T-34/76 and T-34/85 Part I

THE FIRST T-34s

The heavy tank design bureau In Leningrad had reversed many years of Soviet practice by naming their new tank the Klimenti Voroshilov, or KV after the egregious Defence Commissar. With some courage, Koshkin told Voroshilov that the new tank should not be named after another hero of the Soviet Union; rather they should return to using the traditional designations. Koshkin suggested the designation T-34 to commemorate the 1934 state decree which ordered a massive expansion of the Soviet armoured forces. It was also the year that Koshkin had had his first ideas about the new tank. Accordingly, Koshkin’s proposal was accepted.

Once the team received official sanction to build a purely tracked medium tank, they had returned to their original design for the A-32. The T-34 required thicker armour, but it also needed to be equipped with more firepower as well as a reliable transmission. Morozov and the transmission group devoted considerable time and effort to finding a solution to these problems.

The two prototypes were ready by January 1940, and Koshkin took them on a gruelling trial march to prove the hardiness of the design. He drove them from Kharkov to Moscow, and here the tank was presented to the Red Army. Following this presentation, they were sent on to Finland for combat tests against the Mannerheim Line, but unfortunately they arrived too late to see any action. However, Koshkin and his team were able to demonstrate the power of the T-34’s armament against captured Finnish bunkers. There were further firing trials in Minsk, and then it was on to Kiev, and finally back to Kharkov. This round trip had covered a distance of 2880km (1800 miles) in the bitter weather of February and March.

During June the drawings were completed and mass production began. The first production T-34 Model 1940 rolled out of Kharkov in September 1940. During the gruelling winter test-drive, Koshkin had contracted pneumonia, and he died on 26 September 1940. Morozov, now head of conceptual design, took over the T-34 project.

SUMMARY OF ALL T-34 VARIANTS

As the T-34 was produced from different factories, models and types varied. In August 1939, the Soviet Main Military Council accepted the T-34 as the Red Army’s medium battle tank. The new design was completed during December 1939 and became known as the T-34 (Model 1940). On 19 December 1939, the drawings and models of the new T-34 were submitted to the High Command, which accepted them for production, even though the prototype had not yet been completed.

DIESEL ENGINES

The first production-line models were fitted with V-2 diesel engines, but shortages meant that some of these early models were equipped with the older M-17 petrol engine. Problems with transmissions were such that the T-34/76 (Model 40) often went into battle with spare transmission units secured to the engine compartment deck by steel cables.

The Model 40 had a rolled plate turret and a short 76.2mm (3in) L/30.3 (L-11) Model 1938 tank gun mounted in a distinctive cast cradle welded to a flush outside mantle. The Model 40 established a standardization pattern among the T-34 variants of having a great number of interchangeable parts, such as engine, armament, transmission and periscopes. Mechanical simplicity was a prime concern. The hull was of a welded construction throughout, with only three different thickness of rolled plate armour.

The Christie suspension had five large, double road wheels on each side, with a noticeably larger gap between the second and third wheels. The drive sprocket, located for safety to the rear, was of the roller type used on the BT series and powered a cast manganese-steel track with centre guide horns on alternative track links. This first model of the T-34 had a distinctive turret overhang and a clumsy turret hatch occupying the entire rear part of the turret. The Model 40 had one periscope fitted on the front lefthand side. In late 1941, a small number were fitted with the long-barrelled, high velocity 57mm (2.24in) ZiS-4 gun, to engage light armoured vehicles at greater ranges than the 76.2mm (0.303in) L-ll.

T-34 (MODEL 1941)

The second model of the T-34 appeared in 1941 and was essentially a commander’s Model 40 with a rolled plate turret mounting a more powerful Model 1940 76.2mm (3in) L/41.5 gun. The same clumsy turret hatch was retained, but some of these variants had twin periscopes. While there was no change in the layout of the hull, these commander’s tanks had a stowage box on the righthand track guard. The most noticeable feature of the 1941 model was the replacement of the peculiar cast gun cradle by an angular, bolted type. During 1942, a model appeared with a cast turret and it also had new, wider tracks. Some were fitted with a flamethrower (ATO- 41) and had an armoured fuel container on the rear plate of the hull.

T-34 (MODEL 1942)

In 1942 the cast turret (as opposed to rolled plate) became standard in the Model 1942. The new turret weighed 4.4 tonnes (4.32 tons) and had a ring diameter of 1.38m (4.6ft). The Model 1942 had various improvements, taking into account reports from the battlefield. The commander and gunner now had separate hatches, and a new hull machine-gun mounting made the 7.62mm (0.3in) DT machine gun more effective in close-quarter battle.

In early 1942 a team designed a new T-34, the T-34M, with a chassis similar to the KV tank (with smaller road wheels), and a completely new hull and turret layout. However, this tank was not accepted for production, and only the hexagonal shape to the T-34/M turret was retained for the next variant of the T- 34, the T-34/76 Model 1943.

The T-34 Model 1943 was manufactured in response to battlefield reports which showed that one drawback of the current T-34 design was the turret overhang at the rear that was vulnerable to attack by Teller mine-armed infantry tank-hunters. The new, cast hexagonal turret with no overhang became the Model 1943 and included other changes, such as improved fuel capacity and welded armour plate components.

T-34/76E

Subsequent T-34/76 models are best known by their British classification. The Models E and F were both produced in 1943. While the basic hull and turret structure of the T-34/76E remained the same, it had a more effective air-cleaning and lubrication system. The hull design was also improved by using automatic welding processes with improved materials that gave stronger, higher-quality joins. The Model ‘E’ clearly demonstrated the advances made in Soviet industry. This new confidence in tank construction meant that each new T-34 model was more rugged and better equipped.

T-34/76F

The Model ‘F’ had a distinctive appearance as, while it had no commander’s cupola, the model had contoured undercuts around all the sides and the front. The main difference to the F was, however, in its internal workings. The T-34/76F had new, highly efficient automotive components. The old four-speed gearbox was replaced by a five-speed box that made gear-changing easier and increased the speed of the T-34. The air filter was refined further and a level of care and thought went into the mechanics of the T-34/76F that set it apart from earlier models. However, only a limited number of this type were produced as production began to move in a much more radical direction.

By 1943 it was apparent that the 76.2mm (3in) gun on the T-34 was inadequate. The model incorporated many new design features, and had added armour protection, but it was still undergunned. The appearance of the German long-barrelled high-velocity 7.5cm (2.95in) (L/48) and 8.8cm (3.46in) tank guns finally proved that the T-34 had to be up-gunned, and this was to lead to the genesis of the T-34/85.

T-34/85-I

With its 85mm (3.34in) gun, the T- 34/85-I that appeared in 1943 was basically an up-gunned T-34. The T- 34/85 had a new turret originally designed for the KV-85 tank with a ring diameter of 1.56m (5.2ft). This created the space for an extra crewmember and simplified the tasks of the tank commander, who previously had helped with the gun. The T-34/85-I was first issued to elite Guards Tank units, and the new gun soon proved its worth. Based upon the pre-war M-1939 85mm (3.34in) antiaircraft gun, it had an effective range of 1000m (1100yd) and, it was claimed, was able to penetrate the frontal armour of the German Tigers and Panthers.

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