Already the first battles with the participation of IS tanks revealed the insufficient security of the vehicles. The build quality also caused criticism – less than half of the produced tanks passed military acceptance, and the transmission often broke. The question of strengthening the frontal armor of the hull was solved simply and even elegantly – by straightening the upper frontal plate.
It was more difficult with the turret of the tank – originally developed for 85mm guns, after the installation of the 122mm D-25 gun, which became unbalanced. Therefore, it was possible to qualitatively enhance its armor only by designing a new tower. In the spring of 1944, work began on the creation of a deeply modernized IS-2. In parallel with it, a new heavy tank was being developed – the future IS-4.
In the summer of the same year, the project was approved, and by the fall, the first prototype was assembled. The second prototype had the in-plant designation “Kirovets-1”. It already differed significantly from the IS-2 – it had a completely new hull and a newly developed turret in the form of a flattened hemisphere. The Kirovets’ transmission has been strengthened. Having learned about the test results of the future IS-3, Joseph Kotin, who then headed the Experimental Plant at ChKZ, proposed his own version of enhancing the armor.
“The designers of the Experimental Plant managed to develop an original scheme for booking the bow of the tank, which became known under the nickname “pike nose” – and Kotin suggested using it.”
The proposal was accepted. By the spring of 1945, the IS-3 was built with a new booking scheme, and according to the test results, the car was recommended to be put into production. The IS-3 went into production after the war in Europe ended.
Design features
The IS-3 had a classic layout, with the engine compartment in the rear, the control compartment in the front, and the combat compartment in the middle. The tank’s crew consisted of four people: a driver, gunner, loader and commander.
Armored corps and turret
The IS-3 had powerful and highly differentiated armor protection (for its time in 1945), located at optimal angles of inclination and designed, first of all, to protect against the fire of the most powerful modern tank and anti-tank guns in the frontal plane and against the fire of most tank and anti-tank guns – primarily from the German 88-mm rifled tank guns 8.8 cm KwK 43 and 7.5 cm KwK 42, while providing virtually complete protection against the most common towed 75-mm anti-tank guns 7.5 cm Pak 40.
The hull armor of the tank was assembled by welding from rolled sheets of homogeneous armor steel with a thickness of 20, 30, 60, 90 and 110 mm. Frontal armor of the tank was made of armor plates 110 mm thick according to the scheme known as the “pike nose”, and consisted of two left and right upper plates converging in a wedge, located at an inclination of 56 ° to the vertical and with a turn of 43 °, a lower plate located at an angle 63 °, and the roof of the control compartment, which is inclined 73 ° degrees.
Each of the hull sides consisted of two armor plates 90 mm thick: the upper one, located at an angle of 60 ° and forming a side niche, and the vertical lower one. In addition, the upper part of the sides was covered with 30-mm screens located at an angle of 30 °, together with unarmored fenders, which formed additional side niches, which were accessed from outside the tank. The stern part was assembled from 60-mm armor plates: the lower one, located at an angle of 41 °, and several upper ones, which had an inclination of 48 °.
“The roof of the hull was made of several 20-mm armor plates. The bottom of the hull, flat in the area of the transmission compartment and “trough-like” in the rest of the hull, was stamped and also made of 20-mm armor plate.”
The IS-3 tower was a one-piece molded casting of homogeneous armor steel and had a hemispherical shape close to a flattened one, tear-shaped in plan. The thickness of the walls of the tower in the sides and stern ranged from 220 mm in the lower part to 110 mm in the upper part, while in the frontal part it reached 255 mm. In general, the angles of inclination, ranging from −8 ° to 35 °, were selected in such a way that at any point of the tower walls their horizontal thickness was at least 160 mm. In the frontal part of the turret, there were embrasures for a gun and a coaxial machine gun, which were covered by a cast armored mask attached to the barrel of the gun, the thickness of which reached 250 mm.
Armament
The main armament of the IS-3 was a 122-mm rifled tank gun D-25T, model 1943, with a barrel length of 48 calibers / 5852 mm and an initial velocity of an armor-piercing projectile of 800 m / s. The D-25T cannon had a horizontal wedge breech with a semiautomatic mechanical type, electromagnetic and mechanical descent. The gun’s recoil devices consisted of a hydraulic recoil brake and a hydro pneumatic knurler located above the gun barrel on the left and right, respectively.
“The gun was mounted in the frontal part of the tower on trunnions in a coaxial machine gun installation, which allowed its guidance in the vertical plane using a sector-type mechanism in the range from -3 to + 20 °.”
Guidance of the paired installation at the target was carried out using a telescopic articulated sight TSh-17, which had a magnification of 4 × and a field of view of 15 °. In addition, for firing from closed positions, the gun was equipped with a side level and an azimuth indicator.
The gun ammunition consisted of 28 rounds of separate-case loading with armor-piercing and high-explosive fragmentation long steel cannon grenades. Of the shells, 25 were placed in tray stacks along the sides of the turret, 3 more were on stands in the fighting compartment.
Of the shells, 6 were placed in stowages on both sides of the driver, 4 were placed on the upper sheets of the hull fenders, 5 were in the stowage on the floor of the fighting compartment, the rest were placed in yoke stowage: two – on the partition of the engine compartment and one more – on the starboard side housing. Since the high-explosive fragmentation projectiles were larger in size, only armor-piercing projectiles could be placed in 11 of the places of ammunition storage.
A 7.62-mm DTM machine gun was located in a coaxial installation with a cannon. The machine gun had 2,000 rounds of ammunition: 1,200 with a light bullet, 200 with an armor-piercing incendiary, and 600 with a tracer. Of these, 756 cartridges in 12 disk magazines of 63 cartridges each, the remaining 1244 were stored in a standard capping not equipped in stores.
On the roof of the tower, on an annular turret, there was a 12.7-mm anti-aircraft heavy machine gun DShK or DShK, which had a circular fire at angles of vertical guidance from −4 to + 84 °. The machine gun was equipped with a K-8T collimator sight, designed to fire at air targets moving at speeds up to 400 km / h at an altitude of up to 400 m. The machine gun could also be used for firing at ground targets, but its use was associated with a significant risk for the shooter, which had to rise up to the waist from the hatch from under the armor protection for this.
In the stowed position, the machine gun was dismantled from the turret and fixed on the right side of the turret. Machine gun ammunition was 300 rounds in 6 belts of 50 pieces. Of this number, 225 cartridges were equipped with B-32 armor-piercing incendiary bullets, and 75 with BZT armor-piercing incendiary tracer bullets. Also, in the fighting compartment for the crew were placed 25 defensive grenades F-1 or offensive RG-42 and two 7.62-mm submachine gun PPS-43 and 1000 rounds for them.
Surveillance and communication facilities
The driver-mechanic in non-combat conditions monitored the terrain from his hatch, while in battle he used the MK-4 periscope viewing device – a copy of the British Mk.IV, which gave all-round visibility. The device was made easily removable and had to be removed before opening the driver’s hatch cover.
The tanks, upgraded to the IS-3M standard, also had a passive TVN-1-night vision device, which could be installed in place of the MK-4 or on a separate stand when driving with an open hatch. The driver’s viewing device was also redesigned, eliminating unnecessary all-round visibility from the driver’s seat. The tank commander, gunner and loader also had one MK-4 device each, which were located on the roof of the tower. When upgrading to the IS-3M standard, the commander’s MK-4 was replaced with a TPK-1 binocular device more adapted for this purpose, which provided 1 × or 5 × magnification.
For external communication, the IS-3 had a simplex telephone and telegraph radio station 10RK-26, located in the tank turret to the left of the gun and equipped with a whip antenna with a length of 1 to 4 m. 10RK-26 provided telephone communication at a distance of 35-40 km from a place and 20-25 km on the move. For internal communication, the tank was equipped with a TPU-4-bis-F telephone tank intercom for all crew members, connected to a radio station.
Engine and transmission
For the power plant, a V-12 V-11-IS-3 diesel engine was chosen, developing power up to 520 hp. It had a volume of 39 liters and was cooled by a closed liquid cooling system, which received a boiler for heating with a blowtorch of the coolant when using the tank in low temperature conditions. An electric ST-700 was used as a starter, which was duplicated by a starting system using compressed air.
“A mechanical transmission was installed on the IS-3, which received a four-speed gearbox and a range multiplier, thanks to which the tank had 8 forward and 2 reverse gears.”
The rotation was carried out due to two planetary mechanisms.
This design allowed the IS-3 to accelerate to 40 km / h, having a specific power of 11.2 hp / t.
The internal fuel system consisted of 4 tanks with a total capacity of 450 liters, it was supplemented by 4 external ones with a capacity of 360 liters.
The power reserve was at about 185 km on the highway.
Chassis
The undercarriage of the IS-3 on each side consisted of a drive wheel, a sloth, six double cast non-rubberized road wheels with a diameter of 550 mm and three double rubberized cast support rollers with a diameter of 385 mm. Track roller suspension – individual, torsion bar, without shock absorbers.
“Caterpillar IS-3 – 650 mm wide, steel, fine-link, pinned engagement, with an open metal hinge. The caterpillar of each side consisted of 86 tracks, at first – from 43 ridge and 43 flat, but since 1947 the tank tracks began to be assembled only from ridge tracks.”
- Gross weight: 45800 kg.
- Crew: 4 people.
- Length: 6.9 m.
- Width: 3.15 m.
- Height: 2.45 m.
- Reservation:
- body: 20-110 mm;
- tower: 110-220 mm;
- mask and turret forehead: 250 mm.
- Engine: V-11, 12-cylinder, 4-stroke, V-shaped liquid-cooled diesel engine.
- Engine power: 520 hp
- Highway speed: 40 km / h.
- In store down the highway: 340 km.
- Armament:
- 122 mm D-25T cannon, 28 rounds of ammunition.
- 7 mm DShK machine gun, b / k 250 rounds.
- 62 mm DTM machine gun, b / k 756 rounds.
- 25 defensive F-1 grenades or offensive RG-42 and two 7.62 mm PPS-43 submachine guns and 1000 rounds for them.
Modifications
It soon became clear that the IS-3 had quite a few flaws and shortcomings, so in 1946 a commission was convened to analyze them, and from 1948 to 1952, all IS-3s were corrected for design flaws.
At the end of the 50s, they decided to raise the level of the tank to a more modern one, and the result was the IS-3M.
He received a case of increased rigidity, a V-54K-IS engine, new DShKM and DTM machine guns, a TVN-2 night vision device, VTI-2 air cleaners, reinforced suspension assemblies, new electrical equipment and radio communication devices.
“Although such a comprehensive improvement significantly increased the performance characteristics and reliability, its time has already passed, so the IS-3M was put into long-term storage after the modernization.”
On the basis of Is-3, 2 original vehicles were created – Object 704 and Object 757.
Object 704 had a record low height and powerful protection for heavy Soviet self-propelled guns, but the tight layout and long recoil length were too unfortunate for the crew, and therefore this experimental vehicle was never accepted into service. Another name for this ACS was the ISU-152 of the 1945 model.
Object 757 was manufactured in 1952 and fired Rubin guided anti-tank missiles at a range of up to 4 km. Due to the lack of missiles, the appearance of Object 772 and the obsolescence of heavy tanks, it remained in a single copy.
Service history
“Presentation”, as they would say now, IS-3 took place on September 7, 1945 during a parade in Berlin dedicated to the end of the Second World War. The tank duly impressed the representatives of the Western armies, and the Soviet marshals believed that it was the “pikes” that would become the backbone of the renewed tank forces.
The machines were produced in large batches, but at the beginning of 1946, production stopped.
The tank, which was supposed to get rid of “childhood diseases”, the IS-2 acquired new, own ones. And the build quality hasn’t improved. It was just during wartime that it could be tolerated – the tank, if it did not die irrevocably in the first battles, would soon be rebuilt, and in a year it could become outdated and scrapped. And in peacetime “to live” with constantly breaking “pikes” had to be for years. The IS-3 continued to have engine and transmission failures, and most importantly, the complex-shaped hull did not have the required rigidity and was easily damaged.
As a result, since 1948, all released “pikes” went to “eliminate design flaws” – in fact, to restore. The hulls of the machines were reinforced, and more durable clutches were installed. Other improvements were also made – for example, the radio stations were replaced. As a result, the tank became three tons heavier – up to 48800 kg. In the mid-50s, the “pikes” were upgraded to the IS-3M standard. The rigidity of the hull was reinforced again, the B-11 engine was replaced with a B-54, and an oil cooler was introduced into the gearbox design.
The ammunition load included a BR-471D projectile with an armor-piercing tip. This mild steel tip prevented the projectile from ricocheting when it hit the armor. Simply put, such shells worked better on armor with large angles of inclination. The commander’s periscope was replaced with a TPK-1 device with a fivefold magnification, and the driver of the “pike” received a night vision device and an infrared headlight. It became possible to start the engine from the external network, through the outlet at the stern. The crew’s self-defense weapons were replaced with AK assault rifles.
“The Soviet IS-3 tanks took part in the military operation only once – in 1956, during the “suppression of the counter-revolutionary mutiny” in Hungary, whose people demanded the country’s withdrawal from the Warsaw Pact Organization. It is reliably known about one IS-3 destroyed in that operation – a photo of a tank with a turret torn off by an explosion is widely known.”
Later, during the aggravation of relations with China, the “pikes”, together with other heavy tanks – the IS-2 and IS-4, were used to strengthen the Far Eastern borders – some tanks were on alert, and some were buried in the ground like bunkers.
Other IS-3s were used as targets at firing ranges – for example, a report on the test of an unguided S-25 missile, the impact of which left only the bottom and frontal armor plates from the IS-3, has been preserved. At the same time, the tanks “contrived” to survive the Soviet Union – they were officially removed from service only in the 90s.
In the ATS countries, the IS-3 did not arouse enthusiasm – Poland and Czechoslovakia, to which the “pikes” were sent for familiarization, showed no interest. In the DPRK, from the supplied ISs, two regiments of heavy tanks were formed, but nothing is known about their fate since then. But “pikes” were actively supplied to Egypt. Their use was expected already during the Suez Crisis, but this never happened. Throughout the 60s, the fleet of Egyptian ISs continued to grow, and in 1967 they finally went into operation.
It turned out that the 122mm cannon surpasses the 90mm guns of Israeli tanks in terms of range – its rate of fire and sighting equipment were already below any criticism. The armor protected the pikes from the outdated Israeli infantry Bazookas, and provided some protection against the 90mm guns mentioned. But even tanks with 90mm cannons were superior to the IS-3 in maneuverability, and the pike’s armor did not protect against the 105mm L7 cannon at all.
In a number of clashes, the Egyptian IS-3s were defeated by the upgraded Shermans. Effectively “pikes” could operate only from a great distance or from ambushes.
An episode is widely circulated in which an Israeli paratrooper hit the IS-3, which attacked the headquarters of a paratrooper battalion, with a grenade that hit an open hatch. Allegedly, the Egyptians went into battle with open hatches in order to be able to quickly “evacuate”. In reality, the driver opened his hatch to get his bearings. The exact type of grenade can no longer be determined – different sources call either a rifle or a shot from a “bazooka”.
“As a result, the Israelis captured many IS-3s abandoned by the Egyptians – there the tank also did not cause enthusiasm.”
Although captured “pikes” were shown at parades for several years, only one application was eventually found for tanks. As in the USSR, the IS-3 was made an element of fortified lines. Recall that the captured T-55 and T-62 vehicles in Israel were rearmed and actively used.
The tanks that remained in Egypt served until 1980, and then were either sent for processing or sold to museums. According to some reports, the IS-3 was also supplied to Syria, Iraq and China, but there is no evidence of their use in these countries.
But the last chapter in the fighting career of the “pike” was, unexpectedly, written in 2014. The militias of the Donetsk Republic brought the IS-3 standing on a pedestal into working order and used it in battles, using ammunition from 122mm howitzers. After all the ammunition was used up, the tank was abandoned and it was captured by Ukrainian forces.
Service record of the IS-3 tank
Heavy tanks IS 3 did not take part during the Second World War.
For the first time, the IS-3 was shown at the Berlin parade of the Allied Forces of the WWII on September 7, 1945. The IS-3 shown then against the background of the American Pershing was simply magnificent, the Red Army then made it clear that they were not bastard and could once again walk through Europe.
“The heavy tank IS-3 was actively used by Soviet troops in the suppression of the Hungarian uprising in 1956.”
The IS-3 was also used by Egypt in the six-day war against Israel, but even then the IS-3 was inferior in performance characteristics to such tanks as the M48 and Centurion.
Conclusion
The IS-3 as part of the Soviet troops was able to fight only in Budapest in 1956. In 1967, during the Six Day War, the Israeli M48A2 Patton literally defeated the Egyptians on the IS-3M, since heavy Soviet tanks lacked either mobility, or rate of fire, or modern fire control systems, or crew training.
“Best of all, the IS-3 showed itself at the parade in Berlin, although it sounds funny. But don’t blame the tank or its designers for anything. The time of heavy tanks was slowly coming to an end, rocket armament appeared and the view on the use of armored vehicles changed.”
The IS-3 was designed as a highly improved version of the IS-2, rather than a fundamentally new tank. And he did an excellent job with this role.
