• BradleyUffner@lemmy.world
    link
    fedilink
    English
    arrow-up
    43
    ·
    edit-2
    10 months ago

    Sails don’t billow into the wind. They are set at an angle to it. Just enough to inflate them, creating an airfoil. The remaining wind blows across the airfoil, creating “lift” (like vertical airplane wings) that pulls the boat along more efficiently. That’s why sail boats can actually go faster than the wind.

    From this photo, the wind is blowing almost parallel with the sails.

    • Churbleyimyam@lemm.ee
      link
      fedilink
      arrow-up
      5
      ·
      10 months ago

      The type of sail you’re referring to is ‘bermuda-rigged’, like the smaller ones at the front of the boat in the picture. The big ones in the middle of the picture are ‘square-rigged’ which are really only good for sailing downwind.

      • merc@sh.itjust.works
        link
        fedilink
        arrow-up
        1
        ·
        10 months ago

        I think the square rigged sails could be rotated, so you could sail with a cross wind. You would just have a fair amount of trouble sailing upwind.

        • Churbleyimyam@lemm.ee
          link
          fedilink
          arrow-up
          1
          ·
          10 months ago

          Maybe, although I haven’t seen anyone doing it. I’m guessing you would need a sheet to each corner to trim the sail tightly enough which I think would be too much of a headache for the crew. Worth thinking about tho, especially in a castaway situation!

          • merc@sh.itjust.works
            link
            fedilink
            arrow-up
            1
            ·
            10 months ago

            To clarify, it’s not that the square rigged sails themselves can be used to sail upwind. I was talking about how you could rotate the yard so that the sails could continue to catch a wind. But, for sailing upwind, the square rigged sails wouldn’t help much. It’s that square rigged sailing ships had staysails which would let them sail upwind slightly. Apparently a fore-and-aft rigged sailing ship can sail within 20 degrees to the wind, while a square rigged ship could only do about 60 degrees.

            In a castaway situation, I wonder what the best idea would be. Try an experimental modification of an existing sail to give you better mobility? Or be thankful you have a working sail and accept limitations on how much you can steer? Ignoring the sails though, my guess is that in a shipwreck, one of the most likely to be damaged things will be the keel, and trying to sail without a good keel would suck.