In the mid-fifties, the Soviet defense industry temporarily stopped developing new self-propelled artillery installations. The reasons for this decision were associated with numerous technical problems of recent projects, as well as with a change in the concept of development of the ground forces. Nevertheless, literally a couple of years later, the opinion of the command changed, as a result of which a new project for the development of a promising ACS was launched. This model of the armored vehicle became known under the names "Object 120" and "Battering ram".
By the mid-fifties, Soviet scientists and engineers worked out the issue of equipping tanks and other combat vehicles with missile weapons. The missile systems had a very high potential, and therefore, from a certain time, they were considered as a means of completely replacing the existing artillery anti-tank systems. Nevertheless, such projects were notable for their high complexity, because of which their development could be delayed. In this regard, as an aid for missile tanks, it was decided to create a new artillery self-propelled gun with a weapon of increased power.
"Object 120" at the Kubinka Museum. Photo Wikimedia Commons
In May 1957, the Council of Ministers of the USSR issued two decrees, according to which the defense industry was to create several new types of equipment. It is curious that the decree on the development of an armored vehicle with artillery weapons was issued several weeks earlier than a similar document requiring the creation of a missile tank. New research work in the field of self-propelled artillery received the code "Taran".
OKB-3 of the Sverdlovsk "Uralmashzavod" was appointed the lead developer of the promising ACS. The work was to be supervised by G. S. Efimov. The creation of the artillery unit was entrusted to the Perm plant No. 172. These enterprises already had extensive experience in the creation of self-propelled artillery and various weapons, which made it possible to successfully solve all the assigned tasks.
The project of a promising self-propelled gun received the working designation "Object 120", which was used in parallel with the name of the topic. In addition, in some sources the vehicle is designated as SU-152, but such a name can lead to confusion, since the model of the same name was already produced and was in service during the Great Patriotic War.
Until the end of 1957, the necessary research was carried out, the purpose of which was to select the optimal caliber of the gun for the "Taran". Taking into account the current progress in the field of tank armor and weapons, it was decided that systems with a caliber of 130 and 152 mm have the greatest prospects. Were developed two projects of guns M-68 (130 mm) and M-69 (152 mm). In the near future, it was planned to make prototypes of such systems and determine their real capabilities in the conditions of the test site.
SPG layout. Photo Russianarms.ru
In 1958, plant # 172 manufactured experimental barrels, with the help of which it was planned to conduct a new stage of verification. Comparative tests have shown that, despite the significant difference in calibers, the guns surpass each other in some indicators and lose in others. So, the 152-mm gun used a heavier armor-piercing projectile, but accelerated it to lower speeds. The M-68, in turn, was ahead of the heavier system in terms of armor penetration at zero meeting angles, while with an increase in the angle it showed lower performance. In general, from the point of view of technical characteristics, the two guns were equivalent.
The most important advantage of the 152-mm gun M-69 was the proposed range of ammunition. Unlike the smaller caliber system, it could use HEAT shells. High power, gain in some characteristics and the presence of a cumulative shot led to the fact that the M-69 was recommended for use on the "Object 120". Thus, in the end, the 152 mm caliber was chosen.
In parallel with the choice of the weapon, the chassis issue was being addressed. Since the late forties, Uralmashzavod has been working on three promising self-propelled guns, built on the basis of a unified chassis. The latter was based on a number of original ideas and used some new solutions for domestic technology. Nevertheless, the novelty had a negative impact on the course of the project, which is why, even after several years of fine-tuning, the chassis retained a number of serious shortcomings. By the time of the start of the R&D "Taran", two of the three projects were closed, and the development of the SU-100P self-propelled gun was still ongoing, but in order to create a new chassis. It was the modified version of the existing armored vehicle that was proposed to be used in the new project.
The proposed 152-mm gun was distinguished by its large size and made appropriate demands on the fighting compartment. In this regard, it was decided to use not the SU-100P chassis, but its modified version, based on the basic ideas of the closed SU-152P project. In this case, the size problem was solved by lengthening the hull and adding a pair of road wheels. Thus, the new "Object 120" was to be based on a modified and improved seven-wheel chassis.
"Ram" projections. Figure Russianarms.ru
The hull retained the general architecture and layout, but now some reinforcement of armor protection and a certain change in the shape of the units were offered. To increase the level of protection, the thickness of the front plates has been increased to 30 mm. Other elements of the body were 8 mm thick. The armor plates were connected by welding. Riveted joints were not used in the new project. In the frontal part of the hull, the transmission units were still placed, behind which were the control compartment (on the left) and the engine compartment. The aft part of the hull was allocated for the fighting compartment with a full-fledged swivel turret.
Despite some design changes, the body of the "Object 120" was outwardly similar to the existing development. The frontal projection was protected by several inclined sheets placed at different angles to the vertical. The front part of the hull had a sloping roof, equipped with hatches for the driver and for access to the engine compartment. Behind the engine compartment there was a horizontal roof with a shoulder strap for installing the turret. The hull retained vertical sides, on which, however, boxes for property appeared. An interesting feature of the updated hull was the ledge at the top of the stern.
The armament of the new self-propelled gun was supposed to be located in a full-revolving turret, which provided protection for the crew and ammunition from all threats. The use of a cast tower of a relatively complex shape was proposed. The frontal and central parts of the tower had a shape close to hemispherical. A large feed niche was mounted on the back of the main unit, which was necessary to accommodate the packing. On the roof of the tower, at its left side, there was a commander's cupola. There were also hatches and openings for viewing devices or sighting devices.
Self-propelled gun "Taran" retained the power plant and transmission, developed in the framework of the SU-100P project. The engine compartment housed a 400 hp B-105 diesel engine. The engine was mated to a mechanical transmission. It included a dry friction main clutch, a two-way gear and steering mechanism, and two single-stage final drives. Due to its small size, all transmission units were placed in the engine compartment and the front of the hull.
Self-propelled feed: you can consider modifications to the base chassis. Photo Russianarms.ru
The chassis was based on the developments of the SU-152P project, but at the same time it was modified taking into account the experience of the further development of the unified chassis. On each side, with the help of an individual torsion bar suspension, seven double rubberized road wheels were placed. The front and rear pairs of rollers were reinforced with hydraulic shock absorbers. In the front of the hull there were drive wheels, in the stern - guides. Support rollers were installed above the track rollers: four such parts were located at unequal intervals between themselves. A characteristic feature of the "Object 120", as well as of its predecessors, was the use of a track with a rubber-metal hinge. Nevertheless, by the end of the fifties, this was no longer an innovation, since the industry managed to master the production of several models of equipment with such tracks.
The main weapon of the "Taran" was to be the 152-mm rifled gun M-69. This gun had a barrel length of 59.5 caliber with a slotted muzzle brake and an ejector. A semi-automatic wedge gate was used. The gun mount was equipped with hydropneumatic recoil devices, which made it possible to obtain a recoil length of only 300 mm. Horizontal guidance was carried out by turning the entire tower using mechanical drives. Hydraulics were responsible for vertical guidance. There was the possibility of firing targets in any direction with vertical guidance angles from -5 ° to + 15 °. The gunner's workplace had a TSh-22 day sight and a night periscope system that needed illumination. The searchlight was placed next to the gun mantlet.
The M-69 cannon used a separate-case loading and could use several types of ammunition. To defeat manpower and fortifications, high-explosive fragmentation projectiles weighing 43.5 kg were intended, used with propellant charges weighing 10, 7 and 3.5 kg. It was proposed to fight armored vehicles with the help of cumulative and sub-caliber shells. The latter had a mass of 11.5 kg and was fired with a 9.8-kg propellant charge. With an initial speed of 1720 m / s, such an ammunition at a distance of 3500 m could penetrate up to 295 mm of armor. From 1000 m at a meeting angle of 60 °, 179 mm were pierced. Self-propelled gun "Object 120" took on board only 22 separate loading shots. Ammunition was transported in the aft stowage of the turret. In order to simplify the work of the crew, a mechanical rammer was used, and after the shot, the gun automatically returned to the loading angle.
An additional weapon of the new self-propelled gun could be the KPV heavy machine gun. This weapon could be placed on the turret of one of the hatches in the turret roof. In addition, the crew could use small arms and hand grenades for self-defense.
Reconstruction of the appearance of "Object 120". Figure Dogswar.ru
The crew was supposed to consist of four people. In front of the hull, in the control compartment, there was a driver. His workplace retained all the funds provided by previous projects. One had to get into the control compartment through a sunroof. For driving in a combat situation, the driver had a pair of periscopes. The commander, gunner and loader were located in the tower. The commander's seat was to the right of the gun, the gunner's was to the left. The loader was behind them. Access to the fighting compartment was provided by a pair of roof hatches. The crew had at their disposal an intercom and radio station R-113.
The self-propelled artillery unit of the new type turned out to be quite large. The length along the body reached 6, 9 m, the length with the gun forward - about 10 m. The width was 3.1 m, the height was slightly more than 2.8 m. The combat weight was determined at 27 tons. With such parameters, the Taran armored vehicle could reach speeds of more than 60 km / h and overcome 280 km at one refueling. A sufficiently high cross-country ability was provided. Water obstacles had to be overcome by fords.
The development of the Object 120 / Taran project was completed in 1959, after which Uralmashzavod started assembling a prototype. At the very beginning of the next year, Perm gunsmiths made two experimental M-69 guns and sent them to Sverdlovsk. After mounting the guns, the prototype was ready for testing. In the near future, it was planned to check the armored vehicle at the factory range, which is necessary for the subsequent refinement and improvement of technology.
It is known that the experienced "Battering ram" has repeatedly entered the landfill track and traveled a considerable distance along it. In addition, as part of factory tests, several shots were fired at targets. Such checks made it possible to determine the scope of further work and begin to improve the existing design.
Self-propelled gun (highlighted in green) in the museum hall. It is possible to estimate the proportions of the gun without a muzzle brake. Photo Strangernn.livejournal.com
Nevertheless, the refinement of the experimental technique did not last too long. Already on May 30, 1960, the USSR Council of Ministers decided to stop the research work "Taran". This decision was justified by the outlined progress in the artillery and missile areas. By the early sixties, more advanced anti-tank missile systems were created, and in addition, ideas and solutions appeared that made it possible to create smooth-bore guns with high performance. For example, on the basis of new technologies, the 125-mm 2A26 tank gun was soon created, which had certain advantages over the existing M-69. Further development of the 2A26 product led to the emergence of systems of the 2A46 family, which are still in service. There is also a version according to which the rejection of the Taran project was associated with pressure from supporters of missile weapons. Previously, they managed to achieve the rejection of three ACS projects, and the new project could also become their "victim".
One way or another, at the very end of the spring of 1960, work on the "Battering ram" topic was discontinued. No new prototypes were built or tested. A unique and interesting car remained in a single copy. The no longer needed prototype of the Object 120 ACS was later transferred to the Kubinka Armored Museum, where it remains to this day. The use of a long-barreled gun led to interesting consequences. Even after dismantling the large muzzle brake, the self-propelled gun does not fit very well into the existing exhibition hall: the muzzle of the "shortened" barrel reaches the vehicle opposite.
In 1957, two projects of promising anti-tank equipment were launched, one of which involved the construction of an artillery self-propelled gun, and the second - a missile tank. As a result, the Object 120 was constantly compared to the Object 150 / IT-1. Each of the two samples surpassed the competitor in some characteristics, while inferior to him in others. Nevertheless, in the end, the missile tank was considered more perfect and successful, as a result of which it entered service and was produced in a small series. The Taran project, in turn, was closed.
However, the developments on the "Object 120" have not disappeared. A few years after the closure of this project, work began on new self-propelled artillery installations for various purposes. When creating them, the already known and proven solutions borrowed from closed projects were used in the most active way. Thus, the ACS "Object 120" / "Ram" and previous developments, which were abandoned at one time, were still able to help the further development of domestic self-propelled artillery.
