History of The Tank - World War II

World War II

World War II forced armies to integrate all the available arms at every level into a mobile, flexible team. The mechanized combined arms force came of age in this war. In 1939, most armies still thought of an armoured division as a mass of tanks with relatively limited support from the other arms. By 1943, the same armies had evolved armoured divisions that were a balance of different arms and services, each of which had to be as mobile and almost as protected as the tanks they accompanied. This concentration of mechanized forces in a small number of mobile divisions left the ordinary infantry unit deficient in armour to accompany the deliberate attack. The German, Soviet, and American armies therefore developed a number of tank surrogates such as tank destroyers and assault guns to perform these functions in cooperation with the infantry.

Armour experts in most armies, however, were determined to avoid being tied to the infantry, and in any event a tank was an extremely complicated, expensive, and therefore scarce weapon. The British persisted for much of the war on a dual track of development, retaining Infantry tanks to support the infantry and lighter, more mobile cruiser tanks for independent armoured formations. The Soviets similarly produced an entire series of heavy breakthrough tanks.

During the war, German tank design went through at least three generations, plus constant minor variations. The first generation included such prewar vehicles as the Panzerkampfwagen (or Panzer) I and II, which were similar to Soviet and British light tanks. The Germans converted their tank battalions to a majority of Panzer III and Panzer IV medium tanks after the 1940 French campaign. However, the appearance of large numbers of the new generation T-34 and KV-1 Soviet tanks, that were unknown to Germans until 1941, compelled them to join a race for superior armour and gunpower. The third generation included many different variants, but the most important designs were the Panther (Panzer V) and Tiger (Panzer VI) tanks. Unfortunately for the Germans, lack of resources combined with emphasis on protection and firepower and a penchant for overly complex design philosophies in nearly every part of an armoured fighting vehicle's design compromised the production numbers. In 1943, for example, Germany manufactured only 5,966 tanks, as compared to 29,497 for the US, 7,476 for Britain, and an estimated 20,000 for the Soviet Union. However, an assault gun casemate-hulled development of the Panzer III, the Sturmgeschütz III, would turn out to be Germany's most-produced armoured fighting vehicle of any type during the war, at just over 9,300 examples, a popular design which could also be very effectively tasked to perform the duties of a dedicated anti-tank vehicle.

The alternative to constant changes in tank design was to standardize a few basic designs and mass produce them even though technology had advanced to new improvements. This was the solution of Germany's principal opponents. The Soviet T-34, for example, was an excellent basic design that survived the war with only one major change in armament, 76.2-mm to 85-mm main gun.

The United States had even more reason to standardize and mass produce than did the Soviet Union. By concentrating on mechanical reliability, the US was able to produce vehicles that operated longer with fewer repair parts. To ensure that American tanks were compatible with American bridging equipment, the War Department restricted tank width and maximum weight to thirty tons. The army relaxed these requirements only in late 1944.

When Germany invaded western Europe in 1940, the US Army had only 28 new tanks – 18 medium and 10 light – and these were soon to become obsolete, along with some 900 older models on hand. The Army had no heavy tanks and no immediate plans for any. Even more serious than the shortage of tanks was industry's lack of experience in tank manufacture and limited production facilities. Furthermore, the United States was committed to helping supply its allies. By 1942 American tank production had soared to just under 25,000, almost doubling the combined British and German output for that year. And in 1943, the peak tank production year, the total was 29,497. All in all, from 1940 through 1945, US tank production totaled 88,410.

Tank designs of World War II were based upon many complex considerations, but the principal factors were those thought to be best supported by combat experience. Among these, early combat proved that a bigger tank was not necessarily a better tank. The development goal came to be a tank combining all the proven characteristics in proper balance, to which weight and size were only incidentally related. The key characteristics were mechanical reliability, firepower, mobility and protection.

The problem here was that only a slight addition to the thickness of armour plate greatly increased the total weight of the tank, thereby requiring a more powerful and heavier engine. This, in turn, resulted in a larger and heavier transmission and suspension system. Just this sort of "vicious circle" aimed at upgrading a tank's most vital characteristics tended to make the tank less maneuverable, slower, and a larger and easier target. Determining the point at which the optimum thickness of armour was reached, in balance with other factors, presented a challenge that resulted in numerous proposed solutions and much disagreement.

According to Lt. Gen. Lesley J. McNair, Chief of Staff of GHQ, and later Commanding General, Army Ground Forces, the answer to bigger enemy tanks was more powerful guns instead of increased size.

Since emphasis of the using arms was upon light tanks during 1940 and 1941, their production at first was almost two to one over the mediums. But in 1943, as the demand grew for more powerful tanks, the lights fell behind, and by 1945 the number of light tanks produced was less than half the number of mediums.

In 1945-46, the General Board of the US European Theater of Operations conducted an exhaustive review of past and future organization. The tank destroyer was deemed too specialized to justify in a peacetime force structure. In a reversal of previous doctrine, the US Army concluded that "the medium tank is the best antitank weapon." Although such a statement may have been true, it ignored the difficulties of designing a tank that could outshoot and defeat all other tanks.