Quote Originally Posted by jdurand View Post
Used for hydraulic elevators, too. City water in to go up, dump water to sewer to go down. No motor needed in the building, only enough power to operate the valves (and I'll bet there's an all mechanical way to do that)
I saw a post on some forum years back of a guy that built a system like that to lift a platform from street level up to the entry to a house. Maybe 6 feet up or so. He built it as a lift for a friend who used a wheelchair. Lifted him straight up as he had no room for a ramp. Essentially just a big piston that used city water pressure to lift, and dumped the water to his garden out back. A pretty slick system really, simple and effective.