• Military Menu                       

• Introduction
• Systems
• Facilities
• Agencies
• Industry
• Operations
• Countries
• Hot Documents
• News
• Reports
• Policy
• Budget
• Congress
• Links

• WMD
• Intelligence
• Homeland Security
• Space

Grotte Medium tank (tank TG)

The TG, “Tank Grotte” (sometimes the designations TG-1 and “Tank Grotto” are also found - in a number of Western sources, the T-22 index is found), are an experimental Soviet medium tank (due to the powerful weapons in the documents of the time often passed as “powerful medium tank”) under the supervision of German design engineer Eduard Grotte, who worked at the time in the USSR. The tank was distinguished by the use of a large number of original solutions and innovative developments and seriously outpaced the overall level of the world tank building of that time. Due to the high price and the general inconsistency of the Soviet industry with the requirements of the tank production, the TG was not accepted for service and was not mass-produced. However, the experience gained in the design of the machine, allowed the Soviet designers subsequently proceed to the design of the T-35 tank.

In the early 1930s, the military-political situation demanded that the Soviet Union take emergency measures for the technical re-equipment of the army and the implementation of the program adopted by the Council of People's Commissars in 1929 of equipping the armed forces with armored vehicles. However, the lack of the necessary scientific base in the USSR and the experience of tank building greatly hampered the design of new tanks and did not allow creating a project of a full-fledged combat vehicle. After a number of unsuccessful attempts to develop a fully domestic project of the tank, it was decided to attract specialists from abroad, primarily from Germany. In March 1930, a group of specialists invited from Germany headed by engineer Eduard Grotte arrived in the USSR. The group was assigned to develop projects of promising tanks for arming the Red Army.

The choice of Germany was not made by chance. In the mid-1920s. The Soviet government was in very tense relations with the countries of the former Entente (Great Britain, USA, France), which during the First World War achieved the greatest success in tank building and were considered “trendsetters” in this field. The situation with Germany was quite different - the once cruel enemy himself found himself in an unenviable position and was actively prepared to cooperate with Soviet Russia.

In April 1930, the Grotte group was given a technical assignment for designing a tank weighing 18–20 tons, booking about 20 mm and a speed of 35–40 km / h. Armament machines were supposed to be 76.2-mm and 37-mm cannon and 4-5 machine guns. All other parameters were left to the discretion of German engineers. For the design and construction of the prototype, the ABO-5 design bureau was created at the Bolshevik plant in Leningrad. In addition to the Grotte group, young Soviet engineers, such as N.V. Barykov, who later became famous developers of Soviet armored vehicles, were also created.

TG was not put into mass production, so the structure of this combat vehicle included many complex units, which the Soviet industry was not ready to release.

Development of the tank was conducted in an atmosphere of strict secrecy. Representatives of the Revision Council and the Government of the USSR directly observed the work. In particular, on November 17-18, 1930, KE Voroshilov himself arrived at the Bolshevik plant. Formally, the reason for the visit was to check the status of work on the production of serial tanks, but the prototype of the TG that was collected at that moment in a separate workshop was the main interest of the Commissar. According to the results of the visit, K. Voroshilov wrote to JV Stalin: The tank’s readiness today is 85%. There was an unfinished completion of the motor group, gearbox and a number of additional units. The sample is made in a special workshop, where about 130 workers and technicians are employed today. Currently, the construction of the tank is delayed due to the severe illness of E. Grotte, but our engineers suggest that the prototype will be completed on December 15-20.

However, due to a number of technical difficulties, the prototype tank was not manufactured until April 1931. Then tests of the tank began. In case of a positive conclusion on the prototype, the tank should have been launched into serial production with the TG-1 index. In order to master the production of the machine, it was planned to manufacture the first series of 50-75 tanks in 1931, and in 1932 to release and send up to 2000 new combat vehicles to the troops. the tank was to be put into serial production with the TG-1 index. In order to master the production of the machine, it was planned to manufacture the first series of 50-75 tanks in 1931, and in 1932 to release and send up to 2000 new combat vehicles to the troops. the tank was to be put into serial production with the TG-1 index. In order to master the production of the machine, it was planned to manufacture the first series of 50-75 tanks in 1931, and in 1932 to release and send up to 2000 new combat vehicles to the troops.

In 1931, the Bolshevik plant in Leningrad produced a single instance of the Grotte tank, the design of which also differed significantly from the original project.

It should be noted that the design of the TG contained a number of fundamentally new ideas, far ahead of their time. Some of these ideas were embodied later in the designs of other models of tanks. In appearance, the Grotte tank looks more like combat vehicles from the 1940s than tanks from the 1930s. TG was a medium type tank. The TG case was completely welded, which seemed like a novelty for that period of development of military equipment. The hull in the nose was sloping, armor plates were installed obliquely. The subsurface box had a streamlined shape, and two towers mounted one above the other were able to provide circular fire from two guns of 76 and 37 mm caliber.

The TG tank had unprecedentedly powerful armament for an average tank of that time. The main armament of the tank was the 76.2 mm semi-automatic A-19 (PS-19) gun, the most powerful tank gun in the world at that time. The A-19 was developed by P. Syacintov using a 76.2-mm anti-aircraft gun mod. 1914/15 (also known as the Lender or Tarnovsky-Lender anti-aircraft gun). Because of the rigidly specified dimensions, the gun had to be radically reworked.

The hull and tower were fully welded (for the first time in the world). The shape of the hull and turret was distinguished by originality and innovation - the tank had a sloping nose with a sloping installation of armor plates, a tower of streamlined shape and a hemispherical turret. Interestingly, for some of the data the case was water and gas-tight. It was originally planned that the turret logging would also be rotating, however, due to the lack of necessary equipment and experience, the cutting wheeling deformed, and it was decided to make a sample with non-rotating logging. Nevertheless, it was subsequently supposed to eliminate this defect and make a rotating wheelhouse. The front body armor is three-layered in especially dangerous places with a thickness of up to 44 mm. The reservations of the sides reached 24 mm, the cuttings and the towers - 30 mm. In the sides of the hull and in the front sheet of the underside of the box there were ball bearings for machine guns.

The mechanic-driver led the observation of the battlefield through three windows with viewing slits, and the commander used a stroboscope mounted on the roof of the small tower. In the design of the gearbox, which had four speeds back and forth, gears with chevron pinching were used. A special reverse mechanism allowed the tank to move forward and backward at the same speed. The undercarriage of the tank was half covered by armored screens. There were five large road wheels on board with an individual suspension, equipped with pneumatic shock absorbers. The chassis, as applied to one board, consisted of 5 large-diameter road wheels with truck tires and an individual spring suspension with pneumatic shock absorbers, 4 supporting rollers and a drive wheel of the aft layout. The cushioning of the road wheels was carried out very effectively and was conditionally divided into three levels. The first was an individual pneumatic suspension with compressor chambers, the second - individual suspension of rollers with coil springs, the third - semi-pneumatic tires of the “Elastic” type, with which all the rollers were supplied. All this gave the tank an extremely smooth ride. The tank had very soft pneumatic brakes, which supplied not only the drive wheels, but all the rollers. The caterpillar was made of stamped parts and had a high tensile strength. Basic rollers had brakes for an emergency stop in case of a break of a caterpillar. The TG had high firepower, good security and mobility, as well as smooth ride and comfortable crew accommodation.

However, in the manufacture of a single TG model, the large turret shoulder strap underwent deformation, as a result of which the lower rotating tower became stationary. During the assembly of a combat vehicle, a 250-liter compact tank air-cooled engine, developed by Grotte, was replaced by a more reliable heavy aircraft engine M-6.

From June 27 to October 1, 1931, a prototype TG, manufactured at the Bolshevik plant by the end of April 1931, underwent sea trials. During the tests, the maximum speed of the tank was 34 km / h. The tank showed good maneuverability and maneuverability. The TG transmission, which thanks to the applied chevron gears and cam clutches proved to be very durable and reliable, proved itself to work well, and the use of pneumatic drives made the control process extremely easy, especially for a machine of such weight. True, the airways periodically broke down due to the poor quality of the rubber in the seals.

However, many design flaws were noted. For example, the size of the fighting compartment was quite enough for convenient firing of 76.2-mm guns, but the simultaneous shooting of at least one turret machine gun with this was almost impossible. Placing the gearbox and side clutches in one crankcase made it difficult to access them during repairs and led to the overheating of the entire unit while driving. The unsatisfactory performance of the side brakes and the insufficient efficiency of the caterpillar on soft and viscous soils due to the low height of the crests of the caterpillar were also revealed.

Although the Grotte tank was not put into serial production and put into service, in the course of working on the only model of this combat vehicle, experience was gained that Soviet engineers used in developing multi-turret tanks such as the T-28 and T-35.