FCM F4

In the late 1930s, while Germany was erecting the system of defensive structures that would be known as the Siegfried Line, France was reassessing its heavy tank doctrine to account for such fortifications. It issued a request for a heavily armored tank weighing no more than 45 metric tons and, in 1937, received proposals from the firms ARL, AMX, and FCM. FCM’s initial design included a 75mm gun housed in the turret and 47mm gun mounted on the hull; a later variant added another turret with machine guns. All three firms’ designs were rejected for exceeding either the weight limit or allotted budget.