Multihull Structure Thoughts

Discussion in 'Multihulls' started by oldmulti, May 27, 2019.

  1. redreuben
    Joined: Jan 2009
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    Location: South Lake Western Australia

    redreuben redreuben

    Hey Russell,
    Hows your exploration of tortured or compound plywood going ?
  2. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    Russell at; Log into Facebook Roll down to 10 April 2015 and get a few jpegs then roll down to October 2014 and get a 38 second video of the Bebox 333 sailing. The translation of 10 April 2015 is:
    22 October 2014 · In recent weeks, the White Bird has been discreet... He was preparing for a long winter migration to the West Indies !!! A beautiful crossing of the Atlantic in front of him, and why will you tell me? For the adventure and the pleasure of sharing it together: Olivier, Sarah, Stephane and you. Because offshore racing makes us dream, and this year the Route du Rhum will arrive in Guadeloupe, we will be there to welcome and celebrate these great sailors. Designed by David Réard and built with passion by Christophe Legal, the boat had to cross to Brazil. Finally it will be the West Indies but he will have done it his Atlantic !!! And then in the West Indies, cruises are offered on board, with us and with Julien and Pierre from the three Ilets in Martinique. Finally the family will also take up residence on board at the end of February to stroll in the Grenadines. The White bird will take flight for the return at the end of March.
    Attached are some Bebox 333 jpegs. Also some jpegs of David Trek 42 tri. I do not know any details.

    Attached Files:

    Last edited: May 27, 2022
  3. Russell Brown
    Joined: Jul 2012
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    Location: washington state

    Russell Brown Senior Member

    That's quite a facebook page. I really like that guy's work. Some very good looking hard chine monohulls. The Bebox 333 doesn't seem to suffer too much from the wide-at-the-waterline main hull and that sure makes for a roomy interior.

    Redrueben; The tortured plywood hulls came close to going to the tip, but they got saved with some keel surgery. I've got the inner skins and stringers in and am working on the deck mold now. They aren't vey photogenic at this point. I have to get a bit further on the design work to figure out where the connective bulkheads go before gluing the decks on. Can't remove the hulls from the jigs until after the decks go on.
    I'm still planning to complete the book on tortured plywood, (not that I think it will be a best seller), but haven't gotten anything back from all the leads in NZ. I need more photos and details to make the book as good as it can be. I will obviously give credit for photos and design. The photo below would be fantastic if I could get permission to use it and a better image and maybe more details...

    Screen Shot 2022-04-06 at 7.19.23 AM.png
  4. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    The following is short on detail but an interesting concept. EBYD (Ekman – Blomquist) Yacht Design and Linderson Consulting (Torbjörn Linderson associated with Seacart and many other high performance tri’s) were requested to do a trimaran design for production. The concept they produced is 32.5 x 21.6 foot that with swing wing floats can fold to 10.5 foot. The guesstimate displacement is about 5000 lbs. The mast and sail area are unknown. The main hull length to beam is 10 to 1 and the floats length to beam is 13.5 to 1. The rudders are on the floats.

    The concept is to produce a high performance trimaran that is simple from a production perspective and therefore keep the complexity at a minimum. This also to keep the price down. Simplicity and well thought through solutions will be central in the design. This partly because the high level of complexity in existing market trimarans often is seen as a downside. The goal has been a smart and roomy family cruiser but with focus on performance and with a speedy, race inspired design.

    The accommodation has a protected sun bed, huge aft cabin, a galley and toilet. This is a simple but effective layout with 2 double berths and a central cockpit.

    The structure is unknown but Linderson Consulting has only been associated with light foam glass tri’s using e-glass and or carbon fibre. The swing cross arms are very similar to the Dragonfly approach and has waterstays to add to the overall beam stiffness. The jpegs are the only drawings I can find of the design but I hope it makes it to production.

    Finally, I have been doing this thread for 3 years with minimal breaks, life is getting in the way so I will be having a small break until about 1 july 2022. I will occasionally post but it will not be consistent. Please continue to add items while I am “relaxing” for a month.

    Attached Files:

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  5. peterbike
    Joined: Dec 2017
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    Location: melbourne

    peterbike Junior Member

    A very well deserved break. ;)
    I am amazed that you can keep finding pieces to present to us.
    It obviously takes up a reasonable amount of your time ; so a big thank you for giving up your time to keep us entertained & informed. :)
  6. Russell Brown
    Joined: Jul 2012
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    Location: washington state

    Russell Brown Senior Member

    Miss your daily thread, Oldmulti. I did join the Farrier forum, thanks to your suggestion. Now just need to figure out how to avoid being e-mailed anytime anyone posts there.
  7. Adrian Baker
    Joined: May 2022
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    Location: tasmania

    Adrian Baker New Member

    Hi Oldmulti ,a way back on page 5 you gave some info on the ply stressform wingmast ,is it possible to post or email the construction manual
  8. rfin
    Joined: Jul 2016
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    rfin New Member

    Bernie didn't sail the boat single handed to PR. He and two crew members attempted to sail it to England and then down into the Med, but hit a wicked storm 1000 mile east of Bermuda and spent maybe 5 days trying to sail through it to no avail. Eventually Bernie gave up, turned and sailed to Bermuda to sit out the hurricane season and then head to the Caribbean.
    I was one of the crew. 19 years old, never sailed, I was living in a cabin in Colorado when my mom called to say the a boatbuilder her sister knew was building a boat to sail to England and maybe I'd like to join the crew because someone had dropped out.
    It's a fairly long story, but after that trial by fire experience I eventually went through the Gompers boatbuilding program in Seattle and made a career of it.
    Meanwhile, due to getting blown off our mooring in Bermuda and damaging a hull, we left on the race to the Caribbean a day late, but were sitting there at the dock in Tortola when the rest of the fleet began to arrive. We had no radio to let them know our position and no engine, no safety lines ("just stay on the boat"), but Bernie was such a solidly talented boatsman that even when I got hauled up the mast to retrieve a halyard in the midst of the near hurricane force winds, I didn't see it as extreme. The delusion of youth.
    Last edited: Jun 2, 2022
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  9. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    Russell. Go to the farrier forum home page. Left column under home page is subscription, enter subscriptions you should be presented with the membership option, the first entry should be e-mail options look down and you will see a "no email" option. Hopefully this will solve the issue.

    Adrian, when I come off my little break in 4 weeks I will scan in what I have of the stressform wing instructions. It is not small and I do not know if it is the full set.

    Rfin thanks for your contribution, all info is appreciated.
  10. Coastal Ogre
    Joined: Jun 2019
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    Location: Florida

    Coastal Ogre Junior Member

    Whilst OM takes a deserved rest, I thought I might point out a couple of interesting things:

    1. A homemade carbon fiber, 15m catamaran in Germany. Quite the initiative with this family.

    Bo Janu - YouTube

    2. Anyone ever hear about an "Alexander Yacht Design" from Holland? Here's a 15m from '97 languishing in Fiji. Red cedar and epoxy build, hard to tell if it's too far gone for someone to rescue...

    Used Lexline 49, Alexander Yachtdesign for Sale | Yachts For Sale | Yachthub

    What's everyone else looking at??
    bajansailor likes this.
  11. NeilMB
    Joined: Mar 2022
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    Location: Decorah, Iowa, USA

    NeilMB New Member

    If that’s an honest question, then I’ve been looking at Terho Halme’s Ping Pong, a junk-rigged weight-to-windward proa.

    rying to figure out how he did the rudders and the sheeting and avoided too much weather helm when the CE is guaranteed to be behind the CLR of the symmetric underbody. Hmmm.
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  12. Islander63
    Joined: Jun 2022
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    Location: Mahe, Seychelles

    Islander63 Junior Member

    Hi Oldmulti,
    I know this is an old post of you in this still active threat, but i was since a long time looking for more info on this particular design ( Vaka Moana and Vaka Motu)
    I love the hull lines on these designs, and think they are quite "updated" compared to other older designs with similar "character" or appealing, as for example Wharrams style etc.
    I think the simple design would make it a relatively "easy" project for the self builder.
    Who can advice me where i could find plans for building one of those Vakas. Or maybe point me a designer who might find this an interesting project.
    The idea is to built it in foam, glass and epoxy or ply instead of foam.
    50 to 60 foot length, preferable lighter and less payload. Another rig and rudder system as well as another deck-pod or nacelle, could be all worked out in a later state. Mainly the hulls and the beams with the connection to the hulls would be required for a designer to draw up for me.
    Now i dunno if this would cost me an arm n a leg, but it would be for my purposes the best "platform" to build my ideal live-on-board.
    Please any advice, comment, or critics are welcome and appreciated.
    Thanks Islander63
  13. jamez
    Joined: Feb 2007
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    jamez Senior Member

  14. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    Islander63. I am relaxing until July so this is short. Please look at Multihull Structure Thoughts

    “Ontong Java” is a 71 x 22 foot cat that is built from planked timber as you were suggesting on another thread. Please understand “Ontong Java” is a big build that is done by a creative person who got everything cheap. This is not a “normal” build with no guarantee of design, construction or seaworthiness.

    Do your research, strip plank with a moderate layer of glass on either side will give you a Vaka Moana or Vaka Motu style cat. This may end up being cheaper and a better boat. Do not get trapped into a given type of material to build a boat. If you are going to use wood and fiberglass then it doesn’t matter what amount of wood or fiberglass you use. You will have the skills to use both.

    The real issue is build the smallest vessel you can or want, with the least materials you can as it will end up being faster and often cheaper to build. Also look at

    Jamez thankyou for your entry.
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  15. peterAustralia
    Joined: Mar 2006
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    peterAustralia Senior Member

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