View Single Post
  #29   Report Post  
Glenn Ashmore
 
Posts: n/a
Default Main halyard winch, 1sp. or 2sp?



Ryk wrote:


You need to check the page again. The recommendation is based on the
size of the *foretriangle*, not on the size of the headsail. My
*foretriangle* is just over 300 square feet and the Lewmar 46s are a
good match for the loads all the way from the blown out 150% down to
what some of my chums refer to as my "cocktail jib" (short hoist for
about 80% of the foretriangle area).


The foretriangle is what we are talking about. Acording to that formula
your 300 sq ft foretriangle needs a pair of 52s. My I = 58.8 and J =
17.25 so my foretriangle is about 507 sq ft. The formula comes up with
80+ which is obviously out of line.

I think the problem is the 6 factor. It is supposed to be a combination
of 30 knots of wind and all the friction load. It must have been chosen
by a winch salesman. :-)

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com