Oxxxymiron - Ivory Tower. Soviet heavy tank IS Elephant Tower
In 1945, the Leningrad Kirov Plant began designing a new super-heavy tank, designated Object 260, and later IS-7. The design of this combat vehicle, which embodied the entire experience of the war, included many innovative solutions - the world's most powerful 130-mm tank gun with mechanized loading and electric power drives, 8 machine guns, an impenetrable 150-mm "pike nose" and a 210-mm the forehead of a huge cast tower, excellent ergonomics, perfect suspension on beam torsion bars, a powerful 1050-horsepower diesel engine with an ejection cooling system, a caterpillar with a rubber-metal hinge and much more. A whole generation ahead of its time, the IS-7 had no equal in firepower, armor protection, maneuverability and mobility - the 68-ton colossus reached speeds of up to 60 km per hour!
Why was this SUPERTANK, which became the crown of development of its class and was ready to be launched into series, never put into service? When work on super-heavy tanks began in the USSR, which put an end to the fate of the KV-3, how did the experienced KV-220 and T-150 perform in the battles near Leningrad? And whose fault is it promising direction was it folded?
In the new book of the leading historian of armored vehicles you will find comprehensive information not only about the legendary IS-7, but also about the entire “line” of “Stalin’s supertanks” - KV-3, KV-4, KV-5, IS-4, IS-6, - as well as about experimental machines that were far ahead of their time.
By decree of the State Defense Committee of June 26, 1944, a branch of pilot plant No. 100 was created in Leningrad (the latter was located in Chelyabinsk). The branch’s task was to assist in organizing the production of ISU-152 self-propelled guns at the Leningrad Kirov Plant. Let us recall that the enterprise was evacuated in 1941, and since then no tanks have been produced there. But after the blockade of Leningrad was lifted, the State Defense Committee decided to restore the production of armored vehicles at this plant, “loading” it with ISU-152 self-propelled guns - it was easier to establish their production than tanks. For this purpose, a group of engineers, technicians and workers was sent from Chelyabinsk to Leningrad. In addition, the government allocated the funds necessary to restore the plant’s workshops damaged by shelling and bombing, as well as additional machines and equipment.
Naturally, at first there could be no talk of any new developments in Leningrad - all efforts were spent on organizing production and serial production of the ISU-152, which began in small quantities in the spring of 1945. However, the situation soon changed, and work began in Leningrad on a new heavy tank, which could become one of the most powerful combat vehicles of that time. But first things first.
At the beginning of 1945, the GBTU of the Red Army developed tactical and technical requirements for the design of a new heavy tank with powerful armor. In February of the same year, by order of the People's Commissar of the Tank Industry, the development of such a combat vehicle was entrusted to the design bureau of the Chelyabinsk Kirov Plant under the leadership of N.L. Dukhov and design bureau of experimental plant No. 100 Zh.Ya. Kotina. It was supposed to create a vehicle with armor that would provide protection against enemy tank and anti-tank artillery shells of 88-128 mm caliber with an initial speed of 1200 m/s. The armament was to use a high-power 122 mm cannon or a 152 mm gun. The new tank was supposed to have a 1000–1200 hp diesel engine, providing speeds of up to 60 km/h, and a mechanical planetary or electromechanical transmission.
The Chelyabinsk Kirov Plant, busy with work to ensure the serial production of IS-2 tanks and self-propelled guns, as well as the development and testing of its new tank “Object 701,” greatly delayed the design. His version of the powerfully armored vehicle was ready only in the fall of 1946. This tank, designated "Object 705", was a 100-ton vehicle with a crew of five, armed with a 130 or 152 mm gun and five machine guns (three 14.5 mm and four 7.62 mm). It was planned to use a diesel engine with a power of 1800–2000 hp as the power plant, the design of which was carried out by the engine department of ChKZ under the leadership of I.Ya. Trashutina. However, due to work on preparation for serial production of the IS-4 tank and its subsequent modification, the completion of the design of the “705 object” moved first to the autumn of 1947, then to 1948. And in October 1949, all work on “object 705” was stopped.
As for the design bureau team at Experimental Plant No. 100, by May 1945 a preliminary version of the new heavy tank “Object 257” was ready, also designated IS-7. It was approved by the leadership of the People's Commissariat of the Tank Industry, and by September four preliminary designs of the IS-7 were prepared (“object 258”, “object 259”, “object 260” and “object 261”), each in two versions. They differed from each other in weight (the lightest 59.7 tons, the heaviest -65.2), artillery weapons (122-mm BL-13-1 or 130-mm S-26 cannon), crew (four or five people, depending from the gun), power plant (diesel KCh-30 with 1200 hp or a pair of V-16 diesel engines with 600 hp each) and transmission (mechanical or electromechanical). In terms of armor, all vehicles had the same parameters (hull front 150 mm, side 100 mm, rear 70 mm, cast turret front 240–350 mm, turret side 185–240 mm).
The chassis was supposed to use an individual two-shaft torsion bar suspension according to the “torsion bar in a pipe” scheme, double-acting hydraulic shock absorbers, large-diameter road wheels with internal shock absorption and tracks with a rubber-metal hinge. The maximum design speed was to be 60 km/h.
For more effective firing, all vehicles were supposed to be equipped with an optical rangefinder and night vision devices for the tank commander and driver.
In general it was assumed that the new fighting machine will embody all the experience accumulated in the design, operation and combat use of heavy tanks during the war, as well as all new achievements in science and the defense industry.
In October 1945, the projects were submitted for consideration to the technical council of the People's Commissariat of the Tank Industry, as well as the Main Armored Directorate of the Armored and Mechanized Forces Command. Also participating in the discussion of options for a new heavy tank were representatives of the People's Commissariat of Armament and the Aviation Industry (the latter was developing the engine for the new heavy tank).
In general, the developments presented by the designers of pilot plant No. 100 were approved. But to produce prototypes, it was necessary to get the go-ahead from the government. Therefore, based on the results of consideration of projects for a new heavy tank, a explanatory note addressed to L. Beria, which said:
"Design Bureau Comrade. Kotin developed a new heavy tank, significantly superior to all existing domestic and foreign models. Weighing 65 tons, it is armed with a 130-mm cannon designed by TsAKB NKV, the armor-piercing projectile of which, with a mass of 34 kg, has an initial speed of 900 m/s. This gun's muzzle energy (1,380 ton-meters) is 1.9 times greater than the 122-mm D-25T tank gun, and ensures penetration of armor 230 mm thick at a distance of 1,000 m.
To facilitate loading the gun, a special mechanism is provided, which ensures a rate of fire of up to 6–8 rounds per minute...
To increase the efficiency of fire, it is planned to install a protractor, as well as night vision devices.
The frontal armor of the tank is not penetrated by 128 mm armor-piercing shells from any distance at heading angles of 30 degrees, and also withstands hits from cumulative grenades of the 150 mm caliber "Faustpatron" type...
The power plant is a unit of two V-16 diesel engines with a total power of 1200 hp, which in the near future will be replaced by a diesel engine of the same power. This will allow the tank to have a maximum speed of at least 60 km/h.”
At the end of the document, it was proposed to instruct the Kirov plant in Leningrad to produce two samples of a new heavy tank in 1946 and test them. In addition, apparently on the initiative of V. Malyshev, the same note proposed to transfer from Chelyabinsk to Leningrad the chief designer of pilot plant No. 100 Zh. Kotin and a number of engineers from his design bureau. However, a decision on this document was made only in the new year, 1946.
Despite this, until the end of 1945, the designers of pilot plant No. 100 carried out a number of experimental works necessary for the further development of a new heavy tank. For example, together with the TsAKB of the People's Commissariat of Armaments, we studied the possibility of installing 122 and 130 mm artillery systems with a loading mechanism, and with NII-48 we worked out a version of the armored hull and methods for attaching armor plates.
On February 12, 1946, I. Stalin signed a resolution of the Council people's commissars USSR No. 350–142 se, according to which a branch of the experimental plant No. 100, together with the Leningrad Kirov Plant, was to design and manufacture two prototypes of the new IS-7 heavy tank by September 1, 1946. The management of the work on creating a new combat vehicle was entrusted to the designer of heavy tanks Zh.Ya. Kotina.
The same decree established the tactical and technical requirements for the new tank: combat weight - up to 65 tons, armament - 130 mm gun and five machine guns (two of them 14.5 mm), gun shots - 30 pieces, hull and turret armor was supposed to provide protection from 128-mm armor-piercing shells with an initial speed of 1100 m/ (at heading angles from +45 to -45 degrees), the thickness of the hull armor was 150–100 mm, the turret was 350–240 mm, the maximum speed on the highway was 60 km/h, specific power - 18.5 hp/t, cruising range 300 km. It was also planned to install radio and optical rangefinders, night vision devices and a new duplex radio station on the tank.
After the appearance of Resolution No. 350–142, her work on the new IS-7 tank (factory designation “object 260”) intensified significantly. P.P. was appointed senior engineer of the machine. Isakov, the corps group was led by S.V. Mitskevich, motor - G.A. Osmolovsky, transmissions - G.A. Turchaninov, weapons - A.S. Shneidman. The general management of the work was carried out by A.S. Kotin’s deputy. Ermolaev.
But since the design of the new machine was supposed to use all the advanced technical solutions at that time, the designers of the Leningrad Kirov Plant and the branch of Plant No. 100 had to involve representatives of other enterprises to solve emerging problems. Suffice it to say that in the process of designing a new tank alone, about 1,500 working drawings were completed, more than 25 solutions that had not previously been encountered in tank building were introduced into the project, and more than 20 institutes and scientific institutions were involved in development and consultations.
The IS-7 was significantly different from other vehicles developed by the Kirov team during the war.
The tank hull was designed with large angles of inclination of the armor plates.
The frontal part is triangular, similar to the IS-3, but does not protrude so much forward. The armor protection was supposed to provide protection against shells of caliber up to 130 mm inclusive.
The main armament of the IS-7 was initially considered in two versions - 122 or 130 mm guns. Moreover, at first, the 122-mm BL-16 cannon, which was developed by OKB-172 in Molotov (now Perm), seemed more promising. The 25-kilogram armor-piercing projectile of this gun had an initial speed of 1000 m/s, which provided good armor penetration.
In addition, the BL-13 had a lifting mechanism of a new design, ensuring effective firing on the move. In addition, the gun had a loading mechanism, which made it possible to fire at a rate of fire of up to 8 rounds per minute. However, at the beginning of 1946, all work on the BL-16 was stopped, and the designers of the IS-7 refocused on using the 130-mm S-26 cannon.
Its development was carried out by the TsAKB NKV (in 1946, after the reorganization of the People's Commissariats into ministries, the TsAKB was renamed the Scientific Research Institute of Artillery Weapons (NII AV) of the USSR Ministry of Armament) under the leadership of V. Grabin. The 130-mm B-13 naval gun was taken as the basis. But unlike the latter, the S-26 received a semi-automatic wedge bolt and a slotted muzzle brake. For firing, high-explosive fragmentation and armor-piercing (weight 33.4 kg, initial speed 900 m/s) shells were used, loading was separate cartridge case. The gun had a system for purging the barrel bore with compressed air after firing, as well as a loading mechanism developed at the AV Research Institute.
It operated using compressed air (25 atm.), and provided a rate of fire of 6–8 rounds per minute.
During the tests, it turned out that the loading mechanism has significant dimensions, and to install it in the IS-7 it would be necessary to increase the size of the turret. To avoid this, the department of the chief designer of the Leningrad Kirov Plant, together with engineers from the branch of plant No. 100, designed their loading mechanism, taking similar mechanisms of ship artillery systems as a basis. It was this that was subsequently installed at “object 260”:
“This design was powered by an electric drive and was small in size, which, in accordance with the results of field tests of the tower by fire, and the comments of the GBTU VS commission, made it possible to create a tower that was rational in design.”
In addition to the 130 mm gun, the IS-7 was supposed to be equipped with 8 machine guns: one
14.5 mm KPSh and seven 7.62 mm ShKAS. It should be said that all machine guns were developed at the Tula OKB-15 under the leadership of B.G. Shpitalny. The use of these particular samples for the new tank was explained by the fact that OKB-15 had experience in developing machine gun installations with remote control for aviation - the same was planned to be used on the IS-7.
According to the project, the installation with a pair of 7.62-mm ShKASs was supposed to be installed at the rear of the turret in a special armored casing. The machine guns were supposed to have all-round fire, and fire from them was carried out without the crew leaving the tank. To do this, it was necessary to design a special so-called “tracking mechanism”. It was supposed to allow firing from a coaxial installation remotely, from the commander’s position using a special mirror sight, and from the gunner’s position using a standard sight. This was achieved by using a special electric drive. The firing angles ranged from 360 degrees horizontally and from -7 to 45 degrees vertically (depending on the installation position). The armor casing was supposed to protect the entire installation from rifle-caliber bullets and small shell fragments. Reloading the machine guns had to be done using a special electrical device.
In addition to OKB-15, the team of the All-Union Electrotechnical Institute named after V.I. was involved in the development of such a remotely controlled installation and the manufacture of parts for it. Lenin, who was in Moscow. However, neither the OKB nor the institute this work were not fulfilled. As a result, the designers of the branch of plant No. 100 and the Leningrad Kirov plant designed and manufactured the installation on their own. The LKZ report for 1946 said the following:
“The department of the chief designer designed and manufactured, using its laboratory, a synchronous-following electric drive for a machine gun mount using individual elements of equipment and machines of foreign technology. The manufactured sample of the specified machine gun mount was mounted on an experimental tank and is being tested. The synchronous tracking drive ensures high maneuverability of machine gun fire.
In order to further improve machine gun armament and enhance firepower against ground targets, a preliminary layout of a triple machine gun mount (14.5 mm and two 7.62 mm) was developed. Control is carried out from the tank commander’s console.”
Looking ahead, it should be said that the built-in installation was never installed on the tank, and subsequently its use was abandoned.
When designing the “Object 260,” the designers paid great attention to the development of a fire control system. At the same time, it was planned to use all the latest developments in this area in the design of the machine, for which specialized enterprises were involved. In particular, a special automated shot control device was created for installation on the IS-7, which received the symbol “Storm”. The principle of its operation was as follows. The gunner aimed the stabilized sight prism at the target, regardless of the gun, after which the gun was automatically brought to the stabilized aiming line, and when the line and the axis of the barrel coincided, a shot was automatically fired. Assistance to the designers of the Leningrad Kirov Plant and a branch of Plant No. 100 in the development of “Sturm” was provided by specialists from NII-49 of the Ministry of Shipbuilding Industry - this organization already had experience in designing stabilized artillery installations for the Navy.
A tank sight with a stabilized prism (or aiming line) was developed by the Leningrad State Optical Institute named after S.I. Vavilov together with the design bureau of plant No. 393 of the Ministry of Armaments. It was supposed to take the TSh-45 telescopic sight as a basis.
As a result, a new model with a stabilized aiming line was designed, designated TSh-46. It had variable magnification (3.75 and 7.5x) and field of view (19 and 9.3 degrees), as well as an electric heating system for the protective glass to avoid fogging.
By the end of 1946, three automated “Sturm” shot control devices were manufactured, which used TSh-46 sights. One device was sent for testing at Marine Research Institute No. 1, and two were installed on “object 260” tanks.
In addition to the Sturm, the IS-7 was supposed to be equipped with a radio and optical rangefinder. The first was developed by NII-108 of the Ministry of Communications, and the second by the design bureau of plant No. 393. In accordance with the assignment, the radio rangefinder was supposed to provide determination of the distance to the target at a distance of 800 to 4000 m, and the optical rangefinder - from 800 to 5500 meters. The base of the latter should have been no more than 1000 mm. However, until the end of 1946, none of these rangefinders were manufactured.
Based on the results of studying captured German materials for infrared instruments, it was decided to install similar samples at “object 260”. For the first time in domestic tank building, the tank had to be equipped with two night vision devices - for the driver and the commander of the vehicle. The mechanic's device had to provide clear recognition of objects at a distance of up to 50 meters and have a field of view of at least 30 degrees. For illumination, it was planned to install two headlights with a diameter of 250 mm in the front part of the car body.
The tank commander's device had higher requirements - clear recognition of objects at a distance of up to 120 meters and a field of view of at least 25 degrees. And since this device was supposed to be used not only for observation, but also for aiming, it was supposed to make it possible to recognize objects with an area of two square meters at a distance of up to 700 meters. For illumination, one headlamp with a diameter of 350 mm mounted on the tower was to be used.
The development of night vision devices for the IS-7 tank was entrusted to Research Institute No. 801, but the work was not completed by the end of 1946.
It was not possible to do this even before all work on this machine was completed.
Due to the lack of a 1200 hp tank engine. It was planned to install in the IS-7 a twin installation of two V-16 diesel engines from plant No. 77. At the same time, the USSR Ministry of Transport Engineering ordered plant No. 800 to produce the engine necessary for this tank. The plant did not complete the task, and the twin unit of plant No. 77 was late to the deadlines approved by the ministry. In addition, it has not been developed and tested by the manufacturer. Testing and development were carried out by a branch of plant No. 100 and revealed its complete structural unsuitability. Not having the necessary engine, but trying to fulfill the government task on time, the Kirov Plant, together with Plant No. 500 of the Ministry of Aviation Industry, began creating the TD-30 tank diesel engine based on the ACh-300 aircraft. As a result, it was possible to obtain an engine of the required power, which during testing showed its suitability for operation in a tank. However, it turned out that due to poor build quality, the TD-30 required improvement.
When working on the power plant, a number of innovations were partially introduced and partially tested in laboratory conditions:
Soft rubber fuel tanks with a total capacity of 800 l;
Fire-fighting equipment with automatic thermal switches that were triggered at temperatures of 100–110 °C;
Ejection engine cooling system.
A lot of work has been done in the design of the engine air filter. The reporting documents noted the following:
“An inertial oil filter has been designed, manufactured and tested, providing preliminary coarse and fine purification of dust from the air. The filter is installed on “object 260” and is being tested.
In order to further improve the purification of intake air from dust, an inertial dry fabric air filter was designed, consisting of two degrees of purification. The filter automatically removes dust from the hopper by using the energy of exhaust gases.”
The tank's transmission was designed in two versions. The first one had a six-speed gearbox with carriage shift and synchronizers. The rotation mechanism is planetary, two-stage. Hydraulic servos were used for control. During testing, the transmission showed good traction qualities, ensuring high average speeds of the tank.
The second version of the mechanical transmission was developed jointly with the Moscow Higher Technical School named after N.E. Bauman. Transmission - planetary, 8-speed, with a ZK-type turning mechanism. Control of the tank was facilitated by hydraulic servos with advanced gear selection. The report of the Leningrad Kirov Plant noted that this option “has great promise in its further development in terms of power parameters.”
Since the chassis of the new heavy tank had to provide high average and maximum speeds, have small dimensions and be reliable in operation, the designers had to solve many problems that arose during development. In particular, a number of suspension options were designed, manufactured and subjected to laboratory and sea trials on production tanks and on the first prototype of the “Object 260”. Based on these, final working drawings were developed.
The chassis used an individual twin-shaft torsion bar suspension, made according to the “torsion bar in a pipe” scheme, double-acting hydraulic shock absorbers and large-diameter road wheels with internal shock absorption, operating under heavy loads, as well as tracks with cast tracks and a rubber-metal hinge, or as they were called then "silent blocks". Regarding the development of the latter, the following was said:
“Due to the novelty of the case, the Department of the Chief Designer of LKZ carried out a large research on the study of foreign samples. Together with the Research Institute of the Ministry of Rubber Industry and the Rubber Technical Products Plant (Leningrad), the necessary recipes were found and a technology for manufacturing rubber-coated bushings was developed.”
Thus, when designing the new heavy tank “Object 260”, the designers of the Leningrad Kirov Plant and the branch of the pilot plant No. 100 had to solve many technical problems. Moreover, many of them required the involvement of various specialists from specialized enterprises.
In the summer of 1946, drawings for the manufacture of armored hulls and turrets of the “260 object” were transferred to the Izhora plant. By this time, assembly of components and assemblies of the new heavy tank was already underway at other enterprises.
In August 1946, two sets of armored hulls with turrets were sent from the Izhora plant to a training ground in Kubinka near Moscow for shelling tests. They were carried out from August 8 to September 11, firing was carried out from 128 and 88 mm German anti-tank guns, as well as from domestic guns of 57, 122 and 152 mm caliber. As a result of the tests, it turned out that, despite the high projectile resistance, the armored hull has a number of significant disadvantages. First of all, the unsatisfactory configuration of the front part of the turret was noted (shells ricocheting from the nose of the hull destroyed the turret plate), insufficient armor resistance of the lower part of the hull sides, and low strength of the welds. There were also shortcomings in the shape and design of the tower.
The results of the shelling tests were studied by the designers of “object 260”, as a result of which it was possible to modify the design of the armored hull and turret of the vehicle. This experience was already used in the development of new samples of the “260 object” in 1947.
In the plan for research and development work on armored weapons for 1946, drawn up at the State Technical University, work on “object 260” was the first item. A document dated October 7, 1946 stated this:
“New heavy tank with reinforced armor (IS-7). Develop a technical project. Make prototypes. Conduct tests. Develop for the IS-7 tank:
1. Electric drive for vertical and horizontal guidance of the artillery system using an amplidin generator.
2. A device for mechanizing the loading of a gun.”
In parallel with shelling tests of the armored hull and turret of the IS-7, the Leningrad Kirov Plant was manufacturing the first sample of a new heavy tank. The car was assembled in the SB-1 assembly shop - only 85 people worked here, of which 71 were workers. The first “object 260” was ready on September 8, 1946, and after adjusting the mechanisms, it went to factory testing. By the end of the year the car had traveled about 1000 kilometers. The second “object 260” was assembled on December 25, and by the new year it only managed to complete a factory run-in of 45 kilometers.
“Object 260” had a classic layout - control compartment in front, combat compartment in the center, engine and transmission compartment in the rear. The crew of the tank consisted of five people - the driver was located in the control compartment, in the combat compartment, to the right of the gun, there was the place of the tank commander, to the left of it - the gunner and in the rear of the turret - two loaders.
The tank's hull was made of rolled armor plates welded together. The frontal part was similar in shape to the hull of the IS-3 tank. The upper frontal sheets, 150 mm thick, were installed at an angle of 68 degrees to the vertical, and were rotated 58 degrees in the horizontal plane. The lower frontal 150 mm sheet had an inclination angle of 50 degrees. The side of the hull was assembled from three sheets: the top 150 mm, set at an angle of 52 degrees, the middle 100 mm and the bottom 16 mm thick. Both sheets had a tilt angle of 63 degrees. The roof had a thickness of 30 mm, the mass of the body of the “260 object” was 24.4 tons.
The 12-ton cast turret had a maximum thickness of the forehead and sides of 240 mm, and the roof was welded from 30 mm armor plate. The clear diameter of the shoulder strap was 2000 mm.
The armament of “object 260” consisted of a 130-mm S-26 cannon with a slotted muzzle brake and loading mechanism, and eight machine guns. To fire the gun, a telescopic articulated sight TSh-46 was used. Rangefinders (optical and radio) provided for by the project were not installed due to their unavailability.
The turret rotation mechanism and the gun lifting mechanism had an electric motor drive, ensuring smooth aiming at the target. The gun's vertical aiming speed (firing angles from -3 to +15 degrees) ranged from 0.05 to 3.5 degrees per second. The design of the drive allowed, in addition to the gunner, the commander to rotate the turret. In case of failure of the electric motor drive, it was duplicated by a manual one.
The fire control system included the Sturm shot control device. It should be said that by the time of the factory tests of “object 260” it had not yet been fully developed.
The ammunition for the gun was 30 rounds of separate loading. Six of them fit into the loading mechanism mounted in the rear of the turret. The mechanism provided a rate of fire of six to eight rounds per minute.
Of the eight machine guns, seven were ShKAS 7.62 mm caliber. One of them was paired with a gun, four were mounted in special boxes (two on the swinging part of the gun for firing forward and two on the fenders for firing backward) and two in a special remote-controlled installation at the rear of the turret. By the time of testing “object 260” this installation had also not been fully developed.
The carried ammunition for the 7.62 mm machine guns was 2,000 rounds.
A 14.5-mm machine gun designed by Shpitalny (ammunition capacity - 500 rounds) was installed on the roof of the turret for firing at anti-aircraft targets. One of the loaders fired from it.
The power plant of the “260 object” consisted of a TD-30 diesel engine with a power of 1200 hp. The tank capacity was 1200 liters. In total, the fuel system included 14 tanks, some of them so-called soft, made of special rubberized fabric that was highly resistant to diesel fuel. This solution, according to the designers, made it possible to place the tanks in hard-to-reach places: if metal tanks were used, they would have to be made very complex shape, which was difficult and expensive, but a soft tank of complex shape was much easier to manufacture. The transportable fuel supply provided the “260 object” with a cruising range of 300 km.
The tank's transmission is mechanical, single-stage with a multi-disc main dry friction clutch, a three-shaft six-speed gearbox with shift carriages and synchronizers, two two-stage planetary turning mechanisms and two planetary final drives. Brakes - band, dry friction. The transmission used a hydraulic servo control system, as a result of which the forces on the levers did not exceed 8 kgf.
The chassis used a double-shaft tubular-rod torsion bar suspension with hydraulic shock absorbers, double road wheels with internal shock absorption, and a caterpillar track with a rubber-metal hinge. The specific pressure of “object 260” on the ground was 0.98 kg/cm 2 .
For external communications, the tank had a serial 10RK radio station, since they did not have time to develop a special duplex one. Internal communication was carried out by the TPU-4-Bis intercom.
Factory tests of the “260 objects” showed that the vehicles have very high combat and specifications. For example, with a mass of 66 tons, the tank easily reached speeds of up to 60 km/h, and the average speed on a broken cobblestone road was 32 km/h. The leadership of the USSR and the Armed Forces came to get acquainted with the new machine - in the fall of 1946 - in the spring of 1947, “object 260” was inspected by the Minister of Transport Engineering V.A. Malysheva, as well as Marshals of the Armored Forces P.A. Rotmistrov and P.S. Rybalko. However, despite the high combat and technical characteristics, it became clear that the tanks require modification of a number of components and assemblies.
It should be said that by order of the chief designer Zh.Ya. Kotin, work on further improvement of the “260 object” began in the second half of 1946, when the construction of prototypes was just underway. To more effectively use engineering design potential, from January 1, 1947, the departments of the chief designer of the Leningrad Kirov Plant and the branch of the pilot plant No. 100 were merged into one - at the branch of the pilot plant. A special laboratory was also created here to test the fire control system and transmission of the tank. J. Kotin appointed the talented designer Nikolai Fedorovich Shashmurin as the senior engineer of the machine when designing the improved IS-7 model; the general management of the work was still carried out by the deputy A. S. Ermolaev.
Meanwhile, tests of “object 260” continued, and not without incident. So, on April 18, 1947, the first model of the car, which had traveled 1092 kilometers by that time, fell off the bridge during its run. The tank was pulled out only on May 6. The car’s “misadventure” did not end there - on November 12, 1947, while driving through a railroad crossing, the crew did not notice the train. As a result, the locomotive caught the barrel of a 130-mm cannon, mounted “in a stowed manner,” breaking the turret stopper, which was turned almost 90 degrees to the side. There were no casualties in the incident, but the tank required repairs.
Testing of prototypes of the “Object 260” was completed by August 1, 1947. Both vehicles were left at the factory, and were subsequently used as an experimental base for testing components for a new heavy tank.
After a series of consultations and study of materials on testing “object 260,” a joint meeting of representatives of the Ministry of Transport Engineering, designers of the Leningrad Kirov Plant and a branch of the pilot plant No. 100 and the Ministry of the Armed Forces was held. During the discussion, the tactical and technical requirements for the design of a new, improved model of a heavy tank were clarified. Based on these materials, on April 9, 1947, Resolution No. 935–288 of the Council of Ministers of the USSR was signed.
According to this document, the Leningrad Kirov Plant was ordered to produce three prototypes of the new IS-7 heavy tank of an improved design in the second and third quarters of 1947, and in the fourth quarter to produce a batch of ten such vehicles. The resolution also listed the changes that were required to be made to the design of these machines.
It should be said that by the time the resolution of the USSR Council of Ministers was signed, the department of the chief designer of the branch of plant No. 100 had done a lot of work on designing an improved IS-7 model. Thus, a life-size wooden model of the tank was made, the design of the armored hull and turret was redesigned based on the results of the shelling of prototypes in 1946, the suspension design was improved, a new planetary design and chassis was being tested, and the armament was changed.
As for the latter, now it was planned to install the 130-mm S-70 cannon on the “object 260”, which was designed on the basis of the S-26 at the AV Research Institute. Its design included the use of a loading mechanism, a system for purging the barrel after a shot, an improved vertical aiming mechanism, and a small recoil resistance force ensured the stability of the tank.
The gun had a barrel length of 57.2 calibers (7440 mm), a single-chamber mesh muzzle brake, a wedge semi-automatic bolt, an electromechanical trigger mechanism (duplicated by a manual one); the mass of the swinging part of the gun with armor was 4756 kg. It was fired from separately loaded shots with armor-piercing (weight 33.4 km, muzzle velocity 900 m/s) or high-explosive fragmentation shells. The range of a direct shot at a target 2 m high was 1100 m.
Prototypes of the S-60 were produced in 1947, and one of them was tested by cart on the experimental “Object 260” produced in 1946.
In addition to the gun, it was also planned to replace the machine guns on the new tank: their number remained the same (eight), but now two of them were 14.5 mm, Vladimirov’s designs (KPV-44), and the rest were 7.62 mm RP- 46 (a company machine gun of the 1946 model with a belt feed, created by designers A.I. Shilin, P.P. Polyakov and A.A. Dubinin on the basis of the DP light machine gun. - Note author).
The replacement of machine guns designed by Shpitalny was primarily due to the fact that they used special ammunition - for example, metal cartridges for ShKAS. If such weapons were used in tank units, it would be necessary to additionally establish a system for supplying ShKAS with ammunition.
Of the eight machine guns, three (KPV and two RP-46) were to be installed coaxial with the gun, three (two RP-46 m KPV) - in a built-in remote-controlled installation at the rear of the turret, and two RP-46 - in the sides of the hull for firing backwards the progress of the tank.
At the end of May 1947, a joint meeting of representatives of the Ministry of Transport Engineering, the Armed Forces, the artillery and armored departments, as well as factories producing the “260 object” and its components, was held, dedicated to the armament of the new vehicle. During the discussion, a decision was made on the final approval of the tank’s armament, as well as on the production of the TKP-2 commander’s periscope device and the TKB-8 tank stabilized commander’s device with variable magnification (4 and 8x) for installation on “object 260”. Work on these devices was carried out by Plant No. 393 of the Ministry of Armaments.
At the same time, work was carried out to improve the armor protection of improved IS-7 models.
Thus, the strength of the hull was enhanced through the use of a solid bent side sheet. As a result, the weld between the top and middle side sheets was eliminated. In general, ensuring the production of such a bent sheet of armor with a thickness of 150 mm was a significant achievement of Soviet industry at that time. The fastening of the lower frontal sheet was also strengthened. Work to refine the hull was carried out by a group of designers led by B.C. Torotko.
In addition to the hull, the IS-7 turret was redesigned. Like the previous one, it was cast, but had a modified shape. Thanks to the fact that by this time a new, more compact, gun loading mechanism had been developed, it was possible to reduce the height of the turret by 200 mm and reduce its weight by a ton (compared to the “260 object” produced in 1946). Also to the designers K.N. Ilyin and T.N. Rybin, who designed the turret, managed to increase the diameter of the shoulder strap from 2000 to 2300 mm, which significantly improved the working conditions of the crew.
The first two samples of the new turret were cast by the Izhora plant back in December 1946, but were unsuccessful. However, in August 1947, these samples, together with the armored hull of the “Object 260” of a new design, were tested by fire. This made it possible to verify the correctness of the designers’ conclusions and make the necessary changes to the design of armored parts.
Initially, the new IS-7 models were supposed to use TD-30 diesel engines with a power of 1200 hp. Let us recall that such samples, manufactured by Plant No. 500 of the Ministry of Aviation Industry, were installed on the Object 260 tanks produced in 1946. True, by the spring of 1947, four of the five such engines manufactured by Plant No. 500 for the Leningrad Kirov Plant failed.
By a resolution of the Council of Ministers of April 8, 1947, plant No. 500 was ordered to increase the diesel power (it was designated TD-30B) to 1500–2000 hp. However, by July 12, 1947, Plant No. 500 had not started work on modifying the engine.
Back in the spring, due to the threat of disruption to the production schedule for prototypes of the new heavy tank, chief designer Zh.Ya. Kotin turned to the Ministry of Transport Engineering with a request to help attract the special design bureau of the Leningrad Motor Plant No. 800 “Zvezda” to work on tank engines (the latter, like LKZ, was part of the Ministry of Transmash). Here work was carried out to create diesel engines for torpedo boats. As a result, OKB-800, together with the designers of the Kirov plant in short time proposed for use in “object 260” a turbocharged M-50T diesel engine with a power of 1050 hp. this engine was intended for torpedo boats, and was a throttled version of the ACh-30 aircraft engine with a power of 1800 hp.
OKB-800, together with the department of the chief designer of the branch of pilot plant No. 100, prepared a joint project for installing the M-50T in “object 260”. It was intended to develop new scheme layout of the engine and transmission compartment of the tank, using an injection cooling system in the new engine.
This proposal was approved by the Ministry of Transport Engineering and the Council of Ministers of the USSR. The Zvezda plant was instructed to produce 12 M-50T diesel engines, and also to consider the option of increasing its power to 1100 hp.
In connection with the installation of a new engine in “object 260”, a branch of pilot plant No. 100 was hastily forced to conduct additional tests of the M-50T with an injection cooling system, as well as redo the exhaust system and check the possibility of starting a diesel engine from air cylinders. The work was completed successfully and in a short time, and by the end of 1947, Plant No. 800 had manufactured and delivered five M-50T diesel engines for installation in tanks.
However, with the preparation for the release of a new heavy tank, everything did not go entirely smoothly. Thus, on April 27, 1947, the chairman of the state planning commission under the USSR Council of Ministers sent the following letter to the deputy chairman of the USSR Council of Ministers, L. Beria:
“According to Government Decree No. 350–142 ss dated 12.2.46, the Ministry of Transport Engineering is obliged to produce by 1.9.46 two prototypes of a heavy tank designed by Comrade Kotin (IS-7), one of them with electrical, the other with mechanical transmission.
However, during the preparation of the draft Resolution on the tank production plan for 1947, including an experimental batch of IS-7 tanks in the amount of 10 pieces, which was approved by the Council of Ministers of the USSR on 9.4.47, applications for the necessary equipment for the product for the IS-7 Ministry transport engineering was not presented...
For the S-70 cannon, an additional order for 7 pieces. may be adopted by the Ministry of Armament this year, subject to urgent testing of the existing three samples.
Based on the above, the State Planning Committee considers it necessary to oblige the Ministry of Transport Engineering to ensure the timely completion of production of the IS-7.”
In addition to the problems at the Kirov plant, there were also shortcomings in the work of the related factories, which were supposed to supply instruments, engines and weapons for the IS-7. This is no wonder - many of the components and assemblies were developed in our country for the first time, and to create them it was necessary to solve a number of technical and technological problems.
So, on August 7, 1947, the following note was sent to the Minister of Transport Engineering I. Nosenko:
“Statement of main components for IS-7.
Electric drive - 4 samples were manufactured by VEI and are located at the Leningrad Kirov Plant.
Stabilizer - 3 pcs. manufactured by plant No. 212 of the Ministry of Shipbuilding and are located at the Leningrad Kirov plant.
Synchronous tracking drive - 3 sets of these captured devices at the Leningrad Kirov Plant.
The TPK-2 tank command device and the TSh-46v sight - the Leningrad Kirov Plant has one; Plant No. 393 of the Ministry of Armament has agreed to manufacture three.
TKSP tank combined sight - one sample was manufactured by the Leningrad Institute of Precision Mechanics of the Ministry of Armament.
Night vision device - one captured device is available, two samples are manufactured by NII-801 of the Ministry of Electrical Industry...
For diesel engines. Experimental diesel engines TD-30B, supplied by Plant No. 500 of the Ministry of Aviation Industry, when tested in tanks, turned out to be unreliable in operation. By Decree of the Council of Ministers of April 9, 1947 No. 935–288 ss, plant No. 500 was obliged in the third quarter of this year. test three samples of this diesel engine for state tests.
To refine these diesel engines, the Kirov Plant issued a task in which, in agreement with Plant No. 500, a requirement was made to replace the Buchi supercharger with a centrifugal supercharger. In carrying out this work, the Ministry of Transport Engineering will assist Plant No. 500 by providing seven designers. Due to the refusal of the Minister of Aviation Industry, Comrade Khrunichev, to provide the supply of TD-30B diesel engines for the IS-7 in 1947, the Ministry of Transport Engineering is organizing the production of diesel engines for this tank at plant No. 800. The first samples have already been manufactured and are being tested at the stand of the Kirov plant.
According to S-70. To the demands of the Ministry of Armament to supply the Artillery Research Institute with a turret for testing, the Ministry of Transport Engineering refused back in 1946 and confirmed this refusal this year, since it is not necessary to install a gun in the turret to shoot.
To test the GAU cannon, a special Br-2 stand was transferred to the Research Institute of Artillery Weapons of the Ministry of Armaments, on which the first sample of the S-70 is currently being debugged. The other two samples are just being completed by the Artillery Research Institute.
Thus, the indicated three samples of the gun have not yet been presented for testing by the GAU of the Armed Forces. In addition, the GAU of the Armed Forces decided to test these guns complete with a loading automation mechanism. The Research Institute of Artillery Weapons has only just begun to manufacture this mechanism.”
However, the assembly of the first prototype of the improved IS-7 tank was completed by the end of July 1947. From August 26 to October 31, this tank underwent lengthy factory tests. The second sample was collected on October 6, and the third on December 30, 1947.
Like its predecessor, the “Object 260” produced in 1946, the 1947 IS-7 had a classic layout and a crew of five people. In the control compartment there was a place for the driver, in the fighting compartment, to the right of the gun there was a commander, to the left - a gunner, and in the rear behind them - two loaders.
The tank hull was welded using rolled armor plates with a thickness of 150, 100, 60 mm (front, sides, rear), installed at large angles of inclination to the vertical. For the first time in domestic tank building, solid-bent side plates, proposed by designer G.N., were used in the design of a tank. Moskvin, which made it possible to increase projectile resistance and increase internal volume. The bottom and roof were made of 20 mm armor. Behind the driver's seat in the bottom of the control compartment there was an emergency exit hatch.
The 1947 IS-7 received a modified turret (compared to the 1946 vehicles). It was made cast, and had a variable thickness of the frontal part from 210 to 90 mm at angles of inclination from 0 to 45 degrees. On the side the armor was up to 150 mm, and on the stern - up to 90 mm. Unlike the 1946 vehicle, there was no commander's cupola on the roof, and the diameter of the shoulder strap was increased to 2300 mm.
The IS-7's armament consisted of a 130-mm S-70 cannon, which had a system for purging the bore after firing and a single-chamber muzzle brake. The gun had a loading mechanism located in the rear of the turret. It had an electric drive, it housed six projectiles and the same number of charges, which ensured a rate of fire of up to eight rounds per minute. The entire IS-7 ammunition consisted of 30 separate-loading rounds.
Three machine guns were built with the cannon - one 14.5 mm KPV and two 7.62 mm. The installation of a large-caliber machine gun together with a cannon made it possible to use it to combat lightly armored targets, as well as for zeroing, which made it possible to save shells.
Two more 7.62-mm machine guns were mounted in special casings on the sides of the hull and could fire in the rear direction. On the second and subsequent IS-7 samples, two more 7.62 mm machine guns were added, which were mounted on the outside of the turret and could also fire backwards. These machine guns were controlled by the loaders.
On the roof of the turret, on a special swivel, a 14.5-mm KPV machine gun was installed, which could fire at anti-aircraft targets. The ammunition for the machine guns was 400 14.5 mm and 2500 7.62 mm cartridges.
The mechanism for raising the gun and turning the turret had electric motor and manual drives. When firing, the “Sturm” shot control device was used, which ensures automatic aiming of the gun and firing a shot in accordance with the stabilized aiming line.
The first IS-7, produced in 1947, was equipped with a telescopic articulated sight TSh-46V and a periscope sight TP-47A with variable magnification.
The IS-7 tanks produced in 1947 were equipped with a 12-cylinder V-shaped diesel engine M-50T with a power of 1050 hp. at 1850 rpm with liquid ejection cooling system and centrifugal supercharger.
Ejectors made from milled armor plates were used for the first time in domestic tank building. Moreover, five different models of ejectors underwent preliminary tests at the stands of a branch of pilot plant No. 100.
The engine was started by two ST-16 electric starters. In addition, there was a backup system for starting with compressed air from one of the eight cylinders.
To clean the air entering the engine, two-stage air cleaners with automatic dust removal were used.
The fuel supply located in 11 tanks was 1300 liters. As on the tanks of 1946, “soft” tanks made of special rubberized fabric were used that could withstand pressure up to 0.5 atm. The fuel range was about 200 kilometers.
An inertial dry fabric air filter with two stages of cleaning and automatic removal of dust from the bunker using exhaust gas energy was installed on the IS-7 tank produced in 1947. This was the first time such a solution was used in tank building.
The tank's transmission consisted of a mechanical planetary gearbox, designed jointly with the N. Bauman Moscow Higher Technical School at the end of 1946, a ZK-type turning mechanism (Zajchik-Christie), two combined final drives and two reverse gears. The transmission also used dry friction disc clutches and band floating brakes. It should be said that the unstable operation of the clutches made it difficult to control the tank at high speeds and required a certain skill from the driver. The gearbox was controlled using a hydraulic servo drive.
Automatic fire extinguishing system designed by M.G. Shelemina consisted of sensors and fire extinguishers installed in the engine and transmission compartment, and was designed to be turned on three times in the event of a fire.
The chassis included seven large-diameter (730 mm) road wheels on board and did not have support rollers. The rollers were double, with internal shock absorption. To improve the smoothness of the ride, double-acting hydraulic shock absorbers were used (on rollers 1, 2, 6 and 7), the piston of which was located inside the suspension balancer. The shock absorbers were developed by a group of engineers under the leadership of L.3. Shenker.
Beam torsion bars were used as an elastic suspension element, each of which consisted of 18 shafts with a diameter of 25.5 mm.
The 710 mm wide track had cast box-section tracks with a rubber-metal hinge. Their use made it possible to increase wear resistance and reduce noise during movement, but at the same time, they were difficult to manufacture. The mass of each caterpillar was 2332 kg, it consisted of 93 tracks.
The electrical equipment of the IS-7 was carried out according to a single-wire circuit, the on-board network voltage was 24 V. Six batteries and a GT-18F generator with a power of 3 kW were used as sources of electricity.
The tanks were equipped with a 10 RT radio station and a TPU-47 tank intercom for five subscribers.
The prototype IS-7 tank No. 1 covered about 2,500 kilometers by the end of 1947. In addition, tests of gun aiming mechanisms and machine gun armament were carried out on the vehicle.
IS-7 No. 2 entered ministerial testing on November 23, 1947, and traveled about 740 kilometers by the end of the year. A number of modifications were made to the design of this vehicle based on the results of factory tests of the first tank. Machine No. 2 was tested according to a special program approved by the Ministry of Transport and Machinery. Its conditions were quite harsh - the operation of the weapon system and communications equipment was tested on the tank, and its dynamic qualities and terrain maneuverability were also determined. The tank overcame ascents, descents, as well as various artificial obstacles, and moved along roads with different surfaces.
Ministerial tests of the second model of the IS-7 tank ended on March 20, 1948, by which time the vehicle had covered 2,015 kilometers. At the same time, satisfactory operation of the tank’s components and mechanisms was noted; no serious breakdowns were detected. The maximum speed on the highway was 60 km/h, which was a very good indicator for a tank weighing 66 tons. Fuel consumption per 100 kilometers when driving on the highway was 419 liters.
In its conclusion, the commission of the Ministry of Transport Engineering, which tested the prototype IS-7 No. 2, noted that the vehicle passed the ministerial tests and, in its main parameters, corresponds to the tactical and technical characteristics approved for it.
Chairman of the commission that tested the IS-7, chief tester of the Ministry of Transport Engineering E.A. Kulchitsky later wrote in his memoirs:
“I was given a great honor; I received an offer to be the first to move this wonderful tank. It is difficult to express my feelings in words. At speeds in excess of 60 km/h, this heavy machine responds effortlessly to even the slightest effort on the levers and pedals. Gears are switched with a small lever, the car is absolutely obedient to the driver.”
However, along with positive reviews about the IS-7, such as a successful layout, high combat qualities and the possibility of further improving the tank, the commission demanded that the Kirov plant improve the reliability of a number of components and mechanisms of the vehicle and eliminate a number of design flaws identified during testing.
It should be said that some of the comments were eliminated during the runs of the second sample, but more of them were corrected on the IS-7 tank No. 3 - this vehicle was being prepared for interdepartmental testing. At the latter it was planned to finally resolve the issue of adopting the IS-7 for service. Soviet army: The tank made a very favorable impression not only on employees of the Ministry of Transport Engineering, but also on many high-ranking military personnel.
By the way, the tests of the IS-7 tank No. 2 were not without an emergency. So, on March 22, 1948, the engine of the car caught fire. The fire extinguishing system gave two flashes to localize the fire, but was unable to extinguish the fire. The crew abandoned the car and it burned down. However, the second IS-7 sample was restored by May, and it was subsequently used at the plant to test new components and assemblies.
The third prototype IS-7, assembled on December 30, 1947, was tested in January of the new year. In April, the vehicle was sent to the Scientific Testing Artillery Range, where they conducted short-term firing tests of the S-70 cannon, and also checked the reliability of the loading mechanism, lifting and turning mechanisms, and the system for purging the artillery system barrel with air after firing. The 14.5 mm machine guns mounted on the IS-7 were also tested by fire. After this, the tank was returned to the factory and began to be prepared for interdepartmental testing.
On April 30, 1948, the Minister of Transport Engineering I. Nosenko sent a memorandum on the progress of work on the IS-7 to the Deputy Chairman of the Council of Ministers of the USSR V. A. Malyshev, in which he wrote:
“In accordance with Resolution of the Council of Ministers of the USSR No. 935–288 ss dated April 9, 1947, the Kirov Plant in Leningrad produced prototypes of the IS-7 designed by Comrade Kotin in 1947. Two experimental IS-7s were comprehensively tested at the Kirov plant in 1947. One IS-7 is currently fully prepared for interdepartmental testing together with the GBTU VS, and the second tank, due to the late delivery of the S-70 gun, is finishing assembly, and in May of this year it will also be presented for interdepartmental testing. The prototype tanks presented for testing were made in accordance with the tactical and technical requirements approved by Decree of the Council of People's Commissars of the USSR No. 350–142 ss dated 12.2.46. The following were not met from the approved requirements:
1. An optical rangefinder and a radio rangefinder are not installed in the tank. The latter has not been developed, and the radar committee stopped this topic in accordance with Resolution of the Council of Ministers of the USSR No. 2501-767 ss dated July 17, 1947. The State Optical Institute of the Ministry of Armament produced only two prototypes of the optical rangefinder, which were transferred to the Cuban test site BT and MB VS for preliminary tests. To date, the Kirov Plant has not received rangefinders from the customer for installation in the tank.
2. The total capacity of the tanks is 1000 liters versus 1300 liters in the tactical and technical requirements. But this volume, as established by factory and ministerial tests, provides the tank with a highway range of 300 km, which corresponds to the specifications.
The presented IS-7 is equipped with an M-50T diesel engine from plant No. 800. The Ministry of Transport Engineering, instead of the two engines provided for in the task - V-16 and M-50T - created one, based on the M-50 marine serial diesel engine, and as the factory and interdepartmental tests of the IS-7, its power satisfies the specified requirements for the dynamic characteristics of the tank. The M-50 has already passed 100-hour state tests. Currently, the M-50T is undergoing factory 150-hour bench tests, and after completion, the Ministry of Transport Engineering will present the engine for 150-hour interdepartmental tests. The command of the Armored and Mechanized Forces requires interdepartmental testing of this engine for 300 hours.
The following improvements have been made to the IS-7 compared to the tactical and technical requirements:
1. A turret ring with a diameter of 2300 mm was used instead of 2000 mm, which significantly improves the working conditions of the crew.
2. To increase the firepower of the tank, two heavy machine guns were installed instead of one according to tactical and technical requirements, while the total number of specified machine guns in the tank was retained - 8 pieces.
3. To improve visibility, 9 prismatic periscope viewing devices were installed instead of 5 according to tactical and technical requirements.
4. To increase the dynamic qualities of the tank, hydraulic suspension shock absorbers and road wheels with internal shock absorption are installed, which are not provided for in the tactical and technical requirements.
5. The tank is equipped with a combined radio station operating in duplex and simplex modes, which significantly improves the external communication of the tank.
The armored and mechanized forces, citing deviations from the approved tactical and technical requirements, refuse to begin interdepartmental testing of the IS-7. Therefore, the Ministry of Transport Engineering asks you to allow us to begin interdepartmental testing of the prototype IS-7, manufactured with the above-mentioned deviations from the tactical and technical requirements, as well as to conduct 150-hour interdepartmental tests of the M-50T. The results of interdepartmental tests will be reported to the Council of Ministers of the USSR by July 1, as provided for by Government Decree No. 891–284 ss of March 20 of this year.”
Apparently, Nosenko’s letter played a role - already on May 3, 1948, order No. 0061/135 ss “On testing the experimental IS-7 tank” appeared, signed by the commander of the armored and mechanized forces of the Armed Forces and the Minister of Transport Engineering of the USSR. This document stated the following:
“In accordance with Resolution of the Council of Ministers of the USSR No. 891–284 ss dated March 20, 1948, to test IS-7 prototypes of the Kirov plant for the purpose of:
a) determination of tactical and technical characteristics;
b) checking the reliability of operation;
c) giving an opinion on the adoption of Armored and Mechanized Forces and for mass production, we order:
Appoint a commission consisting of:
Chairman, Lieutenant General of Tank Forces Vershinin B.G...”
The document further listed the members of the commission - 22 people in total. They represented all the “involved” organizations: the command of armored and mechanized troops, GBTU, the Main Artillery Directorate, the Ministry of Transport, the Ministry of Rubber Industry, and, of course, the Leningrad Kirov Plant.
But, despite the fact that by this time the prototype IS-7 tank No. 3 was ready for testing, their start was delayed.
The fact is that by this time, the test results of the first two IS-7s produced in 1947 (No. 1 and 2) showed the need to make a significant number of design changes to the design of the tank. Therefore, representatives of the Ministry of the Armed Forces demanded that the IS-7 meet the approved tactical and technical requirements in all respects. In addition, representatives of the interdepartmental commission created to test the tank decided to send the vehicle for additional weapons testing. In accordance with this, on June 16, 1948, the Minister of Transport Engineering I. Nosenko, the head of the Main Artillery Directorate of the Soviet Army N. Yakovlev and the commander of armored and mechanized forces A. Bogdanov decided on the procedure for conducting state and artillery tests of the IS-7. The document they signed stated the following:
"1. Due to the fact that the GAU Armed Forces testing program for IS-7 weapons provides for a comprehensive test of the S-70 for survivability and strength, determination of the gun’s rate of fire, projectile departure angles, gas contamination in the fighting compartment and the operability of the loading mechanism, it is considered necessary to send the IS tank to GNIAP GAU Armed Forces -7 No. 3, since IS-7 No. 1, intended according to an interdepartmental agreement for testing the artillery system, is not prepared by the Kirov Plant to conduct these tests in full (it is impossible to fire for accuracy, accuracy, rate of fire, and check the loading mechanism). Tank No. 3 was sent to the training ground on June 18, 1948.
2. Within 2 days, the Chairman of the commission for testing IS-7 prototypes, Lieutenant General of Tank Forces B. G. Vershinin, must submit for approval changes to the sea trials program, taking into account the conduct of full artillery tests of the S-70 and the firing of the weapons of tank No. 3.
3. Considering the unpreparedness of the tanks for sea trials, go to the Government with a petition to extend the tests of the IS-7 for 2 months.”
In accordance with this document, on June 18, 1948, IS-7 No. 3 was sent to a scientific testing artillery range, where the tank’s armament was tested from June 22 to July 23. During this time, a total of 671 shots were fired from a cannon, 3,671 shots from KPV machine guns, and 64,303 from RP-46.
In general, despite a number of comments, the test results were considered quite satisfactory. Among the advantages in terms of armament, the IS-7 noted, first of all, the ease of operation of the vehicle’s crew: this was ensured both by the use of a rotating floor in the turret, and by the use of a mechanism for purging the barrel bore after a shot, which significantly reduced gas contamination in the tank’s fighting compartment.
The 130-mm S-70 gun showed satisfactory combat accuracy and reliable operation of components and mechanisms. A high rate of fire was also noted - up to six rounds per minute) due to the use of a loading mechanism. The latter, designed by engineers of the Leningrad Kirov Plant, turned out to be simple in design, reliable in operation and ensured convenient loading of shells and charges into it by loaders.
On July 13, 1948, even before the end of the firing tests of the IS-7 tank No. 3, a certificate on the progress of work on the IS-7 tanks was sent to the Minister of Transport Engineering I. I. Nosenko with the following content:
“Leningrad Kirov Plant and a branch of Plant No. 100 in pursuance of Resolution of the Council of Ministers of the USSR No. 891–284 ss of March 20 of this year. prepared the IS-7 for interdepartmental testing, which was reported to the commander of the Armored and Mechanized Forces on March 19 with a proposal to begin testing this tank on March 31. However, the command of the Armored and Mechanized Forces did not agree with the proposal of the Ministry of Transport Engineering, citing the fact that the presented IS-7 in some respects did not meet the tactical and technical requirements approved by the Council of People's Commissars of the USSR in February 1946.
Therefore, the Ministry of Transport Engineering applied to the Council of Ministers of the USSR for permission to allow the IS-7 to be tested with a deviation from the approved tactical and technical requirements. Council of Ministers of the USSR by order No. 6818 ss of May 26 this year. authorized the Ministry of the Armed Forces of the USSR and the Ministry of Transport Engineering to conduct tests of the IS-7, manufactured with deviation from the specified requirements.
However, the interdepartmental commission, appointed by a joint order of the commander of the Armored and Mechanized Troops of the Armed Forces and the Ministry of Transport Engineering, did not begin testing the IS-7, and demanded the implementation of design changes provided for in the drawings for subsequent vehicles of the pilot batch. In connection with the urgent requirements of the command of the Armored and Mechanized Troops of the Armed Forces, the Ministry of Transport Engineering agreed to implement the required changes. In addition, the GBTU VS and the GAU VS changed their initial decision on the procedure for testing the weapons of the IS-7 and 16.6 tanks. this year a new decision was made on these tests, providing for a comprehensive test of the S-70 cannon for survivability, strength, a certain rate of fire, checking the gas content of the fighting compartment, the operation of the loading mechanism, etc. At the same time, a decision was made: the IS previously prepared by the Kirov Plant for interdepartmental testing -7 send to GNIAP GAU Armed Forces to test weapons according to new program GAU VS.
Currently, this tank is at the artillery range, and more than 400 shots have already been fired from the cannon, and all machine guns have been fired.
After the completion of artillery tests, the Kirov Plant must make all the changes required by the GBTU of the Armed Forces to this tank, and then present it to the commission for sea trials.
The second IS-7, intended for sea trials, has already undergone factory testing and is currently being completed. The presentation of this tank to the interdepartmental commission is scheduled for 15.7. this year
Due to the fact that testing the weapons at the artillery range will take at least a month, and due to the large amount of work to remake the tank at the request of the GBTU VS, it will take at least two more months to complete the tests.
Therefore, the Ministry of Transport Engineering turned to Comrade Malyshev and Comrade Bulganin and the Bureau of the Council of Ministers with a request to extend the deadline for completing tests of IS-7 prototypes until September 15, 1948.”
It should be clarified here that the “second IS-7, intended for sea trials” mentioned in the document is the fourth prototype of the IS-7 (vehicle No. 4). Assembly of the tank at the Kirov plant began in early June 1948. It took into account all changes in the design of components and assemblies, the need for which was revealed during factory and ministerial tests of the first three samples of IS-7 tanks (No. 1, 2 and 3). The fourth model of the IS-7 was ready by the beginning of July 1948, and after factory runs, it first entered weapons testing by shooting (from July 21 to July 25, a total of 252 shots were fired from the cannon), and from July 26 to September 25, 1948 it passed interdepartmental tests ( speaking modern language state) tests.
In May-June 1948, sample IS-7 No. 5 was assembled. It should be said that it was not a full-fledged tank - it could not move under its own power, since it was intended to be tested by shelling. However, the main units (engine, transmission elements, etc.) were installed on this machine. From July 16 to July 26, 1948, IS-7 No. 5 was tested by fire at the NIBT training ground in Kubinka near Moscow. The shelling was carried out from German anti-tank guns of 88 and 128 mm caliber (most of the shots were fired from it), as well as from domestic 122 and 152 mm guns (the latter two fired high-explosive shells). In total, 81 shells hit the IS-7 hull and turret, and significantly greater durability was noted compared to the IS-7 hull and turret produced in 1946.
One of the factors that increased the survivability of the hull, as noted in the documents, was the use of solid bent sides. This solution made it possible to increase both the rigidity of the hull as a whole and to reduce the impact load from projectile hits on the connections of the sides with the frontal parts, roof and bottom.
However, the testing of the tank was not without incident. So, during one of the shellings at the training ground, a shell slid along the bent side and hit the suspension block, and it, apparently weakly welded, bounced off the bottom along with the roller.
On August 2, 1948, Deputy Minister of Transport Engineering Yu. Maksarev sent a document to the director of the Leningrad Kirov Plant Suvorov and chief designer Zh. Kotin about the results of a shelling test of the armored hull of the IS-7 tank:
“Tests carried out at the Cuban test site by shelling the hull and turret of “object 260” revealed some shortcomings, as well as low quality armor casting (turret and rear hull). I ask you to urgently work on the issue of strengthening the following hull and turret components:
Change the method of attaching sloth brackets;
Transfer the brackets for the balancer stops to stamping or, while retaining the cast brackets, use higher quality metal with heat treatment;
Increase the strength of the lower suspension blocks;
Increase the strength and survivability of the lower cast body sheet. It is possible to use rolled sheets.
Please communicate your proposals for strengthening these details no later than 10.8.48.”
However, the implementation of this document was delayed, and only on October 28, 1948, a meeting was held dedicated to improving the design of the armored hull of the IS-7 tank. By this time, the turret of “object 260” was additionally tested by shelling - this was due to the fact that the turret of model No. 5, which was fired at in Kubinka, had low casting quality.
At the end of September 1948, the Minister of Transport Engineering of the USSR I. Nosenko and the Deputy Minister of the Armed Forces of the USSR A. Vasilevsky sent a memorandum entitled “On the new heavy tank IS-7” to I. Stalin. This document outlined basic information about the machine, as well as test results:
“In pursuance of Resolution of the Council of Ministers of the USSR dated April 9, 1947 No. 935–288 ss, the Leningrad Kirov Plant developed and manufactured prototypes of the new IS-7 heavy tanks, which in their combat qualities are significantly superior to domestic and known foreign tanks. The creation of this tank was a major achievement of our designers in the field of tank building.
The IS-7 is equipped with a 130-mm cannon with an initial speed of 900 m/s and an armor-piercing projectile weight of 33.4 kg.
For the first time in the history of tank building, mechanized loading and full electrified control of artillery fire were used. At the same time, a high rate of fire of up to 5–6 rounds per minute has been achieved.
The IS-7's armor protects from any distance in the frontal part of the hull and turret and the upper belt of the hull sides from 128-mm shells with an initial speed of 900 m/s, which exceeds the armor protection of existing heavy tanks.
The tank reaches a speed of 60 km/h on the highway, and has a higher average speed on country roads and terrain than medium and heavy tanks.
For the first time, a diesel engine with a power of 1050 hp was installed in the tank. and a planetary transmission for such power. Thanks to the high specific engine power and design features transmission achieved high maneuverability of the tank. An engine cooling system using exhaust gas energy is used, eliminating fans and complex transmission mechanisms to them.
To reduce the concentration of powder gases in the fighting compartment of the tank at a high rate of fire, the gun bore was purged after firing.
To automate the firing control, machine guns with an electro-pneumatic reloading device are installed.
The use of beam torsion bar suspension in combination with hydraulic shock absorbers of the chassis and support rollers with internal shock absorption has achieved high smoothness at high speeds.
In pursuance of the resolution of the Council of Ministers of the USSR dated July 28, 1948 No. 10429, a commission consisting of representatives of the Ministry of the Armed Forces and the Ministry of Transport Engineering tested the experimental IS-7 tank from July to September of this year. On the first experimental IS-7, field tests of firing weapons were carried out according to the program of the Main Artillery Directorate of the Armed Forces.
The second IS-7 was subjected to sea trials according to the program approved by the command of the Armored and Mechanized Troops of the Armed Forces and the Ministry of Transport Engineering, and on September 28, 1948 it covered 1,843 km. The weapons were also fired on this tank.
The sample presented for testing has a deviation from the tactical and technical characteristics approved by the Decree of the Council of People's Commissars of the USSR dated 12.2.46 No. 350–142 ss, in addition to the deviations permitted by the order of the Council of Ministers of the USSR dated 26.5.48 No. 6518 ss.
The main ones are the following:
1. The weight of the tank is 67.97 tons versus 65 tons established in the tactical and technical characteristics.
2. Tank width 3440 mm instead of 3400 mm.
3. Power reserve 200 km instead of 300 km.
4. Night vision device is not installed.
5. The minimum gun descent angle is 1.5 degrees, instead of 3 degrees.
6. Specific pressure 1.0 kg/cm2 instead of 0.95 kg/cm2.
7. Specific power 15.45 hp/ton instead of 16.1 hp/ton.
8. average speed movements:
On the highway 31.4 km/h instead of 35 km/h;
On a country road 28 km/h instead of 30 km/h.
9. Instead of a duplex radio station, a serial 10-RT is installed.
10. The warranty period for the M-50T diesel engine is insufficient. Instead of 300 hours on the stand (established by the Government for diesel engines of new heavy tanks), the engine worked for 84 hours when tested on a vehicle, and failed.
About the weight of the tank.
This weight was recorded only as a result of weighing one car; in the future, the weight will be reduced. Considering that the bodies for the pilot batch of vehicles have already been manufactured, the Ministry of the Armed Forces does not object to their use.
About night vision devices.
The electrical industry has so far supplied the Kirov plant only with night driving devices, which will soon be installed in a pilot plant. Devices for night shooting have not yet been delivered to the Kirov plant, since they have not been accepted by the State Autonomous Institution of the Armed Forces.
About the life of a diesel engine.
Plant No. 800 is currently working to increase the service life of the M-50T to 150 hours. The Ministry of Transport Engineering requests permission to install the IS-7 M-50T on a pilot batch with a service life of 150 hours, which will provide a guaranteed mileage of 2000 km. Plant No. 800 promises to supply two such engines by January 1, 1949.
During testing of the prototype IS-7 at 1843 km, serious defects and breakdowns were discovered in the engine unit, final drives, friction elements, planetary transmission, rubber fuel tanks, track tracks, exhaust manifold compensators due to design flaws and manufacturing defects, as well as insufficiently identified effective work tank cooling system, which limited the ability to move in higher gears. For these reasons, the IS-7 prototype presented for testing did not pass the warranty mileage test, and in its presented form cannot be recommended for adoption and mass production.
However, taking into account the significant advantages of the IS-7 over existing heavy tanks, and based on the results of the tests, we consider it necessary to make design and technological changes to the pilot batch of 15 tanks being manufactured in accordance with the Government Decree to ensure reliable operation of the vehicles.
The Kirov plant has already begun processing the drawings and making the necessary improvements to the IS-7 design. In total, about 1000 drawings are subject to processing, but since this work was carried out in parallel with testing, it seems possible to complete the release of new drawings by 11/10/48.
The Ministry of the Armed Forces and the Ministry of Transport Engineering believe that two IS-7s from a pilot batch of 15 should be subjected to repeated state tests, and based on their results, proposals on the adoption of the IS-7 for service and mass production will be reported to the Council of Ministers of the USSR. The Ministry of Transport Engineering and the Ministry of the Armed Forces consider it necessary to make changes to the design of the tank according to list No. 2.
The Ministry of the Armed Forces and the Ministry of Transport Engineering consider it expedient not to carry out further state tests of the experimental IS-7, but to send the second sample to the NIBT test site for field testing with the participation of representatives of the Kirov plant.”
The proposals set out in the report were approved by I. Stalin, and the Kirov Plant began work on processing the drawings and finalizing the design of the IS-7. By the end of the year, more than 120 different changes had been made to the tank's drawings. In addition, related enterprises were sent a list of comments that needed to be eliminated in the components and assemblies of the IS-7. It was assumed that during 1949 the Kirov plant would carry out all experimental work and research needed to improve the design of the IS-7 tank. In addition, in mid-October 1948, one prototype (vehicle No. 3) was sent to the NIBT test site in Kubinka near Moscow - it was planned to conduct additional tests of this tank.
It should be said that in addition to the planned release of a pilot batch of 15 IS-7s in 1948, there were already plans to produce a batch of 50 such machines in 1949. Moreover, the military already had plans to equip units with these tanks.
Thus, in a memorandum from the commander of the armored and mechanized forces of the USSR Armed Forces, Marshal of the Armored Forces S. Bogdanov, on the plan for the distribution of armored vehicles, sent to the Deputy Minister of the USSR Armed Forces, Marshal Soviet Union A. M. Vasilevsky on November 13, 1948, it was said:
“I present for your approval a plan for the distribution of new armored vehicles coming from industry in 1949:
…2. The plan proposes to issue 50 IS-7 tanks and 300 IS-4 tanks received from industry for rearmament of the following formations:
IS-7 tanks - in the 8th mech. army, meaning to rearm all army divisions with IS-7 tanks.
IS-4 tanks - in the 5th Guards. fur. army to re-equip the 22nd mech. divisions, 7th mech. army for the rearmament of all army divisions, the 1st Tank and 2nd Guards Tank Divisions."
But along with this, the command of the armored and mechanized forces of the Soviet Army had a significant number of questions about the IS-7. They were connected both with the failure of the Kirov Plant to fulfill the plan to produce an initial batch of 15 vehicles in 1948, and with shortcomings identified during testing of the tank. Moreover, the main concern of the military was caused by the design flaws of the machine. On December 24, 1948, the commander of the BT and MB of the USSR Armed Forces S. Bogdanov informed the Minister of the Armed Forces, Marshal of the Soviet Union N.A. Bulganin the following:
“I report that the resolution and order of the Council of Ministers of the USSR No. 891-284ss of 03/20/48 and No. 10429ss of 07/28/48 oblige the Kirov plant in Leningrad to produce a pilot batch of new heavy tanks IS-7 in 1948 quantity 15 pieces.
Production of 50 IS-7 tanks is planned for 1949.
The Kirov Plant did not comply with the Government decree on the production of an experimental batch of tanks and in 1948 will not hand over a single tank for this batch.
In 1948, state tests of one type of IS-7 were carried out.
The tank failed the test.
A number of items need to be added to the design of the tank, the need for which was identified during the testing process.
To determine the possibility of adopting the IS-7 tank into service and mass production, it is necessary to re-conduct state tests of two tanks and military tests of 15 tanks in 1949, and these tanks can only be taken for testing in addition to the 50 tanks scheduled for production in 1949, so the release of an experimental batch of tanks is not included in the plan for 1949.
I consider it necessary to make all changes to the remaining 35 tanks produced in 1949 based on the results of military and repeated state tests.
With this solution to the issue, you can count on receiving 35 conditioned IS-7 tanks in 1949.
I ask for your instructions."
By the way, the military had complaints about the tank industry - they believed that the “industrialists” were not seriously engaged in improving armored vehicles and were not doing everything in their power to equip the Soviet Army with modern armored vehicles. And the story with the IS-7 tank seemed to them very indicative in this sense. For example, Marshal of Armored Forces S. Bogdanov on January 13, 1949 sent to the Minister of the Armed Forces of the Soviet Union N.A. A memorandum to Bulganin, in which, in particular, he wrote:
“I report that the state of the industry producing armored vehicles, as well as the development and research base for its improvement today, despite the decisions of the Government, does not meet the needs of timely equipping armored and mechanized troops with the latest models of military equipment. It also does not satisfy the conditions for such a deployment of development and research work, in which one could be confident that we will ensure the preservation of the advanced role of military equipment in the future...
As a result of the current situation, plans for development and research work, approved by resolutions of the Council of Ministers of the USSR, were not implemented either in 1947 or in 1948, which led to a delay in equipping the armored forces with new types of weapons and, in particular :
By tanks.
a) Resolution of the Council of Ministers No. 935-288ss of April 9, 1947 obligated the Ministry of Transport Engineering and the Leningrad (Kirov) Plant to produce in 1947 a pilot batch of new IS-7 heavy tanks in the amount of 10 pieces. for testing.
This resolution has not been implemented. Not a single IS-7 tank was manufactured in 1947.
Resolution of the Council of Ministers No. 891-284ss of March 20, 1948 and Order of the Council of Ministers No. 10429ss of July 28, 1948 obligated the Ministry of Transport Engineering and the Leningrad (Kirov) Plant to produce a pilot batch of IS-7 tanks in the amount of 15 pieces.
These government decisions have also not been implemented. Not a single IS-7 tank was delivered to this batch, despite the fact that the Minister of Transport Engineering, Comrade Nosenko, assured you that he would still ensure the production of three IS-7 tanks out of fifteen in 1948. Comrade Nosenko did not fulfill his promise.
An inspection carried out by a commission that visited the plant on the orders of the deputy. Chairman of the Council of Ministers of the USSR, Comrade Malyshev, it was established that the Leningrad (Kirov) plant, contrary to the resolution of the Council of Ministers, stopped tank production.”
It should be said here that by the time the above document appeared, the fate of the IS-7 was practically sealed. And although by this time the model of the IS-7 tank No. 3, which had arrived in Kubinka, had managed to undergo a run-in and short-term (from January 10 to 15, 1949) special tests in winter conditions, an order soon followed - to stop the tests and put the tank into storage.
And on February 18, 1949, Resolution No. 701–270 of the Council of Ministers of the USSR was signed, according to which the mass of a heavy tank should not exceed 50 tons. The same document entrusted the Chelyabinsk Kirov Plant with the design and production of prototypes of such a machine - it was later put into service as the T-10 tank. Also, by Decree No. 701–270, further work on the IS-7 tank was stopped, all design documentation for this vehicle, equipment, fixtures and manufactured components (for example, by this time the Izhora plant had manufactured 25 sets of IS-7 hulls and turrets, from which four were used for the manufacture of prototype tanks, and two were used for shelling tests) were supposed to be mothballed and put into the mobilization reserve.
There were several reasons for this decision. Firstly, the excessive mass of the tank, which exceeded the load-carrying capacity of most bridges that existed at that time. In addition, when transporting IS-7 vehicles, problems with transport would inevitably arise - special railway cars would be required (as was once the case with the KV-4 and KV-5). Also, the army did not have tractors capable of evacuating damaged tanks. Secondly, it became clear that organizing serial production of the IS-7 would require significant financial investments and restructuring of production at factories involved in the production of components for the new machine. After all, the design of the tank used units that had not previously been used in domestic (and partly in the world) tank building: a diesel engine with a power of more than 1000 hp, an ejection cooling system, soft fuel tanks, beam torsion bars, tracks with a rubber-metal hinge, a sight with a stabilized field of view, new system fire control, gun loading mechanism, infrared night vision devices and much more. There were also problems with mastering the production of the M-50T engine.
Nevertheless, the IS-7 heavy tank can be considered, without exaggeration, a masterpiece of Soviet heavy tank design. He had no equal in the world in terms of the totality of basic combat indicators. With a combat weight similar to that of the “Royal Tiger,” the IS-7 was significantly superior to this one of the strongest and heaviest production tanks of World War II, created only two years earlier, both in armor protection and in armament. We can only regret that the production of this unique combat vehicle was never launched.
The only example of the IS-7 tank (machine No. 3) that has survived to this day is on display at the Military Historical Museum of Armored Weapons and Equipment in Kubinka, near Moscow.
The base of the IS-7 tank was supposed to be used to create heavy self-propelled artillery installations of large calibers.
Thus, in the second half of 1947, designers of the Leningrad Kirov Plant developed a preliminary design of a machine designated “object 261”. It was a fully armored self-propelled gun with a front-mounted fighting compartment, armed with a 152-mm high-power M-31 cannon (initial projectile speed - 880 m/s). A wooden model of the machine was made, which, along with the drawings, was submitted for consideration to the State Technical University and the State Agrarian University. In general, the project received the approval of the military, but its completion was postponed until the completion of work on testing and fine-tuning the IS-7.
A little later, but almost in parallel with “object 261”, the designers presented another version of the self-propelled gun - “object 262”. It was a semi-open type vehicle with a rear-mounted fighting compartment and a 152-mm M-48 cannon (initial projectile speed 1000 m/s). This option was also presented to the GABTU and the State Agrarian University, and the decision on it was the same as on “object 261”. After the resolution of the USSR Council of Ministers of February 18, 1949, all work on “object 261” and “object 262” was stopped.
In this article we will look at what is significant about the IS series tanks and their contribution to world military science. This series of heavy Soviet tanks was developed and produced during the Second World War and post-war period and was named after Soviet leader Joseph Stalin. Below is an overview of all tanks of this family.
IS 1
The IS 1 tank and the IS 2 tank are the first in the IS series of heavy tanks. They were developed during the Great Patriotic War and began production in 1943. Were taken as a basis soviet tanks KV 1 and KV 13. The prerequisite for the creation of new tanks was the appearance in service German army tanks of the "Tiger" model.
Combat use of IS 1 in the history of the Great Patriotic War was unsuccessful, since the tank's guns could not always penetrate the armor of enemy combat vehicles.
IS 2
The performance characteristics of the IS 2 were no different from the IS 1, the weight was 46 tons, but the tank was equipped with more powerful weapons (122 mm gun), so the decision was made to widely produce this particular model. The rate of fire of the gun, according to the description, was 3-4 rounds per minute, however, according to the description of eyewitnesses, in combat conditions the rate of fire could reach 5-6 rounds per minute.
The combat use of IS 2 is difficult to overestimate. Tank divisions in the best possible way proved themselves during the assault on cities, which at that time were impregnable fortresses. Also, thanks to its heavy weapons, the IS 2 performed well in clashes with German “Panthers” and “Tigers”.
Based on IS 2, heavy tank destroyers ISU-122 and ISU-122S were also developed and put into production, in which the gun systems were significantly redesigned.
Still, the model had weaknesses, such as weak armor and an unreliable engine, so the Soviet command decided to develop designs for subsequent models.
IS 3
Since IS 1 and IS 2 had vulnerabilities, it was necessary to work on new designs. The IS 3 tank was also developed during the Great Patriotic War, but did not take part in any battles, since the first models were released in May 1945. Work on the drawings of the model, originally called “Kirovets-1,” began in the summer of 1944.
The tank was developed primarily as a vehicle capable of withstanding combat with enemy equipment. The frontal part of the tank was capable of withstanding a shell from any tank of that time and an anti-tank gun; the side parts, thanks to the large armor, also protected from most shells.
The tank, like its predecessor IS 2, was equipped with a powerful armor-piercing 122-mm D-25T cannon. Thanks to the characteristic shape of the upper frontal part, the tank received the nickname “Pike”.
Despite the excellent protective characteristics, this model also had weaknesses - engine failure, problems with the chassis and transmission. As a result, in 1946 it was decided to discontinue the tank from production.
IS 4
Work on drawings for a model of a new tank began in 1944. The IS 4 tank was finally developed and adopted by the USSR in 1947. The model is a continuation of the IS 2, but has stronger armor. The weight of the tank was about 60 tons, which is why it was decided to install more powerful V-12 engines with 750 hp. (before this, tanks of this family were equipped with 520 hp engines).
During operation, it was discovered that the tank had weak points. For example, the mass of the tank exceeded the load-carrying capacity of most bridges of that time, the transmission circuit turned out to be very unreliable, so after the release of a small series, the tank was discontinued.
IS 5
The IS 5 tank had an almost identical design to the IS 4. The main difference was the 100-mm S-34 cannon, which, however, could not prove itself. As a result, IS 5 remained a prototype. Despite this, the history of the IS 5 does not end; one of the tank variants, object 730, became the ancestor of the subsequent IS 8 model.
IS 6
Another model, which one might say remained only in drawings and diagrams, was the IS 6 tank. Development of the tank began in 1943. The model had some innovations compared to its predecessors. For example, the tank design provided for an electromechanical transmission. However, the tank's performance characteristics did not have any obvious advantages over the production models IS 2 and IS 3, so the Soviet command decided to close the project.
IS 7
Work on the drawings of the IS 7 tank began in 1945, and the first tests were carried out in 1947. The tank was based on the IS 3 model, but had a number of changes:
the crew was increased to 5 people (due to the fairly large weight of the shells, a second loader was added)
130-mm S-70 cannon, which was developed on the basis of a naval ship gun
semi-automatic gun breech, which made it possible to increase the gun's rate of fire to 6-8 rounds per minute
The bow of the tank was designed according to the “pike nose” design, like its predecessor, but the model’s armor was increased.
The IS 7 turret was very large due to the amount of armor installed, but was notable for its low height.
A review of the tank allows us to conclude that most of its characteristics were ahead of their time, but the tank was never put into service.
Based on the IS 7, variants of self-propelled artillery units were also developed, but they also remained only prototypes.
IS 8
Work on the IS 8 tank began in 1944. There were modifications of this machine, IS 9 and IS 10, but after the death of Joseph Stalin, it was decided to rename the model T-10. Due to its characteristics, the tank was accepted for production in 1954 and was produced until 1966, and was in service right up to 1993, that is, almost 40 years. Despite this, the tank never took part in any battle.
The tank, like its predecessor IS 3, had a “pike nose”, but more powerful armor. The weight of the tank is about 50 tons. The IS 8 was equipped with an already proven 122 mm gun. The tank was also additionally equipped with two 12.7 mm machine guns. The first was coaxial with the main gun, the second had a turret design and was placed on the roof of the turret. In later modifications, 14.5 mm KPVT machine guns were installed instead of DShKM.
Based on the T-10 (IS 8), several modifications of tanks were created:
- T-10A - a new gun with a vertical plane stabilizer was installed on the model, a night vision device appeared
- T-10B - improved aiming system installed
- T-10BK - command version of the T-10B
- T-10M - developed and released in 1957, the tank had several innovations: an improved 122 mm gun, a modified and strengthened turret design, and anti-nuclear protection.
Also, the T-10 (IS 8) became the basis for the creation of such machines as:
- object 268 - self-propelled artillery unit (SAU)
- TPP-3 - mobile nuclear power plant
- RT-15 and RT-20 - launchers created on the basis of the T-10 chassis
- 2B1 - self-propelled mortar launcher designed to fire nuclear weapons
However, most of these and other developments remained only on diagrams and drawings.
Conclusion
This review provides information that starting from the Great Patriotic War and almost until the end of the 20th century, IS series tanks were of great importance in military history. T-10 (IS 8) is one of the last heavy tanks in the world. Since modern army weapons have enormous combat power, heavy tank armor has become less relevant. Light and medium tanks are used in combat, capable of coping with a large number of tasks in lightning-fast combat conditions.
Video about IS tanks
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| Tanks IS-1 and IS-2. Exterior overview |
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The vast majority of IS-1 and IS-2 tanks came from the assembly shops of one enterprise - the Chelyabinsk Kirov Plant. The remark associated with the epithet “overwhelming majority” has to be made due to the fact that, as often happens when we talk about Soviet industry, the period of the war, and here there is an exception - in 1945 a certain number of IS-2s were assembled in Leningrad.
In this article, issues related to production dates and the specifics of assembly plants will not be specifically considered (I do not have sufficient information and do not pose such a task); the work is devoted to another issue, much more pressing for the modeler - the exterior features of the IS-1 and IS tanks -2.
Armor casting for the production of IS-1 tanks was carried out by plant No. 200, located in Chelyabinsk (on the territory of a special mechanical plant No. 78). Most likely, turrets, commander's cupolas, bow parts and turret boxes for the "firstborn" of the IS family were cast at this plant. The same plant poured similar parts for the IS-2 tank. In parallel, for the same tank, a similar range of parts was supplied by the Ural Heavy Engineering Plant (UZTM) in Sverdlovsk. Additionally, armor castings for the towers were manufactured at the Hammer and Sickle metallurgical plant (Moscow) and at the Mariupol metallurgical plant named after. Ilyich (Mariupol) Both factories have been involved in the production of towers since May 1944...
PART 1. TOWERS
Towers produced at plant No. 200
IS-1
For the first modification of the IS (and for the few KV-85s), the turrets were cast at factory No. 200. The only surviving turret from that period is on the KV-85 installed in Avtovo. http://legion-afv.narod.ru/KV-85.html A distinctive feature, in addition to the clearly visible and well-known ones - the symmetrical roof, the slightly convex turret mantlet - is the commander's cupola, inherited from the "Object 233". It can be identified by the cutouts on the turret body, intended to accommodate the antenna output cups -
Commander's cupola of early IS-1 turrets installed on KV-85 tanks
One of the two recesses in the body of the turret for the antenna output is clearly visible. The turret itself was inherited from the experimental tank "Object 233"
It also has a slightly different form of flattening on the vertical walls of the tower. The turret, oval in plan, is no different in size from the turrets on the IS-2.
Such turrets, in addition to the monument tank in Avtovo (which, in itself, is a weak example - since the turret on it is from an experimental tank) are also visible in front-line photos of the KV-85. In the case of the IS-1, with the appearance of archival photos of higher quality, it is also clear that there are cutouts for glasses.
Also, you should pay attention to the convex “mushroom” of the turret fan - the IS-1 turrets had their own, specific one - the supporting surface was wider than the slots for air flow, 130 mm long. -
Fan "fungus" unique to IS-1 turrets
Even on the very first IS-2s, judging by the photos, such “fungi” were no longer installed.
On the IS-1 turrets there was a technological sample on the lower edge of the turret, on the right -
Technological sampling on the lower edge of the tower
The main distinctive features of the armor casting of the turret itself are no different from those on the IS-2 turrets, about which we'll talk below.
IS-2
The main, clearly visible feature of the armor casting of the turrets of this plant is the casting seam in the front part of the turret, passing below the cheekbone -
Casting seam of towers of plant No. 200
At the stern of the towers were located characteristic appearance casting numbers - in the form of a code consisting of a letter and a number in the numerator, and a two- or three-digit combination of numbers in the denominator.
On the towers of early releases, the letters and numbers are small, arranged in two lines without a dividing line - alphanumeric combination on top, and numbers below - 
Casting number on the tower of plant No. 200 of early releases
A later type of casting number - a dividing line and an additional letter appeared -
Casting number of the plant No. 200 on the tower of late releases
It is worth highlighting the “early” tower of plant No. 200. Such a tower was installed at least until mid-March 1944. Her distinctive feature is the tide on the left side, in the area of the commander's cupola -
Pay attention to the tide below the commander's cupola - a distinctive feature of the "early" tower of factory No. 200
a slightly different configuration of the commander’s seat’s widening, and a characteristic cutting of the rear roof sheet, in the area of the commander’s cupola and antenna output -
A characteristic cutout in the rear roof sheet, in the area of the commander's cupola
Such towers were also equipped with commander's cupolas of the early type - oval in plan, with noticeable flattening on the vertical part (but not identical to the command cupola from "Object 233"!), viewing slits 12 cm long -
Commander's cupola manufactured by plant No. 200, installed on IS-1 turrets and on the "early" IS-2 turrets
The casting numbers, apparently, were located in the upper part of the turret.
Subsequently, the towers of plant No. 200 received the form of a “classic appearance” - with an asymmetrical roof and a commander’s cupola, the length of the viewing slots in which was 19 cm. The cupola itself, also oval in plan, was more smoothed out. Casting numbers were located, as a rule, on the top of the turret -
Late commander's cupola produced by factory No. 200
Using the example of the vehicle from Overlun, it can be argued that the turrets that I called “early” could be equipped with commander’s turrets of a later appearance - smoothed out, with long viewing slits.
Also. You should pay attention to the torsion bar tube of the loading hatch - on early turrets it was shorter.
Towers manufactured by UZTM
The plant in Sverdlovsk also produced turrets with a narrow gun embrasure. However, unlike plant No. 200, UZTM initially produced turrets for the IS-2 with a “classic” appearance - designed for the Object 240 - with an asymmetrical roof.
On towers produced in Sverdlovsk, the molding seam pattern is different. It goes right along the cheekbone -
The first version of the casting seam on towers produced by UZTM
from the sides of the tower, below the area of the pistol ports, large areas of fire cutting are clearly visible.
Commander's cupolas (oval in plan), also, were of only one type - they have a pronounced cut from 6 feeders, and a casting seam above the viewing slots (the length of the last 19 cm) -
Commander's cupola manufactured by UZTM
The rear part of the roof, throughout the entire production period, is semicircular -
The rear part of the roof on towers produced by UZTM throughout the entire production period
There are no casting numbers at all -
Turret feed produced by UZTM
Sometimes! there are some symbols (?) in the form of one or two (paired) vertical stripes, approximately equal to the size of the numbers on the towers, but they don’t look like numbers....
Turret stern version produced by UZTM
Many towers produced by UZTM have a different location of the casting seam - horizontal - along the entire perimeter of the tower casting -
The second version of the casting seam on the UZTM towers, probably a later one
There is a photograph of the IS-2, at the training ground, dated in the winter of 1945, exactly such a tower is visible. But in a front-line photo such a tower was captured only once - a tank from the 26th OGV. TTP in Prague, May 45th... There is also a suspicion that a tank with such a turret was included in a newsreel from the winter-spring of 1945, although I am not one hundred percent sure. In any case, a tower with a horizontal casting seam, very rare for wartime.
Perhaps such towers were produced at the final stage of production, and practically did not reach the front, and their prevalence on current ISs installed on pedestals is explained by the fact that higher-quality castings made after the end of the war (or at its final stage) were installed during modernization in the post-war period. A. Sergeev mentioned the replacement of the towers in one of the discussions on the forum...
Closing the review of two factories, which, among other things, produced turrets with a narrow embrasure, it is necessary to cancel some nuances common to them:
The narrow casing of the gun was not symmetrical relative to the center of the barrel; its left part, with the hole for the sight, was 13 cm wide, and the right part was 9 cm wide.
On the narrow casing, the four bolts on the gun flange were not covered with welded “caps” - this detail appears only on the extended gun casings.
The handrails on the tower are of an early type - which are only on top, going around the rear of the tower from the sides - judging by the surviving samples (Overlun, fragmentarily Salantai) were made of pipes with a diameter of 26 mm. (approximately, with a discount for the measurement error with a tape measure) based on measurements from Overloon
SIM plant towers
According to information from Yuri Pasholok, this plant received documentation for the production of towers at the very end of April 44th. It took quite a long time to set up production at the plant - in May, not a single tower was accepted, and things started to more or less start only in August. The castings were sent to UZTM. Distinctive feature of this plant - "calligraphic" number on the stern of the tower -
Casting number on the towers of the SiM plant
At the same time, the tower has a faceted roof, apparently from the summer of 1944 -
Faceted roof on towers manufactured by SiM
at least the tank raised in Lithuania, lost at the end of July '44, still had a semicircular roof.
Com. There could be two types of turrets on them. Both products from factory No. 200 (late, smoothed, with long viewing slits) and UZTM.
The casting seam on the turrets is very similar to UZTM, but, approximately under the pistol port, the seam has a slight downward deflection -
Molding seam on towers produced by the SiM plant
in contrast to towers produced by UZTM, in which this seam is straight, encircling the tower horizontally, until it begins to rise along the cheekbone.
Other differences between SIM and UZTM are that the feeder cuts at the bottom of the turret sides look different (for SIM there is also a clearly visible feeder at the stern), and the vertical casting seams running under the horizontal seam on SIM turrets.
Mariupol Metallurgical Plant named after. Ilyich
According to new information- turrets for IS tanks cast in Mariupol began to arrive at plant No. 200 already in January 1944! We must pay tribute to the labor feat of the plant workers - in such a short time they established production at an almost completely destroyed enterprise. Due to the great similarity with the products of plant No. 200, it is not possible to accurately identify the Mariupol castings. Perhaps they were no different at all, except for the casting number codes, which, without factory documentation, are completely impossible to understand. For now, as working version, We distinguish them by larger casting numbers and rough castings, although this is largely speculative and does not eliminate all questions.
Casting seam on the tower of the Mariupol plant
the casting numbers at the rear of the turret are larger, rougher -
Casting number on the tower produced by the Mariupol plant
The commander's cupola is similar to the late one produced at Factory No. 200. Probably, since the summer of 1944, the roof of the tower has been faceted, just like on the towers produced by SIM -
Aft roof sheet on the tower of the Mariupol plant
Another difference between the turrets from Mariupol is the shape of the tide of the turret's rear machine gun. At first it is only a little rough, compared to similar forms on UZTM or SIM (see above) -
Variant of the stern machine gun tide on the towers of the Mariupol plant
And subsequently transformed into a massive, box-shaped tide -
A more box-like shape of the stern machine gun tide on the turrets from Mariupol
In addition, it is worth paying attention to a large number of welded cracks in the tower casting - it is obvious that in Mariupol there were certain problems with casting, because the plant set up production in emergency mode, immediately after liberation in September 1943.
PART 2. CASE
Specifics of a “broken nose”.
All turret boxes designed for installation of the nose casting of the first sample (the so-called “broken nose”) had the same size, at the junction with the frontal part - in the lower part it was 1600 mm.
There are several types of nasal casting.
Nose casting from factory No. 200
Distinctive features:
- casting numbers on the bow casting, below the driver's hatch plug. It’s difficult for me to say yet about the specifics of the numbers; in general, they resemble similar earlier ones on tower castings (see the section on towers), only in reverse - a three-digit number on top, a letter and a number below. Another letter between them, on the side.
There are several varieties of this part that have external differences:
a) The sheet in which the hatch plug is located is milled, At the bottom of the frontal part, on the sides, there are characteristic rectangular, pronounced tides. -
Broken nose option "a"
b) The same milled sheet with a hatch-plug, but the tides are smoothed out -
Broken nose option "b"
c) There are also similar castings in which the tides are clearly expressed, but the sheet is not milled -
Broken nose option "b"
d) Option when the sheet is not milled and the tides are smoothed out -
Broken nose option "g"
UZTM nose casting
The most recognizable feature of the casting from this plant is the feeder cut in the center of the bend of the upper and lower front plate -
Nose casting produced by UZTM
As far as I can tell, there are no casting numbers on the casting.
Milling was carried out on the lower front sheet, under the towing hooks and towing hook latches -
Lower front sheet on UZTM casting
another one is immediately visible characteristic UZTM castings are a high-lying horizontal casting seam that divides the lower frontal sheet into almost two equal halves (the lower one is still somewhat narrower). Along the seam line, tides are formed and characteristic on the sides of the lower frontal sheet, just like on the casting of plant No. 200, but, accordingly, more elongated in height.
Also known is a completely milled lower front sheet, produced by UZTM -
Fully milled lower front sheet on UZTM casting
How common this is is not known, yet in front-line photos the cast bow parts of the UZTM are clearly identified by the high-positioned casting seam.
A common feature on cars with a broken nose from both plants was that the air duct windows on the roof of the engine compartment were longer than on cars with a straight nose. To do this, cutouts 10 cm deep were made in the turret box, on the line of interface with the roof sheet of the engine compartment. (I measured it myself - there may be errors).
"Extended" air duct window. Late-style air duct grille, with longitudinal strip
As far as is known, the grilles on the IS-1 and early IS-2 did not have a longitudinal bar on the frame. But I can’t say exactly when it appeared...
"Straight nose"
Casting from plant No. 200
For the straightened nose, a new turret box was developed - “widened”. Her Bottom part, at the junction with the bow part, was 1840 mm wide.
At the same time, it is completely possible that the cast straightened nose was installed with an early type turret box, the so-called “narrow”.
The nasal castings themselves, very roughly, can be divided into two types - early and late.
Early nasal castings have a noticeable rounding radius when the planes that form the upper and lower frontal sheets meet -
The first version of the straightened nose produced by plant No. 200
The radius along which the surfaces forming the frontal sheets and the characteristic fire cut meet are clearly visible.
The assumption that this appearance of the frontal casting is typical for the early period of production is based on the fact that the tank raised in Lithuania (lost in the summer of 1944) and the tank from Snegiri (November release of 1944) have this type of nose casting .
Subsequently, the nose casting changed slightly - the surfaces forming the upper and lower frontal sheets were mated at a much smaller radius, forming a noticeable angular joint. The cut of the feeders was also designed in such a way that it created an angle -
The second version of the straightened nose shows a more acute angle along the line of intersection of the VLD and NLD
At this stage I cannot vouch for the absolute correctness of such a division, but based on the serial numbers, I do not yet see any contradictions - nose castings identified as later ones are found on cars produced in 1945.
Unfortunately, in front-line photos it is not so easy to trace these subtle nuances....
Also, the characteristic nuances inherent in plant No. 200 include the hinges on the stern hatch of the inclined stern sheet.
At first they looked like this:
Aft hatch with hinges of the first type
Subsequently, a slot appeared on them -
The second version of the hinges on the aft hatch
Welded frontal part produced by UZTM
Under the straightened nose, produced by UZTM, a “wide” turret box was developed, the width of which, in the lower part (at the junction), was 1856 mm.
Hulls with a straight nose, produced by UZTM, had only one external transformation throughout the entire production period - the method of attaching the lower frontal plate to the upper frontal plate, and the vertical sides of the hull.
Initially, the lower frontal sheet was assembled “into a spike” -
The nose part is made of rolled armor produced by UZTM from the beginning of production, according to the approved drawings.
A good, clear photograph, please do not pay attention to the color - this tank, in revenge for his impotent fear, was mutilated by a Czech fagot named David Czerny.
Late cars (at this moment I can talk about hulls produced no earlier than April 1945) had a sheet without cutouts, welded “into the overlay” -
Lower frontal plate, no later than April 1945.
An important nuance in the appearance of later buildings produced at this plant were three corners welded onto the blind frame -
Building manufactured by UZTM. Three corners welded to the blind frame are clearly visible
This has never happened on cases produced by Factory No. 200.
For a long time, the hinges of the hinged aft hatch on UZTM hulls were no different from the same parts manufactured by plant No. 200. Perhaps they were somewhat shorter, but this moment There is no sample to compare these positions, and it is premature to make such a statement.
Towards the end of production, the shape of the hatch hinges changed -
IS-2 feed produced by UZTM of late production periods. New form hinges on the hinged aft hatch and three corners on the blind frame
Such “triangular” hinges are found only on UZTM bodies with a straightened nose and are necessarily accompanied by three corners on the edge of the blinds. The combination of three corners on the blind frame and “old” hinges is possible, but triangular hinges without three corners on the blind frame are not.
PART 3. CHASSIS, MTO, AND OTHER....
IS-1 tanks did not have the first reinforced balancer.
On the IS-1 and early IS-2 tanks (I’m not ready to indicate the exact period, but there is an assumption that all vehicles with a “broken nose”) were equipped with support rollers without large lightening holes, similar to the KV-1 rollers -
Support roller IS-1 and IS-2 of early production periods
Subsequently, rollers of the “classic” type were installed -
Support roller IS-2, presumably from the summer of 1944
On early vehicles (judging by the surviving vehicles - at least until March 1944), the track tension mechanism was welded high, above the line on which the balancer travel limiters were located -
left side of IS-2 early production period
in this case, the first balancer travel limiter, on the starboard side, was welded vertically -
starboard side of an early IS-2. The travel stop is welded vertically.
Subsequently, the track tension mechanisms were lowered lower, installing them below the line on which the balancer travel limiters were located. To accommodate the right track tension mechanism, the first balancer travel limiter, on the starboard side, was welded obliquely -
Balancer stroke limiter, on the starboard side, inclined towards the rear of the tank
Another feature of early vehicles is the button for communicating between the crew and the landing force. On the IS-1 and early IS-2 it was located on the left side, between the brackets of the external fuel tanks - 
IS-2 released in February 1944. Between the external fuel tanks you can see a button for communication with the crew
Power was supplied by a wire, which was placed in a tube led out through the window of the left air duct -
Left air duct window. In the area of the near corner, the overhead frame with the mesh, you can see the output of the tube with the cable connected to the button.
On early cars, the aft dimensions were installed at the rear of the engine compartment roof, behind the exhaust pipe caps -
Location of the clearance and eye for the lanyard in the aft part of the engine compartment roof
and the eyes for attaching the lanyard were welded in the area of the cut of the inclined side sheet. This arrangement of these parts is typical for the IS-1 and IS-2 of early releases.
Subsequently, the button was moved to the stern. Obviously, for some time (more common on UZTM machines with a broken nose), the button was located on a cut of the top side sheet -
The button is on the rear of the hull, on the left side.
Moreover, the tube for the cable was brought in from the previous point, through the air duct window.
Subsequently, the button “migrated” to the starboard side -
A button on the right side of the stern and a marker welded to the side of the hull
Around the same time, the stern dimensions were moved from the roof of the engine compartment to the sides of the hull. The tube with the cable was connected either to the right aft clearance, or exited through a gap in the junction of the engine compartment roof and the inclined stern sheet.
This position of the button was standard for cars with a straight nose, and on cars with a “broken nose” during the spring-summer of 1944 there was a certain leapfrog with its location, which cannot be tied to the manufacturers of the cases, and to the production period... .
Over time, the lanyard eyes were moved to the upper cut of the side sheet. This has become typical for straight nose cars, but during the spring/summer of '44, a variety of combinations are encountered.
The over-engine hatch, initially (on early IS-1 and IS-2 tanks) had one eye bolt with a ring -
Over-engine hatch on IS-1 and IS-2 early releases
Subsequently, probably by the summer of 1944, there were two eye bolts -
Late type over-engine hatch
An important feature of the IS-1 and early IS-2 tanks (at least until mid-December 1943) was the presence of three bolts at the corners of the inclined rear plate, in the top row -
There are three bolts at the corners of the inclined stern sheet
Three bolts are visible in the left corner of the inclined stern plate. IS-2 with serial number 122-31221, December 1943
IS-2 tanks, produced already in January 1944 (it is possible to talk about the 16th vehicle produced in January 1944) already had a “standard” set of bolts in the corners of the upper part of the rear plate - two on each side.
In conclusion, it is worth paying attention to a couple of points that are not directly related to the production of IS-2 tanks, but relate to their modernization after the war, in the period from 1951 to 1957.
Throughout the entire production period of the IS-2, only one type of mud cleaner was installed on it. Like this -
Dirt cleaner for IS-1 and IS-2 tanks
A different type of mud cleaner (from the IS-3 tank) appeared only during the modernization process.
The location of the locks on the round aft hatches for access to the transmission during the war period was horizontal, i.e. parallel to the transverse planes of the roof and bottom of the tank -
Location of locks on the round transmission access hatch
On the vast majority of IS-2 tanks that have survived to this day, the locks on these hatches are located differently - along the diagonal. However, not a single front-line photo showing IS tanks (and self-propelled guns based on them) shows such an arrangement of locks. Hatches with diagonal locks are found on IS-3 tanks, and, obviously, they appeared on IS-2 tanks in the same way, during the modernization process.
SPECIAL PART. HOW TO IDENTIFY THE MANUFACTURING PLANT BY
STERN?
Often, when choosing a model for a prototype, we see many interesting features and nuances (a striking example is the IS-2 of the 7th Guards TTB Brigade in Berlin, with tail number No. 434" and the name "Battle Friend", on the rear of the turret), but we cannot determine what kind of housing was used to build this IS?
Some observations can help in this matter, provided that the stern of the hull is visible....
The earliest ISs, with a broken nose, produced by plant No. 200, had this arrangement of eyes on the VKD -
The initial position of the eyelets is on the stern, on top, and on the hinged hatch, according to plant version No. 200
At the same time, cars with a broken nose, produced by UZTM, had a slightly different arrangement of these elements - see the upper eyes on the stern -
The initial position of the eyelets according to the UZTM version, on machines with a broken nose
In part, such a scheme, after some time, was adopted at plant No. 200; cars with straight noses demonstrate it everywhere -
An example of changing the location of the eyelets on the body of plant No. 200. Late body, slotted hinges
In this case, I especially draw attention to the change in the location of the eye on the folding part of the upper stern sheet - it is located quite high, very close to the second bolt, from the vertical row. Now the arrangement of the eyelets on the stern parts is completely different from the similar one according to the version of the UZTM plant.
A similar scheme appeared on early hulls with straightened bows produced by plant No. 200. In particular, we see this on a car produced in September, now standing in the Fort IX Czerniakowski Museum in Warsaw, Igor Perepelitsa did an excellent photo tour of it -
Two photos of the stern of the building of plant No. 200, the vehicle was produced in September 1944. Early hull with molded straight nose, non-slotted hinges
By the way, it was on this machine that TAMIYA made its model, and... very accurately conveyed the main nuances of the prototype.
But let's get back to our sheep...
At UZTM they continued to move the eyes along the stern.
Over time, the eyes in the upper part of the stern plate were moved even closer to the center, so that they began to be located directly on the sides of the gun bracket in a stowed manner -
The hull stern of the UZTM plant corresponds to the archival photo of the tank, from the state. tests, release in August 1944. The loops do not yet have a triangular base
And here there is one more nuance - not all UZTM tanks had it!
This can be seen in the photo of the IS-2 from Leshan (completely clean armor where the gun mount supports should be welded), which I cited above, and can also be seen in some front-line photos. incl. and the period of the 45th year...
When triangular hinges of the hinged hatch appeared on the UZTM bodies, the location of the eyelets did not change at first -
The body is made by UZTM, the front plate is “spiked”, the number, unfortunately, is not known. This is a former monument in Kaunas, now in Nizhnekamsk.
However, the latest tanks (we can still talk about April 1945), with NLD in the lining, demonstrate another change in the location of the eyes, on the hinged aft hatch -
Late version of the stern of the UZTM hull. This arrangement of the eyelets is confirmed by front-line photos from the winter-spring period of 1945.
An example of the practical value of these observations is this: with a very high degree of probability, it can now be argued that the famous tank No. 434 “Fighting Girlfriend” has a hull with a cast nose.
This list of nuances is not exhaustive, because New details are constantly being revealed and noticed. Most of the changes in the appearance of this tank are not tied to dates; these materials are still waiting for their researcher in the archives....
I express my deep gratitude to Vladimir Shaikin - the creator of the LEGION AFV website http://legion-afv.narod.ru/, all its authors who filled it with material, as well as Igor Perepelitsa - for many useful photo walks on his website http://modelizm .forum2x2.ru/forum, Oleg Leonov, Yuri Pasholok, Alexander Sergeev - for interesting discussions and valuable materials, as well as to all those who photographed IS-2 tanks in various museums and posted them for free access on the Internet. All photographs were used exclusively for non-commercial purposes.
Everyone Thanks a lot for your help!
Friends! Please note: in order to correctly correct the lyrics of the song, you need to highlight at least two words
[Verse 1, Oxxxymiron]:
Along the asphalt, past the cement,
Avoiding onlookers, to applause
Inhabitants of sleeping arrondissement.
Social bottom, classes of national elements.
Past the buildings municipal center.
And statues of the vice-mayor, whistling concerts;
I'm going down unprecedentedly justified.
And the hypocritically pardoned man is thirty years old.
Fuck, the universe clearly loves me.
If everyone didn’t know me, I would hardly have survived there.
But apparently the mayor needs to sell it to the poor street
There was mercy and generous justice - who knows...
I'm alive, thanks to fortune!
I balance across chasms on stilts.
I walk, stooping, and jumping up and down like a fool,
Through fate and storms, to the elusive Ultima Thule.
I thought time was up, the udder was milked.
There are ruts and potholes, boulders and blocks on the road
On my path between peace and war.
Some people think that I am very cunning.
Others see in me the naive world of games and books.
You understand: I am a hybrid, I grew up both like this and like that.
I was not designed for the spotlight, intrigue.
And adrenaline, the choice of the line of fate is not tricky.
I just wrote and looked out the window for years.
I crossed out, erased, and tirelessly grew fat in my notebook.
Fragile worlds fell apart in the darkness onto the table,
While the dead idols looked from the walls into the courtyard.
I was alone, the universe was leading along the edge.
Now, my f*ck is watching from every kiosk.
But what has changed? There's nothing inside, but it looks great!
After all, they twisted it into a knot the mighty of the world this.
So much so that stress, boiling, running, Quidditch.
I used to think that thirty was the end.
But here I am, you see, Glenfiddich.
They sulked and deflated. Won't you die?
They ask for something and spoil the air and nerves.
The medical examiner is either blood or semen.
For the bitch - a hand and a heart, for publishers - a booker, a deal.
For readers - stuffed animals in a cage.
Hey! I saw your circus from the gallows.
Forget Sun Tzu and Lao Tzu.
After all, there are only two ways in this circus:
Suicide or stoicism.
And if you didn’t choose suicide, then be patient.
Stop whining, let's go at full speed.
And yes, we piss, everyone is full, fear and solipsism,
But to spite the world, we will take off amid the bustle.
[Chorus]:
My city is timeless
Outside of territory, tribe, clan and empire.
Troy, Pompeii, Rome... My city is a mess and a vision,
What does a Bedouin see in the darkness?
My city is on a mountain of ruins.
My city is a labyrinth, I am a blind and inept guide through it;
And my city doesn't believe them. His reign is within,
But not under the mountain, and not in the city hall.
[Verse 2, Oxxxymiron]:
I'm a stoic, like Lucius Seneca,
I descend from the palazzo of the elite to the streets of the Ghetto.
Since you survived, you need to live and breathe deeper.
And the “*badass” Girl left, betraying me, but I will survive this too...
You answer this question for me:
Can a creator live in a tower? Ivory?
Be welcome to the palace or vehemently against the nobles,
Or maintain your neutrality...
[Shot]
[Answering machine entry|Kira.]
Are you not home yet? Strange...
Listen, what can I tell you, except that you are an idiot?!
And I’m very glad that you were released... We all almost went crazy here...
In general, you come back, and while I read “Where We Are Not...”
By the way... The title is crap!
Kiss!
About the song Oxxxymiron - Ivory Tower
- "Ivory tower". Mark was released, he walks through the city and thanks fate for being alive. Alice left him, but he is not worried about it. Mark rethinks his views, understands that as a creator he should only be an observer, and sees his books in kiosks. His thoughts are interrupted by a shot. The agent calls, she is glad that Mark was released and is going to read “Where We Are Not” written in “The Eve”. ©site
Additional Information
Lyrics of the song Oxxxymiron - Ivory Tower.Album "CITY".
Author of the text: Oxxxymiron (Miron Fedorov).
Zhenya Murodshoeva speaks in Kira's voice.
Additional vocals on track: Porchy.
Produced by Porchy.
Recording: Max Kravtsov.
Mixing: Max Kravtsov.
Mastering: Max Kravtsov.
Studio "Contact". City of St. Petersburg.
November 13, 2015.
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