Though nearly obsolete by the beginning of World War II, the T-26 was the most numerous tank in the Red Army's armoured force during the German invasion of the Soviet Union in June 1941.

The simple and easy-to-maintain Vickers 6-Ton was intended for export to less technically advanced countries: the Soviet Union, Poland, Brazil, Argentina, Japan, Thailand, China, and many others.

[citation needed] In early 1930, the Soviet buying committee, under the direction of Semyon Ginzburg, arrived in the UK to select tanks, tractors, and cars for use in the Red Army.

The ability of the two turrets of the Type A to turn independently made it possible to fire to both the left and right at once, which was considered advantageous for breakthroughs of field entrenchments.

The British tanks were sent to Soviet factories for study in preparation for series production and to military educational institutions and training units.

Three British tanks were tested for cross-country ability at the small proving ground near Moscow on Poklonnaya Hill in January 1931.

The T-19 8-ton light infantry tank, developed by S. Ginzburg under that programme at the Bolshevik Plant in Leningrad, was a competitor to the British Vickers 6-Ton.

The hull was subjected to rifle and Maxim machine gun fire with the use of normal and armour-piercing bullets at a range of 50 m (160 ft).

Some tanks, produced in 1931, had sealing zinc shims at the hull bottom between armoured plates for fording water obstacles.

After problems with rain entering the engine compartment, a special cover was installed over an air outlet window after March 1932.

This model, which had a new single cylindrical turret carrying one 45-mm cannon L/46 (length in calibers, which meant quite high initial velocity, over 700–800 m/s depending on ammunition) and one 7.62 mm machine gun,[3] became the most common T-26 variant.

This increased firepower was intended to aid crews in defeating dedicated anti-tank teams, as the original machine gun armament had been found insufficient.

Each bogie consisted of a cast box with four twin rubber-covered road wheels connected by balancing levers and two one-quarter elliptic leaf springs.

The T-26 was equipped with a fire extinguisher, a kit of spare parts tools and accessories (including a tank jack), canvas stowage, and a tow chain fixed on the rear of the hull.

[26] This proved insufficient in the Battle of Lake Khasan in 1938, so the tank was upgraded once more in February 1939 to have an underturret box with sloped (23°) 20 mm side armoured plates.

The Bolshevik Factory needed to convert all tank drawings from imperial units into metric, in order to develop a production technology, special tools, and equipment.

Poor production standards were the reason behind the frequent failures of tank engines, gear boxes, springs in suspension, tracks and rubber-covered road wheels of early T-26s.

The problems with organizing the complicated new technological processes, poor production planning of parts suppliers, a great shortage of qualified engineers and technicians as well as of necessary equipment still resulted in many of the tanks being flawed, and they were not accepted by army representatives.

On 26 October 1932, the Trust of Special Machine Industry, consisting of four factories, was established to solve the problem of tank production in the USSR.

This process went very slowly, with great difficulties because of delays with deliveries of machining equipment and press tools for the newly built factory.

T-26s were used in almost all Spanish Civil War military operations against the Nationalists from 1936 to 1939 and demonstrated superiority over the German Panzer I light tanks and the Italian CV-33 tankettes, both of which were armed only with machine guns.

[citation needed] The next military operation the T-26 light tank participated in was the Soviet-Japanese border conflict, commencing with the Battle of Lake Khasan, in July 1938.

These were the type of tank units that participated in the Soviet invasion of Poland in September 1939 and in the Winter War from December 1939 – March 1940.

Poor quality roads, the vulnerabilities of track design in the early 1930s and inadequate maintenance, recovery and repair services all took their toll.

[citation needed] On 1 June 1941, the Red Army had 10,268 T-26 light tanks of all models on their inventories, including armoured combat vehicles based on the T-26 chassis.

The majority of the Red Army's T-26s were lost in the first months of the German-Soviet War, mainly to enemy artillery and air attacks.

[citation needed] The Finnish Army used captured T-26s of different models during the Continuation War and some tanks served in Finland for various non-combat purposes until 1961.

1939 with appliqué armour weighed 12 tonnes (13 short tons), which caused an overload of the chassis, transmission, and engine of the light tank.

The PS-3 had better specifications in comparison with the series-produced KT tank gun and also had several technical innovations (foot firing switch, original training gear, travelling position fixing, binocular optical sight).

[60] There are about 45 T-26 tanks of various models preserved in different museums and military schools (mainly Russian, Spanish, Turkish and Finnish).