The AA Tank That Came Too Late

The story of a SPAAG on the T-60 chassis that was not fated to enter mass production.

SPAAGs were a sore spot of the Soviet tank design program. It’s not that there weren’t any of them by the start of the Great Patriotic War, but they looked nothing like what was originally envisioned. A class of SPAAGs on tank chassis was conceived and such vehicles were even built. The best example would be the SU-6, a SPAAG on the chassis of the T-26 light support tank. It was even accepted into service with a pilot batch built, but mass production never came. Development of SPAAGs on light tank chassis continued. The T-50 chassis was considered a candidate for a SPAAG, armed with either a pair of MP-6 23 mm auto cannons or a 37 mm 61-K. The actual result was quite sad: two experimental SPAAGs on the T-26 chassis were built in Leningrad and that was it. Mechanized units were covered against air attack by a variety of systems on a truck chassis.

The GABTU considered the installation of a T-90 turret on the T-60 to be a quick fix.

Further work went down the road of creating a universal chassis using T-60 tank components. The chassis was developed under code 31 at factory #37 in Sverdlovsk. The prototype designated SU-31 was quite a good vehicle for its time. The 37 mm 61-K auto cannon was an effective weapon against enemy aircraft. However, work dragged on and factory #37 was rolled into UZTM. Instead of the T-70, it was used to build T-34 tanks. Meanwhile, a German airplane was shot down in late June of 1942. A report was found on board detailing the trials of a Henschel Hs 129A ground attack aircraft. Its 30 mm MK 101 gun could penetrate even the armour of the KV-1 tank. The news that SPAAGs on truck chassis had poor off-road mobility were also bad. The combination of these factors gave rise to the idea of building AA tanks.

The SPAAG only entered trials in July of 1943. Compare this arrival to the due dates in the GKO decree above.

The Doomed Victorious AA Tank

The T-90 AA tank developed by the Molotov GAZ factory that won the tender but never entered mass production.

The situation in Soviet tank production changed radically in the second half of 1942. The experience in 1941 and the first half of 1942 clearly indicated new priorities. It was clear that T-34 production had to increase, as this tank turned out to be the optimal combat vehicle. It had the necessary mobility, decent armour, and powerful armament. The T-34 was often the only tank that could move cross-country in later 1941 and early 1942. The KV-1 was too heavy and the T-60 was too weak. The T-70 light tank that appeared in early 1942 was better than the T-60, but Soviet leadership had no illusions about it. It was clear by the spring of 1942 that the T-70 would not be built at as many factories as the T-60 was. The situation was difficult in the summer, and a decision was made to even spin up T-34 production in Chelyabinsk at the cost of decreasing KV production. Additionally, a decision to build the T-34 in Sverdlovsk at the site of the former factory #37 was made. Only two factories remained for the T-70: the Molotov GAZ in Gorky and factory #38 in Kirov. They would also have been used for T-34 production, but they proved unsuitable.

Status of the work on AA tanks at the GAZ as of September 1942. AA tanks on the T-60 and T-70 chassis are mentioned. In reality, they only worked on the future T-90.

Front line experience in 1942 showed that the decision to change priorities was correct. The first use of the T-70 tank revealed that it had issues when it came to crew comfort and, most importantly, armour. This was not a surprise. The age of light tanks was coming to an end, and the Germans also ceased production of these vehicles in the summer of 1942. Soviet light tanks clinged on for longer, but it was clear that their time had come. This did not mean that light vehicles would disappear altogether. The chassis of light tanks was necessary for the creation of SPGs, which were not obsolete until the very end of the war. Self propelled guns with powerful armament than the tank they were based on were in demand at the front, which experience proved time and time again as the war went on. The development of Soviet self propelled artillery did not differ much from the path it took abroad, even considering that the first SPGs went into production in the summer-fall of 1941 (including SPAAGs).

The T-90 tank prototype, September 1942.