Aluminum Wharram?

Discussion in 'Multihulls' started by New Dawn Fades, Jan 14, 2011.

  1. New Dawn Fades
    Joined: Jan 2011
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    New Dawn Fades Junior Member

    Hi, I studied mutihulls a fair amount but that was quite a few years ago.

    Now I'm highly motivated to build a catamaran within the year, one that can do some world sailing around the Pacific.

    I think a good style that will be quick build in aluminum would be something like a Wharram design, and I think one around 40 ft would be about right for two bachelors.

    I like traditional designs over modern and so I also like te style, with the smaller cabins and the big open deck space with an awning.

    I like aluminum because I have made a couple of smaller boats in heavy welded aluminum, and I think it is a very fast build method if you keep it simple.

    I would like to have a discussion here about the pros and cons of this idea.

    Thanks
     
  2. Boston

    Boston Previous Member

    there's a couple of pretty knowledgeable cat builders in here and hopefully they will chime in. If they fail to find your thread you might go digging through the forum and locate some of the cat build threads where you will find a lot of info

    cheers and welcome to the pile
     
  3. jamez
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    jamez Senior Member

    Its been done. Check out the old forums on Wharrams site. I remember a thread there about alloy wharrams with a couple of responses from a guy with an alloy narai or Oro. Seemed to work for him.
     
  4. Alex.A
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    Alex.A Senior Member

    Google wharram builders and friends.
     
  5. gonzo
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    gonzo Senior Member

    The shape of a Wharram is not the best for aluminum. They will oil can badly. If you can weld aluminum, there are designs specifically for that type of construction.
     
  6. New Dawn Fades
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    New Dawn Fades Junior Member

    Thanks, I did find that forum and joined it.

    I think Wharrams have round hull bottoms and I'll need hard chine in tortured aluminum so I guess I should have said a polynesian style aluminum cat.
     
  7. New Dawn Fades
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    New Dawn Fades Junior Member

    Could you name a few of them please so I can check them out, plywood or aluminum, same shape.

    Remember, I want to build this quickly so it won't be fancy, a bit crude in fact. So I'm basically looking for a good slender hull shape. I know how to make my own shapes, but still.
     
  8. jamez
    Joined: Feb 2007
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    jamez Senior Member

    This one has been for sale here for a while. Obviously based on a Wharram I think rather than following the plans too closely. What the photos don't really show is that londitudinally the topside plating is a series of flat panels. It looks terrible, but it floats.

    http://www.trademe.co.nz/Trade-Me-M...sail-boats/Moored-boats/auction-347099722.htm

    Otherwise all the alloy cats I know of are bridgedeck types. A conversation with Peter Kerr might be worthwhile. http://www.lizardyachts.com.au/products.html

    Also Dudley Dix has this Tiki style boat on his website. He says plans are no longer available, but as he also designs alloy boats, might be able to do something in a similar style, designed for alloy construction.

    http://www.dixdesign.com/38cat.htm
     
  9. New Dawn Fades
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    New Dawn Fades Junior Member

    That does look kind of nasty :) I think maybe I'll pass on that one for now, the interesting thing is that it's in New Zealand and that's where I want to go in my boat. I mentioned my boat will be a bit crude, but I'm referring mainly to the topsides and extras, don't need any thing fancy there, but I want the hulls to be nice.

    Maybe I'll build a small central cabin on top of the deck later, at first it will probably be more like a tent.

    Thank you for the referals, I'm going to contact a local aluminum boat builder (Seattle), and he has a designer he works with, so I'm going to check and see what kind of ballpark figures it would take to make a couple of aprox 40ft WL hulls. I do want the sterns to be Wharram/Polynesian style so it won't get buried if it slides backwards in the water.

    I think that getting the bare hulls made will save me a bunch of time on the big difficult to handle parts, then I'll take the hulls to a boatyard where I can put the crossbeams and other stuff on it, that will keep me busy enough, because I want to be able to sail away in about a year.
     
  10. New Dawn Fades
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    New Dawn Fades Junior Member

    I found the Wharram Forum, but there is no action there anymore.

    I found this thread there: http://forum.woodenboat.com/showthread.php?54225-Junk-rigged-catamaran

    I've been thinking of twin sails like that, and I just found out that the those sails shown there in the second pic are two sided and surround the mast. That seems like a beautiful streamlining idea, and me being an aircraft designer I find that very appealing.
     
  11. jamez
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    jamez Senior Member

    Getting some professional input is certainly prudent. As a recent ex-Wharram owner I'll be interested to see what you come up with. All the best with it :cool:
     
  12. New Dawn Fades
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    New Dawn Fades Junior Member

    That boat in New Zealand for sale has flat bottom hulls and the Tiki series has pointed bottom hulls. I read that the tiki series are faster than the Pahi series so I assume that is because of the sharp hull bottom, is that correct?

    I've been thinking of using a V bottom with sloping sides like a common hard chine power boat to get a wider floor and more vertical sides and wonder if that gives anything away in the speed department to the Tiki style sharp bottom? I also like the wider floors because that will result in shallower draft. Of course a flat bottom will have a shallower draft, but I think the V bottoms will be the most durable in case it bumps down onto some rocks.
     
  13. New Dawn Fades
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    New Dawn Fades Junior Member

    Thanks, I'll draw some sketches of what I have in mind. There are so many threads here on this forum that it is hard to identify desirable info from the thread titles, but I'll look more.
     
  14. terhohalme
    Joined: Jun 2003
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    terhohalme BEng Boat Technology

    Something like this?

    Designed this few years ago on my "junk period".
     

    Attached Files:


  15. New Dawn Fades
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    New Dawn Fades Junior Member

    That looks just like what I had in mind. So ... a few questions.

    How long is it? Is you r design available to purchase? It doesn't need to be highly developed plans, the main thing I'm looking for is the hull shape, mast locations, displacement, etc. It looks like it is plenty seaworthy
     
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