I'm conviced an eskimo style upswept split bow acts like a bulbous bow, but

Discussion in 'Boat Design' started by Squidly-Diddly, Aug 22, 2009.

  1. Squidly-Diddly
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    Squidly-Diddly Senior Member

    different. When the water hits the first bow it will mostly be defected downwards while generating little bow-spray of its own.

    The downward defection, combined with gap, means that the main bow's wave encounters downward moving water and small turbulence that will prevent the main bow from producing a "clean" wave of its own.

    Maybe the idea is the the first wave hits the bottom of the second wave, generally confusing and dissipating both.

    Two smaller waves not as bad as one big wave?

    Can anyone run a simulation of this sort of bow?

    I hear one the problems with bulbous bows is they only work well at a particular speed and design depth.

    An Eskimo bow might work better over a wider range of waterlines/loadings of a particular boat, or work better when sea states dictate changing points of "bow/water" contact.

    Also, unlike a bulbous bow, the forward member of a Split-Bow might be able to brought into position from the deck, and might not need to as permanent.

    I'm interested in reducing spray on my upcoming 40' wave piercing motorsailing cat design, as I hear that tends to be a problem.

  2. messabout
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    messabout Senior Member

    The picture shows only one of the split bow types of the baidarka or similar kayak style boats. Another iteration of the split bow concept resembled a birds mouth. In either case this may well have been more of a case for style or superstition rather than function.
  3. Gilbert
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    Gilbert Senior Member

    I have been under the impression that the main function of the split bow was to make it possible to make the covering taught in both the narrower bottom part and the wider upper part with a pretty straightforward stitching pattern.
  4. rwatson
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    rwatson Senior Member

  5. Squidly-Diddly
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    Squidly-Diddly Senior Member

    Oh well, another theory shot down. RWatson, I was thinking about

    the 'kelp catcher' problem which is why I considered a deck mounted appendage that would have a open gap at the bottom.

    I haven't given up all hope for the concept as I remember hearing about a small aluminum boat that had reduced bow spray at certain speeds after it got a big, sharp dent in the bow after a collision.
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