Thread: Stay sail
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Old 04-14-2016, 10:17 AM   #22
cafesport
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City: Miami
Join Date: Jul 2013
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As a recovering sailor I'll throw some numbers up so my good friend Richard can stop wasting his time. I'm guessing his boat weighs in around 50,000 pounds. Most blue water sailing boats have a sail area to displacement ratio of around 15. Cheoy Lee's famous offshore 53 motorsailer is around 10 and Jim krogen's (yes that one) krogen 38 was a high 16. So lets say Richard wants to be halfway in between at 5. That would be come out to around 425 sq ft of sail which is about 7.7 hp in 15 knots of wind. Doable you say with a 20 x 20 square rigged sail. Here's the problem, the trades average 35 so that's more like 42 hp. The squalls come through at 60 plus or close to 123 hp. The forces on the rigging are 16 times higher at 60 vs. 15. The wind force on the sailcloth is over 6700 pounds oh and what's to there beneath the boat to keep her upright? To further add insult to injury under loading the lehman is going to cost you more in the end.


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