The Captains Nemesis wrote:

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.

And not only for that reason!

There's also no reason to suppose that the 'inverted arch' is rigid - the
sag could be due to its own weight, such that pushing up from below would
straighten it, thus nullifying the principle that an arch depends on.


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