The Russians built many armoured trains in railway depots and car repair factories often incorporating spare parts or recycled damaged tank parts into the designs. The Armoured Train OB-3 'Railroader' was built in Moscow in December 1941 and consisted of four armoured carriages on 20 ton platforms with a T-26 turret on each and an armoured locomotive type Ov in the middle. The armour was 20-30m on the Ov locomotive and 30-40mm on the armoured carriages. The train was crewed by 60-80 people.