View Full Version : Bodie mystery screw

08-13-2007, 01:00 PM
I visited the ghost town of Bodie last week. This wagon had me puzzled. I think it is a hopper cart, although I cannot swear that the floor opens to dump a load. A shaft runs along one side (but not the other) -it has a large helix at each end.

Superficially this looks like it might be a worm, but there is no mating worm gear. It is not a gear profile, more like a sine wave. I thought it might be a feed screw, but there is no surrounding tube or indication that one is missing. And there are the ratchets.

I could have hunted-up a park ranger and asked, but I thought our collective wisdom can figure this out. I am totally mystified.



08-13-2007, 01:12 PM
Well, my shot in the dark is that it held a multi-wrap cable to lift the hopper for side dumping. The rachet suggests some unidirectional action opposed by gravity and being at the ends and just outside of the hopper would keep a cable run free as the components moved. I don't see enough of any other pivots or mechanism to justify this guess so it's just a guess.

08-13-2007, 01:49 PM
Well, my shot in the dark is that it held a multi-wrap cable to lift the hopper for side dumping.

I think you have hit on the answer. The screw looks perfectly shaped for a cable. Don't know why I didn't think of that.

08-13-2007, 02:26 PM
I have to agree that it is a latch and wire rope/cable lift deal for unloading a mine wagon. I have seen something akin to this on other mine carts wagons.

08-13-2007, 03:09 PM
I'd say it a to open a set of fly doors on the bottom of the hopper with a cable system. Not enough wraps to lift the wagon.... and also would be a waste of energy as well. Plus tipping would of cause allot of stress on the outboard wheels and axles.

08-13-2007, 04:40 PM
TG, PT and Tink all have the right idea. The same technique was used in the ore cars on the railroad only the shaft was transverse to the car and actually went throught the load of ore, coal, rock or whatever. Chains were used in the "worm" part and were attached to the drop doors at the bottom of the car.

BTW, really nice photos! Those old mechanisms are truly fascinating.

Thanks for sharing.