US Army

M45 turret

Signal Corps US Army

The M45 was driven by a 12-volt electric motor connected to two variable speed belt-drives, one for traversing and the other for elevating the turret. Power was supplied by two 6-volt batteries connected in series. The batteries were charged by a 300-watt generator connected to a single cylinder, 4-cycle Briggs and Stratton gasoline engine, equipped with a self-starter. The generator never powered the turret directly. A nonlinear speed control system was incorporated with the belt drives in order to provide precise control of the turret at slower speeds. This aided the gunner in tracking his target. The M45 traversed a complete 360° circle, elevated to a fully vertical 90°, and depressed 10° below horizontal. Solenoids fired all four M2 HB machine guns simultaneously If the batteries went dead, the M45 turret could still be elevated and traversed by hand by attaching these manual control rods to the trunnions, as demonstrated by this M51 crew.