A-20

Long been thought that the average tank A-20 takes its origin from a series of light tanks BT, and as prototypes had in mind the BT-5 and BT-7. This view is generally true, but few know that between the occurrence of BT-7 and A-20 was designed by a few intermediate samples of light tanks, which had planned to replace the " seven ".


In 1937, the plant № 183 was deployed active program to upgrade the BT-7, which was aimed primarily at improving its armor . In accordance with the terms of reference issued by ABTU at the Kharkov plant had to create two new versions of the BT-7IS and BT-9, which take into account when developing expertise in development and testing of BT-5IS design NF Tsyganova . The actual leader of the work was an associate Wammen them. Stalin Military Engineer 3rd Rank A. J. Dick. From an earlier BT-5IS were borrowed sloping side and front hull, while the chassis has remained virtually unchanged. Book of the tank increased, increasing to 25-30 mm, which would allow to withstand firing bullets caliber 12,7 mm projectiles caliber 20 mm. Was prepared several conceptual designs of the BT-7IS and started making separate units of the tank, when the summer of 1937, virtually all work on the upgraded BT stopped.
"The ideological mastermind" of this step was a famous designer in the future of MI Koshkin, who in January 1937 led by a tank division "100" with KB-190. In his view, high-speed tank was supposed to have thicker armor, heavier armament, and, most importantly, only a caterpillar. But then, were still strong supporters of the position of wheel-track driver and go directly to the car a completely new type did not work. As an interim measure Koshkin every effort to complete the design work on the BT-7IS and BT-9, which eventually succeeded.

At this time, "top" keenly followed the fighting in Spain, where the Soviet BT-5 and T-26 showed absolute advantage over the Italian and German machines, but they themselves are often victims of field artillery and antitank guns. Now gain reservations it can not be avoided, although light tanks made a small exception - he was supposed to withstand armor hitting 12.7-mm bullets. In turn, to replace T-26 and BT had to create a heavier car with protivosnaryadnoy armor.

This decision has been issued on Oct. 13, 1937 in the form of specifications issued by the № 183 from ABTU. Within three months of the design team under the leadership of J. Dick was to develop three versions of the chassis and build two prototypes of the new tank. In order to speed up the plant pledged KB September 8 best designers, tankers and 30 engineers, and from December 1 - an additional 20 people. In the resulting TTZ stipulates the following characteristics of the tank, which received the designation BT-20 plant, and the index of A-20.
1. Type of wheel-tracked, driven by 6 wheels on the type of Christie
2. Combat weight: 13-14 ton
3. Armament: One 45-mm or 76 mm cannon, three DT machine-gun, flame thrower to protect themselves. Every 5 th tank should have anti-aircraft guns
4. Ammunition: 130-150 rounds dl 45-mm gun and 50 rounds for 76-mm guns, ammunition for the 2500-3000 DT
5. Reservations: forehead - 25 mm, conical tower - 20 mm, board and food - 16 mm, the roof and bottom - 10 mm. Armor entire slope with a minimum angle of inclination armor plates hull and turret 18 °
6. Speed on tracks and on wheels is the same: maximum 70 km / h, minimum 7 km / h
7. The crew of 3 persons
8. Cruising speed: 300-400 km
9. Engine: DB-2 with capacity of 400-600 hp
10. Transmission: the type of wheel-track tank BT-IP (PTO for the wheel of progress after steering clutches)
11. Suspension: Individual, as the spring is desirable to apply torsion springs
12. Install stabilizer shot "Orion" and a horizontal stabilizer tower systems engineer Povalova, install lights for night shooting with a range up to 1000 meters.

To speed up the ABTU allocated Kharkov plant has several specialists, resulting in a new KB on the composition was stronger than the principal. Chief of bureau was appointed A. J. Dick, assistant chief engineer P. Goryun, consultant ABTU EA Kulchitsky, Chief, VM Doroshenko (control), MI Tarshinov (cabinet), Gorbenko (motor ), A. Morozov (transmission), P. Vasiliev (chassis). Thus the real progenitors of the future "Thirty" was A. J. Dick and NF Tsyganov, submitted their draft tank with sloping armor before MI Koshkin.

The chief designer decided to develop ideas previously used in experimental tanks, the BT-IS and BT-SW-2, as well as projects 7IS BT and BT-9 developed in the summer of 1937 they borrowed from the slopes of airborne bronelistov, individual elements of the transmission and chassis parts (guitar, location drive shafts and springs, the design of the guitar, wheel drive). In addition, to improve the load distribution AY Dick suggested a five rollers on board.
The work of this group was interrupted in November-December 1937 This was due to the fact that the chief designer of MI Koshkin organized a new design office of CB-24, which consisted of the best specialists of the KB-190 and CB-35. Development of the A-20 migrated to it, where the project was slightly revised.

While Cat is reorganizing its April 28, 1938 in Moscow, a meeting was held which considered the draft of new tanks. The tank BT-20 offers to produce a layout for October 1 and June 1 to get a prototype. In this case, the type of propulsion guidance was not yet defined.

The next demonstration of a medium-wheeled / tracked tank A-20, and his main rival A-20G (A-32), occurred May 4, 1938 at the enlarged meeting NKO under the chairmanship of V. Molotov. There was also attended by Stalin, Voroshilov, and many other public figures and representatives of the defense industry. More interesting seems the fact of the invitation to this meeting of the tankers, recently returned from Spain. Although if the situation evolved not in favor of the Republicans self-use of tanks in a completely new combat conditions is of great interest. During the debate arose between advocates of mixed and tracked progress in the last Stalin supported, although the arguments for their point of view, they have provided very controversial.
In August, the projects were reviewed by the Military Council, but even then ABTU smacked a clear preference for wheel-track option, relying on him. The outcome of the meeting was to build and test both tanks.

Work on the working drawings and models of tanks to be completed by November 6, leaving them to the state commission. Just a few months in the winter of 1939, there was a new reorganization of design offices, in which KB-24 KB-35 and CB-190 were combined in one unit - the "Front 520" while holding a merger of advanced plants. Chief designer of , as expected, began to MI Koshkin, Chief Bureau and deputy chief designer - Alexander Morozov, deputy chief - NA Kucherenko. Construction of the prototype A-20 was completed on May 26, 1939 The tank had fully welded body of homogeneous armor grade PDs with thick bronelistov corps from 10 to 20 mm. anterior frontal sheet was located at an angle of 53 °. For the A-20 was developed entirely new tower to increase by 70 mm and a thickness of pursuit bronelistov 20-25 mm . By design, it was like the tower of the BT-7, but the shape is more reminiscent of the tower experienced the BT-SW-2. It establishes a 45-mm cannon and 20K paired with her machine-guns. The second DT machine-gun mounted in a ball mount in the frontal body to the right of the driver's hatch. Ammunition consisting of 152 shells and 2,709 rounds of ammunition, was located in the body. A number of components and assemblies with minimal changes came from the BT-7. Wheel Drive is already a 6 wheels, track width has been expanded to 400 mm. The tank, after all the revisions amounted to 18 tons. Thus, the A-20 tank on the composition of arms and the mass of a few do not fit into the specification in 1937, but these flaws considered insignificant. From May to July 1939 tank passed factory tests "winding" 872 km (on tracks - 655, on wheels - 217). Among the identified defects of the most significant recognized insecure guide wheel (idler), a precarious job of lubricating the engine, steering clutches and brakes, poor visibility from the tank. Additionally noted the need to strengthen the bearing of the gear wheel.

Field testing of A-20 began June 15, 1939, when the tank was transferred to military representation ABTU. A month later conducted a comparative test of A-20 and A-32, during which both machines showed good performance. As an advantage, "twenty" said a better mobility and ability to move the tank is damaged a track or two rollers, than the A-32 could not boast. On the other hand, A-20 had a less powerful gun armament and weak armor that can withstand the hit only 12.7-mm bullets. In the report the chairman of military commissions, Colonel VN Chernyaeva was recorded that both the tank tests were successful. So the question with a choice of chassis circuit again become topical.

Meanwhile, A-20 was the current repairs and 5 September 1939 he was sent to the landfill NIBT to show members of the government. There was a demonstration of the new heavy tank T-100, SMC and HF, light T-26 (upgraded, sample 1939) and BT-7M, and experienced medium tank A-32. More effectively made the A-32, but refuse wheeled / tracked tank ABTU no hurry. Decision on this issue was a compromise - September 19, 1939 the Commissariat has set the government the issue of adopting both types of tanks with the ability to build the initial batch of A-20 of the 10 cars to January 1, 1940, and in March they planned to begin mass production to 2500 cars a year. During this time the plant № 183 should eliminate the identified deficiencies and to prepare production. However, in Kharkov, reacted negatively to this decision. The fact that since 1940 the plant was translated to the production of tanks A-34 and production of two types of machines, he was not under force. The company's management turned to a people's issue with a request to transfer A-20 to another plant, and while tankostroitelny Division prepared the working drawings and upgraded the tank, reinforcing its chassis and making a few other smaller improvements. Work on the wheel-tracked tank continued until the summer of 1940, in accordance with the list of required experimental work at the plant № 183 ", but in June the fate of the A-20 was finally resolved. Manufacture initial batch did not take place as the undisputed then considered the favorite A-34, later renamed T-34. Once unclaimed A-20 remained at the training ground near Moscow, where about him remembered during the war.

I must say that the combat use of the A-20 was of rather forced, though this tank proved to be their best. In October 1941, when the Germans came on near the approaches to Moscow, from the reserve began to pull the whole battle-worthy technique. They came, and A-20. The tank was included in a separate company, was formed from the machines at the disposal of the landfill NIBT. Commanded a company captain Semenov. This tanker fate evolved extraordinary. Semenov, participated in the Spanish Civil War and upon his return he was invited to that same meeting May 4, 1938, which solved the problem of selecting a new tank for the Red Army. War, he met a Volkovysk, then commanding the tank battalion formed part of the 6 th Panzer Corps. After losing to the beginning of July all the techniques Semenov got out of the encirclement and was appointed commander of the battalion's newly formed 22 th Tank Brigade, where the A-20. In addition to his team possessed tanks T-34 and BT, so that the "twenty" the chance to compete in combat with the "younger" and "older" model. The brigade participated in the attack on the direction of Moscow, in the area Pavlovskaya Sloboda. Unfortunately, detailed information about its actions have not been able to find, but it is known that on December 1 A-20 tank was destroyed and sent to the rear for repairs. Three days later, he re-entered service and was listed in the 22 th Brigade until mid-December, supporting cavalry Dovatora. Here the tank was again damaged and evacuated to the rear. What happened to him on - history is silent.