Jerry:
If I remember correctly, the OB has a 2 drum winch. One winch works the hammer, the other raises and lowers the tower. I should say "raises" the tower as gravity has the greatest effect on lowering it!
I think it was about 1983 or so there was a NG Convention in Durango. This was early in the D&S years, everyone flocked to DGO to see straight stacked K28's and new K36's going to Silverton. Most fans were ignoring us. We decided on our own to put on a MOW car display for the convention. We got all the flangers, Pile Driver, Derrick, Jordan, etc out and set them out on #1 track with enough space between each for pictures. We decided to stand the pile driver up (hadn't broken its back yet). Russ Fischer, Gary Getman and I spent most of a day pouring oil into the hoist engine and hooked up air from the shop air compressor. We got the hoist to work fine. Our first attempt to stand it up resulted in the hoist engine stalling with the tower halfway up. Even with me standing on the brake, when the clutch was released, the tower came down rather quickly. In the next attempt, we slipped the clutch a bit to keep the engine moving and it stood right up. I should mention the hoist is supposed to operate off a locomotive boiler (180-200 lbs of steam) not shop air (about 75 lbs delivered through 100 ft. of 1 1/2" hose).
We got a bit of PR out of it, even got a pic or 2 in the NG Gazette.