The T-35 was a Soviet multi-turreted heavy tank of the interwar period and early Second World War that saw limited production and service with the Red Army. It was the only five-turreted heavy tank in the world to reach production but proved to be slow and mechanically unreliable. Most of the T-35 tanks still operational at the time of Operation Barbarossa were lost due to mechanical failure rather than enemy action.
Outwardly it was large but internally the spaces were cramped with the fighting compartments separated from each other. Some of the turrets obscured the entrance hatches.
The T-35 was developed by the OKMO design bureau of the Bolshevik Factory, which began work on a heavy tank in 1930. Two teams developed separate designs. The team headed by German engineer Grotte worked on the 100-ton four-turreted TG-5 tank, armed with a 107 mm naval gun, using pneumatic servo-controls and pneumatic suspension. This project was later cancelled.
The concept of large, multi-turreted breakthrough tanks was favored by several European Armies in the 1920s and 1930s. Designs existed in Britain, France, and Germany for such vehicles. The second OKMO team, headed by N. Tsiets, worked on a tank inspired by the British Vickers A1E1 Independent.
By July 1932, a prototype of a 35 ton tank with a 76.2 mm tank gun was completed. The first prototype was further enhanced with four smaller turrets, two with 37 mm guns and two with machineguns. This first prototype had severe defects in its transmission and was considered too complex and expensive for mass production. Therefore work on it was stopped and a new simpler prototype was built.
This new prototype received a new engine, new gearbox and improved transmission. The decision was also made to standardise the turrets used on the T-35 with those used on the T-28, a triple-turretted medium tank. The small machinegun turrets were identical on the two tanks. The large main turret housing the 76.2 mm gun was nearly identical, but those used on the T-28 had an additional, rear-firing machinegun.
The experiences gained with the two prototypes were used for the main production T-35 Model 1935, which was again improved from the second prototype, with a longer chassis, improved hull and 45 mm guns in place of the 37mms. It started production in 1935, and about 35 were built by 1938. In general, throughout its production run small improvements were made to the individual tanks. Production models had turrets similar to the ones on the BT-5, but without the rear overhang. Some models had flamethrowers instead of one of the 45 mm guns. The final batch was a run of six T-35 model 1938s, which had new turrets with sloped armor all around, as well as modified side skirts and new idler wheels.
Western and Russian historians disagree about the inspiration for the T-35's design. The former argue it was copied from the British Vickers A1E1 Independent tank, but this is rejected by many Russian specialists. It is impossible to know the truth for certain, but there is strong evidence to support Western claims, not least failed Soviet attempts to purchase the A1E1. At the same time, the influence of German engineers developing similar designs in the late 1920s at their Kama base in the Soviet Union cannot be discounted. What is clear is that borrowing military technology and ideas from other nations was common to the majority of the armed forces in the inter-war years. The Red Army, with its purchase of the British Vickers Carden Loyd tankette, Vickers E-Light and Cruiser Mk II Medium tanks, and the American Christie suspension, was clearly one of the leading exponents of this practice.
Due to its high cost, the production run of the T-35 ended at just sixty-one tanks.
The T-35 served with the 5th Separate Heavy Tank Brigade in Moscow, primarily for parade duties, from 1935 until 1940. In June 1940, the question was raised whether to withdraw the T-35s from frontline service, with the option to either convert them to heavy self propelled artillery, or to assign them to the various military academies. The choice was made to use them up in combat instead and the surviving vehicles were collected together into the 67th and 68th Tank Regiments of the 34th Tank Division, which served with the 8th Mechanized Corps in the Kiev Special Military District.
During Operation Barbarossa, ninety percent of the T-35s lost by the 67th and 68th Tank Regiments were lost not to enemy action but through either mechanical failure or because they were abandoned and destroyed by their crews. The most common causes of breakdown were transmission-related. The last recorded action of the T-35 took place during the early stages of the battle of Moscow. Four machines were used in training facilities in Soviet rear. One of them is now available for spectators in Kubinka Tank Museum near Moscow.
The T-35 is sometimes cited as having participated in the Winter War against Finland, but according to Soviet sources it did not. In fact, a prototype (multi-turreted) SMK tank had been sent to the front for testing. This tank was disabled by a Finnish land mine and all attempts to recover the 55-ton behemoth failed. Finnish photographs of the previously unknown tank were mistakenly designated T-35C by German intelligence.