In the 1930s, attempts were made in the Soviet Union to create self-propelled artillery installations for various purposes, a number of samples were adopted and produced in a small series.
Self-propelled artillery mount SU-12
The first Soviet serial self-propelled gun was the SU-12, first demonstrated at a military parade in 1934. The vehicle was armed with a modified 76, 2-mm regimental cannon mod. 1927, installed on a pedestal. The three-axle American Moreland TX6 truck with two drive axles was originally used as a chassis, and since 1935, the domestic GAZ-AAA.
The installation of the gun on the truck platform made it possible to quickly and inexpensively create an improvised self-propelled gun. The first SU-12 did not have any armor protection at all, but soon after the start of mass production, a 4-mm steel shield was installed to protect the crew from bullets and light fragments. The ammunition load of the gun was 36 shrapnel and fragmentation grenades, armor-piercing shells were not initially provided. Rate of fire: 10-12 rounds / min.
The firing sector was 270 °, the fire from the gun could be fired both backwards and on the side. Theoretically, it was possible to fire on the move, but the accuracy of shooting at the same time dropped sharply, and it was very difficult for the calculation of the "cargo self-propelled gun" to load and direct the gun in motion. The mobility of the SU-12 while driving on the highway was significantly higher than that of the 76, 2-mm horse-drawn regimental guns, but the artillery mount on the truck chassis was not the best solution. The three-axle truck could confidently move only on good roads and, in terms of cross-country ability on soft soils, it was seriously inferior to horse-drawn carriages. Given the high silhouette of the SU-12, the vulnerability of the artillery crew, partially covered by an armored shield, when firing direct fire was very high. In this regard, it was decided to build self-propelled guns on tracked chassis. The last vehicles were delivered to the customer in 1936; a total of 99 SU-12 self-propelled guns were produced.
In the 1920s-1930s, the creation of self-propelled guns based on trucks was a worldwide trend, and this experience in the USSR turned out to be useful. The operation of the SU-12 self-propelled artillery mounts has demonstrated that placing a direct-fire gun on a truck chassis is a dead-end solution.
Self-propelled artillery mount SU-5-2
In the period from 1935 to 1936, the Leningrad Experimental Machine Building Plant No. 185 built 31 SU-5-2 self-propelled artillery mounts on the chassis of a T-26 light tank. ACS SU-5-2 was armed with a 122-mm howitzer mod. 1910/1930 Angles of guidance horizontally 30 °, vertically - from 0 to + 60 °. The maximum initial velocity of a fragmentation projectile is 335 m / s, the maximum firing range is 7680 m, and the rate of fire is up to 5 rounds / min. Transportable ammunition: 4 shells and 6 charges.
The gun crew was covered with armor in the front and partly on the sides. The frontal armor was 15 mm thick, and the sides and stern were 10 mm thick. The curb weight and mobility of the SU-5-2 were at the level of the later modifications of the T-26 tank.
It should be understood that the SU-12 and SU-5-2 self-propelled guns were intended to provide direct fire support for the infantry, and their anti-tank capabilities were very modest. The blunt-headed 76-mm armor-piercing projectile BR-350A had an initial speed of 370 m / s and at a distance of 500 meters along the normal could penetrate 30-mm armor, which made it possible to fight only with light tanks and armored vehicles. The 122-mm howitzers had no armor-piercing shells in the ammunition load, but in 1941 the 53-OF-462 high-explosive fragmentation projectile weighing 21, 76 kg, containing 3, 67 kg of TNT, in the event of a direct hit, it was guaranteed to destroy or permanently disable any German tank … When the shell burst, heavy fragments were formed, capable of penetrating armor up to 20 mm thick at a distance of 2-3 meters. However, due to the short range of a direct shot, a relatively low rate of fire and a modest ammunition load, the calculation of the SU-5-2 self-propelled gun could hope for success in a direct collision with enemy tanks only in the event of an ambush at a distance of up to 300 m. All SU-12 self-propelled artillery mounts and SU-5-2 were lost in the initial period of the war and, due to their small numbers and low combat characteristics, did not affect the course of hostilities.
Heavy assault tank KV-2
Based on the experience of using tanks on the Karelian Isthmus, in February 1940, the KV-2 heavy assault tank was adopted by the Red Army. Formally, due to the presence of a rotating turret, this machine belonged to tanks, but in many ways it is actually an SPG.
The thickness of the frontal and side armor of the KV-2 was 75 mm, and the thickness of the gun mantlet was 110 mm. This made it less vulnerable to 37-50 mm anti-tank guns. However, high security was often devalued by low technical reliability and poor off-road maneuverability. With the power of the V-2K diesel engine 500 h.p. The 52-ton car during tests on the highway was able to accelerate to 34 km / h. On the march, the speed of movement on a good road did not exceed 20 km / h. On rough terrain, the tank moved at a walking speed of 5-7 km / h. The KV-2's passability on soft soils was not very good, and it was not easy to pull out the tank stuck in the mud, so it was necessary to carefully choose the route of movement. Also, not every bridge was able to withstand the KV-2.
The KV-2 was armed with a 152mm tank howitzer mod. 1938/40 (M-10T). The gun had vertical guidance angles: from −3 to + 18 °. When the turret was stationary, the howitzer could be guided in a small horizontal guidance sector, which was typical for self-propelled installations. Ammunition was 36 rounds of separate-case loading. The practical rate of fire with the refinement of the aiming is 1-1, 5 rds / min.
As of June 22, 1941, the KV-2 ammunition contained only OF-530 high-explosive fragmentation grenades weighing 40 kg, containing about 6 kg of TNT. In the course of hostilities, due to the impossibility of manning with standard ammunition, all the shells of the M-10 towed howitzer were used for firing. Used concrete shells, cast iron fragmentation howitzer grenades, incendiary shells and even shrapnel, put on strike. A direct hit from a 152 mm projectile was guaranteed to destroy or disable any German tank. The close explosions of powerful fragmentation and high-explosive fragmentation shells also posed a serious danger to armored vehicles.
Despite the high destructive power of the shells, in practice the KV-2 did not prove itself as an effective anti-tank self-propelled gun. The M-10T gun had a whole set of shortcomings that devalued its effectiveness on the battlefield. If, when firing at stationary enemy firing points and fortifications, a low combat rate of fire was not decisive, then a higher rate of fire was required to combat rapidly moving enemy tanks.
Due to the imbalance of the tower, the standard electric drive rotated the tower in the horizontal plane very slowly. Even with a small angle of inclination of the tank, the turret was often impossible to turn at all. Due to the excessive recoil, the gun could only be fired when the tank came to a complete stop. When firing on the move, there was a high probability of failure of the turret rotation mechanism and the engine-transmission group, and this despite the fact that shooting from the M-10T tank was strictly prohibited at full charge. Naturally, the impossibility of obtaining the maximum initial speed reduced the range of a direct shot. By virtue of all this, the combat effectiveness of the machine, created for offensive combat operations and the destruction of enemy fortifications, when firing direct fire from a distance of several hundred meters, turned out to be low.
Apparently, the main part of the KV-2 was lost not from enemy fire, but due to the lack of fuel and lubricants, engine, transmission and chassis breakdowns. Many cars stuck in the mud were abandoned due to the fact that there were no tractors at hand capable of towing them off-road. Shortly after the start of the war, the production of the KV-2 was phased out. In total, from January 1940 to July 1941, the LKZ managed to build 204 vehicles.
Improvised self-propelled guns on the chassis of a light tank T-26
Thus, it can be stated that on June 22, 1941, in the Red Army, despite a fairly large fleet of armored vehicles, there were no specialized anti-tank self-propelled guns that could be very useful in the initial period of the war. A light tank destroyer could quickly be created on the chassis of early T-26 light tanks. A significant number of such machines, requiring repair, were in the army in the pre-war period. It seemed quite logical to convert hopelessly outdated two-turret tanks with pure machine-gun armament or with a 37-mm cannon in one of the turrets into anti-tank self-propelled guns. The tank destroyer, created on the basis of the T-26, could be armed with a 76, 2-mm divisional or anti-aircraft gun, which would make such a self-propelled gun relevant at least until mid-1942. It is clear that a tank destroyer with bulletproof armor was not intended for a head-on collision with enemy tanks, but it could be quite effective when operating from ambushes. In any case, the armor with a thickness of 13-15 mm provided protection for the crew from bullets and shrapnel, and the self-propelled gun's mobility was higher than that of towed anti-tank and divisional guns of 45-76, 2 mm caliber.
The relevance of a tank destroyer based on the T-26 is confirmed by the fact that in the summer and autumn of 1941, a number of light tanks that suffered damage to the turret or weapons were equipped with 45-mm anti-tank guns with armor shields in tank repair shops. In terms of firepower, the improvised self-propelled guns did not surpass the T-26 tanks with a 45-mm gun, and were inferior in terms of crew protection. But the advantage of such vehicles was a much better view of the battlefield, and even in the conditions of catastrophic losses in the first months of the war, any combat-ready armored vehicles were worth their weight in gold. With competent tactics of using such self-propelled guns in 1941, they could quite successfully fight enemy tanks.
In the period from August 1941 to February 1942 at the plant. Kirov in Leningrad, using the chassis of damaged T-26 tanks, two series of self-propelled guns were produced with a total of 17 units. Self-propelled guns were equipped with a 76-mm regimental gun mod. 1927 The gun had a circular fire, the front crew was covered with an armor shield. On the sides of the gun there were embrasures for two 7.62 mm DT-29 machine guns.
In the process of re-equipment, the turret box was cut off. In place of the fighting compartment, a box-shaped girder was installed, which served as a support for a platform with a curbstone for the rotating part of the 76-mm cannon. Two hatches were cut into the platform deck to access the shell cellar underneath. The vehicles, produced in 1942, also had armor protection on the sides.
In different sources, these self-propelled guns were designated in different ways: T-26-SU, SU-26, but most often SU-76P. Due to the low ballistic characteristics of the regimental gun, the anti-tank potential of these self-propelled guns was very weak. They were mainly used for artillery support for tanks and infantry.
SU-76P, built in 1941, entered the 122nd, 123rd, 124th and 125th tank brigades, and the production of 1942 - into the 220th tank brigade. Usually four self-propelled guns were reduced to a self-propelled artillery battery. At least one SU-76P survived to break the blockade.
Anti-tank SPG ZIS-30
The first anti-tank self-propelled artillery installation, adopted by the Red Army, was the ZIS-30, armed with a 57-mm anti-tank gun mod. 1941 By the standards of 1941, this gun was very powerful, and in the initial period of the war, at real firing distances, it pierced the frontal armor of any German tank. Very often the 57 mm anti-tank gun mod. 1941 g.called ZIS-2, but this is not entirely correct. From the PTO ZIS-2, the production of which began in 1943, the 57-mm gun mod. 1941 differed in a number of details, although in general the design was the same.
The ZIS-30 self-propelled unit was a wartime ersatz, created in a hurry, which affected the combat and service-operational characteristics. By means of minimal design changes, the swinging part of the 57-mm anti-tank gun was installed in the middle upper part of the hull of the T-20 "Komsomolets" light tractor. The vertical guidance angles ranged from -5 to + 25 °, horizontally in the 30 ° sector. The practical rate of fire reached 20 rds / min. For the convenience of the calculation, there were folding panels that increased the area of the working platform. From bullets and shrapnel, the crew of 5 people in battle was protected only by a gun shield. The fire from the cannon could only be fired from the spot. Due to the high center of gravity and strong recoil, the coulters located at the rear of the machine had to be folded back to avoid overturning. For self-defense in the frontal part of the hull there was a 7.62-mm DT-29 machine gun inherited from the Komsomolets tractor.
The thickness of the frontal armor of the T-20 "Komsomolets" tractor hull was 10 mm, the sides and stern - 7 mm. The mass of the ZIS-30 in the firing position was a little more than 4 tons. Carburetor engine with a capacity of 50 hp. could accelerate the car on the highway to 50 km / h. The speed on the march is no more than 30 km / h.
Serial production of the ZIS-30 began in September 1941 at the Gorky Artillery Plant No. 92. According to archival data, 101 tank destroyers with a 57-mm gun were built. These vehicles were used for anti-tank batteries in the tank brigades of the Western and South-Western Fronts (a total of 16 tank brigades). However, there were ZIS-30 in other units as well. For example, in the fall of 1941, four self-propelled guns entered the 38th separate motorcycle regiment.
The production of the ZIS-30 did not last long and was completed in early October 1941. According to the official version, this was due to the absence of the Komsomolets tractors, but even if this was the case, it was possible to put 57-mm guns, very effective in anti-tank terms, on the chassis of light tanks. The most likely reason for the curtailment of the construction of the 57-mm tank destroyer, most likely, was the difficulty in the production of gun barrels. The percentage of rejects in the manufacture of barrels was excessively high, which was completely unacceptable in wartime. It is this, and not the "excess power" of 57-mm anti-tank guns, that explains their insignificant production volumes in 1941 and the subsequent rejection of serial construction. The staff of the plant number 92 and VG Grabin himself, based on the design of the 57-mm gun mod. 1941, it turned out to be easier to set up production of the divisional 76-mm gun, which became widely known as the ZIS-3. The 76-mm divisional gun of the 1942 model (ZIS-3) at the time of creation had quite acceptable armor penetration, while possessing a much more powerful high-explosive fragmentation projectile. This weapon was widespread and popular among the troops. The ZIS-3 was in service not only in divisional artillery, specially modified guns entered service with anti-tank fighter units and were installed on self-propelled gun mounts. The production of 57-mm PTO, after making some changes in the design under the name ZIS-2, was resumed in 1943. This became possible after the receipt of a perfect machine park from the USA, which made it possible to solve the problem with the manufacture of barrels.
Despite the shortcomings, the ZIS-30 received a positive assessment among the troops. The main advantages of the self-propelled gun were its excellent armor penetration and long range of a direct shot. In late 1941 - early 1942, the 57-mm BR-271 projectile weighing 3, 19 kg, leaving the barrel with an initial speed of 990 m / s, could penetrate the frontal armor of German "triplets" and "fours" at a distance of up to 2 km. With the correct use of the 57-mm self-propelled guns, they have proven themselves well not only in defense, but also in the offensive, accompanying Soviet tanks. In this case, the goal for them was not only enemy armored vehicles, but also firing points.
At the same time, there were significant claims to the car. The main problem with the 57 mm gun was its recoil devices. As for the tracked base, here, quite expectedly, the engine was criticized. In snowy off-road conditions, its power was often not enough. In addition, among the shortcomings, a very weak booking of the base chassis and a high vulnerability of the crew during artillery and mortar shelling were indicated. The main part of the ZIS-30 was lost by mid-1942, but the operation of individual vehicles continued until early 1944.
Although our troops in the initial period of the war were in dire need of tank destroyers, the ZIS-30 became the only Soviet tank destroyer brought to the stage of mass production in 1941. In a number of design bureaus, work was carried out to install a 76, 2-mm USV divisional gun on the chassis of a light T-60 tank and an 85-mm anti-aircraft gun 52-K on the chassis of the Voroshilovets heavy artillery tractor. The project of the U-20 tank destroyer on the chassis of a T-34 medium tank with an 85-mm cannon mounted in a rotating three-man turret open from above looked very promising. Unfortunately, for a number of reasons, our troops received a fairly effective anti-tank self-propelled gun SU-85 only in the fall of 1943. This and other Soviet self-propelled guns used during the Second World War will be discussed in the second part of the review.
