Anti-tank capabilities and service of 76-85 mm Soviet self-propelled guns after the end of World War II
At the final stage of World War II, the Red Army had self-propelled artillery 76, 85, 100, 122 and 152 mm caliber installations. Not all of them were optimal for anti-tank combat, but when enemy armored vehicles appeared within range of their guns, all Soviet self-propelled guns fired at them, for which purpose they had armor-piercing shells in their ammunition. However, self-propelled guns with 122-152 mm guns also demonstrated good results when using high-explosive fragmentation shells. In addition to domestically produced vehicles, captured German self-propelled guns with high-power 75-150 mm caliber guns were used during the war and in the first post-war years.
Initially, I planned to consider in one publication all Soviet self-propelled guns and captured German installations that were in the troops in the first post-war years. But the amount of information turned out to be too significant for one article, and today we will talk about 76-85-mm self-propelled guns that remained in service by 1946.
SU-76M
During the fighting, a need emerged for light self-propelled artillery units capable of supporting infantry units with fire, moving at a distance of 500-600 meters behind the advancing troops. These self-propelled guns were supposed to suppress firing points, destroy fortifications and destroy enemy infantry with their guns. Using German terminology, a typical "artsturm" was needed, capable of effectively firing mainly at visually observed targets. At the same time, the crew had to be provided with protection from small arms fire. weapons and splinters.
This placed different demands on self-propelled guns of this class compared to tanksThe armor of the self-propelled gun for direct artillery support could be thinner, which, while maintaining a sufficiently powerful gun, allowed for a reduction in production costs and made such a self-propelled gun relatively light and mass-produced.
At the end of 1942, deliveries of the SU-76 self-propelled gun began. This vehicle was created on the chassis of the T-70 light tank. Due to the need to accommodate a fairly large gun, the tank hull had to be lengthened, and then the length of the chassis increased. The self-propelled gun had an individual torsion bar suspension for each of the 6 small-diameter road wheels on each side. The engine, transmission and fuel tank were located in the front part of the armored hull of the vehicle. The SU-76 was driven by a model 15 power plant, consisting of two 6-cylinder GAZ-202 carburetor engines with a total capacity of 140 hp. The capacity of the fuel tanks was 320 liters, the vehicle's cruising range on the highway reached 250 km. The maximum speed on the highway was up to 41 km / h. The mass in combat position is 11,2 tons. The thickness of the armor in the frontal projection was 26-35 mm, the side and rear - 10-15 mm. The first serial modification also had an armored 6-mm roof.
The SU-76 was armed with a 76 mm ZIS-ZSh (SH — assault) gun, a specially developed version of the divisional gun for the self-propelled gun. The vertical aiming angles ranged from -3° to +25°, the horizontal firing sector was 30°. The vertical aiming angle made it possible to reach the firing range of the ZIS-3 divisional gun, i.e. 13 km, and to fire at the upper floors of buildings during combat operations in the city. When firing direct fire, the standard sight of the ZIS-Z gun was used, and when firing from closed firing positions, a panoramic sight was used. The combat rate of fire did not exceed 12 rounds/min. Ammunition — 60 rounds.
In off-road conditions, the SU-76 demonstrated good mobility and cross-country ability. The gun's firepower allowed it to effectively destroy light field fortifications, destroy concentrations of manpower, and, in favorable conditions, fight enemy armored vehicles. Relatively light self-propelled guns were capable of operating where heavier vehicles could not be used: in mountainous, wooded, or swampy terrain. Due to the significant gun elevation angle for a self-propelled gun, the sufficiently maneuverable and shrapnel-protected mounts could fire from closed positions with an efficiency no worse than that of towed divisional guns.
However, the first serial SU-76s, despite all their potential advantages, showed themselves unsatisfactorily at the front. The reason for this was the extremely low technical reliability, and due to poor ventilation, the crew suffocated from gunpowder gases when firing. There was a mass failure of transmission and engine components, which occurred due to erroneous technical solutions incorporated during the design and due to the unsatisfactory quality of the parts. To eliminate the main problems that led to mass breakdowns, serial production was temporarily stopped, and qualified repair teams were sent to the front-line workshops engaged in the restoration of the SU-76. Before stopping serial production, the military accepted 608 SU-76s, of which there were none left at the front by the beginning of 1944.
After analyzing the causes of technical failures, a modernized version was developed. In addition to improving the quality of serial machines, changes were made to the design of the engine-transmission group and chassis to increase reliability and increase the service life. The self-propelled unit with an engine-transmission group borrowed from the T-70B light tank is known as the SU-76M.
The protection of the frontal projection and sides of the SU-76M remained the same as on the first version, but the armored roof of the fighting compartment was abandoned. This reduced the weight of the self-propelled gun from 11,2 to 10,5 tons, which reduced the load on the engine and chassis. The transition to an open-top fighting compartment solved the problem of poor ventilation and improved the visibility of the battlefield. In the marching position, the fighting compartment was covered with a tarpaulin to protect it from road dust and precipitation. For self-defense against enemy infantry and aviation The 7,62 mm DT-29 machine gun was introduced, mounted on a folding bracket inside the fighting compartment to the right of the gun or for firing at anti-aircraft targets on a bracket located on a pipe welded to the rear of the fighting compartment from above, as well as to the right and left sides.
Its compact size and low specific ground pressure (0,545 kgf/cm²) allowed it to accompany infantry where medium tanks could not move. The SU-76M could overcome a trench up to 2 m wide, a slope of up to 30° and force a ford up to 0,9 m deep.
By the end of World War II, more than 11 SU-000Ms had entered service, and a total of more than 76 units had been produced by the end of 1945. In 13, when the production of armored weapons in the USSR reached its peak, the production of SU-000Ms quantitatively amounted to about 1944% of the total production of armored weapons and equipment. Several dozen self-propelled artillery regiments were armed with these light self-propelled guns. From the first half of 76, self-propelled artillery divisions were formed (each initially had 25, and later 1944 SU-12Ms), which replaced fighter-anti-tank divisions in rifle divisions. At the same time, they began to form light self-propelled artillery brigades of the RVGK (16 SU-76M, five T-64M and three M76A70 Scout Car armored vehicles). By the end of the war, the Red Army had 3 light self-propelled artillery regiments and 1 self-propelled artillery brigades.
At the time of its appearance, the SU-76M was a quite successful vehicle, demonstrating good efficiency when used correctly. However, many commanders of tank and combined arms units often sent lightly armored self-propelled guns along with medium and heavy tanks in suicidal frontal attacks. A negative role was played by the fact that the self-propelled gun crews were staffed with former tankers who had no idea about the tactics of self-propelled artillery. All this led to unjustified losses. The driver-mechanic was exposed to the greatest risk of the crew members, whose workplace was located next to the fuel tank, and if hit by a shell, he sometimes burned alive.
At the first stage of combat use, the self-propelled gun was not popular among the troops and earned many unflattering nicknames. But when used correctly, the SU-76M fully justified itself and was a very good alternative to the towed divisional gun ZIS-3. As experience was accumulated, the effectiveness of the light self-propelled guns increased.
In an offensive, the SU-76M could be very useful, supporting the attack of tanks, being behind their battle formations and firing mainly from behind cover at the enemy's anti-tank artillery, tanks and manpower, as well as covering the flanks. In defense, a self-propelled artillery battalion armed with the SU-76M was primarily considered as an anti-tank reserve and a means of increasing the combat stability of infantry units. As a rule, the vehicles were placed in pre-equipped positions behind the infantry battle formations or were used as traveling guns. Also, a self-propelled battalion could be used to cover the most likely directions of action of enemy tank units, in which case actions from ambushes were envisaged.
As for the anti-tank capabilities of the SU-76M, much depended on the tactics of use, the level of training of the crew and the tactical literacy of the commander. The use of such strong qualities of the SU-76M as good mobility and high cross-country ability on soft soils, camouflage taking into account the terrain, as well as maneuvering from one shelter to another, often made it possible to achieve victory over enemy tanks.
The armor penetration of the self-propelled 76-mm gun did not differ from the towed ZIS-3. According to reference data, the blunt-nosed armor-piercing projectile 53-BR-350A at a range of 300 m along the normal could penetrate 73-mm armor, at an angle of 60° at the same distance the armor penetration was 60 mm. Thus, the 76-mm gun mounted on the SU-76M could confidently overcome the side armor of the "fours" and "Panthers".
Firing cumulative shells used in regimental guns was strictly prohibited due to the unreliable operation of fuses and the risk of rupture in the barrel when firing from 76-mm divisional and tank guns. Claims that cumulative shells appeared in the ZIS-3 ammunition supply at the end of 1944 are not true.
Operating from a minimum range ambush, with 53-BR-354P sub-caliber projectiles in the ammunition load, the SU-76M crew had a good chance of hitting a German heavy tank. This projectile weighing 3,02 kg had an initial velocity of 950 m/s and was capable of penetrating 300 mm of armor at a distance of 102 m at normal angles. At a distance of 500 m, armor penetration was 87 mm. However, it is worth saying that sub-caliber projectiles were primarily sent to fighter-anti-tank divisions. If they were in the SU-76M ammunition load, then in very limited quantities and were under special control.
There are examples of successful use of 76-mm self-propelled guns against medium and heavy enemy tanks. Thus, on January 14, 1945, 4 SU-76M from the 1897th SAP, during a battle in the vicinity of the village of Lertseghalat, while in ambush behind a railway embankment, allowed nine German Pz.Kpfw. V Panther tanks to approach to a distance of 250-300 m, after which they burned 6 vehicles and knocked out 3 by shooting at the sides.
At the same time, at the final stage of the war, the importance of the SU-76M as an anti-tank weapon decreased. By that time, our troops were already sufficiently saturated with specialized towed anti-tank guns and more effective tank destroyers, and enemy tanks on the battlefield became a rarity. In addition to fire support, self-propelled guns were used as tractors, for the transfer of cargo, infantry and the evacuation of the wounded in off-road conditions.
After the end of World War II, the Su-76M continued to be actively used, and in the first post-war decade, they even tried to modernize them. In November 1947, 5851 machines were listed in combat units.
To increase the capability to destroy armored targets, the ammunition load included shots with modernized BP-350M cumulative projectiles, which finally received reliable and safe fuses. Such a projectile weighing 3,94 kg at an angle of impact of 60° could penetrate armor up to 75 mm thick. The BR-354N subcaliber projectile weighing 3,02 kg had an initial velocity of 950 m/s and at a distance of 500 m at normal penetrated 125 mm armor. In 1955, production of cumulative non-rotating BK-354M projectiles with increased armor penetration began, but by that time the SU-76M was already at the end of its career.
In 1950, the Molotov Gorky Automobile Plant began production of model 15A power units designed for installation on SU-76M self-propelled artillery units during their major repairs. This power unit consisted of two GAZ-51 engines connected in series by a flexible coupling. The GAZ-51 engine was a modernized GAZ-11 engine, which was manufactured by the Molotov Gorky Automobile Plant for paired units of model 15 (GAZ-203) during the Great Patriotic War. After modernization, the total power of the power unit reached 170 hp, but to increase the service life in peacetime, the maximum speed was limited to 30 km/h.
By the end of the 1940s, the SU-76M no longer fully met the modern requirements of this type of installation, but was still capable of providing fire support to infantry and fighting armored vehicles. Although it mainly posed a threat to lightly armored vehicles, of which the former allies had many.
The mass write-off of SU-76M in the Soviet Army began in the late 1950s, but some of the vehicles survived until the first half of the 1960s.
In the 1950s, 76mm guns were removed from some self-propelled guns, and until the troops were saturated with specialized vehicles, they were used as armored personnel carriers and light artillery tractors.
SU-76M took part in combat operations on the Korean Peninsula. According to reference data, the DPRK troops received 132 self-propelled guns.
US servicemen inspect a Su-76M that was shot down in Korea
Until the end of the 76s, the SU-1960M self-propelled guns were in service in the armed forces of the states that were part of the Warsaw Pact and in Yugoslavia. In Albania, they were in service until 1994.
SU-85
By 1943, the protection and firepower of enemy tanks and assault guns had increased significantly. Although the Germans had few Pz.Kpfw. VI Ausf.H Tiger heavy tanks, and they did not have a significant impact on the course of military operations on the Eastern Front, new modifications of the Pz.Kpfw. IV medium tanks with thick frontal armor, armed with long-barreled 75-mm guns, as well as modernized StuG.III and StuG.IV tank destroyers with new guns and enhanced protection appeared en masse.
Thus, the German tank Pz.Kpfw. IV Ausf.G, protected by 80 mm frontal armor, was armed with a 1943 mm Kw.K.75 L/40 cannon since the spring of 48. An armor-piercing shell fired from it was capable of penetrating 1000 mm of armor at a distance of 85 m. Thus, the new German medium tanks in 1943 had a significant advantage over Soviet tanks in terms of armor penetration of their guns, and in terms of the level of protection in the frontal projection they approached heavy tanks.
The strengthening of the armor protection and artillery armament of enemy tanks required our response. One of the measures aimed at compensating for the emerging qualitative superiority of the Panzerwaffe was the development in the USSR of a tank destroyer armed with an 85-mm D-5S-85 cannon.
The self-propelled gun, designated SU-85, was created on the basis of the SU-122 (with a 122-mm M-30S howitzer), which was produced at the Ural Heavy Machinery Plant (UZTM) in Sverdlovsk.
The 85-mm gun with the ballistics of the 53-K anti-aircraft gun had good capabilities for fighting armored vehicles. The barrel length of the D-5S-85 was 48,8 calibers, the direct fire range reached 3,8 km. The maximum firing range of a fragmentation grenade was 12,7 km. The vertical aiming angles were from -5 ° to +25 °, the horizontal firing sector was ±10 °. The combat rate of fire was 5-6 rounds / min, the maximum - up to 8 rounds / min. The ammunition load of 48 unitary rounds, in addition to fragmentation shells, included armor-piercing caliber: 53-BR-365 (blunt-headed) and BR-365K (sharp-headed) weighing 9,2 kg, as well as a 53-BR-365P spool-type sub-caliber projectile weighing 5 kg. According to reference data, the 53-BR-365 armor-piercing projectile with an initial velocity of 792 m/s at a distance of 1000 m at a normal angle could penetrate a 102-mm armor plate. The 53-BR-365P sub-caliber projectile with an initial velocity of 1050 m/s at a distance of 500 m when hitting at a right angle overcame armor protection 140 mm thick. Thus, the SU-85 was capable of effectively fighting enemy medium tanks at distances of more than a kilometer, and at shorter distances, penetrating the frontal armor of heavy tanks.
During serial production, tank destroyers were also equipped with D-5S-85A guns. This modification differed in the barrel manufacturing method and breech block design, as well as the weight of the swinging parts: 1230 kg for the D-5S-85 and 1370 kg for the D-5S-85A. Self-propelled guns armed with D-5S-85A guns were designated SU-85A, but the SU-85 and SU-85A had no external differences.
In terms of mobility and protection, the SU-85 was roughly equivalent to the T-34 medium tank of 1942. In combat position, the vehicle weighed 29,6 tons. The thickness of the frontal armor, inclined at an angle of 50°, was 45 mm. The sides and rear were also 45 mm thick. The gun was covered by a 60 mm mask. Maximum road speed was 47 km/h. Cruising range was up to 400 km.
When driving in the city, wooded or very rugged terrain, the driver had to be especially careful, since when turning there was a higher probability of catching the long trunk on a building or tree, as well as scooping up soil on a steep descent.
The crew of the self-propelled gun consisted of 4 people, located in the fighting compartment, combined with the control compartment. The crew boarded and disembarked the self-propelled gun through the driver's hatch and a double-leaf hatch located in the rear part of the roof and the rear plate of the cabin hull. Based on combat experience, when designing the SU-85, the designers paid special attention to ensuring the proper level of visibility and command control. On the right side of the cabin roof was a commander's cupola without an entrance hatch, which served the self-propelled gun commander for observing the terrain and adjusting fire.
The SU-85 used units and assemblies that had been well tested on the T-34 tanks and the SU-122 self-propelled guns, and the reliability of the vehicle was quite satisfactory. The first batch of self-propelled guns had manufacturing defects, but after mass assembly began and the identified deficiencies were eliminated, there were no particular complaints about the quality of production. In 1944, the front rollers were reinforced, which increased their service life.
According to the initial staffing table, medium self-propelled artillery regiments were supposed to have 16 self-propelled guns (4 batteries with 4 SU-85s each) and one T-34 commander's vehicle. A BA-64 light armored car was available for communications. In February 1944, all regiments were transferred to a new staffing table, according to which the SAP had 21 vehicles: 4 batteries with 5 units and 1 self-propelled gun for the regiment commander. In addition, the regiment received a company of machine gunners and a platoon of sappers. Self-propelled regiments of SU-85s were introduced into tank, mechanized, and cavalry corps and were intended to provide fire support and increase anti-tank capabilities. Self-propelled guns were also used in fighter anti-tank artillery brigades as a mobile reserve.
The SU-85 received a positive assessment from the troops. The self-propelled guns entered combat in the fall of 1943 and performed well in the battles for left-bank Ukraine. But in fairness, it should be said that the installations armed with 85-mm guns were at least six months late. The use of these machines in the summer of 1943 could have had a serious impact on the course of military operations and reduced our losses.
In direct confrontation with enemy tanks, much depended on the skills and coordinated actions of the crew. The horizontal aiming sector of the gun was small, and the driver-mechanic took direct part in the process of aiming the mount at the target. The working conditions in the SU-85 fighting compartment were better than in the turret of the T-34-85 tank, which was also armed with an 85-mm gun. The presence of a more spacious cabin and convenient access to the ammunition stowage had a positive effect on the practical rate of fire and accuracy of fire. At the same time, the crews of the self-propelled guns complained that prolonged shooting at maximum speed was difficult due to poor ventilation.
At the time the SU-85 SPGs appeared on the front, their 45 mm hull and cabin armor no longer provided adequate protection from the enemy's 75 mm long-barreled guns. The German 7,5 cm KwK 40 L/48 tank gun confidently penetrated the frontal armor of the Soviet SPG from a distance of 1500 m. However, due to the SPG's low silhouette, it was more difficult to hit it than a tank, and the SU-85 had a good chance of defeating the "Four" in a duel. Successful combat with the PzKpfw. V and Pz.Kpfw. VI heavy tanks was possible with the right tactics. Crews of Soviet 85 mm SPGs repeatedly destroyed Tigers and Panthers without losses, operating from ambushes. During real combat clashes with German heavy tanks, it was established that the 85-mm gun penetrates the frontal armor of the Tiger from a distance of 600-800 m, and its side from 1000-1200 m, which generally corresponds to the data obtained at the proving ground.
The SU-85 suffered its main losses when the self-propelled guns, intended to strengthen anti-tank defenses, were used as line tanks by tactically illiterate infantry commanders, throwing them into attacks on well-fortified enemy defenses and minefields.
After the SU-85-equipped SAPs suffered heavy losses in the late autumn of 1944, the General Headquarters issued orders prohibiting the use of SPGs as tanks. In addition, it prohibited the use of self-propelled artillery regiments, which were part of the fighter-anti-tank brigades, to accompany tanks and infantry in isolation from the rest of the brigade units.
In terms of the power of the 85-mm fragmentation grenade O-365K weighing 9,54 kg, it was slightly superior to the 76-mm projectile, but still, when conducting offensive actions, the power of this ammunition was often insufficient for the reliable destruction of long-term firing points and buildings. Considering that T-34-85 tanks armed with an 85-mm cannon went into production, and mass production of better protected self-propelled guns armed with 100, 122 and 152-mm guns began, the production of the SU-85 was curtailed. In total, from August 1943 to 1944, the military accepted 2315 vehicles.
When talking about the SU-85 self-propelled gun, it is impossible not to mention the SU-85M, which was a transition to the SU-100. This vehicle had a new cabin with 75 mm thick frontal armor and was 2 tons heavier. The appearance of the SU-85 was caused by the fact that the enterprise that produced the 100 mm D-10S cannon did not keep up with the production of armored hulls, in addition, at the time of the creation of the SU-100, the required number of 100 mm rounds was not available.
Self-propelled artillery unit SU-85M from the 13th SAP of the Polish Army
From September to November 1944, 315 SU-85M self-propelled guns were produced, some of which were used in the Polish Army until the mid-1950s.
Currently, the only surviving example of the SU-85M is on display in the armored vehicle museum in Poznan.
At the end of World War II, the Red Army had about 600 SU-85 and SU-85M self-propelled artillery units. But unlike the light SU-76M self-propelled guns, their service in artillery regiments was short-lived. In the active army, the 85-mm self-propelled guns of military production were replaced by the new SU-1940 by the end of the 100s, which had more powerful weapons and better protection.
Most of the decommissioned SU-85s were stripped of their metal parts, after having been dismantled of the components and parts that could be used on T-34-85 tanks. Several dozen disarmed vehicles were used to train driver-mechanics until the mid-1950s. Some of the least worn-out SPGs were simultaneously converted into tractors and armored repair and recovery vehicles during major repairs. During the conversion, an armor plate was welded in place of the dismantled gun, and winches and cranes were installed on the vehicles. The space freed up inside the armored cabin made it possible to place additional repairmen, tools, and welding equipment. In this form, some converted SPGs survived until the early 1970s.
To be continued ...
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