Introduction

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.

Development

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.

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.

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.

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.