Specification Crew : 2 Engine power : 70 hp Combat weight :5,900 kg (13,009 lb) Max speed : road 44 km/h (27.32 mph) Length : 4.11 m (13.48 ft) Range : 360 km (223.56 miles) Width : 2.33 M (7.64 ft) Main gun : 12.7mm(0.50 in)machine gun Height : 1.95 m (6.40 ft) Armour : 7 mm (0.28 in) to 14 mm (0.55 in)

When the shortcomings of the T-37 / T-38 light tanks were recognized attempts were made to produce more viable successors.Production was assigned to factories normally producing automobiles.The two-man T-40 was a simple design and made extensive use of automobile components whenever possible including the engine and transmission.Early T-40's were armed with a 12.7mm heavy machine gun , later models had a 20mm cannon. The most noticeable feature of the T-40 was its bulky boat-shaped hull produced by two flotation tanks which kept the vehicle afloat in the water , while a propeller at the rear provided propulsion.The engine was on the right hand side of the welded hull.The first T-40s were used during the latter stages of the Winter War with Finland.Their thin armour drew criticism as the vehicles could be penetrated even by anti-tank rifles issued to Finnish infantry units.The T-40A had more armour (the hull outline was altered) and the T-40S intended to be introduced in 1942 was even better protected.However the extra weight involved meant that the T-40S lost its amphibious capability.As a result the whole light amphibious tank concept was scrapped and production concentrated on the Light Tank T-60.Most T-40s in service at the time of the German invasion were destroyed or captured in the vast encirclements of 1941.