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Thread: Proas: Why Add Bowsprit ?

  1. #1
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    Default Proas: Why Add Bowsprit ?

    I have seen a few proa builds where the owner later added bowsprits and at least a couple where the bowsprits were built in.

    e.g.
    brailing and extensions.jpg

    This is totally-idle curiosity, but can somebody comment on the reason(s)?

  2. #2
    Join Date
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    Fort Worth, Texas, USA
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    Default Re: Proas: Why Add Bowsprit ?

    The designed the boat wrong to begin with, or didn't get the performance they thought they would.

    OR

    Fashion

  3. #3
    Join Date
    Jun 2007
    Posts
    580

    Default Re: Proas: Why Add Bowsprit ?

    Probably to get the CE well ahead of the CLR. Traditional proas that lack rudders, leeboards, etc. have a substantial amount of weather helm when broad reaching or running.

  4. #4
    Join Date
    Dec 2011
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    Default

    If you have an asymmetric hull as your only way of producing side force the CLR is way forward (I found out the hard way) and so the sail and CE has to come way forward also. The issue is amplified with short hulls and big areas, the crab claw rig with all the area at the back does help.

    Though not a crab claw I think this picture helps, also this design had a board



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  5. #5
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    Default Re: Proas: Why Add Bowsprit ?

    As somoene said, simple is better, except when complicated looks good....?
    “Ignorance more frequently begets confidence than does knowledge” - Charles Darwin (1809–1882)

    Nutshell Pram Build pictures ; https://photos.app.goo.gl/1GdBcckcgBAWsbVg1

  6. #6
    Join Date
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    Default Re: Proas: Why Add Bowsprit ?

    I go with Dusty. Possibly -- though I doubt it -- you can adjust the sail height with a delta sail, so that when it sets lower, it is best for reaching, and when set higher (pointed higher, as in higher aspect ratio) it is better for windward work; then the tack could be hauled back on this proa to point-up the sail. But the mast on this proa does not look like it would allow that, so never mind, it was just interesting to consider :-)

    Variable sail-setting like this would usually done with a halyard, but again, this proa's mast seems too short for that variability (See Marchaj, in his Sail Performance, where he discusses crabclaws/delta sails for proas, and the effects of theuir setting angles).

    You see the high-setting mode on Micronesian proas, which are fastest of the proas on all points, some people say. The high-set and forward-canted crabclaws on these seem as though they would cause lee-helm, but they actually counteract the drag of the ama to balance out. Was this sail larger than usual, and so the bow sprit(s) was necessary? -- Wade
    Last edited by wtarzia; 04-10-2018 at 12:14 PM.

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