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Old 05-11-2012, 12:40 PM   #12
H. L. Chauvin
Senior Member
 
Join Date: May 2010
Posts: 4,179
Default Re: Seat belts for Fordor

Hi Bill,

In not trying to degrade or counter what others have done or proposed with Model A seat belts, for safety & structural integrity, sincerely glad to see your structural comprehension of just the "double" force on the seat belt center-bolt.

One can realize that there are millions of Americans who use "common sense" to provide structural wood & structural steel connections every day, even though they are not graduate structural engineers. If in doubt, maybe consult with one of these type of guys.

After hearing of & seeing articles written on attaching the seat belt center bolt to the lightgage sheet metal pan behind the Fodor front seat, (with or without a 40" long x 2" wide x 1/4" steel plate), another commom sense way to imagine the strength of this attachment in a Fodor is to try to picture obtaining a large, approximately 40" wide x 24" Commercial Kitchen sheetmetal baking pan & attaching it up high into a fixed, rigid wood ceiling framing opening, with tiny shoe nails or shoe tacks like that of the Model A floor pan attached to wood sub-sills.

Through the center & on the front side of the baking pan, provide a seat belt bolt attached to a tow strap below, (about 8 feet long), with a 200 pound block of concrete attached to the other end of the strap, resting on top of an 8 foot high step ladder.

Next, let the 200 pound block of concrete fall off of the ladder & drop down 8 feet.

Look to see what happened to the de-formed lightgage baking pan which was assumed to be securely attached to the perimeter wood frame with tiny shoe nails.

Make sure your safety conscious wife sees this experiment because when it come to children's safety, women clearly see things that men can never see.

Most of the seat belt articles do not recommend attaching the center seat belt bolt to the wood cross member. The Fodor front wood cross member behind the front seat, (as is), is large enough to resist the force in bending; however, the weak point, as is the weak point in all wood beams & columns occurs at the end joint connections, in this case the thinner mortise & tenon connections at both ends which can easily fail in shear because many of these Model A wood joints already have split wood tenons from bouncing on rough roads & pot holes in the 1930's.

The rear Fodor seat belt anchorage to mortise & tenon wood, (as is), is not much better; & the lightgage sheetmetal over the differential is rather flat & attached to small wood members with the same type of tiny nails, thus offering no resistance.

I'm in the process of providing seat belts in my 1930 Briggs Town Sedan & after looking at what one has for anchorage, with the Fodor Model A as is, in my humble opinion, it would be like jumping out of an airplane with your heavy duty harness attached to your parachute with two (2) small safety pins.

With todays court system, as opposed to that of the 1930's, writing a detailed article recommending on how to attach Model A seat belts could be risky.

Hope this helps a little.
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