Windlass Mechanism of Canaan Springs Rim
This contraption was used to lower timber from the rim of Vermillion Cliffs, and if I understand the mechanics right, it used to have the second barrel of a slightly different diameter on its left. The two cables seen in the background form a loop between the two barrels. As the barrels turn, the cable unspools from the slightly larger barrel and is reeled back onto the smaller barrel, and so it lowers the load just a bit with each turn of a crank.
Canaan Mtn thru hike, 5/31/09