Throughout the Great Patriotic War, heavy tanks of various types were the most important component of the armored forces of the Red Army. The most successful and perfect example of this class is the IS-2, which was put into service on October 31, 1943. It combined the successful developments of past projects and effective promising solutions, which made it possible to obtain very high tactical and technical characteristics and combat qualities. All the positive features of the tank have been repeatedly confirmed both at training grounds and in battles.
Consistent development
The development of Soviet heavy tanks during the war years was carried out by gradually improving and changing existing designs. A number of tanks were created, some of which were mass-produced and used by the troops. The most interesting processes in this area, which resulted in the future IS-2, took place in 1942-43.
In the winter and spring of 1943, a captured German tank Pz. Kpfw was tested. VI Tiger, which showed its high performance. It turned out that the existing heavy tanks of the Red Army cannot always fight such an enemy. To solve such problems, new vehicles with enhanced armor and weapons were required.
The development of such a tank was entrusted to SKB-2 of the Chelyabinsk Kirov plant and experimental plant No. 100. The result of these works was the appearance of the IS-1 tank, which was put into service in August 1943. However, this vehicle was not mass-produced - from October 1943 to January 1944, a little more than a hundred tanks were produced.
From the beginning of 1943, tank builders and gunsmiths studied the issue of increasing the caliber of tank guns. The principal possibility of equipping a promising heavy tank with a 122 mm rifled gun similar to the existing A-19 was determined, and soon Plant No. 9 began developing a new tank gun based on its ballistics. In the future, such a weapon received the D-25T index.
At the same time, the issues of installing a new cannon on a heavy tank were being worked out. The existing IS-1 chassis was taken as a basis for such a combat vehicle, which should have been equipped with an updated turret. The new project of Chelyabinsk designers received the number "240". Subsequently, the IS-2 and IS-122 indexes were assigned to him - they indicated the "origin" of the project and the caliber of the gun.
Object 240
The first version of the future IS-2 retained the basic features of the previous vehicle, although it had significant differences. Thus, the hull of the traditional layout retained the differentiated cast and rolled armor with a welded connection. An improved cast turret of sufficient volume was proposed for the installation of a new large weapon. The power plant and chassis did not undergo fundamental changes.
Tank "240" in the original version received a cast block of nose armor up to 120 mm thick at the top. The largest middle part of the forehead was 60 mm thick and inclined 72 °. The lower armor element with a thickness of 100 mm tilted forward by 30 °. The curved forehead of the cast turret was 100 mm thick. The side projection was protected by 90 mm rolled sheets; the upper elements of the hull and side of the turret sloped inward.
The main armament of the IS-2 was a 122 mm tank gun mod. 1943 or D-25T for single-case loading shots. The gun mount provided vertical guidance from -3 ° to + 20 °, and there was also a mechanism for fine aiming in the horizontal plane. For the D-25T, three types of projectiles were intended - the sharp-headed armor-piercing BR-471, the blunt-headed armor-piercing with a ballistic cap BR-471B and the high-explosive HE-471. All shells were used with a full charge of Zh-471.
Provided for the installation of a whole set of DT machine guns: coaxial, frontal in the hull and aft in the tower. Later, a turret was introduced for a large-caliber DShK on the turret. New tanks received it at the factory, old ones - right in the units.
Mobility was provided by a 12-cylinder V-2-IS diesel engine with a power of 520 hp. The design of the power unit as a whole repeated the IS-1, but some new elements were used, such as planetary swing mechanisms. The chassis was also borrowed with some modifications and changes.
The preservation of the power plant and chassis led to some reduction in mobility in comparison with previous heavy tanks. The IS-2 became heavier up to 46 tons, which reduced its power density and driving performance.
Running trials
At the end of the summer of 1943, the construction of an experimental tank "240" began at the plant No. 100. The car was not built from scratch, it was built on the basis of one of the Object 237 / IS-1 prototypes. In the shortest possible time, all new units were manufactured and installed, with the exception of the gun mount. D-25T and other details had to wait until the end of September.
In the middle of the month, Plant No. 9 made an experimental cannon and then spent about a week testing it. The gun showed its best side, but some details needed to be improved. The main complaints were caused by the insufficiently strong muzzle brake. A few days later, an experienced D-25T was sent to Chelyabinsk, and on September 30, she got up on the carrier. After that, tank "240", slightly different from the design, was ready for full-fledged factory tests.
The tests began with an accident and almost led to a tragedy. The tank made its way to the shooting range and fired several shots. With the next shot, the already damaged muzzle brake tore apart, its fragments almost killed several people. Fire tests had to be temporarily stopped - until a new muzzle brake was received.
On October 1-4, 1943, the prototype Object 240, together with the 237 tank, was tested on a 345 km track. The average speed on the route exceeded 18 km / h. Unlike "Object 237", "240" did without serious problems and malfunctions. At the same time, he twice had to work as a tug and pull out his "entrenched" brother.
On October 6, new sea trials took place on a route of more than 110 km, mainly on rough terrain. Despite some problems, the future IS-2 coped with the task and showed fairly high performance. The tests continued, and by the end of the month the prototype had covered more than 1200 km.
Firepower
In mid-October, Plant No. 9 completed the modification of the D-25T gun and carried out new tests. The improved muzzle brake again did not show a sufficient resource, claims were made against other units. However, the gun was tested and allowed for further work - after correcting the shortcomings.
The modified D-25T cannon was installed on the experimental "240", after which a new stage of testing began. The most interesting results from a practical point of view were obtained in December 1943, when the "Object 240" fired at captured samples of German armored vehicles. The tank clearly showed its firepower.
According to the "tabular" data, at a distance of 500 m at a meeting angle of 90 °, the sharp-headed BR-471 projectile was supposed to penetrate 155 mm of homogeneous armor; for 1 km - 143 mm, for 2 km - 116 mm. For the BR-471B blunt-headed projectile, penetration reached 152, 142 and 122 mm, respectively.
When using two armor-piercing shells of the 471st series, tank "240" confidently hit the frontal projection of the "Tiger" at distances up to 1500-2000 m. m. At distances of up to 1 km, the D-25T could hit the 200-mm armor of the Panzerjäger Tiger (P) Ferdinand self-propelled gun.
Beginning of the series
Thus, the future IS-2 was distinguished by outstanding firepower and could effectively fight any modern and promising enemy armored vehicles. At the same time, it was protected from enemy fire in a wide range of ranges and showed good mobility for its class.
According to the results of the first stages of testing, on October 31, 1943, the tank "240" was adopted by the Red Army under the designation IS-2. By this time, ChKZ began preparations for mass production, and in December it produced the first 35 machines. By the end of the spring of 1944, the rate of production was increased several times. Since June, Chelyabinsk has been shipping at least 200-220 tanks monthly.
New armor
In February 1944, work began on the modernization of the IS-2 by improving protection. The frontal armor, borrowed from the IS-1, in a number of situations could not cope with German shells, and it had to be strengthened. SKB-2 ChKZ and Plant No. 100 were again involved in the work. The latter began to study options for a deep modernization of equipment, while ChKZ limited itself only to reworking the nose of the hull - this made it possible to quickly introduce reinforced armor into mass production.
Based on the results of a short search, a new design was chosen with a straightened upper frontal part 100 mm thick at an inclination of 60 °, devoid of the characteristic "box" with a hatch and driver's sighting devices. The bottom element had the same thickness but a different angle. The possibility of making a forehead by welding from rolled parts or by casting in the form of a single unit was considered.
During the tests, it was shown that the top of the welded forehead withstands a shot from a 75-mm KwK 42 cannon from any distance, but the lower part breaks through, and cracking of the welds was also observed. The cast forehead even withstood 88 mm shells. To hit the improved IS-2 head-on, a German tank would have to come within a guaranteed penetration distance of the D-25T cannon.
In June 1944, manufacturers began preparations for the serial production of the IS-2 with new frontal armor. Over time, all production issues were resolved, and the tank with straightened armor replaced its predecessor in production.
Production rates
ChKZ manufactured the first serial IS-2s at the end of 1943. Production continued and gained momentum until it reached the level of up to 250 tanks per month - such figures were maintained from August 1944 to March 1945. In the future, the plan began to be reduced, and in June Chelyabinsk produced the last five tanks. Thus, in 1943 ChKZ gave the army 35 IS-2 tanks, in 1944 - 2210, and in 1945 - 1140. Total, almost 3400 units.
After the final lifting of the blockade, it was decided to deploy the IS-2 production at the Leningrad Kirov plant with the involvement of a number of other local enterprises. In particular, the armor was supposed to be made by the Izhora plant, which had already participated in the production of heavy tanks. The first machines were planned to be received in October 1944.
The restoration of Leningrad in general and LKZ in particular turned out to be extremely difficult, and the plans for the release of the IS-2 had to be revised several times. The assembly of equipment began in the fall, and the first batch of five tanks was completed only in March 1945, but its acceptance was delayed. The second batch went to the Red Army in May, and the first was accepted only in June. At this, the production of the IS-2 at LKZ ceased.
Combat victories
From the beginning of 1944, the IS-2 tanks entered the Red Army units. Their main operators were separate guards heavy tank breakthrough regiments (ogvtp). The main task of such units and their heavy armored vehicles was to strengthen the army formations in order to break through the enemy's defenses in critical sectors. Heavy tanks IS-2 were distributed among 25 breakthrough regiments.
Also, the IS-2 was supplied to units from the guards tank brigades, where they were supposed to serve along with the T-34 medium tanks. In this case, the task of the IS-2 was to follow the T-34 and defeat enemy vehicles from long distances.
Regardless of their affiliation and role on the battlefield, the IS-2 tanks with powerful armor and weapons proved to be a convenient and effective means of fighting the enemy. They could hit all the main armored vehicles of the Wehrmacht at significant distances, incl. from a safe distance, which gave known advantages of a tactical nature. The number of enemy tanks and self-propelled guns destroyed - and the consequences of this in the context of further combat - can hardly be overestimated.
The enemy quickly assessed the new Soviet technology and saw it as a serious threat. Even the appearance of the IS-2 on the battlefield could predetermine the outcome of the battle. Since the middle of 1944, in the reports of the Red Army tankers, there are references to the enemy's attempts to escape a collision with Soviet heavy tanks.
The creation of new types of equipment as a whole did not have a decisive importance in the course of battles. So, the episode of the Lvov-Sandomierz operation in August 1944 is well known, when the 71st rifle regiment collided with the newest Pz. Kpfw. VI Ausf. B Tiger II of the 501st heavy tank battalion. As a result of the battle, the Germans had to write off six Tigers-2; The Red Army suffered no losses. One of the tanks participating in this battle is now an exhibit of the museum in Kubinka.
However, the IS-2s were not fundamentally invincible. So, in 1944, more than 430 tanks were recorded as irrecoverable losses. Subsequently, their number increased. Hundreds of tankers were injured or killed.
The defeat of the tank in the upper frontal plate was virtually impossible; at the same time, there are known cases of penetration of the lower part with different consequences. German artillerymen and tankers, whenever possible, tried to hit the side, if possible from a short distance. So, at distances of up to 900-1000 m, the side armor could not always protect against 88-mm shells of the Tiger tank or against more powerful weapons.
After 1945
Heavy tanks IS-2 quickly became the most important component of the armored forces of the Red Army, capable of effectively solving special tasks. They were responsible for breaking through the defenses and supporting the advancing troops, worked as part of assault groups in cities, etc. In all cases, the powerful armor and 122mm cannon were the most serious arguments against any enemy arguments.
The IS-2 was actively used in all operations of the Red Army in 1944-45. The last shots of the D-25T cannons at real German targets were already fired in Berlin, incl. on the garrison of the Reichstag. Soon, a number of tanks were sent to the East to participate in the war against Japan.
In the post-war period, the IS-2 remained in service, transferred to friendly countries and underwent modernization. At the same time, the modernization of the fleet of heavy tanks was carried out due to the decommissioning of outdated and exhausted equipment and the supply of the latest machines - the IS-3 and T-10. Some of the tanks were transferred to friendly foreign states.
In 1957, another modernization program was launched, the result of which was the IS-2M tank. Replacement of some of the units and installation of new equipment made it possible to continue to operate. Small innovations were carried out later, until the end of the sixties.
However, the number of IS-2M tanks in units was gradually decreasing - as completely new vehicles arrived, they were transferred to training, sent for storage or disposed of. Later, the rejection of heavy tanks as a class began, and they were replaced by modern MBT. However, the official order to remove the IS-2 from service was issued only in 1997. Until that time, only monumental tanks and individual "tactical objects" at training ranges survived.
Best in class
The heavy tank IS-2 was the result of many years of development of the most important direction in the field of armored vehicles and combined the best practices of Soviet engineers. His appearance in the Red Army units had a most positive effect on their combat capability, giving them new tactical and strategic capabilities.
Despite the relatively small number, the IS-2 tanks and their crews took an active part in all the main operations and made a significant contribution to the overall victory. The merits of tankers who solved special tasks were marked by thousands of state awards, incl. the highest. After the war, the modernized armored vehicles and tankers continued their service and for many years supported their comrades on newer and more advanced equipment.
Taking into account such a history of service, features of combat use and design, the IS-2 can rightfully be considered the best domestic heavy tank of the Great Patriotic War, as well as one of the most important milestones in the history of our tank building.
