The GM Diesel/Detroit Diesel model 6051 Quad power pack consists of four inline 2-stroke diesel 6-71 engines mounted to one gearbox, usually with one shaft coming out of the power unit. The power units were fitted on landing craft and ships during World War II, ships including LCI(L),^[1] Prab (741) and Nahka (751) were fitted with two of these power units to drive two propellers, Mataphon (761) was fitted with three. There is a later model of this power pack which has a standard solid shaft for fixed pitch props while the 6051 model is specially designed with a hollow main shaft and a sliding inner shaft with a hub on the end that changes the pitch on the propeller.