The USSR began working on the issues of protecting armoured vehicles from air attack in the early 1930s. The first plans were to create specialized self propelled anti-aircraft guns, but work on these topics did not pan out. Instead, the Red Army received tanks with AA machine gun mounts. This mount was developed at experimental factory #185. It was accepted into service as the P-40 in 1935 and entered production a year later. M.A. Shufrin was the lead engineer on this project. Ironically, his initials were rarely seen in association with factory #185, even though this was one of the few products of factory #185 that truly saw widespread use. Mass production of the mount began in 1937. Variants were installed on the T-26, BT-7, T-28, and T-35. At its inception it was the best anti-aircraft gun mount in existence. It allowed the DT machine gun installed on it to rotate a full 360 degrees. The DT machine gun was equipped with AA sights.
|The KV-1 was the only new generation Soviet tank equipped with an AA machine gun, although it was not used frequently.
|P-40 machine gun mount on a T-26 tank. The AA sight is not installed.
|AA machine gun mount on the KV-1 tank.
|Browning M1919A4 machine gun on the Light Tank M3. The traverse range was limited.
|The mount is folded for travel.
|AA gun cupola on the Medium Tank M3. The machine gun could only be aimed by watching the tracers.
|Lakeman Mounting on the Matilda III.
|The Churchill III had the best variant of the Lakeman Mounting, although disk magazines completely obscured the gun sight.
|Bren gun mount carried in the Universal Carrier. It could be used to fire at aircraft, just not from inside the vehicle.
The results of these trials were quite interesting. On one hand, Soviet mounts were clearly superior. On the other hand, by the time the trials were held production of the KV-1 had ended. The KV-1S did not have an AA machine gun mount. The study of AA gun mountings was rather theoretical. Another burst of activity on this topic followed the Battle of Kursk, where German ground attack aircraft dealt palpable losses to our tanks. Designers remembered both SPAAGs and AA machine guns, but soon forgot them again. Production finally began after some motivation from above, but even then only for heavy tanks and SPGs. An AA machine gun mount was introduced on the SU-76M in the spring of 1945, but medium tanks had to wait until 1947 and the production of the T-54.