AT-1 (Artillery Tank-1) - according to the classification of tanks of the mid-1930s, it belonged to the class of specially created tanks; according to the modern classification, it would be considered an anti-tank self-propelled artillery installation of 1935. Work on the creation of an artillery support tank based on the T-26, which received the official designation AT-1, began at the plant No. 185 named after. Kirov in 1934. It was assumed that the created tank would replace the T-26-4, the serial production of which the Soviet industry did not manage to establish. The main weapon of the AT-1 was the 76.2 mm PS-3 cannon, designed by P. Syachentov.
This artillery system was designed as a special tank weapon, which was equipped with panoramic and telescopic sights and a foot trigger. In terms of its power, the PS-3 gun was superior to the 76, 2-mm gun mod. 1927, which was installed on T-26-4 tanks. All work on the design of the new AT-1 tank was carried out under the leadership of P. Syachentov, who was the head of the design department for the ACS of the experimental plant No. 185 named after. Kirov. By the spring of 1935, 2 prototypes of this machine were produced.
Design features
ACS AT-1 belonged to the class of closed self-propelled units. The fighting compartment was located in the middle of the vehicle in a protected armored chamber. The main armament of the ACS was the 76, 2-mm PS-3 cannon, which was mounted on a rotating swivel on a pin pedestal. Additional armament was the 7.62 mm DT machine gun, which was installed in a ball mount to the right of the gun. Additionally, the AT-1 could be armed with a second DT machine gun, which could be used by the crew for self-defense. For its installation in the stern and sides of the armored jacket, there were special embrasures, covered with armored deflectors. The ACS crew consisted of 3 people: the driver, who was located in the control compartment on the right in the direction of the vehicle, the observer (who is also the loader), who was in the fighting compartment to the right of the gun, and the artilleryman, who was located to the left of it. In the roof of the cabin there were hatches for embarkation and disembarkation of the self-propelled crew.
The PS-3 cannon could send an armor-piercing projectile at a speed of 520 m / s, had panoramic and telescopic sights, a foot trigger, and could be used both for direct fire and from closed positions. The angles of vertical guidance ranged from -5 to +45 degrees, horizontal guidance - 40 degrees (in both directions) without turning the ACS body. Ammunition included 40 rounds for the cannon and 1827 rounds for machine guns (29 discs).
The armor protection of the self-propelled gun was bulletproof and included rolled armor plates with a thickness of 6, 8 and 15 mm. The armored jacket was made from sheets with a thickness of 6 and 15 mm. The connection of the armored parts of the hull was provided with rivets. The side and stern armor plates of the cabin were made folding on hinges for the possibility of removing powder gases during firing at half their height. In this case, the slit is 0.3 mm. between the flaps and the body of the self-propelled guns did not provide the crew of the vehicle with protection from being hit by lead splashes from bullets.
The chassis, transmission and engine were unchanged from the T-26 tank. The engine was started using an electric starter "MACH-4539" with a capacity of 2.6 hp. (1, 9 kW), or "Scintilla" with a power of 2 hp. (1.47 kW), or using the crank. The ignition systems used the main magneto of the Scintilla, Bosch or ATE VEO type, as well as the starting magneto Scintilla or ATE PSE. The capacity of the fuel tanks of the AT-1 unit was 182 liters, this fuel supply was enough to cover 140 km. when driving on the highway.
The electrical equipment of the AT-1 ACS was manufactured according to a single-wire circuit. The voltage of the internal network was 12 V. Scintilla or GA-4545 generators with a capacity of 190 W and a voltage of 12.5 V and a 6STA-144 battery with a capacity of 144 Ah were used as sources of electricity.
The fate of the project
The first copy of the AT-1 SPG was submitted for testing in April 1935. In terms of its driving characteristics, it did not differ in any way from the serial T-26 tank. Firing tests showed that the rate of fire of the gun without correcting the aiming reaches 12-15 rounds per minute with the greatest firing range of 10, 5 km, instead of the required 8 km. In contrast to the previously tested SU-1 installation, firing while moving was generally successful. At the same time, the shortcomings of the machine were also identified, which did not allow the transfer of the AT-1 for military trials. Regarding the PS-3 gun, the 3rd rank military engineer Sorkin wrote the following in his letter to the People's Commissar of Defense:
According to the results of the tests of the AT-1 ACS, satisfactory operation of the cannon was noted, but for a number of parameters (for example, the inconvenient position of the turning mechanism, the location of the ammunition, etc.), the ACS was not allowed for military tests.
The second copy of the AT-1 self-propelled guns was pursued by the same failures as the first. First of all, they were associated with the work of the artillery installation. In order to "save" their project, the specialists of the Kirovsky plant came up with a proposal to install their own L-7 gun on the ACS. Unlike the PS-3 cannon, this gun was not created from scratch, its prototype was the 76, 2 mm Tarnavsky-Lender system gun, due to which the L-7 gun had ballistics similar to it.
Although the designers claimed that this weapon was superior to all available tank guns, in fact the L-7 also had a fairly large number of shortcomings. An attempt to equip the AT-1 with this weapon did not lead to success due to a number of design features, and it was considered inexpedient to design a new armored car. Comparing all the available data on the ABTU project, it decided to release a small pre-production batch of 10 AT-1 self-propelled guns, which were equipped with PS-3 cannons, as well as an improved chassis. They wanted to use this batch in extended field and military tests.
The production of PS-3 cannons was planned to be established at the Kirov plant, the SPG hulls were to be produced at the Izhora plant, and plant No. 174 was to supply the chassis. At the same time, instead of preparing the car for serial production and addressing the identified shortcomings of the PS-3 artillery system, the Kirovites were actively promoting their designs. After the failure with the L-7 gun, the factory offered to try its improved version, which received the designation L-10. However, it was not possible to install this weapon in the AT-1 wheelhouse. The situation was aggravated by the fact that factory # 174 was loaded with the production of serial T-26 tanks, so even the production of 10 chassis for the AT-1 self-propelled guns became an overwhelming task for him.
In 1937, P. Syachentov, the leading self-propelled gun designer at plant No. 185, was declared an "enemy of the people" and repressed. This circumstance was the reason for the termination of work on many projects that he oversaw. Among these projects was the AT-1 ACS, although the Izhora plant had already produced 8 armored hulls by that time, and plant No. 174 began assembling the first vehicles.
One of the produced AT-1 corps was used only 3 years later, during the Soviet-Finnish war. In January 1940, at the request of the commanders and soldiers of the 35th Tank Brigade, which was fighting on the Karelian Isthmus, plant No. 174 began work on creating a "sanitary tank", which was intended to evacuate the wounded from the battlefield. This initiative was approved by the head of the ABTU RKKA D. Pavlov. As a base for the creation of the machine, one of the AT-1 corps available at the plant was used, which, on the spot, without any drawings, was converted for the evacuation of the wounded. The plant workers planned to donate a sanitary tank to the tankers for the holiday on February 23, but due to delays in production, the car did not get to the front. After the end of hostilities, the T-26 sanitary tank (as it was called in the factory documents) was sent to the Volga Military District, nothing is known about the further fate of this development.
Summing up, we can say that the AT-1 was the first self-propelled artillery installation in the USSR. For the time when the military was still fond of machine-gun wedges or tanks armed with 37-mm cannons, the AT-1 ACS could justly be considered a very powerful weapon.
Tactical and technical characteristics: AT-1
Weight: 9.6 tons.
Dimensions:
Length 4, 62 m, width 2, 45 m, height 2, 03 m.
Crew: 3 people.
Reservation: from 6 to 15 mm.
Armament: 76, 2-mm cannon PS-3, 7, 62-mm machine gun DT
Ammunition: 40 rounds, 1827 rounds for the machine gun
Engine: in-line 4-cylinder air-cooled carburetor from the T-26 tank with a capacity of 90 hp.
Maximum speed: on the highway - 30 km / h, on rough terrain - 15 km / h.
Progress in store: on the highway - 140 km., On rough terrain - 110 km.
