J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Halyard Loads

Alan,

The equations you are looking for are in the Harken Catalog at http://sailingsource.com/harken/pr_lod-e.pdf

The equations for jib and mainsail show the load increasing as the square of the wind velocity but do not account for the reduced sail area exposed as the boat heels. The equations are therefore conservative. The mainsail equation accounts for the fact that the mainsheet attachment is not quite at the end of the boom. (E=13.0, X=0.75 on my J/30).
If you want the main halyard load, which is a little less than the mainsheet load, set X=0.0.

Jim Ingles
Rosebud, Hull 201