Normandy as armored recovery vehicles with dummy guns. M4 Sherman The M4 was one of the best known and most used American tanks of World War II. Like the Lee and Grant, the British were responsible for the name, with this tank's namesake being Civil War General, William Tecumseh Sherman. The M4 Sherman was a medium tank that proved itself in the Allied operations of every theater of World War II. The Sherman was a relatively inexpensive, easy to maintain and produce combat system. Similar to production efforts on the part of the Soviet Union with their T-34 tank system, the M4 Sherman was the same class of mass-produced tank weapon. The new design was put into action beginning on 31 August 1940. This medium tank would have to mount a 75 mm main gun armament into a fully-traversable turret. The new tank would also have to incorporate the engine, transmission, tracks and suspension systems of the M3 Lee medium tanks in an effort to ease production and save time. This new medium tank would also have to reduce the crew from six to five and feature improved armor allocation without increasing the vehicle's overall weight. The design appeared as the T6 pilot model: it proved acceptable to U.S. Army officials and production was ordered for the new "M4" on 5 September 1941. Before production on the M4 ramped up, however, the M4 design was further revised to include a heavy-barrel .50 BMG M2 Browning on the turret for anti-aircraft defense. A .30-06 M1919 Browning was then added to the upper hull bow plate. The Army had seven main sub-designations for M4 variants during production: M4, M4A1, M4A2, M4A3, M4A4, M4A5, and M4A6. These designations did not necessarily indicate linear improvement: A4 was not meant to indicate it was better than the A3. These sub-types indicated standardized production variations, which were in fact often manufactured concurrently at different locations. The sub-types differed mainly in engines, although the M4A1 differed from the M4 by its fully cast upper hull; the M4A4 had a longer engine system that required a longer hull, a longer suspension system, and more track blocks; M4A5 was an administrative placeholder for Canadian production; and the M4A6 had an elongated chassis, but fewer than 100 of these were produced. One main problem for the Sherman design, in its various forms, was the heavier guns on the German tanks