In 1930, the Soviets purchased a fleet of twenty Carden-Loyd mark VI "tankettes" from Britain as well as acquired the rights to locally produce the type. They operated the original forms under the designation of "K-25" and based their local, evolved form on this very design. This work begat the "T-27" tankette / light tank which went on to see production surpass 2,500 to 3,300 units before the end (sources appear to vary wildly on a precise total).
Compared to the original British design, the Soviet T-27 was given an enlarged superstructure with revised chassis component and, in turn, larger fuel stores for increased operational ranges. The running gear was also modified to utilize as many off-the-shelf automotive components as possible to keep production and procurement costs in check. Slightly wider tracks were installed for better ground pressure and control while the original machine gun mounting was replaced by the Soviet-style DT-machine gun mounting system. The crew of two was retained in side-by-side seating and power for this diminutive vehicle was from a single GAZ-AA 4-cylinder "Otto" gasoline-fueled engine developing 40 horsepower to the track-and-wheel drive system. Road speeds reached 42 kmh and range was out to 120 kilometers.
Production of series vehicles began in 1931 and ended as soon as 1933, manufacture handled by the Bolshevik Works of Leningrad as well as the GAZ Automobile Works of Gorki. The vehicles entered service with the Soviet Army in 1931.
The 2.7 tonne vehicle was of particularly compact form measuring a length of just 2.6 meters with a width of 1.8 meters and a height of 1.4 meters. Armor protection reached 10mm at the critical facings, mainly the front and side hull panels, and this provided security against only small arms fire. No turret was featured so the primary machine armament stuck out from the right-side crewmember's compartment. The vehicle, more or less, has to be turned into the direction of fire as training the machine gun offered limited results. A bogie suspension system was fitted which limited the vehicle's cross-country capability and no radio / communications system was carried.
In practice, the vehicles proved their worth for what they had been designed for - fast reconnaissance and very-light infantry support. However, some issues with the product soon showcased themselves including cramped fighting conditions for the two men and poor traversal on soft / wet terrain due to the still-narrow width of the track-link system. Even before the end of the decade, the series was being removed from service as more capable designs were coming on line so this left the T-27 to undertake second-line roles such as mover vehicle and tank driver trainer. Various experiments were had using the T-27 chassis that included flamethrower tanks, dedicated gun carriers, and remote-piloted models - with mixed results. The T-27 was also the subject of a "flying tank" project in which a sole example was carried under a Tupoleov TB-3 bomber to be air-dropped into combat in support of airborne forces, a practice later refined and proven useful in the fighting of World War 2 (1939-1945) and beyond.
Concerning the immediate pre-war period and World War 2 itself, the T-27 was in wide circulation when the fighting began so it was able to take part in actions across Asia, in the occupation of Poland during late-1939, and in the "Winter War" against neighboring Finland during 1939-1940. Several thousand were still on hand when the Germans invaded the Soviet Union during "Operationa Barbarossa" but this lot was quickly subdued under the might (and superior tactics) of the German Army and Luftwaffe services. A collection was known to be in service during the defense of Moscow during this tumultuous period.
The series was eventually given up for good in 1941-1942 when it recorded its last actions for the Soviets. It was exported to both Mongolia and Turkey who took on stocks of ten and six, respectively.