One way to figure loads on various hardware, deck fittings,
and the like, is to look at how much strain would be on a
tow line pulling the boat at speed.


Wayne.B wrote:
Interesting idea but that is not how the professionals do it.

Perhaps I should have said "Figger" instead of "figure,"
since I did not mean to imply how to calculate the load
mathematically. Instead, just trying to get an intuitive
idea of how much force is involved. A lot of people can't
seem to grasp the idea that to move a big boat at speed
takes a lot of grunt, and all that force (and more) is
transmitted to the hull by the rig.

.... I once
had the pleasure (or misfortune) to work with Ben Hall designing a new
rig for my old Cal-34. I wanted to increase sail area by turning it
into a fractional rig, same fore triangle, larger mainsail.


That's a great idea. Did you go ahead with it? While I have
sailed a lot of mast head rigs, I've always liked fracs more.


The first thing that Ben wanted to know was the righting moment
(stability) of the hull, because that was the ultimate determinant of
how much rigging load could be created.


All that tells you is when you'll have to reef. You could
put a 70' mast on the boat and a 1000 square foot mainsail,
if you didn't mind tucking in your third reef in 15 knot winds.

Fresh Breezes- Doug King