The Oldest IS

It often so happens that a truly unique tank stands in shadow, unknown to those around it. There are many examples. For instance, the T-34 tank "Kantemirovets" on display at the Road of Life exhibit is no simple tank. It turns out that this is the only "general's" T-34 that used to carry an RSB-F radio. Now it needs to be reunited with its former components, but that's a whole separate affair. Secret past lives of tanks that appear to be well known are discovered every so often.

How the hero of this article looks today.

The Kirov Factory in St Petersburg has an IS-2 installed as a monument on its grounds. It was installed here in 1947. This tank is fairly well known. It is often referred to as an IS-2 from the first production batches. However, this tank is even more interesting than this. It is actually one of the progenitors of the whole IS tank series with a very complicated fate.

The creator of the tank. Nikolai Ivanovich Shashmurin made the IS-2 into what we know today.

The story of this tank began on May 5th, 1943, when Stalin signed GKO decree #3289 "On improvement of the armament of tanks and SPGs. This decree ordered the installation of 85 mm guns into the KV-1S and IS (blueprint #233, although it was almost never referred to by this designation). This was the end of the IS-1. There were already complaints about its running gear and cooling system. The concept of a high speed heavy tank with the mass and dimensions of a medium ended in failure.

This is what the tank looked like at first.

Shashmurin assumed the role of the lead engineer of the KV-13 (IS-1) after the death of N.V. Tseits. He opposed this concept from the beginning and considered a fully fledged heavy tank to be the only option. Now he finally had an excuse. Work on the Object 237 began in May of 1943. This tank was a further development of the IS-1, but this time it was a heavy tank in every respect. Its mass reached 44 tons and the top speed of 50 kph was abandoned. The tank was equivalent in mobility with the KV-1S even though it had tougher armour.

Later it was equipped with the D-5T 85 mm gun.

The tank that is displayed at the Kirov factory today is an Object 237, the second prototype. It was built by July 22nd, 1943, and made its first trial run without a turret. It later received a turret with the 85 mm S-31 gun. This didn't last long. The tank received a new turret with the D-5T gun in early August. Both Objects 237 were then sent to the Gorohovets ANIOP proving grounds for trials. The D-5T was already accepted into service with the Red Army and these trials just underscored the fact that this decision was correct.

The next step of evolution, Object 240.

The tank was sent to Moscow after trials where it was show off at the Kremlin on September 8th. According to the diary of People's Commissar of Tank Production V.A. Malyshev, Stalin visited the tank personally and even climbed up on it. The tank was later sent to Chelyabinsk where it underwent a metamorphosis once again. While the first tank went through trials, the second was converted into the Object 240. The experimental 122 mm D-25T gun was installed in its turret. The muzzle brake used on the gun burst almost immediately and its shards nearly hit P.K. Voroshilov. As a result, the tank was sent to mobility trials with a tarp over its barrel.

The tank was later equipped with a second turret and a D-25T gun with a sliding breech.

The tank drove for another 1250 km, after which it was sent to the Gorohovets ANIOP again. A new muzzle brake was already sent there. Even though trials revealed a number of defects, they were considered to be successful overall. The D-25T was accepted into service, as was the Object 240 which received the designation IS-122. The prototype drove for another 1162 km by the end of October and its trials were far from over. The tank was used as a test chassis for yet another project.

The same tank with a third turret and a 100 mm S-34 gun. Note the raised headlight. This tank was called Object 248.

The tank was used to test various components of the running gear, engine, and transmission groups. By the end of December 1943 the tank had driven for 2584 km. Another 1354 km was driven in January while testing a turret ring without a separator for the upper ball bearings, new types of bearings, new fuel tank plugs, and a gearbox with a rigid mounting. The tank was used to test a D-25T gun with a sliding breech from February 1st to February 6th, 1944. A new engine with a new engine deck were also tested. The tank returned to the Gorohovets ANIOP.

The same raised headlight.

The Object 240 remained at the Gorohovets ANIOP for a few months and returned to factory #100 for another metamorphosis. The tank went through refurbishment, as a part of which it received a new raised headlight. The turret was replaced again. This time it housed the 100 mm S-34 gun. Since this gun needed the loader to be on the left, the commander and gunner were moved to the right. The rebuilt tank was indexed Object 248 in June of 1944.

For obvious reasons, the tank is very hard to get to.

After proving grounds trials held from July 1st to July 6th, the tank ceased to be interesting as a test bed. However, the transformations didn't stop. The tank returned to Chelyabinsk, where it received yet another turret. It was taken from the KV-122 (KV-85 with the turret of an IS-2 tank) which was no longer necessary. This is how the tank remains to this day.

Scale model makers should not look too close at this tank. It's an experimental vehicle and differs from production types.

Unlike the KV-85 (Object 239), which is open to the public, the Object 240 is one of the least accessible IS tanks. To reach it, one has to make it to the very center of the Kirov factory grounds, a place that few can gain access to. This was key in preserving the tank. It looks a lot better than its cousin.

This kind of rear plate and exhaust pipes are a clear indicator that this is an Object 237. Production tanks were already different.

This is somewhat of a trap for model makers and historians. Until recently, this tank was considered to be an early IS-2. This is not correct. This kind of rear plate and T-34 type exhaust pipes are a sign of the Object 237. Production tanks had a different shape of hull and different exhaust pipes.

The turret was built sometime in the spring of 1944.

There are also differences in the front of the hull. Trials showed that the driver's observation port was located too low and vision was poor as a result. It was reworked, which is demonstrated by the weld seams around the vision port. The observation periscopes were also different. Production tanks had their periscopes held in regular sockets, but this tank had caps over them. The only question was which Object 237 this is. The raised headlight and characteristic indentation in the left side of the turret platform indicate that this is the second prototype.

The gun on the KV-122 was extracted through the roof of the turret.

This tank should not be used as a reference by model builders. As mentioned above, it was constantly reworked, even after trials were finished. For instance, the tank has non-standard mountings for its fenders. It is not clear why this was done, but the production tank is different. The running gear is from a production tank, but with some nuances. It was last updated in the summer of 1944, but measuring the running gear is not a good reason to gain access to a secure facility. 

The spare track links were moved to the front of the hull in 1944.

The turret is similar to a production one, but not identical. It was clearly used for experiments, for instance to see how the gun could be extracted through the roof. There is a cutout for a hatch where the periscopic sight is. The turret itself was built at factory #200 (Chelyabinsk) in the spring of 1944. It still has old style handrails but already had a D-25T gun with a semiautomatic breech. The gun mount was still designed to take the old refracting sight, the TSh-17 was installed in turrets with a wider mantlet.

The running gear on the tank is original. This is the modernized variant without toothless tracks.

The tank is an important historical artefact. It kicked off the series of IS-2 tanks, the best Soviet tank of the second half of WW2. This tank also played an important role in how the IS-2 tank changed over the course of its production and rightfully belongs at the Kirov factory. Whoever installed it as a monument fully understood its importance. There are many IS-2s in the world, but this one is unique.

The author thanks Mikhail Yuryevich Velikoselsky, head of external communications and media at the Kirov factory, for his help with this article.

Original article by Yuri Pasholok.