DEVELOPMENT
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| IS-3 along side its brother IS-2 |
The military authority in the Soviet Union (including Stalin himself) wanted an even more heavily armed and armoured heavy breakthrough tank than what the Soviet had in 1944- the IS-2 which boasted 120 mm of frontal hull armour as well as being armed with the very powerful yet slow firing 122mm D-25T gun.
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| Kubinka's very own IS-3, possibly the IS-3M (the two had no external differences, only internal) |
The IS-2 had the ability to be able to reliably penetrate the frontal hull of the Panther at a range of 200-400 metres with its 122mm regular AP round. However it had trouble penetrating the thick front of the Tiger I even at close range. The new German Tiger II was pretty much out of the question for the IS-2. As a result, the Soviet authority designed a brand new heavy tank with revolutionary design features and an improved version of the 122mm D-25T.
The design bureau at Leningrad took their concept of sloped and angled armour to an entire new dimension. As seen previously on the famous T-34/76 and 85 medium tanks, sloped armour provided more chances for an incoming round to bounce or ricochet off. The new design included two pieces of 110mm upper frontal armour being joined at such an angle that can guarantee frequent bounces. The result was the the armour is pre-angled and require no manual angling by the driver. This "pike nose" shaped hull front led to the IS-3 crew calling the tank a "Shuka" - Pike in Russian.
Another revolutionary design feature was the semi-spherical turret. Being both 175mm thick at the front and being well-rounded, the turret on the IS-3 is very hard to penetrate unless APCR or APFDS high penetration rounds can be placed square on. The turret was very low and thus contributed to the overall low profile of the vehicle.
However this low profile brought problems that would continue to plague Soviet tank crews all throughout the Cold War. The crew fighting compartment is extremely cramped, the compartment is only really comfortable for crews who are small or medium statured. Since the turret is very low, this limited the amount of gun depression. Thus the IS-3 have constant issues with using a hull down tactic.
The gun on the IS-3 is also updated to be able to punch through the front of a Tiger II. The improved 122mm D25-T firing regular AP rounds can knock out any tank on the battlefield in 1945. But this kind of firepower came with a price, the barrel of the 122mm was worn out after only around 200 rounds fired. This called for frequent repairs and replacements- which was a nightmare on a constantly moving battlefield.
Other features such as the four external drop tanks and wide tracks from the IS-2 were kept and proved to be invaluable to the IS-3's toughness.
At the beginning of the 1960s, IS-3s were modernised into IS-3Ms. The upgrades included infra-red gun sights, hydraulic gun stabiliser, targeting computers and NBC protection.
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| The IS-3's debut during the Allies Victory Parade in Berlin in 1945 |
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| Taken out Egyptian IS-3 |
COMBAT RECORD
The IS-3 arrived too late to see active combat in Europe, it however did participate in the Allied Victory Parade held in Berlin in 1945. The Americans and the British were shocked and surprised to see a new Soviet heavy tank that could out gun any of their own heavies. Some records from the Soviet archives had shown that one regiment of IS-3s were sent to fight the Japanese in Manchuria as part of an occupation force. The reliability of the source is questionable but there were accounts of Japanese soldiers in Manchuria facing never before seen Soviet heavy tanks.
During the Cold War, the IS-3 participated in the Invasion of Hungary in 1956 and the Prague Springs in 1968.
The IS-3 also saw extensive service with the Egyptian Army during the Arab and Israeli conflicts. Egypt purchased numerous IS-3Ms to counter Israeli armour. The conflicts revealed the weaknesses that the IS-3 had when numerous units were taken out by Israeli modified Super Shermans and hand held anti-tank weapons.
