Trimaran lifting foil alternative

Discussion in 'Multihulls' started by kiwi_bob, Aug 27, 2011.

  1. kiwi_bob
    Joined: Aug 2011
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    Location: New Zealand

    kiwi_bob Junior Member

    Building a retractable DSS system is adding the complexity, weight and effort I was hoping to avoid... but yes it would be a good soln but not for me.

    I may revisit this once I have my tri complete and if I find my smaller volume floats an issue - in the meantime my plan for the very heavy conditions will involve reefing :-(. Thanks guys esp Doug for your input (Doug, do you ever sleep??)

    Cheers

    Dean
     
  2. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Bob-Dean, what boat are you building? Is it designed to fly the main hull?Hope it goes well!
     
  3. kiwi_bob
    Joined: Aug 2011
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    Location: New Zealand

    kiwi_bob Junior Member

    I'm building a trimaran for the Kiwi 8.5m box rule. Yes the plan is to get the main hull flying - float rudders etc. The floats are I believe adequate volume for that purpose but time will tell. I'd like to get the basic boat going first and then look to apply some appropriate foil technology down the track...
     
  4. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    ------
    Two last questions: 1) what is the Length divided by Beam ratio of the ama
    2) what is the total immersed displacement of the ama compared to total boat weight incl crew? (80%, 100% ??)

    Thanks for the info and good luck!
     
  5. kiwi_bob
    Joined: Aug 2011
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    Location: New Zealand

    kiwi_bob Junior Member

    Hi Doug

    Length divided by beam is 8.5/.07 = 12.14%

    and total displacement of ama is approx 1800kg - weight with crew (with luck) should be approx 1200kg (I hope, possibly less) - should give a value of approx 150% (which as I understand it is the minimum for hull flying - hence why I'm interested in foils - each ama weighs approx 80Kg. I hope to be sailing this southern summer.

    Cheers

    Dean
     

  6. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Dean, here's Farrier's F-85SR design to the NZ 8.5 rule:

    Basic dimensions are
    L.O.A. - 8.5m (27' 10")
    B.O.A. - 6m (19' 8")
    Mast Height - 11.3m (37')
    Sail Area (main and jib) - 42sq.m (455sq.ft)

    (uses F-32 curved foils cut down)

    click on image:
     

    Attached Files:

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