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Dan Maliszewski
01-01-2003, 05:39 PM
Forgive my newbyism, but has anyone fitted a higher aspect main sail rather than a loose footed one. Shouldent that have more drive/less heeling per given wind?

Theis
01-01-2003, 06:20 PM
I guess that would depend on how you get the higher aspect. If you keep the luff the same length and simply shorten the foot, you would likely get less heeling, but your sail area would be substantially reduced. If you kept the foot the same but increased the luff (extended the mast) you would have more sail area and it would tip easier. If you tried to keep the same sail area and reduced the foot somewhat, while increasing the luff somewhat, there would be greater tipping torque/leverage, and in the same winds the boat would heel more.

When a sail is reefed, only a portion of the heeling moment is reduced through the reduction in the sail area. Probably more important is that the center of effort is brought significantly lower, causing a marked reduction in the torque that puts the boat on its side.

Ed Ekers
01-02-2003, 06:37 AM
I am not sure this is what you are looking for but on Pathfinder we fitted her with a main sail that has and increased roach in the main. The sail was used for the one design racing on S. F. Bay and we were very successful with it. At the time the method of measurement was to measure the luff and foot and you were restricted by the length of your battens. We had the sail cut to the max lengths but built in an oversized roach (leech). The luff of the sail extended at least 2- 4 inches beyond the back stay in the upper third of the sail.

After a year or so of trying different sail trims we found the if we twisted the main using traveler and sheet adjustments it would produce a great deal of forward drive and not sacrifice any point. The obvious question was about chaffing, which we found to be minimal. The down side to the cut were the restrictions to the battens. There was not enough strength at the top of the sail to hold a clean shape and over time the sail ended up falling off to leeward.

The end of the story is that we lobbied the fleet to remove the restrictions on the battens, which we did, but now we have a method of measurement that has restrictions to the size of roach that can be cut in to the sail. Let me know if this is what you were looking for.......ed

commanderpete
01-03-2003, 06:08 AM
How come this topic gets 703 views in 2 days? Doesn't even have a photo of a scantily-clad young lady.

Must be some sailors lurking out there.

Dan Maliszewski
01-05-2003, 09:34 PM
Theis pretty much nailed my question, although I had to whip out my trusty Royce's Sailing Illustrated, what with all those luffs and roaches and whatknot, Seriously, thanx for all the replies. My best bet is to reef when needed and save the full main for light airs. I'm just a cruiser, and my palms sweat when I heel more than 20 degrees.

Also, just so Pete isn't too bummed out, here is shot of my favorite chick:

commanderpete
01-07-2003, 10:28 AM
Good looking bird.

In a pinch, I bet it would taste a whole lot better than a seagull.

http://www.cbsnews.com/stories/2002/09/24/national/main523178.shtml