COMPOUNDING A BOATHOUSE LIFT
Compounding a boat lift consist of adding pulleys at the cradle or slings for a total of 8 pulleys instead of just the straight line configuration of 4 at the top. The end result makes a hoist that has limited ability able to lift twice as much load. The "down side" of compounding is that it adds 4 extra pulleys to maintain and that it reduces lift speed by 50%.