The road to the war-winning T-34 Medium Tank for the Soviets in World War 2 (1939-1945) went through designs such as the T-50 Light Infantry Tank. This track-and-wheel combat vehicle was developed in the immediate pre-war period from 1939 into 1941 and ultimately resulted in 69 to 75 examples being completed before the end. However, the T-50 arrived at a time in Soviet armored history when the value of light-class tanks in warfare was fast fading - it was ultimately given up in favor of producing more T-34 tanks.
The Soviet participation in the Spanish Civil War (1936-1939) clearly showed the limitations of its existing stock of T-26 Light Tanks and BT Fast Tanks. Their armor was weak and their armament proving weaker in more contemporary battlefield settings and environments. Kirov Works, Plant No.185 was therefore ordered to begin development of a new light-class, infantry-minded battle tank in 1939 built around improved protection while not sacrificing speed. World War 2 then began in September of that year with the German invasion of neighboring Poland and the Soviet Union joined in shortly after. It then committed to war with neighboring Finland to being the "Winter War" of 1939-1940.
During the tumultuous period of Stalin's "Great Purge", in May of 1940, Kirov Works was combined with Voroshilov Works, Plant No.174 which delayed development of the new tank some but work was ultimately resumed. Before the end of the year, Soviet engineers presented two pilot vehicles for review, one emerging from each plant (Kirov and Voroshilov). Both were based in an earlier approach, the "T-126" and were therefore designated "T-127" and "T-126SP", respectively. The T-126SP was selected ahead of the Kirov design and officially designated as "T-50" in February of 1941.
The finalized version was somewhat reminiscent of the soon-to-be T-34. Angled facings were given to the hull superstructure for basic ballistics protection and the vehicle was straddled six double-tired road wheels, rear-set drive sprockets and forward-mounted track idlers. Three track-return rollers were used in an arrangement that incorporated wide track links for balanced ground pressure when going over soft terrains. Inside was a crew of four that included a driver, commander, gunner and radioman. A complete radio kit was installed which was notable during a time when tanker crews principally communicated via hand signals and flags on the battlefield.
The turret was designed to house three of the crew and given a relatively low profile look complete with a commander's cupola. Again, angled facings were instituted for ballistics protection. The primary armament became 1 x 45mm 20K L/46 weapon seated in the frontal turret face and this was backed by 1 x 7.62mm DT machine gun in a coaxial mounting as an anti-infantry measure. Armor reached up to 37mm in thickness at the crucial facings (namely front and sides) which offered strong protection for a light class vehicle of the late-1930s. Drive power came from the all-new 1 x W-4 6-cylinder, diesel-fueled engine outputting 300 horsepower to the track-and-wheel arrangement. All told, the tank could reach a road speed of 60 kmh and range out to 350 kilometers. Combat weight reached 15 tons while structural dimensions included a length of 5.2 meters with a beam of 2.5 meters and a height of 2.2 meters.
Another design note was the T-50 being completed with a torsion bar suspension system offering much-improved good cross-country mobility. This was a departure for Soviet tanks that had previously mainly relied upon the American-originated Christie suspension systems or complex multi-bogied track-and-wheeled arrangements.
The new tank was ordered into production in July of 1941. Of note during this time was the surprise German invasion of the Soviet Union in June of 1941 (through Operation Barbarossa) which formally ended the alliance that began the war in Europe back in September of 1939. Voroshilov Works managed a stock of about fifty T-50 tanks before the production facilities were abandoned under the might of the German offensive. These lines were reinstated in the Urals before the end of the year and the T-50 was in more demand than ever. However, the initiative lasted only into February of 1942 for the T-50 was found to have consistent engine stability issues and its per-unit cost and manpower matched or exceeding the better T-34 model. About twenty more T-50 tanks were added to the stable but little else came from the effort.
Those T-50 battle tanks that managed to make it into service during the war were primarily featured near the Leningrad region with some ending their careers in the Caucasus. While the T-50 became largely a footnote in the long-running and storied history of Soviet armor, experience gained in its development undoubtedly helped to streamline the effort that was to produce the famous T-34.