Actually, the winch was located directly on top where the three legs join together. It looked like a flat plate, maybe 4" x 4" with a hole going down through the middle of it with the chain attached.
I watched this guy use this when cooking things like steaks, pork chops, potatoes, etc. on a grate. He was able to adjust the height according to the heat that he wanted during the various stages of cooking.
It was pretty slick and he never had to unhook anything, which would be handy if you had a cast iron dutch oven full of food.