The introduction of the SU regiments has been covered already. A brief note on the SU equipment, which was divided into three main types. The SU-76 was the Light SU for the entire war, and included both the original SU-76 and the SU-76M (M = ‘modification’ or ‘modified’), and the SU-76i, which was a Soviet 76mm gun mounted on captured PzKpfw III chassis. Almost half of all SUs built were SU-76 types.
The medium SU regiments were originally equipped with the SU-122, a 122mm howitzer mounted on a T-34 chassis. 600 of these were built in 1942-43, but they had less artillery effect than the heavy SU-152 and no antitank capability to speak of, even with a shaped charge round for the 122mm howitzer. They were largely replaced by the end of 1943 by the SU-85, an 85mm gun on a T-34 chassis that was sometimes referred to as an Self-Propelled Antitank Gun instead of an SU. 2600 of these were built in 1943-44, and by late 1944 they not only equipped SU regiments in the tank and mechanized corps, but a regiment of SU-85s was replacing towed guns in some of the antitank brigades. Since even the 85mm gun could not damage the heaviest German tanks from the front except at very short ranges, starting in October 1944 the Soviets started replacing the SU-85 with the SU-100. The SU-100 remained in regular service into the 1950s.
The heavy SU regiments were originally equipped with the SU-152, a 152mm howitzer mounted on a KV-1S chassis. The first 25 of them were rushed into service in time for the Battle of Kursk, where the effect of their 100 pound shells on German Panthers and Tigers earned them the nickname ‘Zvierboi’ (‘Big Game Hunters’). The SU-152 was only in production during 1943, and 670 were built. They were increasingly replaced in 1944 by two heavy SUs on the chassis of the new IS-II tank: the ISU-152, which was built until 1948, and the ISU-122, of which 2400 were built in 1944-45. The ISU-122 was the ultimate “Big Game Hunter”: it could penetrate a Panther turret at up to 2,000m range, and it out ranged the 88mm on the Tiger I.
The Soviets used “Self-Propelled Gun” (or SP Artillery) for every fighting vehicle that consists of a gun mounted on a chassis.
The Soviets used term “Istrebitel tankov” (Tank Destroyer) for the SU-85 and the SU-100.
The Soviets used term “Shturmovaya Artilleriiskaya Ustanovka” (Assault Gun) for the SU-122, SU-152, ISU-152, ISU-122.
The Soviets used term “Shturmovoi Tank” (Assault Tank) for the KV-2.
The Red Army called their assault guns for “samokhodno-artilleriiskie ustanovki” abbrevation Kyrrillic “CAY”, with our letters “SAU”. the other version “samokhodno ustanovki” abbrevation Kyrillic “CY”, with our letters “SU”.
The first word “samokhodno” could be translated to self-propelled.
The next word “artilleriiskie” does not need further clarification.
Finally “ustanovki” could be translated with gun carriage.
These assault guns was organized into heavy “samokhodno-artilleriiskie” regiments with 21 assault guns. In Operation Bagration the four fronts initially had 2 Assault Guns brigade and 57 Assault gun regiments.
1.Baltic had four regiments (of which three were heavy).
3.Belorussian had 16 regiments (of which five were heavy) .
2.Belorussian had 10 regiments (of which two were heavy).
1.Belorussian had 27 regiments (of which five were heavy) and two brigades (8. in 3rd Army and 12. in 69th Army).
