T-34

Origins

In 1939, the most numerous Soviet tank models were the T-26 infantry tank, and the BT series of fast tanks. The T-26 was slow-moving, designed to keep pace with infantry on the ground. The BT tanks were cavalry tanks, fast-moving and light, designed for manoeuvre warfare. Both were lightly armoured, proof against small arms but not anti-tank rifles and 37 mm anti-tank guns. During the Battles of Khalkhin Gol, an undeclared border war against Japan in 1939, General Zhukov deployed nearly 500 BT-5 and BT-7 tanks against the Imperial Japanese Army (IJA). Although the IJA Type 95 light tanks had diesel engines,the BT tanks did not. Their gasoline engines, commonly used in tank designs by most nations at the time, often burst into flames when hit by IJA tank-killer teams using Molotov cocktails; poor quality welds in the Soviet armour plates left small gaps between the plates, and flaming petrol from the Molotov cocktails easily seeped into the fighting compartment and engine compartment.The Soviet tanks were also easily destroyed by the Japanese Type 95 tank's 37 mm gunfire, despite the mediocre performance of that gun,or "at any other slightest provocation." Both were Soviet developments of foreign designs from the early 1930s; the T-26 was based on the British Vickers 6-Ton, and the BT tanks were based on a design from American engineer Walter Christie, featuring a unique high-speed suspension.
In 1937, the Red Army assigned engineer Mikhail Koshkin to lead a new team to design a replacement for the BT tanks at the Kharkiv Komintern Locomotive Plant (KhPZ). The prototype tank, designated A-20, was specified with 20 mm (0.8 in) of armour, a 45 mm (1.8 in) gun, and the new Model V-2 engine, using less-flammable diesel fuel in a V12 configuration designed by Konstantin Chelpan. It also had an 8×6-wheel convertible drive similar to the BT tank's 8×2, which allowed it to run on wheels without caterpillar tracks.[18] This feature had greatly saved on maintenance and repair of the unreliable tank tracks of the early 1930s, and allowed tanks to exceed 85 kilometres per hour (53 mph) on roads, but gave no advantage in combat. By then, track design had improved and the designers considered it a waste of space and weight, despite the road speed advantage.The A-20 also incorporated previous research (BT-IS and BT-SW-2 projects) into sloped armour: its all-round sloped armour plates were more likely to deflect anti-armour rounds than perpendicular armour.
A-8 (BT-7M), A-20, T-34 Model 1940 and Model 1941
Koshkin convinced Soviet leader Joseph Stalin to let him develop a second prototype, a more heavily armed and armoured "universal tank" which could replace both the T-26 and the BT tanks.[notes 1] Koshkin named the second prototype A-32, after its 32 mm (1.3 in) of frontal armour. It also had a 76.2 mm (3 in) gun, and the same V-2 diesel.Both were tested in field trials at Kubinka in 1939, with the heavier A-32 proving to be as mobile as the A-20. A still heavier version of the A-32 with 45 mm (1.8 in) of front armour and wider tracks was approved for production as the T-34. Koshkin chose the name after the year 1934 when he began to formulate his ideas about the new tank, and to commemorate that year's decree expanding the armoured force and appointing Sergo Ordzhonikidze to head tank production.
Lessons from Khalkhin Gol regarding armour protection, mobility, welding and main guns were incorporated into the new T-34 tank,and Koshkin's team completed two prototype T-34s in January 1940. In April and May, they underwent a grueling 2,000-kilometre (1,200 mi) drive from Kharkiv to Moscow for a demonstration for the Kremlin leaders, to the Mannerheim Line in Finland, and back to Kharkiv via Minsk and Kiev.Some drivetrain shortcomings were identified and corrected.

Overview

The initial T-34 version had 76.2 mm gun,and is often called the T-34/76 (originally a World War II German designation). In 1944, a second major version began production, the T-34-85 (or T-34/85), with a larger turret mounting a larger 85 mm gun.The T-34 had the coil-spring Christie suspension of the BT, using a "slack track" tread system with a rear-mounted drive sprocket and no system of return rollers for the upper run of track, but dispensed with the heavy and ineffective convertible drive. It had well-sloped armour, a relatively powerful engine and wide tracks.Initial 1940 production tanks were installed with the 10-RT 26E radio set, but this was soon replaced by the 9-RS model (also installed on SU-100). From 1953, T-34-85s were installed with the R-113 Granat ("garnet") radio sets.
The T-34, like many other contemporary tanks, required the tank commander to aim and fire the gun while having to coordinate with other tanks and potentially also being a platoon commander. Contemporary German medium tanks (but not light tanks) had three man turret crews that divided the work between commander, gunner and loader. This problem, which had been recognised before the war, was to be corrected with the addition of the upgraded three-man turret on the T-34-85 in 1944. Some tanks also had appliqué armour of varying thickness welded on to the hull and turret. Tanks thus modified were called s ekranami (Russian: с экранами, "with screens").

Firepower


The T-34's 76 mm (3 in) gun with anti-tank ammunition was able to penetrate any German tank's armour at normal combat ranges. The F-34 gun firing APCR shell had the capability to penetrate 92 mm of armour at 500m.The best German tanks of 1941, the Panzer 4 Ausf F had 50 mm frontal armour and Panzer III had only 50 mm.This gun also fired an adequate high explosive round.
The gun sights and range finding for the T-34's 76.2 mm F-34 L/42.5 gun, either the TMFD-7 or the PT4-7,were rather crude, especially compared to those of their German adversaries, affecting accuracy and the ability to engage at long ranges. German soldiers found that the Soviet armour attacked in rigid formations and took little advantage of terrain.[54] As a result of the T-34/76’s two man turret, weak optics and poor vision devices, Germans noted:
T34s operated in a disorganised fashion with little coordination, or else tended to clump together like a hen with its chicks. Individual tank commanders lacked situational awareness due to the poor provision of vision devices and preoccupation with gunnery duties. A tank platoon would seldom be capable of engaging three separate targets, but would tend to focus on a single target selected by the platoon leader. As a result T-34 platoons lost the greater firepower of three independently operating tanks.
The Germans noted the T-34 was very slow to find and engage targets while the Panzers could typically get off three rounds for every one fired by the T-34.
The 85 mm ZiS gun of the T-34-85 greatly increased firepower over the previous 76.2 mm F-34 cannon on the T-34/76. The length of the 85 mm gun barrel (4.645 meters) made it necessary for crews to be careful not to dig it into the ground on bumpy roads or in combat; A.K. Rodkin commented: "the tank could have dug the ground with it in the smallest ditch. If you fired it after that, the barrel would open up at the end like the petals of a flower."