T-34-85

The T-34 that shocked the Wehrmacht in 1941 was, by 1943, being outfought. Its 76.2 mm F-34 put roughly 55 mm of penetration on a plate at 1,000 m, and the vehicles it now met at that range were the Tiger I, with 100 mm of flat frontal armour, and the Panther, whose glacis was worth about 140 mm. The arithmetic was simple and it was bad: the T-34 could not kill either of them from the front at any range worth the name, while both could open it anywhere.

Kursk in July 1943 settled the argument. The Red Army did not want a new tank — the T-34 hull was sound, the factories were tooled for it, and production could not be interrupted. What it wanted was a gun that worked, dropped into the tank that already existed.

The answer was already in service pointing at the sky. The 85 mm M1939 (52-K) anti-aircraft gun had the muzzle velocity and the shell weight the tank needed, and adapting an existing weapon was faster than designing one. The first tank version was the D-5T, which went into production at Zavod #112 in January 1944.

It was replaced almost at once. From March 1944 the ZiS-S-53 took over on the assembly lines — the same ballistics, but simpler to build and more reliable, which at that stage of the war mattered more than refinement. Only some 255–300 tanks were completed with the D-5T; every one after that carried the ZiS-S-53.

The gun is what the tank is named for, but the turret is what changed the fighting. The T-34's original turret held two men, and the commander served the gun himself: he aimed, he fired, and in between he was supposed to command his tank and, if he led a platoon, the tanks around him. In practice he could do one job or the other, never both.

The T-34-85 received an enlarged cast turret for three, with a separate gunner, a loader, and a commander's cupola with all-round vision. For the first time a Soviet tank commander could keep his head out of the fight and watch the battle. Against German crews who had worked that way since 1939, it closed a gap that no amount of armour had ever addressed.

Below the turret ring the tank was the one Koshkin had drawn. The glacis was still 45 mm at 60°, worth about 90 mm against a horizontal shot, with the lower plate at 45 mm at 53° — roughly 75 mm effective, and the reason the weak spot in the front was low down. The upper sides remained 40 mm at 40°, the V-2 diesel and the Christie suspension were unchanged.

What the new turret cost was ammunition and weight. The bigger rounds cut stowage from about 77 to 56–60, and the tank grew to roughly 32 tonnes without gaining power, which took a little off its speed and a little more off its already hard-used transmission. The turret front went to 90 mm — twice the 45 mm of the 76 mm tank, and the only part of the vehicle whose protection genuinely improved.

The type went into major action in the Korsun–Cherkassy pocket in Ukraine in February 1944, in the winter fighting that encircled two German corps. Production was still measured in hundreds and the tanks arrived among far larger numbers of 76 mm T-34s.

Three plants were building it by the summer — #112 at Krasnoye Sormovo from January, #183 from March, and #174 at Omsk from June 1944. From that point the Red Army could put the new turret into the field faster than the Germans could replace the tanks it was meeting.

It is worth being exact about what the 85 mm did and did not do. Firing the BR-365 against a plate laid at 30°, it made about 85 mm at 1,000 m and 97 mm at 100 m. Against the Tiger I's 100 mm vertical hull front that was still not enough at any distance a tank fight normally opened at, and against the Panther's glacis it was hopeless.

What it did was restore the possibility of a fight. The T-34-85 could kill a Panzer IV or a StuG III outright, could defeat a Tiger's 80 mm side plate from a flank, and could hurt a Panther anywhere but the glacis. Combined with a commander who could actually see, that was the difference between being hunted and manoeuvring — and there were far more Panzer IVs in the German order of battle than Tigers.

Roughly 12,000 T-34-85s had been delivered by the end of the war in Europe, out of a wartime total in the order of 23,000. It became the standard Soviet medium tank of the last year of the war and the vehicle that carried the Red Army from the Vistula to Berlin.

The chassis it shared also armed the turretless tank destroyers built alongside it — the SU-85, and then the SU-100 whose 100 mm gun made 110 mm at 1,000 m, the figure the tank version never reached.

Production did not stop in 1945. It restarted under licence in 1951 in Poland and Czechoslovakia, which between them built some 1,380 and 2,700–3,200 more by 1956, and Soviet-bloc armies kept the type on strength for decades.

T-34-85s fought in Korea, in the Middle East, in Africa and in the Balkans, and were still being used in combat in the 1990s — half a century after the turret was designed to deal with a Tiger.

• Steven J. Zaloga & Jim Kinnear, T-34/76 Medium Tank 1941–45 and T-34-85 Medium Tank 1944–94 (Osprey, New Vanguard).
• Peter Samsonov, Designing the T-34: Genesis of the Revolutionary Soviet Tank (Gallantry, 2019).
• Robert Michulec & Mirosław Zientarzewski, T-34: Mythical Weapon (Air Connection, 2006).
• Wolfgang Fleischer, Russian Tanks and Armoured Vehicles 1917–1945 (Schiffer).