And they sell a product to "prevent all those problems"? I can argue very well that cruising cat rudders are nothing like the transom hung, high aspect, thin bladed, high speed racing beach cats.

If you substitute a monohull in that article, the same thing is true. Just because there are two rudders in a steering system does not mean that one of them now experiences greater forces because the other merely exists.

Again, I cannot see your point about these differential rudder loads. Are you trying to convince catamaran owners to get rid of a rudder? Are you saying that monohull rudders do not see the same loads? Are you saying that none of the catamaran designers know what you know and now there are 50,000 or more time bombs out there?

Exactly why do you keep going on about catamaran rudders experiencing different loads? Exactly what is your point there?

Crossbar connection of rudders is very common in catamarans - most have them. The compression forces are well known and easily engineered. I have yet to see a broken or bent crossbar on a cruising catamaran.

Mark