The forty millimeter Swedish Bofors medium-range anti-aircraft gun began replacing a battleship's inadequate one point one-inch guns in the fall of 1942, and by November 1943 the ship carried fifteen quadruple mounts. Each mount had a crew of eleven men, with additional men passing ammunition in clips of four shells to the loaders, and all four guns on a mount moved together in elevation and train. The pointer station had the firing pedal, and the guns could operate automatically by remote control from a nearby gun director, locally with the gun pointer controlling the mount's power drives and firing, or manually with the trainer and pointer using hand wheels for train and elevation while the pointer fired. To address the problem of engaging fast-moving aircraft, the Mark 51 Gun Director with Mark 14 Gunsight used computerized gunsights; its pointer aimed the director, tracked the target, and fired, while the range setter adjusted range, range rate, deflection, and elevation spots. The gun had an effective range of 4,000 yards, a rate of fire of 130 to 150 rounds per minute, a loaded and fused shell weight of 2 pounds, and a total crew per mount of fifteen to twenty including ammunition passers. Moisture could disable the amplifier section on top of the hydraulic unit, forcing manual operation that was too slow against attacking aircraft, and one sailor recalled drying the amplifier with a hair dryer though saltwater often had already damaged it. Another recalled four planes emerging from the clouds at about 10,000 feet, with one diving toward the force and then veering toward the aircraft carrier Wake Island before a forty millimeter gun hit it in one of the closest calls he had seen.