The design of the T-34 tank left a lot of reserves for modernization. The chassis dealt with a 5 ton increase in weight during its production run. A result of a thorough modernization, the T-34-85, entered production in early 1944. This tank received a new turret and an 85 mm gun. The crew increased to 5 people. The T'34's armament was radically improved, but the armour of the Soviet tank remained the same. The T-34-85M tank with improved armour was an attempt to resolve this situation.
Second try at more armour
The idea of improving the T-34's armour surfaced back in the spring of 1941. The T-34 was supposed to receive applique armour to increase the thickness of front armour to 60 mm. The T-34M (a thorough modernization of the T-34) would also have 60 mm of armour. The work that was started in the spring resulted in the creation of two prototypes, but the story didn't end there. On December 25th, 1941, Stalin signed GKO decree #1062ss "On T-34 and T-60 tanks". According to this document, all T-34 tanks were supposed to receive applique plates on the front armour to increase its total thickness to 60 mm as of January 15th, and as of February 15th all T-34 tanks would be produced with 60 mm thick monolithic armour. A few hundred tanks with applique armour were built, but none with thickened base armour. On February 23rd, 1942, Stalin signed GKO decree #1333 that cancelled the applique armour.