Mast Deflection Speeds (esp dinghies)

Discussion in 'Sailboats' started by PI Design, Jun 26, 2007.

  1. BWD
    Joined: Aug 2006
    Posts: 229
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    Location: Virginia, US

    BWD Senior Member

    Amen. But that's just the macro scale.
    It works on the shorter time frame/smaller impacts too, as I wrote above, with the boat/board running over chop/waves/ripples, 50 or 100 or 200 times a minute.

    With good windsurf rig it really is like having a crew who can trim and tune your rig several times a second. I think anyone interested in speed who doesn't know this from experience should at least look at slow motion video of windsurfers in choppy water.

    The spars are a bow the wind and sea are constantly bending to shoot the board and the sailor forward.
    The board is an arrow that carries its own bow.
    Unstayed carbon (on the windsurfer scale at least) allows the "bow" to unbend in a fraction of a second and shoot the board forward before the next gust or wave bends it again.
    I eagerly await the genius who can succesfully scale this up to a 40 footer. Wylie is part of the way there at least... but there are power to weight problems and materials limits, so it may be a long wile.
  2. water addict
    Joined: Jun 2004
    Posts: 317
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    Location: maryland

    water addict Naval Architect

    I understand these concepts, and did before this thread. So perhaps I am up to speed on them? Is that all you have to offer? Sorry for the somewhat pointed diction, but since you seem to have no trouble trouncing on me, I'll give a little pissyness right back at ya.

    The rate of deflection and how it relates to the boat speed is way more complicated than that dude. And it will be variable depending on a whole host of factors on a particular boat in given conditions. My original comment that weight aloft, mast dimensions, and static stiffness will have orders of magnitude more impact in the average boat speed still stands. I think I'm at least as up to speed on this as you are, buckwheat, at least from the subjective, very basic conceptual stuff you've offered up so far.

    I also understand that none of these lesser effects are readily quantifiable as you say. They are often interpreted by the sailor and designer without strict controls, as that is the only reasonable way to address the issues without monstrous budgets. The pseudo engineering of deflection v. load on the fiberspar web site to a trained engineer is a big "so what". Yes 2+2=4. Been done before.

  3. frosh
    Joined: Jan 2005
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    Location: AUSTRALIA

    frosh Senior Member

    Hi Water Addict, lets call a truce on this issue. I concede you probably know your stuff pretty well, it's just that the message you convey is that so why is reflex response very important at all? You probably know a lot more about static and dynamic loads on rigs on larger yachts than me, and I have no wish to prove otherwise. After all, isn't boating your profession? For me it's a passion only, and I am really only into sailboards and high performance small dinghies and multis. I really have no wish to trounce anyone; OK?
    Regards, Sam
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