The T-111 (Object 111), also known as T-46-5, was an interesting tank trying to combine the light “fast tank” role with that of infantry support. This would result in a tank more on the medium scale in weight paired with the 45mm 20-K cannon.
Prior to the Second World War, tanks primarily still fell under the two main categories of “fast tanks” meant to overwhelm the enemy with speed, and “infantry tanks” which were meant to support the infantry and be more heavily armed and armoured compared to their counterparts. However, in certain countries, such as the Soviet Union, there was an idea to combine the roles into one uniform vehicle. This had been ongoing with many projects prior to the T-111 attempting to create one universal light tank instead of the BT series and T-26 series, eventually resulting in the T-46.
In February 1936, S.A. Ginzburg, head of OKMO’s experimental division at Leningrad, proposed a design to the ABTU of the Red Army for a tank with 50mm of angled armour. Unfortunately, due to the purges and the siege of Leningrad nothing else can be found upon what this tank would have looked like.
Despite that and with the T-46 project giving some experience to the designers at Factory No. 185, by 1937 the design of the T-111, also known as the T-46-5, would begin. Work was slow due to S.A. Ginzburg being watched at the time.
By 1938, work resumed on the tank, with the first prototype being produced in March. The tank’s armour was assembled from cemented, rolled armour plates 60-20mm thick by electric welding. This was very innovative for the time, though it was also very complex. With this armour added the tank now weighed 32 tons — far greater than the projected 20 ton design.
The tank was powered by a 300HP MT5 12 cylinder engine which allowed a maximum speed of 30km/h. Six twin road-wheels were used on the tank with the drive sprocket at the front and the idler at the rear. The tank had a crew of 3, those being a loader, commander, and driver.
As the vehicle left for trials in 1938 it proved to be successful at withstanding 37mm and 45mm ammunition, along with being quite easy to handle and manoeuvre despite the increased weight. In spite of all the successes on trials, the tank had one major issue holding it back: the armament. Because of the turret shape, the proposed 76mm PS-3 and L-10 cannons could not be fitted to the vehicle. This issue, coupled with the larger weight than initially calculated, meant that the project would be shelved. A small production series was initially planned for 1939, but it was cancelled due to the troubles with the DMT-8 engine proposed to be added to the vehicle.
Despite its initial success, the weight held it back and it became known as a cumbersome tank. With the KV-1 and T-34 now in development the T-111 was deemed outdated for what the future threats were assumed to be. It is unknown what happened to the two pilot vehicles, however it is most likely that both were lost in the 1939-1940 Winter War as final tests to see the tanks’ combat worth in battle, just like how the multi-turret heavies were used.
Even though the T-111 project ended, the development led to the T-126 and eventually the T-50 — the pinnacle of World War II era Soviet light tanks.
Dimensions (L-W-H): 5.26x3.11x2.41m (17’3’’ x 10’2’’ x 8’0’’ ft)
Total Weight: 32 tons
Crew: 3 (Driver, Loader/Gunner, Commander)
Propulsion: MT-5 petrol engine, 300hp
Power to Weight Ratio: 9.38 hp/ton
Suspension: Torsion Bar Suspension
Top Speed: 30km/h (18.6 mph)
Main Armament: 45mm 20K (unknown maximum capacity)
Secondary Armament: 3x DT-29 7.62mm machine guns (located coaxially, bow mounted and rear mounted)
Armour: Hull: 60mm front, 50mm sides and rear, 20mm top and bottom
Turret: 60mm front, 50mm sides and rear, 20mm top
Production: 2 vehicles