Bow Wing

Discussion in 'Sailboats' started by Andrew Evans, Sep 28, 2005.

  1. Andrew Evans
    Joined: Sep 2005
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    Andrew Evans New Member

    The Vendee Globe boat "Ocean Planet" added a bow wing to stop the boat from diving when surfing. Look at the photo at: http://tinyurl.com/86d3g
    Bruce said it worked very well.

    I'm considering doing the same thing on my Olson 30 before sailing to Hawaii. Does anyone have experience with this, or just comments?

    Andy Evans
    Foolish Muse
    Victoria, Canada.
     
  2. dougfrolich
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    dougfrolich Senior Member

    Trade the olsen in for a moore24 and you wont need the wing, and you wont crash either. but if you want wings, check this...
     

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  3. usa2
    Joined: Jan 2005
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    usa2 Senior Member

    the wings on AAPT/Grundig are there to prevent lazy spinnaker sheets from getting sucked under the boat during gybes.
     
  4. Andy P
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    Andy P Junior Member

    Int moths used bow wings ~ 1970 ? in early UK Magnum designs.
    But when nosediving, the extra drag of the wing caused more pitchpoling instead of less. The wing angle had to be set high ( and therefore high drag in most situations of a moderate nosedive) , because if the angle of the dive was greater than the angle of the wing - the wing force was down = superfast pitchpole.
    The 1990's and later moths use the foil on the rudder ( T foil ) which is self regulating, and very efficient.
     
  5. mistral
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    mistral Senior Member

    pitchpoling is a sudden and impulsive process. Once that you have entered into it, you have a great inertia to deal with, i don't think a violent pitchpoling could be stopped by some dozens of lbs. of displacement placed in bow wings.
    May it would be wiser to trim the boat to avoid nosediving.
    Inertial water ballast at the stern: have you consiedered them??

    fair wind
    Mistral
     
  6. yokebutt
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    yokebutt Boatbuilder

    Concur with Doug, the Olson 30 is certainly a fast boat, but not forgiving enough to be a really effective singlehander. Don't get me wrong, I know at least two guys that have done the SHTP with them, but the Moore is a lot better behaved near the edge, and the power is much easier to modulate without having to crawl up on the foredeck.

    Yoke.
     
  7. D'ARTOIS
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    D'ARTOIS Senior Member

    It is just a sprayrail of some kind. No effect in heavy seas whatsoever, more a gimmick than a uasable item.....
     
  8. gonzo
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    gonzo Senior Member

    Added-on foils and other appendages are usually an indication of poor design. It is a fix for an unforseen or badly calculated problem.
     
  9. Doug Lord

    Doug Lord Guest

    Foils and other appendages

    Thats a pretty broad statement with the evidence of how well "foils and other appendages" work on real boats. Like the t-foil on the(pre-foiler) Moth and Biekers version of a T-foil on an I14. The banana boards on Patient Lady and the same on the Orma 60 Tri's. The fixed wings on IACC boats and the fixed wings on Andy Dovells canting keel boats used to generate lateral resistance. Not to mention the foils on all out foilers like the Moth, Rave and Hobie trifoiler.
    I think "foils and other appendages" are in the early stages of applications in both mono's and multies to allow changes in hull design, righting moment and/or wetted surface impossible without them. In my opinion, there is a bright future for all sorts of variations on this theme as an intrinsic part of sailboat design....
     
  10. cyclops
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    cyclops Senior Member

    As a non racer, and reading all the statements. It is obvious you surface sailboaters are starting to over power your boats in calm and storms to the point that the boat now is being forced below the surface. Race ONLY in calmer conditions OR, get a hell of a lot better in the diving characteristics of submarines. If you try to have one hull do both conditions, IT will look like a complete freak of a boat. The cost of equipment destroyed and lives murdered in the uncontrolled need for more speed is really that of a very sick mind. You are about at the PRACTICAL limits of SAFE sailboating. Hard to admit ,but you are there. Rewrite the classes in danger to values that provide 1/2 the speed and danger. Racecars have done it to stop the murdering of the car drivers. It is now time for sailboating to do the same.
     
  11. Doug Lord

    Doug Lord Guest

    Limits?!

    I think there is a lot more potential for improvement in speed ,handling and seaworthiness by learning more about "foils and other appendages" and their applications. And far from operating under the surface the tendency appears to me to be moving above the surface to one degree or another.
    No where near the practical limits of safe sailboating!
     
  12. cyclops
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    cyclops Senior Member

    Pitchpoling at 5mph is painfull. At +25 mph, its deadly due to the stonewall effect of water at that speed slaming a human body into wire stays, masts and all the other nonflexing parts of a racer. It is a instantanous slaming into all of the boats structure. It becomes a meat grinder for the crew. Has any builder designed that condition out of the race boats. Some examples are needed. All hands on deck is crap at 50 mph. There is no hint of giveing a crap about the human beings safety at speed. Against the solid water coming at him. I have seen what is left of bodies that are pushed along the decks of WWII destroyers at 53 mph and leaning so far over with full rudder that salt water was found in the smokestacks. The bodies had arms and legs ripped off by impact on anything that did not give. +50 in a sailer or a destroyer causes the same injuries.
     
  13. gonzo
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    gonzo Senior Member

    I am referring to foils and appendages added on to correct problems instead of those that are part of a design.
     
  14. John Perry
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    John Perry Senior Member

    As Andy P has said above, if a bow wing fails to prevent a pitchpole in the early stages it could easily start to develop downforce and actually make the situation worse. One way to overcome this problem might be to have a bow wing which is self pitching. I can envisage a tube through the bows a little above the waterline, with needle bearings in each end of the tube supporting an inner rotating tube to which wings are attached. The wings would have a vee shape looking fore and aft, i.e. the tips would be higher than the roots. They might even be 'gull wing' shaped, that is with steeper vee angle near the root than the tip. With this kind of geometry I think it should be possible to get the wings to stay at a constant angle of attack to the local water flow in much the same way that the blades of an 'Autoprop' propeller pitch automatically. This way the bow wings could maintain a constant upward force as the bows go deep under the water and this should surely do quite a lot to stop a pitchpole. Probably most beneficial for a fast multihull.

    John
     

  15. Jocko
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    Jocko Junior Member

    benefits of added foils

    Two quick observations about air/hydrofoils:
    1.) Open wheel racing revolutionized by wings and downforce
    2.) Fish

    A billion Tuna can't be wrong. So what's wrong with foils on a sailboat? Besides, I find my own appendages worthwhile.
     
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