Experienced heavy tank "237" / IS-1. On its basis, the IS-2 will be created later. Wikimedia Commons Photos
Throughout the Great Patriotic War, the most important component of the armored forces of the Red Army were heavy Tanks different types. The most successful and perfect example of this class should be recognized as the IS-2, adopted for service on October 31, 1943. It combined the successful achievements of past projects and effective promising solutions that 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 the training grounds and in battles.
The development of Soviet heavy tanks during the war was carried out by the gradual improvement and modification of existing structures. 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, tests of the captured German Pz.Kpfw tank took place. VI Tiger, showing its high performance. It turned out that the existing heavy tanks of the Red Army can not always fight such an enemy. To solve such problems required new cars with enhanced armor and weapons.
The development of such a tank was entrusted to SKB-2 of the Chelyabinsk Kirov Plant and pilot plant No. 100. The result of these works was the appearance of the IS-1 tank, which was put into service already in August 1943. However, this machine was not mass-produced - from October 1943 to January 1944, a little more than a hundred tanks were produced.
Scheme IS-2 arr. 1943 Graphics Tanks-encyclopedia.com
From the beginning of 1943, tank builders and gunsmiths studied the issue of increasing the caliber of tank guns. The fundamental possibility of equipping a promising heavy tank with a rifled gun of 122 mm caliber like the existing A-19 was determined, and soon Plant No. 9 began developing a new tank gun based on its ballistics. Subsequently, such a gun received the index D-25T.
In parallel, there was a study of the issues of installing a new gun on a heavy tank. The basis for such a combat vehicle was the existing IS-1 chassis, 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 indices were assigned to it - they indicated the “origin” of the project and the caliber of the gun.
The first version of the future IS-2 retained the basic features of the previous machine, although it had significant differences. So, the case of the traditional layout retained a differentiated cast and rolled reservation with a welded joint. An improved casting tower of sufficient volume for the installation of a new large gun was proposed. The power plant and chassis did not undergo fundamental changes.
Tank "240" in the initial version received a cast block of nasal armor with a thickness of up to 120 mm in the upper part. The largest middle part of the forehead had a thickness of 60 mm and was located at an angle of 72 °. The lower armor element at a thickness of 100 mm leaned forward 30 °. The curved forehead of the cast tower was 100 mm thick. The side projection was protected by 90 mm rolled sheets; the upper elements of the hull and side of the tower leaned inward.
Reservation IS-2. The parameters of the initial project are shown at the top, and after completion in 1944, the Wikimedia Commons graphics are shown.
The main armament of the IS-2 was the 122-mm tank gun mod. 1943 or D-25T under separate shell loading. The gun mount provided vertical guidance from -3 ° to + 20 °, there was also a mechanism for fine aiming in the horizontal plane. For the D-25T, three types of shells were intended - the pointed-headed armor-piercing armor BR-471, the blunt-headed armor-piercing armor with the ballistic cap BR-471B and the HE-471 high-explosive fragmentation shell. All shells were used with a full charge of the Zh-471.
It was planned to install a whole set of DT machine guns: coaxial, frontal in the hull and stern in the tower. Later they introduced a turret for a large-caliber DShK on the tower. New tanks received it at the factory, old tanks - right in the units.
Mobility was provided by a 12-cylinder V-2-IS diesel engine with a capacity 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 rotation mechanisms. The chassis was also borrowed with some modifications and changes.
The preservation of the power plant and chassis has led to some reduction in mobility compared to previous heavy tanks. IS-2 was heavier to 46 tons, which reduced its specific power and driving performance.
At the end of the summer of 1943, the construction of the experimental 100 tank began at factory No. 240. The car was not made from scratch, it was made on the basis of one of the prototypes of “Object 237” / IS-1. In the shortest possible time, we manufactured and installed all new units, with the exception of the gun mount. D-25T and other details had to wait until the end of September.
Ammunition gun D-25T. Shells with a charge Zh / ZhN-471, high-explosive fragmentation grenade OF-471, as well as armor-piercing shells BR-471 and BR-471B. Wikimedia Commons Graphics
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 complaint was caused by an insufficiently strong muzzle brake. A few days later, the experimental D-25T was sent to Chelyabinsk, and on September 30 she got up on the carrier. After that, the tank "240", slightly different from the design, was ready for full-scale factory tests.
The tests began with an accident and almost led to tragedy. The tank reached the shooting range under its own power and fired several shots. At the next shot, the already damaged muzzle brake tore apart, its wreckage nearly killed several people. The fire tests had to be temporarily stopped - until a new muzzle brake was received.
On October 1-4, 1943, the experimental “Object 240”, together with the “237” tank, underwent trials along the 345 km long 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 in tow and pull out the "seated" fellow.
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 before the end of the month the prototype car passed more than 1200 km.
In mid-October, Plant No. 9 completed the completion of the D-25T gun and conducted new tests. The improved muzzle brake again did not show a sufficient resource, claims were made to other units. However, the gun passed the test and was allowed to further work - after correcting the shortcomings.
IS-2 early series at the front. Wikimedia Commons Photos
The modified D-25T gun 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 on captured models of German armored vehicles. The tank clearly showed its firepower.
According to the “tabular” data, at a range of 500 m with a 90 ° meeting angle, the BR-471 pointed-headed projectile had to penetrate 155 mm of homogeneous armor; for 1 km - 143 mm, for 2 km - 116 mm. For the blunt-headed projectile BR-471B, penetration reached 152, 142 and 122 mm, respectively.
When using two armor-piercing shells of the 471st series, the “240” tank confidently hit the frontal projection of the “Tiger” at distances of up to 1500-2000 m. The 80-mm frontal sheet (57 ° slope) of the medium tank Pz.Kpfw.V Panther made its way from 1500 m. At distances up to 1 km, the D-25T could hit the 200-mm armor of the self-propelled Panzerjäger Tiger (P) Ferdinand.
Beginning of the series
Thus, the future IS-2 was distinguished by outstanding firepower and could effectively deal with any modern and promising enemy armored vehicles. Moreover, he was protected from enemy fire in a wide range of ranges and showed good mobility for his class.
IS-2 with a straight nose in the museum. Wikimedia Commons Photos
According to the results of the first stages of testing, on October 31, 1943 the “240” tank was adopted by the Red Army under the designation IS-2. By this time, ChKZ began preparations for mass production, and already in December produced the first 35 cars. By the end of spring 1944, the pace of production was able to increase several times. Starting in June, Chelyabinsk shipped at least 200-220 tanks monthly.
In February 1944, work began on upgrading the IS-2 by improving security. The frontal armor borrowed from the IS-1, in some situations, could not cope with German shells, and it should be strengthened. SKB-2 ChKZ and Plant No. 100 were again involved in the work. The latter began to study options for deep modernization of equipment, while ChKZ limited himself to only processing the nose of the hull - this made it possible to quickly introduce reinforced armor into mass production.
As a result of a short search, they chose a new design with a straightened upper frontal part 100 mm thick with a 60 ° tilt, devoid of a characteristic “box” with a hatch and driver sightings. The lower element had the same thickness but a different angle. The possibility of making a forehead by welding from rolled parts or by casting as a single unit was considered.
During the tests, it was shown that the top of the welded forehead withstands a shot from the 75 mm KwK 42 gun from any distance, but the lower part breaks through, and cracking of the welds was also observed. Cast forehead withstood even 88 mm shells. To defeat the improved IS-2 in the forehead, a German tank would have to approach the distance of guaranteed penetration by the D-25T gun.
IS-2 on the streets of Berlin, spring 1945. Photo by Armor.kiev.ua
In June 1944, manufacturers began preparations for the serial production of the IS-2 with a new frontal armor. Over time, it was possible to solve all production issues, and a tank with straightened armor replaced the predecessor in production.
ChKZ manufactured the first serial IS-2 at the end of 1943. Production continued and gained momentum until it reached the level of up to 250 tanks per month - such indicators were maintained from August 1944 to March 1945. In the future, the plan began to be reduced, and in June Chelyabinsk released the last five tanks. Thus, in 1943, the 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 IS-2 at the Leningrad Kirov Plant with the involvement of a number of other local enterprises. In particular, the Izhora plant, already participating in the production of heavy tanks, was supposed to make armor. The first cars were planned to be received in October 1944.
The restoration of Leningrad as a whole and the LKZ in particular turned out to be extremely difficult, and plans to produce the IS-2 had to be reviewed 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 IS-2 at LKZ ceased.
Since the beginning of 1944, the IS-2 tanks arrived in the Red Army. Their main operators became separate guards heavy tank breakthrough regiments (ogvttp). The main objective of such units and their heavy armored vehicles was to strengthen the army’s formations in order to break through the enemy’s defense in critical areas. IS-2 heavy tanks were distributed between 25 breakthrough regiments.
IS-2 in the center of the German capital. Photo Armor.kiev.ua
IS-2s were also supplied to units from the Guards Tank Brigades, where they were to serve along with T-34 medium tanks. In this case, the task of the IS-2 was to follow the T-34 and defeat enemy equipment 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 considerable distances, including from a safe distance, which gave certain tactical advantages. The number of enemy tanks and self-propelled guns destroyed - and the consequences of this in the context of further battles - is difficult to overestimate.
The enemy quickly appreciated the new Soviet equipment and saw in it a serious threat. Even the appearance of the IS-2 on the battlefield could determine the outcome of the battle. Since mid-1944, in the reports of tankers of the Red Army there are references to attempts by the enemy to get away from a collision with Soviet heavy tanks.
The creation of new models of equipment as a whole did not have a decisive significance on the course of battles. So, the episode of the Lviv-Sandomierz operation of August 1944 is well known, when the 71st military police department collided with the latest Pz.Kpfw machines. VI Ausf. B Tiger II 501st heavy tank battalion. As a result of the battle, the Germans had to write off six Tigers-2; The Red Army did not suffer losses. One of the tanks participating in this battle is now an exhibit of the museum in Kubinka.
However, the IS-2 was not fundamentally invincible. So, in 1944 more than 430 tanks were recorded in irreparable losses. Subsequently, their number increased. Hundreds of tankers were injured or killed.
IS-2 tanks transferred to friendly China, 1959. Photo by Wikimedia Commons
The defeat of the tank in the upper frontal leaf was virtually impossible; at the same time, cases of breaking through the lower part with different consequences are known. German gunners and tankers, if possible, tried to hit the side, if possible from a short distance. So, at distances up to 900-1000 m, side armor could not always protect against 88-mm shells of the Tiger tank or from a more powerful weapons.
IS-2 heavy tanks quickly enough 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 defense and supporting the advancing troops, worked as part of assault groups in cities, etc. In all cases, a powerful reservation and a 122-mm gun were the most serious arguments against any arguments of the enemy.
IS-2 was actively used in all operations of the Red Army in 1944-45. The last shots of D-25T guns at real German targets were fired already in Berlin, including 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 postwar period, the IS-2 remained in service, transferred to friendly countries and underwent modernization. At the same time, the fleet of heavy tanks was modernized by decommissioning obsolete and exhausted equipment and supplying the latest vehicles - IS-3 and T-10. Some tanks were handed over to friendly foreign countries.
In 1957, the next modernization program was launched, the result of which was the IS-2M tank. Replacing part of the units and installing new equipment allowed to continue operation. Minor innovations were carried out later, until the end of the sixties.
Some IS-2Ms still underway, 2016. Photo by Vitalykuzmin.net
However, the number of IS-2M tanks in units was gradually reduced - as completely new vehicles arrived, they were transferred to training vehicles, sent for storage or disposed of. Later, the abandonment of heavy tanks as a class began, and modern MBTs replaced them. However, the official order to remove the IS-2 from service was issued only in 1997. Until that time, only tank monuments and separate “tactical targets” at the training grounds survived.
Best in class
The heavy tank IS-2 was the result of many years of development of the most important area in the field of armored vehicles and combined the best practices of Soviet engineers. His appearance in the Red Army units in the most positive way affected their combat effectiveness, giving new tactical and strategic opportunities.
Despite the relatively small number, the IS-2 tanks and their crews most actively participated in all major operations and made a significant contribution to the overall victory. The merits of tankers who solved special tasks were awarded with thousands of state awards, including the highest. After the war, modernized armored vehicles and tank crews continued their service and for many years supported their comrades with newer and more advanced equipment.
Given such stories service, combat use and design features, the IS-2 can rightfully be considered the best domestic heavy tank since the Great Patriotic War, as well as one of the most important milestones in the history of our tank construction.