Cold War, Soviet-Russia, WWII

IS-3 – The Soviet Heavy that Scared the West

The IS-3 heavy tank was a late World War Two Soviet tank design that was an
improvement on the IS-2. Although the IS-3 arrived too late to see combat in WWII, it would become the main Soviet tank of the immediate Cold War period and participate in conflicts throughout the 1950s and ’60s and even into the modern day.

The IS-3 caused significant alarm in the West when introduced due to its powerful armament and advanced protection, which combined raw thickness with complex angles.

However it would come to earn a rather poor combat record, becoming something of a “paper tiger”. This has resulted in controversy amongst some who suggest that the IS-3 was overrated, and others that claim the tank’s poor record was due to poor training and tactics.



The development of the IS-3 (originally known as Object 703) started in late 1944 at the Factory No. 100 Kirovskiy Works as an improvement on the IS-2. Development of the IS-3 took into account lessons that had been learned from the design and combat experience of the IS-2. As a result, it was an almost complete redesign from its predecessor.

An IS-2M museum display.
The IS-2 was similar to the IS-3 in many ways. The two different most clearly in their armor layout.

As development for the IS-3 did not occur until late 1944, and it was a major departure from the IS-2, the tank did not come off the production line until May 1945 although some pre-series vehicles were issued to the Red Army that spring.

The IS-3’s Unique Design

Even though the main armament and engine of the IS-3 remained unchanged from the IS-2,
many other features were radically different. The IS-3’s armor was highly complex for the time, incorporating many angles that greatly improved effective thickness and the chances of ricochets.

One of the IS-3’s most distinguishing features was its semi-hemispherical cast turret. This shape, which is often described as an upturned soup bowl, would become a standard feature on Soviet tanks from that point on.

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This style of turret improved protection but it also significantly reduced crew space, limited
122 mm ammunition capacity to 28 rounds and restricted the main gun’s maximum
depression as the gun breech had restricted room inside the turret to elevate. Therefore, the IS-3 possessed reduced capability to adopt hull-down positions.

IS-3 heavy tank in a museum.
Note the highly rounded shape of the IS-3’s turret. This shape increases the effective thickness of the turret while reducing its size, and increases the chance of a ricochet. The downside is reduced interior space. Image by Billyhill CC BY-SA 4.0

This was not a big problem for the Soviets though, as their doctrine was heavily oriented around attacking, rather than defending.

Another unique feature of the IS-3 over the IS-2 was its redesigned front hull that produced a
distinctive pointed nose. This feature resulted in Soviet tank crews nicknaming the IS-3 as the
Shchuka (Pike) due to the hull’s resemblance to the nose of that particular fish. The pike nose was 110 mm thick as well as being heavily sloped.

The side armor of the IS-3 was equally unique. Its 90 mm thick side armor angled outwards, creating a partially “V” shaped hull.

IS-3 heavy tank armored shape.
The IS-3’s “pike” nose, as seen from the front. It was angled on two axis, greatly improving the tank’s frontal protection. Image by Alf van Beem.

The armament of the IS-3 was also considered to be powerful for its day with the same D-25T 122mm main gun of the IS-2. As well, the IS-3 was equipped with a secondary armament of a 7.62mm DT coaxial machine-gun and a turret-mounted 12.7mm DShK heavy machine-gun for anti-aircraft purposes.

The IS-3 ran on a torsion bar suspension system that was lowered and supposed to be
mechanically improved. Thanks to this and the improved armor layout, the IS-3 was 28 cm lower than previous versions while maintaining roughly the same weight.

IS-3 armor diagram.
The IS-3’s unique armor layout, viewed from the front. Note the side armor, which steps out at an angle. This is covered by sheet metal, hiding the armor’s true shape.

The IS-3 maintained the same engine as the IS-2, the V-2-IS 12-cylinder diesel that produced 520 horsepower, giving it a top speed of 37km/h and a range of about 125 miles (200 km).

A crew of four operated the tank: commander, gunner, loader and driver.

However, the IS-3 suffered from a rather long list of problems. One of the most concerning of these was the tank’s welds, which tended to crack open.

IS-3s parading on Red Square.
IS-3s parading on Red Square.

Because of these teething troubles, another Soviet heavy tank, the IS-4, entered service as a precaution. The IS-4 had simpler, but much, much thicker armor. It was also marred with troubles.

The IS-3’s general layout and design would evolve, resulting in future vehicles such as the IS-7 and T-10.


As previously mentioned, the IS-3 was introduced too late to see action in WWII, although there is some debate on this as there are unconfirmed reports of pre-series models being involved in combat after the German surrender. There is also other unverified reporting that IS-3s saw limited action against Japan during the very last days of the war.

Regardless, it would become very involved in conflicts immediately following the war. The first public demonstration of the IS-3 came on the 7th of September 1945, at the Allied victory parade in Berlin.

As it rolled down the Charlottenburger Chaussee in Berlin, its appearance caused major alarm for the West as the tank was much better protected and armed than any tanks in Western arsenals at that time.

IS-3s at the Berlin Victory Parade of 1945
Soviet IS-3s roll along Charlottenburg Chaussee in Berlin during the Berlin Victory Parade of 1945.

Its very existence influenced the designs of many tanks, such as the Swedish Kranvagn and AMX-50 series of tanks, both of which utilised a “pike nose”.

The Americans and British developed their own heavy tank programs to tackle the IS-3 with the M103 and Conqueror, as well as the eventual development of the 105mm L7 tank gun.

After NATO was formed in 1949, the IS-3 would remain a significant concern and the Soviets played on these fears, with IS-3s featuring in multiple Soviet military parades and exercises of the 1950s.

A Conqueror MK.II.
Britain developed the Conqueror to tackle heavy Soviet armor such as the IS-3.

However, the IS-3’s less than stellar combat performance would severely damage its reputation in the West.

It would first see confirmed “action” during the Sino-Soviet split and subsequent border
clashes of the late 1950s, albeit in a limited role as dug-in pillboxes along the border. The IS-3’s first main combat action would be during the 1956 Hungarian Revolution. It was during this action that several IS-3s would be destroyed, with pictures of destroyed tanks being published worldwide.

There were several factors that contributed to these loses, ranging from poor leadership and communications to improper urban warfare tactics by the Soviets that allowed Hungarian
fighters to target the IS-3’s thinly armoured top portion of its turret with Molotov Cocktails and grenades.

The next combat appearance for the IS-3 would not occur for another 11 years, during the Six-Day War in 1967.

A destroyed IS-3 hull in Budapest.
The hull of an IS-3 that was destroyed during the 1956 Hungarian Revolution in Budapest. Soviet tanks were attacked by improvised weapons. Image by Nagy Gyula CC BY-SA 3.0.

More than 100 IS-3 tanks had been provided to the Egyptian Army, many of which would see action against the Israeli Army who considered the IS-3M to be a very dangerous opponent due to its protection and firepower.

However, the actual performance of the IS-3 would see mixed results. At normal ranges, the tank’s thick armour enabled it to withstand hits from infantry anti-armour weapons and the 90mm gun of the Israeli M48s. Even the French-built 105mm tank guns of the M-51 “Super Sherman” had difficulty penetrating the IS-3s thick armour.

A captured Egyptian IS-3.
An IS-3 at a museum in Israel. It was captured off Egypt. Image by Bukvoed CC BY-SA 3.0.

Only the few Israeli tanks equipped with the L7 105 mm gun were able to destroy the IS-3 at combat ranges. Several Israeli tanks were destroyed by IS-3s in multiple engagements during the Six-Day War.

In spite of these successes, the IS-3 demonstrated performance issues and around 70 were lost during the (although some sources state 46). The Israeli Army was well aware of the protection and firepower of the IS-3 and adopted their tactics to avoid direct frontal engagements as much as possible.

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The low morale and limited training of the Egyptian Army further worked to hamper the performance of the IS-3 with several incidents of fully operational tanks being abandoned by their crews and captured by the Israelis.

The rear of an IS-3.
The IS-3’s rear was 60 mm thick and highly angled.

IS-3s captured by Israel were not fast enough to be put into service as frontline tanks, so many were used as static pillboxes, similar to those on the China-Soviet border.

The IS-3 was employed by the Soviet Army during the Warsaw Pact invasion of Czechoslovakia in 1968 to put down the Prague Spring but details on its performance during this conflict are scarce.

As the Cold War progressed, more modern tanks such as the T-54/55 and T-62 were introduced into the Soviet Union’s armed forces, but the IS-3 remained until the late 1970s, when the remaining tanks were either mothballed or turned into range targets.

Unlike the aforementioned T-54/55 and T-62, the IS-3 was not widely exported other than the
dozens of tanks that were sent to Egypt. Czechoslovakia, Hungary and Poland each received two IS-3s during the late 1940s for trials, but none of them adopted the tank. Several IS-3s were donated to North Korea, with some sources suggesting that the tank remains in active service with the Korean People’s Army. If true, this would make North Korea the only remaining nation to have active IS-3s in service.

Long barrel overhang of the S-70.
The IS-7 was an extreme evolution of the IS-3’s basic premise. Image by VORON SPb CC BY-SA 3.0

Indeed, even though the IS-3 has long been retired from active service, it has continued to see
sporadic combat action around the world.

In 2014 pro-Russian insurgents reactivated an IS-3 that had been a war monument in the village of Aleksandro-Kalynove in Donetsk, Ukraine. Novorossiyan militants used this IS-3 in combat until the village, and the tank, were recaptured by Ukrainian forces on 7 July 2014.

It almost seems fitting that this incident has been shrouded in controversy, much like the IS-3s
combat reputation, with one source stating that main gun of the captured IS-3 was inoperable
while pro-Russian forces claimed that the DT-25T was still functional and could fire 122mm
ammunition from the D-30 122 howitzer.

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Regardless, the usage of the IS-3 in the 2014 conflict suggests that perhaps the final chapter of the combat history of this tank has yet to been written.