Detroit Diesel 6051 Quad-71

The Detroit Diesel 6051 Quad-71 was a marine power pack from General Motors that coupled four inline six-cylinder Series 71 two-stroke diesel engines to a single gearbox, usually with one output shaft coming out of the unit. Each engine displaced about 7.0 litres and the pack was rated at 900 horsepower in total. It was fitted to landing craft and ships during World War II, with some vessels carrying two units to drive two propellers and one vessel carrying three. The 6051 was specially designed with a hollow main shaft and a sliding inner shaft that changes the pitch of a controllable pitch propeller, and a later model of the pack used a standard solid shaft for fixed pitch propellers.