Twin keel sailboat

Discussion in 'Sailboats' started by GRussell, Mar 18, 2012.

  1. GRussell
    Joined: Mar 2012
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    Location: Hilton Head Island, SC

    GRussell New Member

    My Uncle, Ralph G. Dunham, was a part-time boat builder. His Father was a
    sailmaker and became Chief Sailmaker at the Brooklyn Navy Yard, Henry C.
    Dunham. Uncle Ralph told me about a sailboat he, Ralph, had designed for some shallow Florida waters. It had twin keels. The two keels made a
    45 degree angle with each other. All the members of this group will understand the thinking involved. I have been searching the web for some
    reference to such a design with no success. So I submit these questions:
    Is such a twin-keel sailboat being made anywhere ? &
    Could my Uncle Ralph have possibly originated that concept ? It would have
    been circa 1950.
    Thank you for any help. George grussell@hargray.com
     
  2. hoytedow
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    hoytedow Wood Butcher

    Those are quite common in Europe and have been discussed at some length on this forum. See bottom of this page for related threads.
     

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  3. hoytedow
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    Location: North of Cuba

    hoytedow Wood Butcher

  4. GRussell
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    GRussell New Member

    Thank you...........Geo.
     
  5. Cataphract
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    Cataphract Mechanical Engineer

    Do the keels both start from the centerline of the boat or are they mounted farther up the hull?
     
  6. hoytedow
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    hoytedow Wood Butcher

    You are welcome, George and welcome to the forum. You too, Cataphract.

    Twin keels are mounted at points between the centerline and the waterline. They are sometimes referred to as bilge keels. Bilge keels on freighters are long and stubby and serve a somewhat different purpose, which is mainly as a roll dampener. On canoes it is just an additional addition of 2 lateral keels whose function is just to protect the canvas from abrasion.

    http://drinian.smithwrite.net/twins.htm

    http://drinian.smithwrite.net/images/keels.gif
     
  7. GRussell
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    GRussell New Member

    Hoytedow.......Thank you, I believe I already have my answer.
    I wondered if my Uncle invented the twin keel, he did not. He was
    building twin keel boats in the '40s and they originated in England
    in the '20s. I don't know the details of his twin keels....Geo.
     

  8. Cataphract
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    Location: New York/ Cambridge

    Cataphract Mechanical Engineer

    Thanks! OK I've definitely heard the term bilge keel used more often.
     
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