Quote:
Originally Posted by mariner2k
I've created a pattern for a bronze alloy mast cap for my new mast. But the guestamate on the weight was about 25-30 lbs. I made it a bit thick for overkill strength, but ultimately thought it necessary to reduce the thickness and weight, which I've done. I know that weight aloft effects the performance/ righting moment of the boat, but how much? I'm happy with the pattern now but I am still curious. The boat is 47' loa with a 55' mainmast.
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Assume a 30 degree heel then roughly the weight aloft will be about half as important as weight on the rail -- scaled by the distance away from the boat pivot point. 25 pounds up 60 feet is about 750 foot pounds. Weight on the rail might be 6 feet out and is about 85% effective at 30 degrees so to get 750 foot pounds at 6 feet is about 150 pounds, just as Brion said.
Allen
L-36.com