Wednesday, August 13, 2014

Gin Pole Rigging

Started rigging the Gin Pole this morning.
The purpose of the Gin Pole is to transfer the load to the ground. Compressive strength for a 6" X 6" PT is approx. 26000 lbs. Buckling pressure is approx. 1285 PSI. It will be plenty strong enough to take the load of the boat as it's flipped. I estimate the weight of the hull is about 1100 lbs and at no time will it actually be picked up off the ground, it will slide on on the frame that will be built around the hull.

I used 2 X 1/2" U-Bolts. Couldn't definitively find their load carrying capacity but I figure their breaking strength at somewhere in the 3-4000 lb range. The backing plates are 1/8" mild steel plate.
The shackle is 1/2" and rated for about 4000 lbs. The only pulley block I could find at Princess Auto is one rated for about 850 lbs. We'll do a lift test on it and if it's not good enough I'll upgrade to a better block. Pulling force will come from a 2500 lb 12V electric winch I'll mount to the pole. Sideways pulling of the boat frame as it's rolled will be with a 600 lb hand winch.
The upper u-bolt, shackle and pulley will carry the load. The lower one is for the ratchet straps that will hold it vertical. There's another ratchet strap that'll pass through this u-bolt and exit the side of the shed to a ground anchor.

I suspect I'll also brace the Gin Pole on the inside with some lumber to help distribute the load to the ground and keep the pole upright.

This afternoon I've got to move the pole out of the way and start to bring in the lumber for the rolling frames.