From the period of 1931 to 1941, the Red Army utilized the Carden-Loyd-inspired "tankette" through the locally-modified T-27, operated by a crew of two and produced to the tune of some 2,540 units which saw service prior to - and during - World War 2. Exposure to the tankette inspired new doctrine for the Red Army as well as further design and testing of compact vehicles centered around a greater Soviet influence. Such endeavors gave birth to the T-37A amphibious light tank of 1932 which entered mass production the following year and reached 2,552 units into 1936. These too saw service in World War 2 until the line was itself superseded by the newer T-38 series in time.
Design of the T-37A was attributed to N. Kozyrev out of Factory No. 37. Work began as early as 1931 and spanned into 1933 before a finalized design was adopted. The vehicle took on a rather simplistic from with a broad, angled glacis plate, thin tracks over a wheeled base and a one-man turret offset to the right from center. Conditions inside were understandably cramped for such a smallish design and her crew stood at just two - a driver and commander/gunner. Power was from a single GAZ-AA engine of 40 horsepower (originally Ford Model AA engines were used) which provided a maximum road speed of 22 miles per hour and an operational range of 115 miles. The suspensions system was of the sprung variety and amphibious qualities were inherent, allowing for cross-country travel and water traversal. Armament was limited to a single 7.62mm DT series machine gun held in the turret while armor protection was minimal at 3mm to 9mm in thickness across the various presented faces. Dimensions included a length of 12 feet, a width of 7 feet and a height of 6 feet and the T-37A's reporting weight was 3.5 tons (short).
Having entered service at a critical time for the Red Army, the T-37A would prove highly useful in the early stages of what would become World War 2. The vehicle formed a portion of the Soviet offensive against Poland from the East which was already dealing with an invasion along its Western border from Nazi Germany. With Poland eventually subdued, the Soviets moved against neighboring Finland which begat the "Winter War" and these mission types reflected the tankettes light-class design - fast reconnaissance, communications support and infantry support. Her machine gun armament limited her offensive usefulness to enemy infantry and very light-armored vehicles. When Germany invaded the Soviet Union on June 22nd, 1941 during Operation Barbarossa to open up the East Front, the Soviets suffered many major defeats which also led to many tanks and aircraft being destroyed - including large stocks of T-37As. With dwindled numbers, the vehicle held a small footprint in the war going forward. Some remained as battlefield vehicles while others were relegated for training service. Into 1944, the T-37A was officially released from her frontline duties. Other fought on in captured form under the flags of Germany, Hungary, Romania and even Finland.
The T-37A was also known under the designation of "M1936". The T-37TU represented special command version tanks.