The Somua SM heavy tank prototype was developed by the French SOMUA company in 1946 in parallel with the M4 tank by the company AMX as an alternative. The main difference in the Somua SM was that it was originally designed as a heavy tank (Char lourd) with a projected mass of around 60 tonnes due to its enchanced hull armor, which was significantly superior to the competitor. The development was discontinued in 1953, and the tank wasn't accepted into service in favor of the AMX-50. The prototype is equipped with a 1000 hp engine which allows the tank to reach a maximum speed of 40 km/h. The armament on the Somua SM consists of a 100 mm Arsenal de Tarbes SA47 rifled main gun in an oscillating turret.