Bow sprit in high seas.

Discussion in 'Sailboats' started by Shack, Oct 12, 2009.

  1. Shack
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    Shack Junior Member

    I'm looking for stories or opinions about bowsprits and their effects during heavy weather (high sea states). Does anyone have experience with bow sprits getting buried in waves and causing damage to a vessel?
     
    Last edited: Oct 12, 2009
  2. jalmberg
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    jalmberg Junior Member

    I've never heard of such a thing, but I guess that is an argument for the spar-style bowsprit, as opposed to a platform-type. It's hard to imagine a spar-type breaking by a wave, but I suppose a platform-type could take quite a pounding.

    -- John

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    Check out my blog: http://unlikelyboatbuilder.com
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  3. gonzo
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    gonzo Senior Member

    I have been submerged more than once working out in the bowsprit. There isn't usually problems with the boat but with crewmembers getting washed off.
     
  4. Omeron
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    Omeron Senior Member

    If you are burying your bowsprit in solid water, you are probably shipping green water on your decks as well. If that is the case, the sprit may be further down on your list of worries!
     
  5. gonzo
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    gonzo Senior Member

    Not for the bowman
     
  6. ancient kayaker
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    ancient kayaker aka Terry Haines

    Is there a benefit in having a bowsprit in such conditions? For example, ability to carry sail further forward.
     
  7. Shack
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    Shack Junior Member

    slower recovery?

    Two boats bury their bows. One with and one without a bow spirit. How much slower is the recovery by the boat with bow sprit versus the one without?
     
  8. sharpii2
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    sharpii2 Senior Member

    Depends on the bow design.
    Many boats without bow sprits have pinched bows.
    This is no accident. The pinched bow is often to extend the bow forward, so the bowsprit is not needed.

    Boats that have bowsprits usually have fuller, more buoyant bows.
     
  9. sharpii2
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    sharpii2 Senior Member

    Often there is.

    With long keels, the Center of Lateral Resistence (CLR), not to be confused with the Center of Lateral Area (CLA), often ends up quite far forward.

    This is very likely to be the case with full length keels that are level and have no downward slope aft.

    Comercial sailing ships had to contend with draft as an issue, so were forced to have level long keels.

    You see long bowsprits on just about all of them.
     
  10. jalmberg
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    jalmberg Junior Member

    Assuming a well designed boat, negligible.
     
  11. Shack
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    Shack Junior Member

    Effects of sprit.

    Sharpii2. (and Jalmberg)
    Just for the purpose of discussion, let's isolate the effects of the bow sprit and assume identical bows. How much difference could one reasonably expect?
     
  12. jalmberg
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    jalmberg Junior Member

    Let's assume this Ingrid somehow dug her bowsprit underwater and didn't pitch pole, that probably means her foredeck is underwater too. The resistance of the bowsprit is trivial compared to the upward force of the buoyancy of the bow and the downward leverage being exerted by the weight in the stern. (Not to mention the lofting effect of your prayers.)

    [​IMG]

    The difference would not be zero, of course, but I doubt you'd notice the difference.

    A better strategy is to heave to and avoid the scenario altogether!

    -- John
     
  13. MikeJohns
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    MikeJohns Senior Member

    Yes I have lots of experience offshore with bowsprits and I like them for several reasons and anchor handling is a huge plus.

    They have a damping effect on the pitching too. As the bowsprit enters the water it's travelling fast and throws up a lot of spray the pitch slows, stops and the bow recovers but slower than it entered so there is a greater slamming resistance and a slower recovery. The boom is stayed and it will not break off unless the stays break and they should be sized and attached accordingly.

    If you look to the working boats of sail and their design rules of thumb you'll get a good idea of robust bowsprit design since the loss would have been catastrophic.

    It's very common to ship green water as the sounding reduces and the waves get steeper and closer together .
     
  14. capt vimes
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    capt vimes Senior Member

    i do not want to have my forestay mounted to the bowsprit.... sail a blister, gennacker or whatover from it - yes - but the forestay i like to have securely mounted to the hull....

    apart from that, i am with mike...
     

  15. gonzo
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    gonzo Senior Member

    Bowsprits have their own stay. There is a forestay attached to the bowstem or close to it
     
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