Multiple Gun Motor Carriage T52. The T52 Multiple Gun Motor Carriage was a failed design for a self-propelled anti-aircraft vehicle armed with one 40mm Bofors gun and two machine guns. The T52 was the result of a proposal from the Firestone Tire & Rubber Company that happened to match a set of requirements that was developed at a US Army conference in May 1942. The Firestone design was for a ball type turret (rather resembling a barrel), with a single 40mm Bofors gun mounted in the center and two .50-in machine guns mounted on the ends of the barrel. The turret carried a crew of two - the gunner on the right had to aim and fire the gun and reload the right-hand machine gun, while the loader on the left had to load the 40mm gun and the left-hand machine gun and set the range indicator. The Artillery and Automotive Subcommittee of the Army recommended that the Firestone mount should be tested out on two pilot vehicles. Ordnance approved, and on 30 July 1942 the mount was given ...