Feb 22, 2008

Cave Tram Operational

I installed a cable, rope, and a tram in my cave to make removing dirt and rocks faster and more fun. You can see a video of my cave tram on youtube.

I have a box/tram that rides on the cable (two pulleys) with a rope in a loop that can pull the tram up or down. The rope goes through a pulley near each end of the section of cable the tram rides on. I park the box just above where I want to dig. From where I sit I sort of have two ropes to play with and I call them the "up-rope" and the "down-rope" as they can pull the box up or down (really one big rope in a loop).

At the moment the tram hits some rock before it gets all the way to the back of the cave. There is about 4 feet that I will need to make between 6 inches to 1 foot lower. I can loop the up-rope around the bull-pin in the lower left part of this picture to park the tram exactly where I want it for the next loading.

The right side is almost clear.

I can pull on the down-rope and pull out a pin that lets the door/bottom of the box open up. But the pin was coming out sometimes when it was not supposed to, so I now put some of the down-rope inside the box and put some dirt and small rocks on the rope. Now I have to pull harder to release the pin and there have been no more accidental dumps.

The box is 2 feet long, 1 foot wide, and 6 inches high at the ends and 4 inches high at the sides. It can carry a rock that is almost as large as I can comfortably lift while on my side in the cave.

Close up of the release pin (eye-bolt with threads cut off). The black rope is tied to the down-rope so that when I yank on the down-rope the pin is pulled out and the door/bottom can open.

My two older boys helped put in some of the screws and with the painting. I could not find a paint brush, so we just rubbed the paint on with some old cave gloves. A good time was had by all.

The end of the down-rope goes over a pulley and to an eye-bolt in the door/bottom so I can pull it closed. You can just make out the silver of the eye-bolt next to the shadow of the black rope. The cave is not big enough for the tram to pass through with the door/bottom open.

Again, the down-rope goes over the pulley and to the door/bottom so I can pull it closed while still inside the cave. You can also see the latch mechanism without the pin.

Where the pin/latch is can bump at this spot so I will have to widen it a bit.

The 3/4 inch plywood and little block of wood were left over from some concrete forming. I drilled the holes in the box for the ropes to go through with my 3/4 inch hammer drill so a bit of extra wood came off. The cable is 1/4 inch and the rope is 1/2 inch.