Boat Forum / Building / December 2004

Brian,

I too find misspelling an irritant and apologize for the lapse.

I knew better but have seen stanchion misspelled as stantion so many
times I guess I too must guard better against this, apparent,
susceptibility.  :-)

Then again, what is 'proper' spelling other than a commonly agreed upon
convention which as we both know, evolves, in fact maybe by this very
device.

Courtney

Brian,
I applogize for the misspelling and brain fade. I knew it was wrong, but
sent it anyway.
Marc,
Stephen Baker's reply is spot on. Do not use inadaquate materials. On my
boat I have a 12" wide steel plate the runs all around the deck that is
welded to the steel hull on the outside and on the inside it fastenens to a
steel space frame design that supports the teak deck. Under each of the 30"
stanchions, which are made of prepolished 1.25", 316 SS tubing, I used 1.5"
x .250" SS carraige washers. Through which I run a single 3/8 x 16 cap screw
threaded to welded nut plates at the bottom of each stanchion. My logic was
to support the base of the stanchion with a single screw, because at the top
of the stanchions I have a continuous run of the same prepolished tube all
welded together for stiffness. In addition, I have 3 runs of 6mm SS wire
equally spaced, through the stanchions around the boat. The wire terminates
with rigging screws at the pushpit and supports netting and spray protection
cloths at the cockpit. This sounds very stiff, but it isn't. There is a
maximun of 3" of in/out motion at the rail, in the center of the boat. It is
however, very strong. The single screw is designed as the rail failure
point, rather than the deck and it works as designed. I had the mast
horizontally above the deck, supported at the bow and stern by 6 x 6 beams
holding a cover over the deck. In a 70 mph gale, the 6 x 6 supports failed
and the mast fell. The rail deformed at the collision points and 2 stanchion
mounting bolts broke, but the rail held the mast and all the attached debris
without any deck damage.

In your FG case, the same solution would work, but I would recommend the use
of backing plates to spread the load at the deck level. The use of tubing
for stanchions fastened with a single bolt is weak by itself, but coupled
with tubing at the top and the SS wires tieing all the elements together as
a common structure, is easily strong enough to capture and hold a 200 lb man
in a collision. Additionally, the slight give at the rail will absorb a
considerable amount of energy, which could significantly reduce injury in a
mishap.
Steve