In 1930 the Kharkiv Komintern Locomotive Plant, as a plant that had gained some experience in tank designing and manufacturing, received an especially important task - to begin the work on creating and organising production of a special fast tank which was needed by mechanised units of the Red Army. To render assistance and improve the management of the work on creating the first fast tank, N.M. Toskin, an experienced military engineer, was delegated to the bureau from the Administration of Mechanisation and Motorisation of the Red Army.

Work on the fast tank (designated the BT, 'BT' standing for 'fast tank') outgrew the planned limits and transformed into a creative process of designing not only new components, but an entirely new layout of the vehicle. Its main design feature was the presence of wheel-and-track propeller so that the vehicle could run either on its wheels (on public roads) or tracks (during cross-country movement). All the work connected with the BT tank was being done under the leadership of N.M. Toskin. The first tank called the OBT (experimental fast tank) was assembled late in September 1931. With some minor modifications introduced and final elaboration of the design completed, the tank was put into series production under the designation of the BT-2.

On November 7, 1931 the first three production BT tanks took part in the military parade on the Red Square in Moscow.

Especially Important Task

N.M. Toskin

As the problem of creating a fast tank had been solved, N.M. Toskin (as a regular military engineer) was summoned back to the Administration of Mechanisation and Motorisation of the Red Army to continue his service. On December 6, 1931 A.O. Firsov was appointed the Chief of the Tank Design Bureau.

Further work on enhancement of the combat and technical capabilities of wheeled/tracked tank led in 1933 to replacement of the BT-2 tank by a new version of the latter - the BT-5 tank. Very significant in this vehicle was the replacement of the imported Liberty engine by a locally produced M-5 aviation engine designed by A.A. Mikulin. Besides, the BT-5 mounted a more powerful 45mm gun (instead of a 37mm gun installed in the BT-2). The prototype tank Model 1935 had a 76.2 mm gun. This vehicle came to be called 'artillery tank' and was intended to provide fire support for attacking tanks.

The BT-5 tanks meant for commanding personnel were manufactured equipped with the 71-TKI radio-station with handrail aerial on the turret.

Throughout 1932-1933 design work was directed towards joining armoured parts of the hull and turret by means of electric welding instead of rivets. The BT-2 tank with welded hull and turret was designated the BT-4.

Carrying out further improvement of the BT series tanks, the designers of the T2K Design Bureau created in 1935 its follow-on version - the BT-7 tank. This tank was fitted with a M-17T carburettor aviation engine with better characteristics, and there were major charges to the transmission assemblies. Some of the tanks were equipped with anti-aircraft machine guns.

A.O. Firsov

Leader of the T2K design bureau of the Kharkiv Komintern Locomotive Plant in 1931-1936