Hole-Less Hydraulic – How Does It Work? The Hydraulic Holeless Passenger Elevator is popular for public buildings up to 5 levels. This elevator requires just a 4 ft deep pit. It is not necessary to sing the hydraulic jacks into the ground. They are positioned above the pit floor and entirely in the hoistway. The cab is lifted by 2 hydraulic jacks, one on each side, working in sync. The hydraulic jacks are powered by a pump unit in a nearby equipment room. The jacks attach near the top of the cab. In this configuration, the elevator can be lifted 1 level with a single stage jack as shown. A 2-stage or 3-stage jack will allow the cab to lift to additional levels.