AMX M4 mle. 45

The end of WW2 left the French Army with no modern tanks carrying a heavy armament. The ARL 44 was being developed, but this vehicle, though to be armed with a powerful 90 mm gun, could hardly be called modern, and its suspension system was completely obsolete. Therefore in March 1945 the French industry was invited to design a more satisfactory vehicle. That same year the AMX company (Atelier de Construction d'Issy-les-Moulineaux) presented its projet 141, a project to build the so-called M 4 prototype, armed with a 90 mm Schneider gun.

Development history

The M 4 closely resembled the German King Tiger in general form, though the turret was to be made of welded sections; but to limit the weight to a desired thirty metric tonnes the proportions were rather smaller and the armour had a maximum of just thirty millimetres. Like the later German tanks of the war it had, in this case eight, overlapping road wheels. Part of the project was to study whether a modern torsion bar suspension should be used or the height lowered by ten centimetres through a fitting of leaf or coil springs. Unfortunately, while copying German idea of overlapping suspension wheels, French engineers had no idea why German engineers had used this maintenance heavy solution. The Germans were motivated by a shortage of high quality rubber, necessitating large road wheels to lower tyre tension, which were then made to overlap in order to better distribute the load pressure. As France had no trouble obtaining rubber of the desired quality, this feature was superfluous. Two prototypes of the M 4 were ordered, but the Army soon indicated that a protection level of thirty millimetres was unacceptably low. In response, the armour was increased and it was decided to install a novel oscillating turret which resulted in the first prototype under the designation of AMX 50. No prototypes under original M 4 specification were produced.

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