Cat hull design for L foils

Discussion in 'Multihulls' started by waynemarlow, Sep 17, 2014.

  1. waynemarlow
    Joined: Nov 2006
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    Location: UK

    waynemarlow Senior Member

    OK the buzz is that L Foils or near equivalent ( uptip ) are the way foward. But everyone then complains that launching and beach handling are going to be a problem with the exposed foil below the hull being likely to be damaged should any grounding occur.

    So why are we not putting a small dimple ( the shape of the foil ) in one half of the hull so that when fully up, the base foil will then sit into this recess. I cannot believe that at sub foiling speeds ( say 6 knots ) that it will make very little difference to the drag of the hull nor once the hull is air bourne will it make any difference.

    Taking it to the extreme the T foil versions could also simply have a dimple right across the bottom as again the extra drag of the hull at such slow speeds is going to be negliable.
     
  2. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Hull dimples

    I think that's an excellent idea, Wayne. Having sailed foilers with retractable foils I'm not sure it's necessary. On two person foilers, one guy holds the boat the other gets the dolly-couldn't be simpler. With singlehanders it might be beneficial but that would mean you're ok with the hull touching sand(down here).
    The way it is here at Kelley Park, the A Class guys can come in and put their bows lightly on grass -just above the sand line-and get the dolly. The drop off is steep enough that if they had UptiP foils retracted against the bottom they would never touch.

    PS- The 18' Flying Phantom uses the standard Tornado beach dolly.
     
  3. waynemarlow
    Joined: Nov 2006
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    Location: UK

    waynemarlow Senior Member

    Yup being a single hander is a pain. I sail in a concrete fish bowl with relatively shallow angle sides and often an on shore wind. The number of times I have damaged my TFoils through simple things on the concrete has been numerous. Now foils that are scratched just ain't going to work that well.

    Has anyone on this forum actually put in a small faired in dimple into Delftship or such like and seen just what it does to the hull drag ?
     
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