M6 heavy tank

The Heavy Tank M6 was an American heavy tank designed during World War II. The tank was produced in small numbers and never saw combat.

Development

Because of limited budgets for tank development in the interwar years, at the outbreak of World War II the US Army possessed few tanks, though it had been keeping track of the use of tanks in Europe and Asia. Successful employment of armored units in 1939 - 1940, mostly by the Germans, gave momentum to a number of US tank programs, including a heavy tank program. The United States possessed a massive industrial infrastructure and large numbers of engineers that would allow for mass production of tanks.

Following the Chief of Infantry recommendation from 20 May 1940, the US Army Ordnance Corps started to work on a 50-ton heavy tank design. Initially a multi-turreted design was proposed, with two main turrets armed with low-velocity T6 75 mm (2.95 inch) guns, one secondary turret with a 37 mm gun, and a coaxial .30 caliber (7.62 mm) machinegun, and another secondary turret with a 20 mm gun and a coaxial .30 caliber machine gun. Four .30 caliber machine guns were to be installed in ball mounts, two in the glacis (front) plate and two in the rear corners of the hull. The project was approved on 11 June 1940 and the vehicle received the designation Heavy Tank T1. The design was somewhat similar in concept to multi-turreted breakthrough tanks developed in Europe in the 1920s and throughout the 1930s, such as the 1925 British Vickers A1E1 Independent or the Soviet T-35 of the early 1930s. Disadvantages of these "land dreadnoughts", namely their excessive size, difficulty in coordinating actions of the crew, and high production costs, led to abandonment of the concept in Europe.

Heavy tank

A heavy tank was a subset of tank that provided equal or greater firepower as well as armor than tanks of lighter classes, at the cost of mobility and maneuverability and, particularly, expense.

The origins of the class date to World War I and the very first tanks; designed to operate in close concert with the infantry and facing both artillery and the first dedicated anti-tank guns, early tanks had to have enough armor to allow them to survive on no man's land. As lighter tanks were introduced, the larger designs became known as heavies. The same basic role remained into World War II, with the British referring to them as infantry tank indicating this close support role.

As tank combat became more common, especially tank-vs-tank, the heavies also became platforms to mount very powerful anti-tank guns, and the role of the heavies began to change. By the end of the war they were a primary class, used both for dealing with heavy fortifications as well as forcing its way through enemy tank formations. They were also known as breakthrough tanks, indicating their purpose of spearheading the attack. In spite of this, in practice they have been more useful in the defensive role than in the attack.