I ran into a guy at my local grocery store yesterday. He had a mechanically restored 1937 chevy pick up that was a tow/wrecker parked beside me.
The hoist was gear driven by hand crank. Said, the dump trucks back then were hand operated also. In regard to the posts above. My granfather served as a paratrooper in the Korean War. He talked everday of his life about that experience. I bet he may have seen that vehicle a time or 2. Unfortunately, he's not in his right mind these days. I would have liked to ask him about that. Pretty damn sure what his answer would have been.