Leech lines

[TIM WEBB]

OK, here's one for y'all:

My (pretty much) new sails (Neil Pryde) have a very thin diameter line that runs inside a sewn channel down the length of the leech, fixed at the head and free running at the clew. Both jib and main have these lines, and there are plastic jam cleats just above the clews for making them fast.

Tonight while out in very light airs, I decided to play around a bit with them. I assume that their purpose is to give the sails a more "rounded" shape, for more power in light winds? Unfortunately, the wind pretty much died altogether before I really had a chance to see what effect they had on the sails ...

Anyone else have these lines on their sails, and if so, have you had any luck in getting better performance using them?

Thanks!

- Tim

[Adrift]

OK, here's one for y'all:

I assume that their purpose is to give the sails a more "rounded" shape, for more power in light winds?

Leech lines allow the sail to be cut & sewn with a looser leech (less broadseaming). This can give a better aerodynamic shape but at the risk of causing the sail to flap / flutter / hum at the leech. (That flapping will wear out the leech.)

Start with the lines loose. If the leech flutters then tighten the line just until it doesn't flap.

[TIM WEBB]

Thanks, that's pretty much what I figured.

They've been loose since I got the sails, but maybe now I'll pay a little more attention to that leech, and adjust the line as neccessary ...