Originally Posted by NORCALROOTS
In order to create the strongest anchor point, I intend on dropping the gas tank and bolting 1/4" steel rails on the underside of the vehicle to displace as much of the weight over the sheet metal of rear floor. I'm doing this more because I've been told this is the "safe" thing to do but I'm unclear how a bolted seat would pull through the seat metal. I'm assuming the thinking is that during an accident a person would create enough friction to pull the seat out but if they have their seat belt on, how would they move in a direction to pull the seat out? Either way, I'll err on the side of caution and use the re-enforced railings..
I can imagine. Seen it.
Imagine the jeep hitting a tree at 50 mph. It stops instantly. The rear seat just bolted through the tin floor - bolt heads pull right out- instantly, and the seat (and occupant if so equipped) continue heading for the windshield...
Adding some flat plate under the floor is smart - as large an area as possible.
Let me show you something by way of example - in the pic below - notice the Warn M8000 next to the cop on the right?
It was secured in the truck bed. A receiver like this one http://g-ec2.images-amazon.com/images/I/4149CG9DDEL.jpg
was bolted to the rear fender well, with a piece of 3/16 steel about 4x8 for a backing plate. The multi mount winch was stored on that, with a hitch pin to secure it. A very safe installation. In the accident, the winch and mount ejected through the roof, over the cab, hit the semi and bounced back to where you see it in the photo. It took a 4x8 section of the fenderwell with it!
Such are the forces unleashed during accidents.
(In case anyone wonders, that old Yota belonged to my father. He survived, but only by the grace of God and some incredible gifted first responders, a helicopter ride, and a well equipped hospital. But he's never been the same...)