Saturday, 30 March 2013

World of Tanks History Section: Rheinmetall Leichttraktor


At the end of WWI, Germany ended up on the losing side, tied by harsh sanctions. Reichswehr was heavily limited, losing 90% of its heavy armament, but never lost all of it. In 1919-21, Germany was engulfed in a revolutionary spirit. In order to prevent the fall of the Wiemar Republic, a commission of allied countries allowed Germany to have a small amount of armoured cars, up to 150 in total. The situation with tanks was more difficult. After quelling the Berlin uprising, Germany was forced to destroy its A7V and captures MkIV tanks, as well as prototypes of the K-Wagen "Kolossal" and light LK-I and LK-II.

In early 1919, Germany made an agreement with Hungary, in which they built 14 LK-II tanks. Another batch of LK-II tanks was build for Sweden. The deal was made by the Steffen & Heyman company. Sweden also received German specialists to help with assembly. The LK-IIs were accepted into service under the name Stridsvagn m/21. In the early 1930s, they underwent modernization, and remained in service until 1941. With this, tank building in Germany stopped for some time. However, the Germans not only retained their experience, but managed to obtain some novelties from their former adversaries.

Work on a light tank, designated VK 31 (called Kleintraktor, or small tractor, for secrecy), started two years after the heavy Grosstraktor. This project was launched by the Reichswehr, on March 28, 1928, by announcing a request for tender for a tracked combat vehicle up to 12 tons in weight. Prototypes were to be constructed by 1930 and cost less than 50 000 Reichsmarks. The winner would receive an order for at least 17 tanks.

The request was delivered to three companies: Daimler-Benz, Krupp, and Rheinmetall-Borsig in May of 1928. By that time, the weight requirement was lowered to 7.5 tons. Additional requirements included 14 mm of front and side armour and a crew of 4. The armament of the Light Tractor was to be a 37 mm semi-auto gun and a 7.92 mm Dreyse machine gun. The tank also had to have a radio to provide voice communication with a range of 2-3 km and a telegraph for 7 km. Chemical protection was also required, in case of a gas attack. Maximum highway speed was 25-30 kph (40 kph by some sources), and 20 kph off-road.

Daimler-Benz refused to participate, leaving Krupp and Rheinmetall-Borsig in the competition. Both companies developed a "Kleintraktor" (renamed "Leichttraktor", or light tractor) together, and their results were very similar. Not having much experience with tank suspensions, Rheinmetall engineers used the tracks from a tow tractor. Each side had 12 road wheels, two wheels per bogey, one tension idler, and two support idlers, a front directing, and a rear leading wheel. In order to protect this system, a side screen was retained, with three openings to clean the mud out of the suspension. The hull was a combination of welded and bolted, from armoured steel 4-10 mm thick. The layout was inherited from a tractor. The front, which had the transmission, also housed a Daimler-Benz M36 carburator engine, 36 hp in power. The middle part had the control compartment (the driver sat on the left side). The driver had a small rectangular turret with vision ports above his head.

Krupp engineers did not trust tractors, and built their own chassis. Krupp's vehicle was slightly longer and taller, which allowed two hatches on the side for entrance and evacuation. The Krupp tank had 6 small diameter road wheels per side, with a vertical spring suspension, grouped in two groups of three, with the front-most and rear-most wheels slightly larger than the others. There were also two idlers, a front directing, and a rear leading wheel. Rheinmetall was responsible for both turrets. All VK 31s had radio stations.

The Soviet Union took a large part in creating Germany's tank army. A treaty on the creation of a Soviet-German tank school in Kazan was signed in Moscow, in 1926. It was headed by the Reichswehr colonel Malbrandt, whose name led to the project being codenamed KaMa (Kazan-Malbrandt). All four light tank prototypes were shipped here, numbered 37 and 38 (Krupp), 39 and 40 (Rheinmetall). The Special Technical Commission (TEKO), created to exchange experience in the area of tank building, began its work.

By 1933, each prototype traveled from 1660 to 1865 km. Soviet specialists agreed that these vehicles are not of any interest to the RKKA. However, Soviet engineers were interested in the suspension and the turret layout (namely the coaxial machine gun), as well as the tanks' radios. German specialists were not in awe of their vehicle either. Further modernization and up-armouring was not possible without increasing weight, and reducing the already unimpressive mobility of the tanks.

All four Leichttraktors were shipped back to Germany in 1933, when KaMa was closed down. In 1934, the tanks were moved to Munster for the winter. From 1935 to the start of WWII, they were used as training vehicles in Pultos.

Original article available here.

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