End boom sheeting and mistake in marketing blurb

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B

Been there

This site links to a Hunter marketing blurb that reads, in part, "on most cruising boats, the mainsheet is anchored to the coachtop. but that design applies powerful loading forces to the deck and rig, plus makes piles of mainsheet to handle the heavy purchase requirements of this inconvenient forward location. Clearly, the best location for the traveler is at the leech .." Whoever wrote this does NOT understand purchase. True, sheeting from the leech gives about 2:1 purchase over sheeting from mid-boom. But it does that BY VIRTUE of the fact that the movement at the end of the boom is twice as much, requiring twice as much sheet. In any mechanical system, purchase is precisely the ratio of control motion to effect motion. Same purchase means same amount of sheet in the cockpit. There ARE advantages to end boom sheeting. (a) It puts less strain on the boom and bail. (b) It puts the sheet closer to the helm. (c) It requires fewer blocks to achieve the same purchase. There are also advantages to mid-boom sheeting, eg, a traveler of equal width has greater effect. But no matter where the sheet connects to the boom, identical purchase as experienced by the trimmer means identical length of sheet trimmed. (Friction throws in a monkey wrench, but even with mid-boom sheeting, its effects will be minor if the blocks are good, and even with end-boom sheeting, its effects will be terrible if the blocks are shot.)
 
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Karl Berntson

Mid-boom sheeting better?

Some time ago I read an article by Gary Jobson where he compared mid and end boom sheeting. Unfortunately I can not recall the reasoning, but he concluded that mid-boom sheeting was a better configuration from a sail point of view. He did not address where the forces are absorbed or any other differences in hardware. With some serch I'm sure you could find his article. It was in one of the magazines he writes for.
 
B

Been there

I think it is a matter of preference

There are advantages to both. It also depends on other aspects of boat configuration, especially where the boom ends. I like Hunter's use of a cockpit arch to locate the traveler. It puts the sheet convenient to the helm, without having it cross the cockpit during tacks and jibes.
 
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Jay Hill

Preference...

...is a major deciding factor. I like the mid-boom location with the end-boom sheeting configuration; go figure. See http://www.c-2.com/upload/display.tpl?folder=Hill73048236635ampersandherefno=17 and make sure there's an ampersand between the 5 and the f in the link.
 
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