Multihull in stages!

Discussion in 'Multihulls' started by Pondlife, Sep 8, 2017.

  1. Pondlife
    Joined: Nov 2015
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    Pondlife Junior Member

    Hello All,
    I have been planning a build for a long time. I have various ideas, its not until I say them out loud that i realise their credibility. I have trawled the usual design websites but cant find exactly what I am looking for. I have found some free plans here;

    https://spccfpstore1.blob.core.wind...ication/pdf&rscd=inline; filename="VAN-2.pdf"

    I am drawn towards traditional looking boats, and want to make everything including the sails. This boat would be a good start for me but would it be possible for it to be part of the end plan as well? Could eventually 2 be made and employed as a catamaran? And eventually could a central hull be made to make a tri? Or are they too heavy for trimaran amas? Am I being incredibly niave? Hard to tell sometimes, but i generally find asking advice is the best way of putting an idea to rest if it is the wrong one.

    My main problem is limited build space. I do have room but couldnt tie it up for too long, so the thought of building a hull at a time and taking it to my club and using it appealed to me.

    Thanks for your thoughts,
    Mark
     
  2. UpOnStands
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    UpOnStands Senior Member

    Welcome to the school of "we need more facts"
    "have room but not for too long" ?? months only? max length?
    "building a hull at a time and taking it to my club and using it"? you mean something so light you can carry it on your car's roof?
    "building a hull at a time and taking it to my club and using it"? the demi-hulls should be usable in isolation?
    how many in the crew?
    day trip only?
    inland lake sailing only?
    rowable?

    this page has a group build of several Northeastern dories 17' 100 lbs - scroll down for the video
    Light-weight Rowing and Sailing Dory That You Can Build http://www.clcboats.com/shop/boats/wooden-sailboat-kits/northeaster-dory-rowing-sailing-kit.html
    umm, two together in catamaran fashion, close in the fore peaks to the masts for storage and flotation. twin unstayed masts, daggerboards. tasty.
     
    Last edited: Sep 8, 2017
  3. upchurchmr
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    upchurchmr Senior Member

    +1 for asking for more information.

    If your Trad boat is ballasted making it into a caramaran will mean you need to take off the ballast. Even then each individual hull will be so wide the cat will be really slow. If it is not a very wide cat, the narrow spacing between the hulls will pile up water and the boat will be even slower.
    The wide individual hull will actually offer nothing to enhance the stability. The very heavy weight will of course.
    Its a waste of effort to make a trad monohull and turn it into a catamaran without expecting to get anything but a barge. It would basically defeat the only rational reason for making a catamaran.
    A Tri would be even more useless.
    You could make the monohull and add skinny outriggers to make a tri. It would be less useless. Still slower than reasonable. To take advantage of the tri configuration, you would need to double the size of the sail plan. If you like this idea, there have been multiple people who made a tri from a Soling. Search on Soling trimaran. But that was not a trad boat for you to start with, and you wouldn't be building everything like you wanted

    This reflects my bias that multihulls are a good way to get more speed.

    So if you can answer the questions about your intended useage, we could get past my bias and get you some more useful answers.
     
  4. UpOnStands
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    UpOnStands Senior Member

    That Northeastern dory has no ballast, is intended to roll on its sides till the wind spills.
    Your point is taken BUT, build one hull. See if its doable within his space, time, and budget constraints.
    If Pondlife decides to drop the idea, he has a perfectly usable brand-name dory he can sell or use as a mono.
    Sure the hull shape is not perfect for cats, but realistically how much efficiency is he giving up?
    The hull is actually narrow (relatively) at the waterline and wide only at the gunwales.
     
  5. upchurchmr
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    upchurchmr Senior Member

    Where did he say he wanted to build a Northeastern dory?

    I saw a little information on a 7.1 M outrigger canoe.
     
  6. UpOnStands
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    UpOnStands Senior Member

    We are not really sure what he wants, as the end result.
    My first reply started out as a simple call for more details.
    Then I thought, umm, using two of the 7.1m vakas for a catamaran, why not?
    My main objections are the low freeboard, low stability w/o the ama, and build difficulty (ama weight is shown as 50 kgs?).
    The "keel" on the vaka is needed for lateral resistance? but seems to be a lot of complication in the build.
    If build time is critical and he wants to build in stages, and he wants to use what he builds, my first thoughts were the
    Northeastern dory. AFAIK, never been used as demi-hulls. But it is designed to be light & to sail and row, large numbers have been built and all reports seem positive.
    My preference is not for a proa. At this size it seems cute but turning yourself around in that narrow canoe body to tack/shunt would wear me out.
    But let's wait for him to tell us more of his thinking.
     
  7. upchurchmr
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    upchurchmr Senior Member

    So it was your idea not his to use the dory.
     
  8. UpOnStands
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    UpOnStands Senior Member

  9. Pondlife
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    Pondlife Junior Member

    Morning, thank you for your replies. Yes I am guilty of wanting everything from a boat. I had planned the outrigger canoe to be used as a canoe to begin and then a cat and then a tri. The last one was a long shot lol.
    I am looking to build a small catamaran to begin with. Something for weekends or trail-able to warmer climates.
    Basically I am drawn to the trad looks of the wharram's and the self build minimal tech a plus, but find the freeboard of the tiki's a tad low and the price of the plans steep.
    I have also looked at the woods cats and they offer more room with good plan detail, better plan prices. can't find a design that really grabs me.
    I was also looking at the Bit&Kontell 5.50. I like the look of this as a micro cruiser, not sure if any have been made. Also would like it made bigger, say about 21/22 feet.
    Are there any other designers of small cruising cats that i am missing?
    Thank you for your counsel
     
  10. Pondlife
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    Pondlife Junior Member

    Timespan probably months. Length 21-26 feet. I would buy a flatbed trailer to transport. probably scrapped the idea of using the single hull as an outrigger. the max crew would be 2 adult 2 kids, the kids in the hulls and the adults in a deck tent/cuddy type configuration. would like weekend capable. coastal use. outboard. construction in foam sandwich over moulds prefered over ply.
     
  11. Corley
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    Corley epoxy coated

  12. UpOnStands
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    UpOnStands Senior Member

    Big thing is your "in stages" comment. Once you settle on a small cat from the beginning then things become much more focused, design-wise.
     
  13. Pondlife
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    Pondlife Junior Member

    Yeah, when i say things out loud i realise how stupid they sound. So this is therapy. A small cat is the way forward.
     
  14. semelis
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    semelis Junior Member

    Just to stir the pot ...
    Switching from outrigger to 2 (more or less equal) hulls was traditional doing in Melanesia.
    waka_pg25_big.jpg
     

  15. Pondlife
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    Pondlife Junior Member

    That was the sort of thing I was thinking. On reflection the practicalities like upwind performance and resale would lean me towards a well known designers plans. I find it difficult to do the sensible thing, but have seen alot of unique builds that the owners are struggling to sell and not getting a fraction of what they paid to build.
     
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