Upstaged

04 February 2015     Editor    5 Comments.

Little Tri
Little Tri

GALLERY | Click images to enlarge

Multihull designer Bernd Kohler has thus far been solely devoted to catamarans, but his latest design is for a simple small trimaran, logically named LITTLE TRI. I like Bernd’s work because he places simplicity of build and economy high on the list of design priorities, and yet still manages to come up with appealing boats. His latest is a classic example, where he sidesteps the usual trimaran complexities by employing a readily available local industrial product for the outriggers, instead of building up the amas from scratch out of plywood. It’s much the same approach that SE Asia takes with their outrigger canoes, building the amas from readily available bamboo, and Bernd does make the point that LITTLE TRI is closer to that model than the modern, high buoyancy ama trimaran.

This example is the first LITTLE TRI built by an owner/builder.

Via Small Trimarans.

 New Designs  Designers  Trimarans  Smallcraft

5 Comments

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  • I bought these plans, but having a little trouble getting the Oakume and aluminum tubing . they all want to cut it in shorter pieces to ship to me or I can’t buy the plywood because the shipping is as high as the wood it’s self. I will keep on gathering, just may take me longer. . I may make me some laminated birds mouth arms until I find the aluminum. I just don’t want to get too far away from Mr.  Bernd Kohler’s great design

    2015-12-30 17:02 | by Ronald E. Gillis

  • Instead of okoume you can take simple 4 mm birch plywood or multiplex sheets, covered with epoxy and 200g glass cloth it is even better than okoume and also cheaper. Instead of aluminium tubes you can take irrigation tubes made from PVC, coat them with epoxy carbon or glass ( cheaper but heavier ) fiber sleeve squeezing out surplus material by rolling adhesive tape
    ( about 2,5 cm broad, otherwise you get too much wrinkles ) when the epoxy is still moist. In addition of two or three layers of 6 mm kevlar rope ( breaking load 2000 kp ) you get ultra light and strong beams.
    Regards
    Dieter

    2016-10-01 04:18 | by Dieter Brockschmidt

  • Those PVC-tubes for the Amas cost > € 50/m, so at least in Germany very expenseive. When designing the Amas from 4mm ply instead, someone can made them much lighter and stronger compared to glassed PVC-tubes, they also generate more lift to get in and out of the boat when moored on an harbour pontoon.
    Also the styling can have a much better look, as the amas could have a similar style as the Vaka.
    Also the beams, which seem very flexible could also be made as squared profiles to get more stiffnes in.
    Dte disadvance of those design changes would be more time to build Amas & Akas in ply.

    2023-02-28 00:46 | by Jörn Bütow
    • I found 6" diam. PVC tubing for $8.93/ft. at US Plastic Corp. You'd need 3 tubes because they aren't sold here at 4m (13') length, which would be $269 for 3 10' tubes. Plus tax and shipping. So not as bad as Germany, but not super cheap either. I agree with all your points about the advantages of building with ply/epoxy, however.
      2023-02-28 15:25 | by Editor
      • Hello Editor, Thanks for the comment. But i dont belive, that 6" (= 152mm minus wallthickness) tubes with 4m lenght are sufficient, as those will generate lift per Ama of only 69 Kilos. Those tubes might be much cheaper also in Germany, but i have calculated with tube diameter of 180mm (minus wallthickness), which are available also in 4m length and which will generate about 96 Kilos lift per Ama. Another point against tubes: I am not sure about the stiffnes of the tube-Amas direct in front of the foreward Aka , when punching in the waves @ highspeed.
        2023-03-01 09:40 | by Jörn Bütow