The need for the creation and development of self-propelled artillery was determined by the views of Soviet military science in the 1930s. Their essence boiled down to the fact that in order to conduct successful hostilities, tank and mechanized formations of the Red Army may need to increase firepower. Since towed artillery is significantly inferior in mobility to tanks, self-propelled artillery should have increased the firepower of the units. In accordance with these views, the USSR began to create small, light and heavy self-propelled guns. Self-propelled units, designated SU-5, were part of the so-called "small triplex". This term referred to the self-propelled guns of incomplete booking, created on the basis of the light tank T-26 and representing a universal self-propelled gun carriage, on the basis of which it was possible to place 3 guns: SU-5-1 - 76-mm divisional gun mod. 1902/30, SU-5-2 - 122 mm howitzer mod. 1910/30 g, SU-5-3 - 152-mm divisional mortar mod. 1931 g.
According to the theory widespread at that time, the presence of this triplex could fully cover the entire existing range of tasks of the army at the divisional level. For the development of all three systems, the Design Bureau of the Experimental Mechanical Engineering Plant named after V. I. Kirov (plant No. 185) under the leadership of P. N. Syachentov and S. A. Ginzburg. V. Moskvin was appointed the responsible designer of this project.
Design features
The light tank T-26 mod. 1933, the production of which was established in Leningrad. Due to the fact that the existing tank layout was completely unsuitable for an ACS, the T-26 hull was significantly redesigned.
SU-5-1
The control compartment, together with the ACS controls, the driver's seat, as well as the transmission elements, remained in place in the nose of the car. But the engine compartment had to be moved to the center of the hull, separating it from the rest of the self-propelled gun compartments with armored partitions. In the engine compartment, a standard gasoline engine from a T-26 tank with a capacity of 90 hp was installed, the main clutch, a shortened propeller shaft, a radiator, a fan, oil and fuel tanks, which were separated by sealed baffles. The engine compartment of the ACS SU-5 was connected by means of a special pocket with side holes, which served to eject cooling air. On the roof of the engine compartment there were 2 hatches for access to candles, a carburetor, valves and an oil filter, as well as openings with armored shutters that served to enter cooling air.
The fighting compartment was in the rear of the vehicle. Here, behind the 15-mm armor shield, the armament of the self-propelled guns and places for the calculation (4 people) were located. To extinguish recoil during firing, a special opener, located in the rear of the machine, was lowered to the ground. In addition, additional side stops could be used.
The chassis has not changed in comparison with the serial T-26 tank. For each of the sides, it consisted of the following components: 8 road wheels, which were assembled into 4 bogies (the first and second / third and fourth bogies had a common suspension with shock absorption on leaf springs), 4 support rollers. The steering wheel is rear, driving is front.
SU-5-2
All three self-propelled guns had a single chassis and differed mainly in the weapons used:
1. The main armament of the ACS SU-5-1 was a 76, 2-mm divisional gun mod. 1902/30 (barrel length 30 caliber). The muzzle velocity is 338 m / s. The vertical pointing angles of the gun ranged from -5 to +60 degrees, horizontal angles in the 30-degree sector, without turning the body of the installation. When firing, the crew used a telescopic sight and a Hertz panorama. The maximum firing range was 8,760 meters with a gun elevation angle of 40 degrees. The rate of fire of the gun was 12 rounds per minute. Shooting was carried out from a place without the use of openers with the loader's floor lowered. The transported ammunition of the self-propelled guns consisted of 8 shots.
2. The main armament of the SU-5-2 self-propelled guns was a 122-mm howitzer model 1910/30. (barrel length 12, 8 caliber), which differed in the modified design of the cradle. The muzzle velocity was 335.3 m / s. The guidance angles in the vertical plane were from 0 to +60 degrees, horizontally - 30 degrees without turning the installation body. When firing, the crew used a telescopic sight and a Hertz panorama. The maximum firing range was 7 680 m. The use of a piston bolt provided a decent rate of fire at the level of 5-6 rounds per minute. Shooting was carried out from a place without the use of openers with the loader's floor lowered. The ammunition carried consisted of 4 rounds and 6 charges.
3. The main armament of ACS SU-5-3 was 152, 4-mm divisional mortar mod. 1931 (barrel length 9, 3 caliber). The initial velocity of the projectile is 250 m / s. The pointing angles in the vertical plane were from 0 to +72 degrees, the pointing angles in the horizontal plane were 12 degrees without turning the installation body. When shooting, the calculation used Hertz's panorama. The maximum firing range was 5,285 meters. The use of a wedge bolt provided a rate of fire of 4-5 rounds per minute at elevation angles up to 30 degrees and 1-1.5 shots at elevation angles over 30 degrees. The ammunition carried consisted of 4 rounds. When firing, 2 openers were used, which were installed outside the aft part of the ACS.
To deliver ammunition to the SU-5 ACS on the battlefield, it was supposed to use a special armored ammunition carrier.
SU-5-3
The combat weight of the ACS SU-5 ranged from 10, 2 to 10, 5 tons, depending on the modifications. The ACS crew consisted of 5 people (driver and 4 crew members). The capacity of the fuel tanks with a volume of 182 liters was enough to cover 170 km. march on the highway.
The fate of the project
Factory tests of all three triplex machines took place from October 1 to December 29, 1935. In total, the self-propelled guns passed: SU-5-1 - 296 km., SU-5-2 - 206 km., SU-5-3 - 189 km., While the last one on November 1, 1935 was sent to the parade in the capital. In addition to the run, the vehicles were tested and the SU-5-1 and SU-5-2 self-propelled guns fired 50 shots each, the SU-5-3 self-propelled guns fired 23 shots.
Based on the results of the tests carried out, the following conclusions were drawn: “ACS are distinguished by tactical mobility, which allows them to move on and off roads, the transition to a combat position for the 76 and 122 mm SU-5 is instant, for the 152-mm version, 2-3 are required. minutes (since shooting involves the use of stops). During the tests, the machine's shortcomings were also identified, which included: insufficient strength of the bracket, which connected the cradle with the trunnion holder, as well as weak tires of the support wheels. All identified defects were of no fundamental importance and were easily eliminated.
According to plans in 1936, it was supposed to make a batch of 30 self-propelled guns SU-5. Moreover, the military preferred the SU-5-2 version with a 122-mm howitzer. They abandoned the SU-5-1 in favor of the AT-1 artillery tank, and for the 152-mm mortar, the SU-5-3 chassis was rather weak. The first 10 production vehicles were ready for the summer of 1936. Two of them were almost immediately sent to the 7th mechanized corps to undergo military trials, which lasted from June 25 to July 20, 1936 and took place in the Luga area. During the tests, the cars went under their own power for 988 and 1014 km. respectively, firing 100 shots each.
According to the results of the conducted military tests, it was established that the SU-5-2 ACS passed the military tests. SU-5-2 were quite mobile and strong during the campaign, possessing sufficient maneuverability and good stability when firing. As a rule, self-propelled guns were used to fire from open positions, acting as escort artillery. When a number of additions are made to their design, these self-propelled guns should preferably be adopted by mechanized formations, as a means of direct artillery support.
The main identified shortcomings of the vehicle were: insufficient ammunition, it was proposed to increase it to 10 shells. It was also proposed to increase the engine power, since the ACS was overloaded and to strengthen the springs. It was proposed to move the muffler to another place, and equip the control compartment with a fan.
Some of these complaints from the military were eliminated during the production of the remaining 20 self-propelled guns, but it was not possible to increase the engine power and strengthen the suspension. A number of the last machines, which were produced in the fall of 1936, also received additional armor plates, which covered the seats of the gun crew from the sides. It was proposed to make changes to the design of the SU-5 ACS and according to the results of military tests, after which to launch their mass production, but instead, in 1937, work on the "small triplex" program was completely curtailed. Perhaps this was due to the arrest of one of the designers P. N. Syachentov.
The already produced self-propelled guns from the first batch entered service with the mechanized corps and individual brigades of the Red Army. In the summer of 1938, these vehicles even took part in hostilities against the Japanese near Lake Hassan. SU-5 operated in the area of Bezymyannaya and Zaozernaya heights as part of artillery batteries from the 2nd mechanized brigade of the Special Far Eastern Army. Due to the short duration of the hostilities, which ended on August 11, 1938, the use of self-propelled guns was very limited. Despite this, the reporting documents indicated that the self-propelled guns provided significant support to the infantry and tanks.
In September 1939, during the "liberation" campaign in Western Belarus and Ukraine, the SU-5 battery, which was part of the 32nd tank brigade, made a 350-km march, but did not participate in military clashes with Polish troops. After this march, one unit was sent to the plant for overhaul.
As of June 1, 1941, the Red Army had 28 SU-5: 8 self-propelled guns in the Western Special and 9 in the Kiev Special Military Districts, 11 on the Far Eastern Front. Of these, only 16 were in good condition. Any information about the use of ACS data in the Great Patriotic War has not yet been found. All of them, most likely, were abandoned due to malfunctions or lost in the first week of fighting.
Performance characteristics: SU-5-2
Weight: 10, 5 tons.
Dimensions:
Length 4, 84 m, width 2, 44 m, height 2, 56 m.
Crew: 5 people.
Reservation: from 6 to 15 mm.
Armament: 122 mm howitzer model 1910/30
Ammunition: up to 10 shots
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
Progress in store: on the highway - 170 km.
