The AMX-50 was a promising French heavy tank venture appearing shortly after World War 2. France, in an effort to reassert its global position as a world military power, took to design of new tanks almost immediately after Paris was liberated by the Allies of its German occupation. At the end of the war, however, the French Army lacked anything remotely modern in its inventory and made due with reconstituted German Panther and Tiger tanks for the interim. A heavy tank venture, the "ARL 44", became a wasted attempt at designing and producing a modern French heavy tank - the design incorporating both old and new approaches to produce a very basic - yet outmoded - end product. The French heavy industry concern of AMX (Atelier de Construction d'Issy-les-Moulineaux) delivered their "Project 141" study that proposed a 90mm-armed, heavy-class tank under the "M4" pilot designation - its hull design externally mimicking (on a somewhat smaller scale) the German Army wartime "King Tiger" Heavy Tank. French authorities commissioned AMX for two M4 prototypes for evaluation.
The general idea behind the M4 was to produce a tank that brought together all of the outstanding qualities of the proven wartime tanks - including those on the German and Soviet sides. The tank was intended to be well-armored and well-armed though still agile in an effort to counter any proposed armor threat appearing from the Soviet Union. The long term optimistic goal for the program was to create a combat tank suitable for all of European allies (bringing with it commonality in parts) while at the same time being of indigenous origins to help reestablish French credibility on the world stage.
The original specification was slightly altered by the French Army to include more armor protection (the original specifications called for just 30mm of armor). This design change naturally added to the vehicle's intended operating weight so other design elements had to compensate. The French concern of FAMH produces a unique "oscillating" turret which allowed for a smaller and inherently lighter turret system still capable of managing large-caliber armament. The turret would be essentially be made up of two distinct components - an upper half and a lower half. The upper section contained the main gun mounting and system could pivot itself to achieve elevation. The lower section controlled turret traversal in a conventional manner. The main gun of choice became a 90mm installation and this was to be fed its projectile ammunition via an automatic loader. The engine was a problematic selection for the required output necessary in the design. As such, a diesel and gasoline form were entertained with the gasoline form winning out - the engines coming from captured stores of German Maybach HL 295s. The general hope was always that French engineers could muster much horsepower from the Maybachs though, in the end, the engine failed to impress. The M4 prototype - in its finalized form - was now designated as the "AMX-50" to denote both the intended manufacturer and the general weight class of the vehicle (50 tons).
Two distinct AMX-50 prototypes were eventually produced, the first appearing in 1949. The initial prototype was armed with a 100mm main gun instead of the originally intended 90mm offering; the second prototype was also completed with the 100mm main gun but this was fitted to a different turret. Both M4 pilot vehicles utilized a twin 7.5mm Reibel machine gun setup on the turret roof to counter low-flying aircraft - a feature eventually dropped from later proposed designs. The pilot vehicles underwent standard evaluation and trials from a period spanning 1950 into 1952. The use of the larger caliber main gun naturally forced a redesign of the automatic loader system to which the new mechanics proved somewhat unreliable over the original. Three further M4 prototypes joined the initial pair - the third incorporating a larger turret while the forth increased armor protection. The fifth prototype introduced a rounded lower cast hull. The M4 appeared on parade during Bastille Day celebrations in 1950. In 1953, a new initiative proposed a 120mm-armed form with improved armor protection and a strengthened suspension system. This version was formally known as the "AMX-50 120mm".
As completed, the AMX-50 Heavy Tank weighed in at 63 Short Tons and featured a running length of 7.35 meters, a width of 3.4 meters and a height of 3.35 meters. Armor protection ranged from 80mm to 120mm across its various facings. Primary armament was the 120mm main gun fitted to the oscillating traversing turret set well ahead of amidships in the design. Secondary armament consisted of a pair of 7.5mm Reibel machine guns for self-defense - one fitted coaxially in the turret and the other on the turret roof for defense against low-flying aircraft. Power was supplied by a single Maybach HL 295 12VC gasoline engine developing 850 horsepower. The hull utilized a torsion bar suspension system and a top speed of 51 kmh was listed. Externally, the hull of the AMX-50 resembled that of the German wartime Panther Medium Tanks to an extent - especially the large sloped glacis plate at the front. The sides of the hull was flat as was the rear facing. There was no hull superstructure but, instead, a flat roof tall enough to fit the engine and crew. The turret sported a rear overhang to make room for the required autoloader. The turret appeared in several unique forms throughout the short life of the tank but all were rather similar in overall form and function. The barrel protruded a ways ahead of the forward hull and was capped by a baffled muzzle brake. The tracks were wide when viewed in the forward profile, mimicking that of the Panther design. there were nine overlapping road wheels to a track side - this another German-inspired design initiative. The drive sprocket was positioned at the rear of the vehicle with the track idler at the front. No track return rollers were present nor was side armor skirts to protect the tracks, wheels and sides of the tank. The engine was fitted to a rear compartment. The standard AMX-50 operating crew consisted of four personnel - a driver, tank commander, gunner and radio operator. Interestingly, the addition of the autoloader did not result in the deletion of one of the crew for the radio operator was also responsible for reloading the autoloader's ammunition stores with fresh shells from the hull. All told, the AMX-50 was more in line with medium-class tank offerings of the day - despite its French "heavy tank" classification.
Much like the ARL 44, the AMX-50 was simply outclassed by the newer generation of tanks being showcased at increasingly feverish paces. The Americans, disappointed with the outcome that was the M47 Patton Medium Tank in action during the Korean War, set about to "right its wrongs" and produced the M48 Patton Medium Tank, making its M47s available in some number for European allies for free. The French jumped at the chance to upgrade its armored divisions and accepted the M47 into service. This more or less spelled doom for the future of the AMX-50 and other French attempts at post-war tank designs. Furthermore, advances in projectiles rendered the concept of the dedicated "heavy" tank obsolete in modern warfare, bringing with it the more defined classification of "Main Battle Tank" instead. The AMX-50, for all intents and purposes, became another failed French tank design project - though experience and data garnered in its effort would prove priceless in the long run. Success would not find French tank engineers until the development of the AMX-30 Main Battle Tank of 1966 - of which 3,500 were eventually produced and shipped across the globe to interested parties, some still in service even today.
Of note in the development of the M4 pilot vehicle program was the "Canon Automoteur AMX-50 Foch", another prototype endeavor though this intended as a heavy-class tank destroyer / self-propelled gun and armed with a 120mm main gun. The design appeared in 1950 and it was intended to serve alongside the AMX-50 in the fire support role, delivering potent ordnance at distance. However, much like the AMX-50 itself, the Foch design fell into obscurity.
In all, just five AMX-50 vehicles were produced.