The T-34 rolled off Soviet assembly lines unpainted and straight into the fires of Stalingrad, and more than 80,000 were eventually built. This episode traces the tank from its origins in the border clashes with Japan in Manchuria, where petrol engines and riveted armor turned Soviet tanks into death traps, to engineer Mikhail Koshkin's vision of a universal tank with a V-12 diesel engine, wide tracks, and heavily sloped armor. Koshkin drove two prototypes 1,200 miles through the winter of 1940 to prove the design, a journey that cost him his life just as the first production models appeared.

We then follow the desperate relocation of Soviet industry over the Urals to Tankograd, the automated submerged arc welding of Evgeny Paton that cut the unit cost in half, and the rough welds, leaking joints, and brittle armor that American engineers d ...