: I've seen this design of fitting and it strikes me that when you apply
: load (from deck lines) to the little cross pieces, the force gets transferred
: to a really small area of the deck just at the ends of the fittings. Assuming
: that the wooden cross piece is strong enough, I can imagine them pulling
: through the deck leaving a ragged hole.

Good point. Perhaps a heavy glass "donut" at each deck fitting location would reinforce it sufficiently. I'm thinking a couple of layers of 9 oz. glass ~3" in diameter.