Construction pile driving: Vulcan 505 25,000 ft-lb 60 inch stroke single-acting air-driven air/steam hammer drives structural steel H pile into the ground. The ram, marked "505", is attached to the piston of the cylinder at the top of the figure. On each cycle, the cylinder raises the piston and ram to the top of the cylinder with compressed air received through the vertical compressed air hose to the left of ram. When the piston reaches the top of the cylinder (left figure), the piston and ram are released and drops/falls by gravity to impact the top of the pile (right figure), through a pile cap that protects the top of the H pile below it. Piles and hammer are supported and guided by swinging leads, which are supported by the crane boom and cable. Delonis Shelter, Ann Arbor, 2003.