On Fri, 8 Aug 2008 21:21:12 -0400, "Glenn Ashmore"
wrote:

Just verifying my standing rigging specs before approving my order and need
someone to confirm my calculations. All the formulas I have found for
standing rigging loads are based on RM@30 but all I have is RM@1. The
formula for RM is RM=Displacement*GM* SIN but I don't have the metacenter
height (GM) either so working backwards;
RM/GM=Displacement*SIN
therefore (I hated that word in 10 grade algebra)
GM= RM/Displacement*SIN
Substituting:
GM=1952/24,400*.01745
GM=4.58
Now, to get RM@30:

RM@30=55,931 (Say 60K lb.)

Am I on the right track?

Probably but I would strongly encourage you to work with professional
rigging specialists such as Hall Spars or Navtec. It is important
that the calculations be backed up with a "reasonability check" based
on what similar boats are successfully using.

Another good resource would be Tom Anderson at Hathaway, Reiser and
Raymond in Stamford, CT. Tom and Ben Hall both gave me a great deal
of help when I re-rigged my old Cal-34.

http://www.navtec.net/home/index.cfm

http://www.hallspars.com/

http://www.hathaways.com/