Non-foiling trimarans under 20'

Discussion in 'Multihulls' started by Tom Makes Things, Sep 25, 2019.

  1. waynemarlow
    Joined: Nov 2006
    Posts: 419
    Likes: 39, Points: 28, Legacy Rep: 134
    Location: UK

    waynemarlow Senior Member

  2. kleppar
    Joined: Jan 2016
    Posts: 24
    Likes: 3, Points: 3, Legacy Rep: 10
    Location: Stavanger, Norway

    kleppar Junior Member

    Yes, at an early stage I considered both the Tricat 20 and the Astus 20.5, but that was for the cabin trimaran project. In fact, I made a comparison of a bunch of 20-30 ft. cabin trimarans; published here. But then I decided to go for a roomier, slightly longer and arguably faster boat. Tricat and Astus are popular in France; Astus slightly a the budget end of market, Tricat more expensive. I am sure they are excellent value for their purpose.
     
    Last edited: Sep 3, 2020
  3. Cholsson
    Joined: Aug 2015
    Posts: 90
    Likes: 28, Points: 18, Legacy Rep: 14
    Location: Gothenburg

    Cholsson Junior Member

    I think both that Sting 600, and Trikat and Astus 16.5 / 20.5, then could be great choices! Also The Pulse 600. But those are litter heavier than your requirement.

    BTW!
    How many small trimaran out there can actually fly on one hull for real?
    "Greater than 100% ama volume - to fly the main hull.
    that you where talking about in another tread


    Chris
     
  4. upchurchmr
    Joined: Feb 2011
    Posts: 3,058
    Likes: 154, Points: 63, Legacy Rep: 579
    Location: Ft. Worth, Tx, USA

    upchurchmr Senior Member

    Kleppar,

    The weight of the boat is 410#, the displacement of the ama is 700#.
    That leaves 290# for 2 sailors, and personal equipment.
    So if you hit 290# with sailors and equipment, the hull will be driven down to the deck line, before the main hull starts to lift.
    That is a recipe for disaster. Any gust or wave could drive the ama underwater, resulting in a rapid stop or a cartwheel.
    Having done that in the past on Hobies I want an additional margin of ama displacement.
    Especially since I am 225# in my older age.

    Wing masts are another place where "experts" disagree on their value.
    Probably because so many things go into making a sail rig successful.
    One little mistake in the entire rig geometry may invalidate the perceived advantage.
    And a wing mast may improve upwind performance, but not on other points of sail.
     
    Cholsson likes this.
  5. kleppar
    Joined: Jan 2016
    Posts: 24
    Likes: 3, Points: 3, Legacy Rep: 10
    Location: Stavanger, Norway

    kleppar Junior Member

    Maybe we have different modes of sailing in mind - no plans to lift the main hull for me. As for weight, I am about 80 kg.....the boat should be able to carry me, a crew member, and sustain our style of more moderate sailing. One of my important reasons for choosing a trimaran is comfort - no more heeling, no more perching on the gunwhale, etc. W17, with its roomy and sheltered cockpit, fits that purpose well in my opinion. Beiing restless, I also like to move around in the boat, and this is also possible with a roomy cockpit.
     
    Last edited: Sep 3, 2020
    Cholsson likes this.
  6. patzefran
    Joined: Feb 2011
    Posts: 229
    Likes: 21, Points: 18, Legacy Rep: 10
    Location: france

    patzefran patzefran

    Disagree : Having experimented both submersible and insubmersible hulls, I can say well designed submersible floats for trimarans are very safe. I built/own a Strike 15 for 7 years now
    and I always recovered from such "disasters", even in very strong wind, wheras I flipped many time sidewind with catamarans (insubmersible floats !).
    As soon as you lift the mainhull, the only thing wich can stop capsize is to ease the sheets ! Hobies marginal case as they are just to the limit !
     
  7. kleppar
    Joined: Jan 2016
    Posts: 24
    Likes: 3, Points: 3, Legacy Rep: 10
    Location: Stavanger, Norway

    kleppar Junior Member

    Patzefran, is this your boat?

    How would Strike 15 compare to W17?
     
  8. patzefran
    Joined: Feb 2011
    Posts: 229
    Likes: 21, Points: 18, Legacy Rep: 10
    Location: france

    patzefran patzefran

    Yes, it is mine. I have also built a Strike 20, wich is very powerful and easily above 15 kt, she will be for sale at the end of the year. W17 is a little cruiser, and Strike 15 a performance day sailer with a single crew.
    Not the same use ! it depends on your needs. Strike 15 is much lighter and start from the beach. According to his higher length, W17 should be faster in strong wind.
     
  9. kleppar
    Joined: Jan 2016
    Posts: 24
    Likes: 3, Points: 3, Legacy Rep: 10
    Location: Stavanger, Norway

    kleppar Junior Member

    I am planning to beach launch/dry sail W17 by means of a flatbed cart, as suggested by the designer. It should be possible with the use of rope and pulley, so that I do not need a car. Weight of boat is a little less than 200 kg.
     
  10. kleppar
    Joined: Jan 2016
    Posts: 24
    Likes: 3, Points: 3, Legacy Rep: 10
    Location: Stavanger, Norway

    kleppar Junior Member

    Last edited: Sep 3, 2020
  11. patzefran
    Joined: Feb 2011
    Posts: 229
    Likes: 21, Points: 18, Legacy Rep: 10
    Location: france

    patzefran patzefran

    Beware of the light displacement from the architect, they are alway optimistic !
    I will add that a Strike 15 was very easy and fast to built. multiple chined WS17 will be more difficult and long to build !
     
  12. kleppar
    Joined: Jan 2016
    Posts: 24
    Likes: 3, Points: 3, Legacy Rep: 10
    Location: Stavanger, Norway

    kleppar Junior Member

    Patzefran, I notice you use carbon tubes akas, non folding. Actually, W17 folding is not important. I might ask the designer if such an arrangement is possible; tubes could also be sliding, as on Astus (but the designer is not too fond of this method).
     
  13. patzefran
    Joined: Feb 2011
    Posts: 229
    Likes: 21, Points: 18, Legacy Rep: 10
    Location: france

    patzefran patzefran

    I used this solution because It is lighter and easier to buid, however it is much longer to assemble. From my experience, Richard Woods implemented a slot in an aluminium (or carbon !) tube option
    for the strike 15 which looks easy to build and fast to assemble. You will notice that my boat has a center hull without cockpit box on the mainhull as per plans (always to be light !)
     
  14. upchurchmr
    Joined: Feb 2011
    Posts: 3,058
    Likes: 154, Points: 63, Legacy Rep: 579
    Location: Ft. Worth, Tx, USA

    upchurchmr Senior Member

    Pratzefan,

    I agree that a submersible ama is safe.
    Not what I want, I'm not interested in sailing a sofa.
    My disaster comment assumed you would be trying to get the maximum performance out of the boat. I don't want to stuff the ama bow drastically slowing the boat and putting that force on the aka.

    Submersible is safe with a distinct limit on the performance.
    To each his own.

    Yes, you have to be actually sailing and paying attention on a tri with non submersible floats - releasing or easing the main sheet is your safety.
     

  15. kleppar
    Joined: Jan 2016
    Posts: 24
    Likes: 3, Points: 3, Legacy Rep: 10
    Location: Stavanger, Norway

    kleppar Junior Member

    upchurm, I have followed your comments on various issues; you seem to be of a highly critical nature about various boat designs, so it would be interesting to know which boats fits your requirements, or are there none?
    There seems to be several well performing trimarans under 20 ft. (to stick to the thread) in my view, such as (in order of boat length):
    Strike 15 (drawings and self build)
    Kanka 14 (drawings and self build, or a production boat made in France)
    Astus 16.5 (production boat made in France)
    W17 (drawings and self build)
    etc.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.