy including the rig, but not the sails or motor. (Honeycomb was 1/2 the cost of marine plywood where I live - it's ridiculously expensive to buy here.)
     
  3. Jetboy
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    Jetboy Senior Member

    You would think someone would build a very high performance tri by simply using a high performance cat. The formula is simple: take high performance cat, add low volume center hull that's intended to fly plus folding or plug in beams, keep the original rig possibly and rely on the stability to add the power, final beam of about 16-18'.

    Should be pretty easy to even build a kit for existing high performance cat conversions.

    Possibly there's just not a market for them right now? Or possibly there would simply be better performance for your $ by just extending the beam of a 20' racing beach cat to 12' or so.
     
  4. Doug Lord
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    Doug Lord Flight Ready

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    Seems to me ALL the production cats 20' and under are high performance boats with few exceptions- Nacra 20, Nacra 17 Olympic, F 18, A Class, F 16 and so on.
    I tend to think that the application of the technology that would make a high performance over square tri viable tends to boggle the mind to some extent. But thats probably wrong because, well, just look at the cats.
    From my perspective a high performance tri should be only very slightly heavier than a cat its own length. It should use sail area comensurate with an oversquare platform and, of course, foils(like most of the aforementioned production cats) to keep all that power under control. Probably use very small amas and ama foils(or planing amas or both). Foils on the main hull for early takeoff and pitch control. This kind of tri could have a nice cockpit that would not require the crew to run across the boat and still be faster than an equivalent sized cat. For the runners, putting a couple guys on trapezes would simply raise the top end speed. Designed right, this kind of tri at 18' would be maybe 10-20% more costly than the same length cat.
     
  5. upchurchmr
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    upchurchmr Senior Member

    Corley,

    I have the greatest respect for Farrier, I just don't want as big of a boat as he designs.

    How many Hobie 16's were sold? On the Hobie site I saw a sail number of 110,000+. Interesting comparison to Ian's proudly stating that over 3000 boats of his design are sailing.

    Seems that Farrier missed the facts of the matter. His problem was that he designed boats to be 10x or more the cost of the boat most can afford.

     
  6. Corley
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    Corley epoxy coated

    Well Farrier has struck a formula that works for a lot of people not me or I would be building or buying one of his designs. I guess what I'm trying to say in my post is that sitting bums on multis is a positive development. Whether beach tri's can make a business case for themselves time will tell the Weta seems to be building one design fleets so there is some positive there.

    With his F22 he is trying to make an affordable small trimaran that is easily trailed but still has some appeal as a family boat. I think he will sell quite a few of them because they will make sense in terms of a small cruiser for families with some racing credentials.
     
  7. warwick
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    warwick Senior Member

    May be part of it is, because it becomes a Three hulled catamaran when you start to look at flying the main hull. As well and the added expense of the main hull why make three hulls when two will do.
     
  8. upchurchmr
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    upchurchmr Senior Member

    Three hulls perform better in a light wind, which face it, is where a lot of the sailing occurs.
    To compete with a cat the tri needs to be able to get on one hull in high wind, which is what a beach cat does. Why do so many people want to limit the tri when they don't the cat?.

    If a cat was so overwhelming, why did Oracle win in the America's Cup?

    All these "discussions" don't matter to me. I want a Tri and a daysailor. The Farriar 22 does not hit the type of boat I want no matter how many he sells, at least at this time. The investment in the Farriar will also stop my interest.
     
  9. RHough
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    RHough Retro Dude

    Because I can buy a A Class or Nacra with sorted out foils and I have to build one if I want a Tri?

    The fact is that given the same building techniques and materials the Tri will be heavier at that size. Once you are sailing on one hull you might as well have a cat anyway.

    To get a central cockpit and comfort you have to compromise and I don't see and easy way to get around giving up performance for comfort.

    The idea of a daysailer that I can take the wife and dogs out in for a relaxed sail *or* tear up a race course with is very appealing but I don't see it happening.

    Notice that once you want to have some semblance of overnight ability and performance the situation is reversed. There are many F boats and Corsairs available but no Cats in the 20-32 foot range that are performance racer/cruisers. There are no 40+ performance multis except for Gunboats that I know of.

    I think an under 20' tri that could beat a F-18 or even keep up will require the crew to be every bit as wet and every bit as athletic as the cat. I can be wet and fast for less money than I can try to be dry and fast.

    I did buy plans for a W-17 and was thinking that lifting foils in the amas would be cool ... but I don't see my life becoming simple enough to allow me the time to ever build it.

    If I could buy a completed tri about the same size and specs as the W-17 I'd be all over it.
     
  10. upchurchmr
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    upchurchmr Senior Member

    RHough,

    Did you have anything positive to say?
    No facts, nothing new, just negative opinion.

    That was pretty easy wasn't it.

    What about the Windrider 17? At least you will have time.
     
  11. Doug Lord
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    Doug Lord Flight Ready

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    Hey, Randy-welcome back! I disagree here because starting with design and equal use(more or less) of technology the tri:
    1) doesn't have to be heavier than the equivalent cat- using small amas and carbon beams can see to that,
    2) using a square or oversquare trimaran platform can allow there to be a comfortable center cockpit where the crew can sit with their legs down and only have to move to the other side of the cockpit(not the boat) when they tack and still carry more SA than the cat with two guys on trapezes. And it can fold in two minutes for trailering.
    3) Using foils on the main hull can allow the thing to take off in light air keeping the main hull clear of the water for a dry, comfortable, very fast ride. But there is more to it: a "DSS for multihulls" horizontal foil or a curved lifting foil can be used on a small ama. The combo works like this:
    a- the main hull foils allow light air take off and as soon as the main hull lifts off they begin to unload until at X speed they are not carrying any load what soever-except that they will work 100% for pitch control. The ama foil becomes more and more loaded until its carrying nearly 100% of the boats weight. The "wand" on the main foil allows for gust response by adding RM as necessary. There is a thread here where I compared this type of tri with an F18-wins in every case except for cost. A production version compared to a production F18 will cost 10-20% more but you get a non-athletic ,high speed boat that will beat beach cats with a comfortable cockpit and no running side to side.
    4) My observation is that almost every current production cat-at least most of the 20' and under ones- use lifting foils ,yet there is not one single trimaran 20' or under designed to use the same technology. Weight is simply a non-factor in a properly designed tri that uses foils. To build this kind of boat yourself would require skills that many people don't have but, also, it appears to require something from most designers and production boat builders that isn't there. Too bad because the idea of beachcats being the fastest multihulls in 2012 is laughable given the collective design knowledge that is available. And it is unfortunate for a whole lot of sailors that could go fast as hell and still be comfortable!

    Pictures: 12' singlehander trimaran using the system above with planing amas(would also probablyuse small foils in the amas)
    click-
     

    Attached Files:

    Last edited: Jul 1, 2012
  12. RHough
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    RHough Retro Dude

    That wasn't negative at all. If my friend Doug thinks it was I will apologize.

    He asked a question and I answered it with my opinion. Why are your knickers in a twist?

    Randy
     
  13. Doug Lord
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    Doug Lord Flight Ready

    ======================
    It was your opinion, done your way and its ok by me(even if it is wrong)-no apology necessary! Glad to hear from you, Randy.... Hows it going in the land just under?
     
  14. RHough
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    RHough Retro Dude

    I'm back in the great white north for a few months ... it has been cold and raining for three weeks ... :-(

    There is a difference between what is possible, what is possible at a price point, and what the market demands.

    IMO the people that want to go fast and might be in the market for a foils assisted cat don't mind trampolines and trapezes. I'm not certain a more relaxed daysailer would appeal to them. As they get older a market might emerge for a boat that allows them to sail as or nearly as fast as they used to without having to buy stock in Advil. :)

    I know I share your desire for fast fun and comfort. Short of going the folding F-Boat folding cruiser/racer route the W-17 seems to be the most attractive option I've come across. The other option would be to find a Hobie 18 with racks that was in decent shape and call it good. Not state of the art by any means but certainly faster for daysailing than most 40 foot monos.

    There is almost certainly more tooling and labour involved to make three hulls compared to two. If you are going to sail on one hull, the ama has to have large volume and I don't agree that a 2 amas and a main hull (Vaka?) that is even bigger could be built as lightly. If you go with the full foiling design you might be able to match a cat for weight since you don't intend to sail on the ama and that is a direction that I had not considered.

    That opens the door for a new idea: A Faux Tri

    One of the structural advantages of a Tri is the beams can be lighter since they are shorter. Why not design a fast foiling or foil assist Cat with a center cockpit? If the goal is driving from a more or less traditional cockpit and having centralized controls there is no need for a bouyant central hull. Just replace the trampoline with a command pod and give the whole thing a 1:1 Beam/Length ratio.

    Advantages would be that in very light air the wetted surface starts going down with each degree of heel rather than going up until the main hull starts to lift. (reference the design brief for Alinghi's Le Black) Would two moth style wand/foil combos be made to work so that the windward foil would go negative and add RM? (to eliminate the need for crew on the wire for ballast).

    Now the only drawback is an 18 x 18 platform folding to legal trailer width. If you had the amas hinge at the outer edges of the command pod you could get about 16' beam in a 8' road legal package.

    Just thinking outside the box a bit... :)

    R
     

  15. Doug Lord
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    Doug Lord Flight Ready

    Randy, I almost got this boat built. I hurt my back a few weeks ago and had to back off for now and start a much smaller boat..(see Crossbow fl thread in Sailboats) But it would have been lighter than an F18 by about 80lb even with the 280+ sq.ft. rig to be added later. It uses a hull I have-not an ideal hull and 40% heavier than the ideal main hull. There is no question, after having put this design together, that the system I described earlier can produce a much more powerful platform equal to or lighter than a catamaran-and much more comfortable and substantially faster.
    It seems to me the Faux Tri you describe would be heavier than a normal cat which means it would be heavier than a tri using my foil system. And if it used a foil system like a Rave, Osprey or Trifoiler it would also have two main foils developing induced drag instead of one in my system. In my humble opinion, after many hours research and development you can't beat a well designed tri using my foil system with a "normal" tri or with any cat.

    The thread: http://www.boatdesign.net/forums/multihulls/dream-flyer-fl-18-daysailing-trimaran-42340.html


     
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