The T57 heavy tank was an experimental heavy tank developed by the American military during the Cold War era as a further development of the M103 heavy tank. Featuring heavy armour and a long range 120 mm rifled gun, the T57 was supposed to serve as a replacement to the M103 in service with American heavy tank units in Europe. Armor on the hull front was to range between 137-203mm in thickness and the turret was to be 152mm at maximum on all sides. Like the French AMX 50 project, it was to feature an oscillating turret and was also to receive a 153mm gun. Experiments were also conducted to look into the possibility of the tank being able to mount a 203mm gun, but this was soon found to be infeasible. When multiple problems were discovered in the turret oscillation system on account of the excess weight of the heavily armored turret and the gun, the project was dropped.