Crabclaw rigs

Discussion in 'Multihulls' started by guzzis3, Jun 19, 2019.

  1. Clarkey
    Joined: Aug 2010
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    Clarkey Senior Member

    Well this is interesting...... in Poland I think, from the very active proa scene there.
    [​IMG]
     
  2. Michael_P
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    Michael_P Junior Member

    you are right. and that was one of my biggest fears, when I was first thinking about using a crab claw rig on a katamaran. the question for me was, whether the equation would be a)"windward handicapped rig+windward handicapped hull shape = windward handicapped boat" or in worst case option b) "windward handicapped rig+windward handicapped hull shape = unusable boat". At the end I made the experience, that the equation is rather of type a. The disadvantages don't add up to a disaster at all.
     
  3. rwatson
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    rwatson Senior Member

    a)"windward handicapped rig+windward handicapped hull shape = windward handicapped boat" ISNT a disaster???

    You must have a good engine.
     
  4. Michael_P
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    Michael_P Junior Member

    I am fine with my paddle and glad to have it for no-wind-conditions. So well, until 3 years ago I was not sailing at all, just windsurfing. And in comparison to my windsurfing-equipment (which is really mostly high tech stuff), the windward abilities of my diy-catamaran are simply AMAZING :) But anyhow, thanks for your "equal and opposite criticism". Without that, this thread would be pretty boring.
     
  5. Michael_P
    Joined: Sep 2019
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    Michael_P Junior Member

    anyhow, I for my part was a lot inspired by this project here:
    Crab Claw Plywood Catamaran: Design http://www.rclandsailing.com/catamaran/design.html
    my original idea was to build a shiftable mast, which I did when I designed my first katamaran 2 years ago. But the rig was too heavy in the end, and also the quality of the hulls was poor. so I made the next model.
    I never had recognizeable problems while sailing windward. Here is a screenshot of one of my sailing trips. The moderate angle while going up in wind-direction is not caused by limitations of the crabclaw sail, but due to shivering of the fore-sail, which I am going to solve during the next season.
    kurs.JPG
    It is clear, that there are better boats for sailing close to the wind. But as mentioned earlier, a crab claw rigged catamaran is not a windsurfer or a kiteboard.

    image007.jpg

    image004.jpg
     
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  6. rwatson
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    rwatson Senior Member

    It's not really the "no-wind" situation I was referring to.
    Its the "lots of wind", but you have to beat off a lee shore, and you cant get past the rocks because you can't make it at a decent angle.
    That's when you need a decent engine, or just stick to short voyages in nice weather.
     
  7. luff tension
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    luff tension Junior Member

    Whats old is new again!
    These are cool and based on the same principle, I had a play with one over the weekend.
     

    Attached Files:

  8. Michael_P
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    Michael_P Junior Member

    what can you tell us about the required sail-area? do you need more or less sail-area in comparison to a conventional windsurfing-rig?
     
  9. Michael_P
    Joined: Sep 2019
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    Michael_P Junior Member

    the proa on the right side is probably from Janusz Ostrowski, he is experimenting with proas and crabclaw sails since more than 10 years. meanwhile he sells them all inclusive as "Pjoa Laguna". PJOA Outrigger Canoes http://www.pjoa.eu/ nice boats designated for transport on the roof of a car.
     
  10. luff tension
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    luff tension Junior Member

    Foiling with a 4sqm wing in 10 -12 knots of breeze. Using quite large foils though.
     
  11. guzzis3
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    guzzis3 Senior Member

    Thank you for that post, really interesting. If it were me I'd have tried to get the upper spar more vertical and ditch the foresail, but each to their own. As long as you are having fun.

    I'm not about as much lately as I'm sick and procedures are knocking me about. Sorry for the late reply.
     
  12. garydierking
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    garydierking Senior Member


  13. rwatson
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    rwatson Senior Member

    "I can never figure why anyone would install a windward handicapped rig on an already windward handicapped hull shape."


    Is this supposed to be some kind of proof for performance?

    Like most "crab claw" tests, it was done by "eye" and "feel"

    "52 foot long over the stems - the average width is 32.2cm(12.6”)." - so, basically an extreme hull shape, with little load/crew-carrying capacity
    " I did not have the advantage of a hand held wind gauge " - of course not.
    "The formula we used was to divide the number of seconds it took a piece of crumbled paper to float the length of the waterline" - yeah, of course, no GPS

    Oh, and was there any 72 foot hulls with Bermuda rigs to compete against? Of course not.
     
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