Originally posted by IOR Geezer
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Anybody have a good resource or knowledge regarding the properties of the lateen rig?
I still haven't completed my dinghy project, though I did cobble it together enough to go sailing a few times. For the sail this time, instead of polytarp, I sacrificed an old heavy rip-stop nylon staysail which I thought would be better. Sure does look nicer, but I had trouble getting the little boat to perform upwind as well as I remember it doing.
The rig has two booms, hinged at the front and, as in its previous incarnation, the sail is basically duct-taped to the booms sock-fashion with both ends of the leach screwed at the ends of the booms. It has a halyard, downhaul, leach line and, previously, a topping lift and a reef point. (Never quite convinced myself that the topping lift was useful.)
After reading Phillip C. Bolger's article on how sock-mounted sails promote laminar flow by smoothing the transition between the mast and the sail, I abandoned my intention of cutting sail tracks into my new booms so that the sails could mount with bolt ropes and allow for outhaul adjustment, but instead spent some time trying to work out how I could design the boom hinge so that it would allow the sail shape to be manipulated.
But considering the rig's performance, I now recall that I used to think that when close-hauled, that the sail was actually driving off the leach rather than the luff.
See this picture:
http://en.wikipedia.org/wiki/File:Inhambane-dhow.JPG
The sail is on the "bad tack" you can see that maximum draft is along the leach. I had streamers on the leach of my old polytarp sail and I used to trim so that they'd stream straight back.
Any Sunfish -- or other lateen -- sailors out there? What say you?
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