4260

T28E1 CGMC of the 443rd AAA Battalion in Saint-Raphaël, France

In September 1941 work began on a project to mount a heavier anti-aircraft gun on a half track, with the designation T28 Combination Gun Motor Carriage. This carried an M1A2 37mm autocannon and two .50in machine guns (mounted above and to the sides of the cannon) on a large open mount carried on a rotating platform on the back of an M2 half-track. The mount was too large to fit within the normal armoured sides of the half-track and so the sides and rear walls of the fighting compartment were removed, leaving an open platform.
The twin .50in machine guns were usually used with tracer rounds to allow the gun crews to hit their target. Once the machine gun fire was accurate the 37mm gun would open fire, hopefully making more effective use of the more limited supply of 37mm ammo.
In June 1942 the Armored Force asked for a crash programme to develop a mobile anti-aircraft weapon for use in the upcoming North African campaign. The T28 project was revived as the design had reached a stage where it could easily be rushed into production. The only major change to the design was a switch from the M2 half-track to the slightly longer M3 half-track, and the vehicle was then accepted for production as the expedient standard T28E1. Eighty T28E1s were completed by August 1942, and most of them went to North Africa.
The Tunisian campaign was one of the few occasions when the US Army fought the Germans without air superiority and so the anti-aircraft weapons came into their own. The T28E1 claimed 78 victories in three months during 1943, with 39 German aircraft shot down during the fighting in the Kasserine Pass alone. At least one T28E1 was captured by the Germans during this battle and later used as a transport vehicle. The T28 was also used during Operation Husky - the invasion of Sicily and in the invasion of Italy. Some were used during Operation Dragoon, the invasion of the South of France in August 1944.
http://www.historyofwar.org/articles/weapons_M15_CGMC.html