Steve Lusardi wrote:
Your assumptions are incorrect Keel spepped masts NEVER bear on the deck.

Never? My previous boat, a Nonsuch 30, had tons of stress on the deck.
And fractional rigs frequently have fore and aft loads. Certainly
many dinghies control these loads at the deck.

It
would create a stress concentration that would cause mast failure all on its
own. The only forces on the base of the mast in all cases is down force. All
other forces are born by the standing rig.

Again, certainly not the case in some rigs. And I'm trying to imagine
how all side forces can be managed by stays that only attach to the
upper half of the mast. Can all of the forward force be taken by the
backstay???

Please remember that the mast
base must be movable in the fore/aft plane in order to tune the center of
effort. Please also note that some keel stepped masts terminate on support
tables below deck that can be well above the bilge level.. In my case, the
sliding step is 40" above the cabin sole. My mast's static downforce is in
excess of 30 tons. Mast forces on the hull are applied by the rig which
attempt to bend the hull both in the fore/aft plane and across the beam
between the chainplates compressing the deck. On conventional construction
these forces are contained by the deck carlins for the athwort ship forces
and hull stiffness in the fore/ aft direction.
Steve