Specification Crew : 5 Engine power : 500 hp Combat weight : 30,900 kg (68,134 lb) Max speed : road 55 km/h (34.16 mph) Range : 300 km (186.30 miles) Length : 6.95 m (22.80 ft) Width : 3 m (9.84 ft) Height : 2.32 m (7.61 ft) Main gun : 122 mm (4.81 in) howitzer Armour : 20 mm (0.79 in) to 45 mm (1.78 in)

The SU-122 was an assault gun based on the T-34 medium tank.The turret was replaced by an armored superstructure housing a modified 122 mm (4.81 in) field howitzer.The first production examples designated the SU-122 Medium Mechanized Gun , was issued to the Red Army in January 1943. The SU-122 proved to be effective as an assault gun delivering direct fire during attacks on strongly defended positions.Unfortunately the anti-armour performance of the 122 mm (4.81 in) howitzer was less then expeted.A shaped charge HEAT (high explosive anti-tank) projectile was developed but it was only accurate at short range and armour penetration was still disapointing.Replacing the howitzer with a 122 mm field gun overloaded the chassis so the SU-85 was produced instead.The SU-122 soldiered on sometimes with the armed forces of the Soviet allies until the war ended.In place of the usual awkward-looking armored mantlet used on most SU-122s late production models had a ball mantlet similar to that adopted on the SU-85. The Germans were happy to employ as many SU-122s as they could capture , usually banded into special units and liberally decorated with German markings.Since it was based on the T-34 which had also been captured in large numbers there were usually sufficient spare parts to keep the SU-122s operational for a reasonable period.Ammunition presented little problem either as the 122 mm field gun was already used by the Germans as well.