Sidney Greenstreet wrote:

It's not a loose footed main, there's a rope bolt!

The force is from the sail distributed along the length of the boom.
The boom keeps the sail from pulling up, that's right!, pulling up!!
The forces of the mainsheet in the downward direction are minimal and
occur at a point, not along the boom. The force of the vang, at best
only 1/2 downward are on the front portion of the boom.

It's a shelf foot. If my understanding of a shelf foot is correct, the
forces from sail are on the ends of the boom, similar to a loose foot. Since
the mainsheet is mid-boom, and since the boom bends downwards in the middle,
your arch theory is wrong.


--
Wally
www.makearatherlonglinkthattakesyounowhere.com
Things are always clearer in the cold, post-upload light.