Wiki Article: Leichttraktor | besserwiki.org (2024)

The Leichttraktor (Vs.Kfz.31) was a German experimental tank designed during the Interwar Period. ⓘ

The designation Leichttraktor (also L.Tr.) was the camouflage designation of the German Reichswehr and later Wehrmacht for the development of a light armored fighting vehicle. Four prototype vehicles were developed while the Weimar Republic was still in power. Together with the Großtraktor, they were the first German armored vehicles to be created after World War I. ⓘ

Development

Prehistory

Under the Treaty of Versailles, the German Empire was prohibited from possessing an armored weapon, so efforts were made early on to circumvent this prohibition. In 1928, two years after the development order for the Großtraktor, the Rheinmetall, Krupp and Daimler-Benz companies were instructed to develop a light experimental tank with the project name Kleintraktor, which was to weigh ten to twelve tons. ⓘ

There is evidence of a corresponding note on this project in the Kraftfahr Rüstungsprogramm of April 17, 1928, which states that the first prototypes (test pieces) were to be delivered in October 1929 so that testing could take place in 1930. Then, starting in 1931, a company of 17 vehicles to be procured was to be established with the available budget. ⓘ

Development

The starting point was that Inspectorate 6 (Motor Vehicles) (In 6 (K)) of the Wehramt formulated its general requirements for such a vehicle. These functional requirements were in turn forwarded to the Army Ordnance Office, and the Wa Prüf 6 department there (represented by Col. Gaissart and Capt. Pirner) used the general requirements to develop the conceptual profile (drawings) and the technical specification, with which the development orders were given (on April 25, 1928) to the designated firms. The firms' development proposals were then again reviewed by Wa Prüf 6 and In 6 (K), with the appropriate change requests. Since the Wehramt controlled the budget, it was ensured that the requirements of the Heereswaffenamt did not drift into utopian territory, for the vehicles had to remain affordable. In conservative thinking, which is occasionally found in military departments, the design of a light tank appears to have been based on the German model L.K. II of World War I, but took a contemporary approach to the concept with a rotating turret. ⓘ

The companies Friedrich Krupp AG, Rheinmetall and Daimler were to be involved in the development project. Two prototypes were to be built for each company. It is interesting that Wa Prüf 6 agreed to supply the rubber tracks, the military equipment of the vehicle and the turret. Furthermore, the companies received a promise that the development costs would be reimbursed if a competitor won the contract. ⓘ

Krupp gave its commitment for the production of two small tractor prototypes on May 8, 1928, stating that the vehicle was too weakly powered according to specifications. Realizing that the previous project would result in a medium-sized tank and with the ulterior motive of creating a lighter tank, it was decided on May 26, 1928, that the new vehicle would be called Leichttraktor (L.Tr.), thus leaving the name Kleintraktor free for the smaller vehicle. On that day, the following specification parameters were established: a Rheinmetall 3.7-cm armament with 200 rounds, a crew of three or four, a maximum weight of 6-t (like the Vickers-Armstrong, which was developed in the same year), 40 km/h on the road and 20 km/h off-road, gradients up to 60° and a fuel tank capacity of 150 l. The vehicle was to be equipped with a fogging system. Furthermore, the vehicle was to have a fogging apparatus, a gas filter and radio equipment. ⓘ

In addition to its function as a combat vehicle, the L.Tr. was also to be built as a supply tractor, ammunition transporter and in a civilian version. With foresight, it was decided on June 10 that if Daimler turned down the order, one of the other companies would build a third vehicle as an armored replenishment vehicle and the other company would build a version as a 3.7-cm combat vehicle-defense self-propelled gun carriage. ⓘ

On June 16, 1928, Col. Gaissert sent a contract offer to Krupp, Rheinmetall and Daimler-Benz (Attn: Dr. Porsche). Daimler dropped out of the project in July 1928 with a clear rejection. This information was given to Wa Prüf 6 on July 27. ⓘ

In letter IV No. 560/28, In 6 (K) laid down the final specification for the development of the light tractor. ⓘ

Krupp light tractor

The first design proposal by engineer Hagelloch was sent to Wa Prüf 6 on July 3, 1928. Feedback was that the required top speed and gradeability required a 100-hp engine. A 100-hp Maybach or a 15/70/100-hp fuel-injected Daimler engine were offered. Krupp recommended the Daimler engine, which was smaller in dimensions. The design drawing SK.99 was supplemented with a comprehensive description of the vehicle. ⓘ

In addition, the drawing SK.99a also addressed the subject of the light tractor (L.Z.). This variant was to be equipped with a 50 HP engine and reach a maximum speed of 30 km/h on the road. It was assumed that the long rubber track would produce less ground pressure than the tracks of the Cletrac and Holt tractors, and thus be superior to them. ⓘ

Drawing SK.112 dealt with the ammunition and spare vehicle. By adding an armored superstructure, the turretless vehicle, including the driver, should be able to carry a squad of 15 men. Omitting the seating, the vehicle could be used for transport duties. ⓘ

With the drawing SK.107 an alternative superstructure observation vehicle was presented. Here there should be options for use in medical service. Work on the tank destroyer concept self-propelled gun for 3.7-cm gun had not yet been completed, but it was already categorically ruled out that the vehicle in its present form was suitable as an artillery self-propelled gun self-propelled gun for 7.5-cm field gun. ⓘ

On October 9, 1928, Krupp presented a wooden model to Wa Prüf 6, the cost of which was borne by Wa Prüf 6 under a subsequent contract dated October 19, 1928. Wa Prüf 6 objected in the presentation to the engine, the position of the radiator (on the side), the Linke-Hofmann steering gear not being of sufficient strength, and they demanded the installation of a model on the Cletrac principle. A commercial truck transmission provided by Krupp was criticized and a transmission with a claw clutch from ZF (Zahnradfabrik-Friedrichshafen) was proposed. ⓘ

The development and prototype contract between Krupp and the Army Ordnance Office was signed by HWA on October 15 and by Krupp on October 24.On October 31, 1928, some final decisions were made. The M 36 commercial Daimler engine was to be installed, forming the propulsion unit with a 3-speed Friedrichshafen-Soden transmission and an auxiliary gearbox from Krupp. An observation dome with kinon glass was to replace the stroboscope solution and some mechanical components were to be taken over from the large tractor for the mounting of the rollers. Work continued on the wooden model and it was inspected again on February 19, 1929. ⓘ

On January 14, 1930, a demonstration of the Krupp Light Tractor took place before a high-ranking military commission at a Krupp plant in Meppen. The feedback from the military was extremely positive and agreement was reached on when a prototype could be delivered to the Kummersdorf proving ground and two more to a site at Unterluess. Since the turrets came from Rheinmetall and additional superstructures had to be mounted, April 1 and May 1 were given for the first two vehicles. In the end, the vehicles were sent to Unterluess on February 15 and February 25, where acceptance took place on March 27. The military superstructure was mounted on one vehicle and it was demonstrated on the factory premises on April 26. The other vehicle was tested in the open on the same day without the superstructure. ⓘ

Rheinmetall light tractor

Rheinmetall's development did not begin until 1929 at the Unterluess plant. Rheinmetall's own design relied from the outset on a Cletrac steering gear. A 100-horsepower Daimler engine was used to achieve a top speed of 35 km/h. The fuel tanks were mounted in tracks. Space was gained in the interior by mounting the fuel tanks in track boxes. A band brake served as an auxiliary steering system. A hinged vision dome above the driver had kinon multilayer glass blocks in three viewing directions. ⓘ

The combat weight of the Rheinmetall development was 8.920 tons. ⓘ

Rheinmetall's third vehicle was a self-propelled gun equipped with an L/45 3.7-cm gun (like the 3.7-cm anti-tank gun). ⓘ

Testing

After the end of World War I, Germany was restricted in military development by the Treaty of Versailles. However, a secret program under the cover name "Traktor" was developing armoured military vehicles and artillery. Its engine was mounted inside the front portion of the hull and the turret was mounted above the fighting compartment in the rear of the tank. Both Rheinmetall and Krupp produced prototypes, and in 1928, Rheinmetall's design was chosen and was awarded an order for 289 tanks. However, some time later, the order was cancelled. Krupp models had coil spring suspensions, while Rheinmetall had leaf spring suspensions. ⓘ

The Germans tested the tank in the Soviet Union under the Treaty of Rapallo – agreed between the USSR and Germany in 1922 under high secrecy and security. The testing facility used from 1926 to 1933 was named Panzertruppenschule Kama, located near Kazan in the Soviet Union. The location was a joint testing ground and tank training ground for the Red Army and Reichswehr. It was codenamed "Kama" from the words Kazan and Malbrandt because the testing grounds were near Kazan and Oberstleutnant Malbrandt was assigned to select the location for testing. ⓘ

Leichter Traktor ("Light tractor") was a cover name for all three medium tank designs produced there. In the early years of World War II it was used as a training tank. Although these designs were not used in actual warfare, they gave a good intuition on how to build tanks when Germany had previously only made one official tank, the A7V, and this design led to the creation of the Panzer I. ⓘ

All four vehicles were taken to the Kama tank school, a secret training site as a result of the Treaty of Rapallo, in the summer of that year and tested there with the Red Army. The Krupp light tractors (No. 37 and No. 38) arrived at Kama on May 19, 1930. The two Rheinmetall vehicles (No. 39 and No. 40) arrived at the training area on June 4, 1930. An order for 289 light tractors was placed in 1931, but was canceled a year later in favor of the Panzerkampfwagen I. ⓘ

A Rheinmetall tank (late chassis) was later placed as a memorial on the Putlos military training area. None of the vehicles remained after the war. ⓘ

Technology

The prototypes supplied by the two companies differed fundamentally in the running gear. While Rheinmetall used a caterpillar-like undercarriage with twelve small double running wheels - suspended in two pairs each in six double swing arms - Krupp's consisted of six interconnected double running wheels, which were damped by means of coil springs and fitted with an additional guide wheel at the front and rear. ⓘ

The armament consisted of a semi-automatic 3.7-cm KwK with a barrel length of 1.67 m and an MG 13 light machine gun; 150 rounds were carried for the gun and 3000 for the MG. With front and side armor of 14 mm, the vehicle offered protection only against hard-core projectiles from infantry rifles. ⓘ

All prototypes were powered by the Daimler-Benz M36 6-cylinder engine. This engine, which came from the truck sector, was liquid-cooled and weighed 360 kg. With a tank capacity of 150 liters of gasoline, a driving range of about 140 kilometers could be achieved on the road. Furthermore, a four-speed transmission from ZF was installed. ⓘ

The crew consisted of four men: commander, gunner, radio operator and driver. The first two were in the turret mounted at the rear, while the radio operator sat on the floor offset to the right behind the driver (on the Rheinmetall type the radio operator sat at the same height on the other side of the engine). The built-in radio had a range of two to three kilometers, while Morse code operation was possible up to a distance of 17 km. ⓘ