Aluminium Cat designs

Discussion in 'Multihulls' started by John Coulson, Mar 14, 2018.

  1. John Coulson
    Joined: Mar 2018
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    Location: Scotland

    John Coulson cacador

    I have been looking for designs for a Cat in the 40 range with a bit of speed to it. My main reason for wanting to work with aluminium is because I really hate working with fiberglass.
    Does anyone have some links for good alloy designs? OR contacts for people who have built fast multis?
     
  2. TANSL
    Joined: Sep 2011
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    Location: Spain

    TANSL Senior Member

    40 feet or 40 meters? (I guess 40'). At what maximum speed are you thinking?
     
  3. John Coulson
    Joined: Mar 2018
    Posts: 14
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    Location: Scotland

    John Coulson cacador

    Sorry, 40'. As far as speed goes, something that could get to 12 knots or so without much effort.
     
  4. John Coulson
    Joined: Mar 2018
    Posts: 14
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    Location: Scotland

    John Coulson cacador

    wow, i just reread my first post, i guess i left some info out. I am looking to sailing cat designs
     
  5. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    Sailing cats are out of my comfort zone. Anyway, let me ask you, 12 knots with the engine (it may be a lot) or with sails (it could be little)?
     
  6. Richard Woods
    Joined: Jun 2006
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    Richard Woods Woods Designs

    40ft is about the minimum size for aluminium and even then it won't be a great performer compared to a wood or foam sandwich boat. And that will be if keeping it empty inside. Most people prefer a wood or lined interior, not a "tincan", if for no other reason to reduce condensation. So you end up building a boat within a boat, which adds to time and weight. The bigger you go the less the aluminium weight penalty matters. But of course costs and effort to build/sail/maintain also go up.

    What do you want to do with our boat once you have it sailing? For example, if oyu plan a lot of high latitude sailing then aluminium makes sense, unfortunately a catamaran doesn't if you go through a lot of pack ice.

    Richard Woods of Woods Designs
    www.sailingcatamarans.com
     
  7. John Coulson
    Joined: Mar 2018
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    Location: Scotland

    John Coulson cacador

    Sailing in mid latitudes and tropics. mid 40s is looking like a good size. I spoke with a local boat builder and he said that a multi-chine would be the cheapest to build. That said, your not going to come even close to fiber glass prices.
     

  8. hump101
    Joined: Oct 2004
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    Location: Brittany, France

    hump101 Senior Member

    We have a 15m, 50kts trihull powerboat design that is built in alloy as that is what the client boatyard wanted. All of Richards comments apply, even at that size/speed.
     
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