SU-152 Heavy self-propelled artillery mount

During the Great Patirotic War, there were two self-propelled guns with a caliber of 152 mm - SU-152 and ISU-152 . Outwardly, they are perhaps not readily distinguishable. The most important difference between the two self-propelled guns is their base , which, despite the external similarities, had a lot of differences. Su-152 was built on the basis of the Soviet heavy tank KV-1C. The ISU-152 was built on the basis of the IS-2 tank. Both self-propelled guns were armed with a 152-mm howitzer ML-20s. ISU-152 had better armor and more rational angles of inclination of armor plates. The gun mount in the ISU-152 is taller than the SU-152, and is not as forward mounted.

The appearance of new heavy tanks Pz.VI Ausf.H “Tiger” on the Soviet-German front in September 1942 in some way took the Soviet command by surprise. Up to this point, it was believed that Germany would increase the production of modified Pz.VI medium tanks, and heavy-class vehicles could appear in service before 1943. The strike was more painful also because the Soviet anti-tank artillery was practically powerless against the thick frontal armor of the “tiger”. The most common army guns ZiS-2 (57 mm) and ZiS-3 (76.2 mm) could successfully deal with heavy tanks only at extremely close distances, not exceeding 300-500 meters, and 45 mm guns could penetrate the side the armor of the “Tiger” except at point blank range. Much better performance could be achieved by using howitzer guns of the ML-20 or M-30 type.

However, a few months before this moment (in March 1942), the designers G.N. Rybin and K.N. Ilyin developed the self-propelled gun U-18, based on the design of the heavy assault tank KV-7. Then, abandoning the idea of a multi-gun installation, the possibility of replacing it with one ML-20 howitzer was calculated. A U-18 prototype was even built, but it did not receive approval from the military.

The installation of a 152.4-mm gun on a tank chassis was remembered only in the autumn of 1942, when the situation on critical front sections was more or less stabilized. Actually, then the specialization “destroyer of pillboxes” faded into the background. The first priority was the fight against German heavy tanks such as the Pz.V “Panther” and the Pz.VI “Tiger”. As mentioned earlier, shooting at captured tanks showed the insufficient effectiveness of existing anti-tank weapons. At the same time, the Soviet side did not have artillery systems, like the German PaK43 or PaK43 \ 41 88-mm caliber, which had high power.

The way out of this situation was seen only in increasing the caliber, but this inevitably entailed a decrease in the initial velocity of the projectile and a deterioration in its armor penetration. The calculation was made on that even if the shell does not penetrate the frontal armor of the same “tiger”, it will inflict enormous damage to less protected parts or as a result of a dynamic strike, the crew of the enemy machine will be shell-shocked and will not be able to continue the battle. Similar conclusions were drawn on the basis of the combat use of large-caliber guns, and not only from the Soviet side. However, a much bigger problem was the lack of reliable armor-piercing and cumulative shells, which appeared in sufficient numbers only at the end of the war.

After reviewing the NKTP project, it was concluded that the installation of a large-caliber gun on the chassis of the KV-1s tank was quite advisable, but then it was decided to design the self-propelled guns on a competitive basis. For discussion on January 2, 1943, three self-propelled gun projects were submitted. The Uralmash variant, brought to Chelyabinsk by the chief designer F.F. Petrov, retained all the tank units on the proposed chassis, but provided for the modernization of the gun itself, which required additional time. The second project, proposed by L.S. Troyanov, kept the artillery system unchanged, but required an extension of the hull taken from the serial heavy tank KV-1C.

According to the third draft put forward by J. Ya. Kotin already at the time of discussion, the swinging part of the ML-20 152-mm howitzer guns was mounted practically unchanged in the frame and, together with the ammunition and crew, were placed in a specially designed conning tower on the KV tank chassis. The design of the artillery system practically did not change, with the exception of a slight revision of recoil devices and the location of the trunnions of the gun. Such a technique made it possible to reduce recoil force during firing and to reduce the length of the cradle, on which a reinforced clip with pins was mounted. In this case, the armor shield, in addition to protection from shells, also served as a balancing element.

The selection committee chose the Kotin option, not taking into account the objections of F.F. Petrov, who insisted on the completion of the gun. The arguments of the “gunners” were more than weighty - first of all, it was necessary to increase the initial velocity of the projectile, which was only 600 m / s, to modernize recoil devices and, in general, to make the ML-20S more acceptable for installation on a tank chassis. At the same time D.F. All this led to several major miscalculations in the design of self-propelled guns, originally designated as KV-14 . Self-propelled installation, with the exception of the new conning tower, did not differ much from the serial KV-1s.

The chassis of the self-propelled guns consisted of 6 dual track rollers on each side with a torsion bar suspension, 3 support rollers, a front guide and a rear drive wheel. The track tension mechanism was helical and for each track consisted of 86-90 single-ridge tracks 608 mm wide and 160 mm pitch. A four-stroke V-shaped 12-cylinder diesel engine V-2K with a capacity of 600 hp was installed on the KV-14. The engine was started by two SMT-4628 starters with a power of 6 hp. each or with compressed air from two tanks with a capacity of 5 liters in the fighting compartment of the machine.

The self-propelled guns had a tight layout, in which the main fuel tanks with a volume of 600 and 615 liters were located both in the combat and in the engine-transmission compartment. The armored body of the self-propelled gun was welded from rolled armored plates 75, 60, 30 and 20 mm thick, and the vertical frontal plates of the conning tower had rational angles of inclination. The gun was mounted in a frame-type installation to the right of the center line of the machine. ML-20C anti-recoil devices were protected by a fixed cast armored casing and a movable cast spherical armored mask. The crew embarked and exited through a rectangular double-wing hatch at the junction of the roof and rear sheets of the armored cabin and through a round hatch to the right of the gun. The round hatch to the left of the gun was not intended for the crew to enter and exit; it was required to bring out the extension of the panoramic sight. The hull also had a bottom hatch for emergency leaving the self-propelled crew and a number of small hatches for loading the ammunition, and access to the necks of the fuel tanks.

Among the serial Soviet self-propelled artillery mounts of the first generation, the SU-152 occupies a somewhat isolated place - as the most successful multi-purpose machine suitable for all its tasks. Other self-propelled guns - SU-76 , SU-122 and SU-85 - only partially met their expectations. It turned out to be very difficult to use SU-122 against tanks due to the low persistence of the fire of its guns; the fire power of the SU-76 and SU-85 for unarmored targets was in some cases insufficient, in addition, the SU-76 of the first modifications were equipped with an unsuccessful power plant, which forced it to be radically reworked subsequently.

Due to the combination of mobility and great firepower, the SU-152 was used both as an assault gun , and as a tank destroyer, and as self-propelled howitzers . However, the low rate of fire of the gun due to the large mass of shells significantly reduced the quality of the machine as a tank destroyer, and the small elevation angle together with the closed fighting compartment did not favor the use of the SU-152 for firing from closed positions. To these shortcomings, which were caused by the armament and layout of the machine, the SU-152 had a number of its own - the lack of forced ventilation of the fighting compartment (especially manifested when the engine was turned off, there were even cases of crews burning during firing) and a defensive machine gun, insufficient frontal armor for 1943, a close fighting compartment. Almost all of the SU-152’s own shortcomings were managed, if not eliminated, at least to smooth out the ISU-152’s successor while maintaining the main armament and layout of the vehicle, which were found to be adequate not only for World War II, but also after the war.

Among foreign vehicles, the SU-152 did not have direct and close-in-time counterparts in its mass category. Armed with long-barreled guns of caliber 150-155 mm, the German self-propelled guns Hummel (Hummel) and the American Gun Motor Carriage M12 were lightly armored self-propelled howitzers with semi-open or open installation of main armament based on medium tanks and, unlike the SU- 152, failed at the first close explosion of a heavy high-explosive fragmentation shell, and therefore were much more vulnerable to artillery fire and counter-battery fire . German self-propelled guns armed with 88 mm guns StuK 43 based on the heavy tanks Ferdinand and Jagdpanther were specialized tank destroyers (the first also had one of its official designations as an "assault gun" and more than one and a half times exceeded the SU-152 in mass). The penetration of their guns and frontal armor protection significantly exceeded these parameters in the SU-152, but the high-explosive fragmentation shell was significantly weaker.

A total of 670 such machines were produced.