Tatra Streamline: 1942 Steyr Raupenschlepper Ost

Hans Ledwinka is rightly remembered for his advanced automobile designs in the 1920s and 30s, but of course, he depended on a team of skilled engineers to work on the technical details of his automobile designs. While Hans is credited as the designer of Tatra's famous series of rear-engined streamliners, much of the detailed design was done by his son, Erich Ledwinka and engineer Erich Uberlacker. The two Erichs had been tasked to update Tatra's long-running Tatra T12 model in 1932, but Hans judged the result to be merely a rehash of the existing model. So disappointed was he with the result that he had threatened them both that they'd be looking for alternative employment if they didn't deliver. Hans' biting criticism stirred the Erichs to develop a new model, the T57, which would go on to become Tatra's best selling and most popular car, and also presented an entirely new concept vehicle, the T570 rear engine budget car. The V570 inspired Hans to pursue this exciting new concept and in 1934, the revolutionary Tatra T77 was unveiled at the Prague Motor Show.

The revolutionary Tatra T77 unveiled at the Berlin Motor Show 1934.

Erich Uberlacker would be instrumental in the detailed design and development of all Tatra's prewar streamliners, including the T77a, T87 and T97. However, after the German occupation of the Sudentenland in 1938 and the shutting down of the automotive design studio at Tatra, Uberlacker decided to take his experience elsewhere. Hans and Erich Ledwinka would stay on at Tatra throughout the war.

In 1938 Uberlacker moved to Steyr in Austria as technical engineer. Steyr was a smaller automotive concern than Tatra and its automobile division had been shut down in 1938 by the Schell Plan, which rationalised the automobile industry by removing 'surplus' types. Ultimately the Schell Plan was a mechanism for preparing the Greater German economy for war. Steyr would manufacture trucks and weaponry for the German war effort. Their Steyr 1500, designed by Ferdinand Porsche's design studio, would become the standard light to medium truck of the Werhmacht and would be built under license by many different companies.

Uberlacker's first project at Steyr was to help the Porsche team design a 3.5 litre air-cooled V8 petrol engine, which made great use of Uberlacker's experience at Tatra. Had Tatra not been virtually nationalised by the Nazis the infringement of Tatra's numerous patents for forced-air-cooled petrol engines would have bought an immediate lawsuit from the litigious Ringhoffer's, owners of the Tatrawerkes and its many air-cooling patents. Such patents were of no importance to the German authorities so Steyr was free to press ahead with what was clearly a Tatra derived design. The 3.5 litre engine would be put to use in the Steyr 1500 in 1940.

After Germany invaded in the Soviet Union in 1941, the problems of supply and logistics along Russia's terribly poor road system required immediate action. Wheeled trucks had struggled with the Russian terrain, especially the raspusista, the 'mud season.' Steyr responded to the problem by developing a simple and rugged catapillar tracked truck, the Raupenschlepper Ost which literally meant 'catapillar tracked truck for Eastern service. Reusing many parts from its current truck manufacturing program, the Raupenschlepper was given high road clearance, a slack running track without overlapping road wheels to avoid mud build up - a major problem afflicting German half-track designs. Body was a simple wooden tray with canvas covering. The Raupenschlepper proved extremely successful in trails and manufacturing was approved in 1942.

Earlier versions had a pressed steel cab, but by 1943 this was replaced with an open topped, largely wood-framed cab to simplify construction. Steyr were unable to keep up with construction and contracts were issued to other German truck manufacturers, such as Wanderer and Daimler.

A version was even built as a self-propelled artillery unit, but this was not a successful conversion.

Erich Uberlacker and his team worked on improving the V8 engine, which was very noisy and relatively low powered for its size. An improved version was built by Daimler-Benz and indeed, Erich Uberlacker would move to Daimler in 1944 to work on turbine engines. After the war Uberlacker was interviewed by Allied technical specialists about engine and vehicle design as part of the Joint Intelligence Objectives Agency (JIOA) program. He happily provided technical details and sketches of the Steyr V8 engine for their reports, one of which is reproduced below. In 1949 he took a position as chief designer at Borgward, staying with them until he retired in 1961.

FIAT Final Report 603. The 3.5 Liter, 8 Cylinder, Air-Cooled, Automotive Engine of the Steyr-Daimler-Puch AG. By Alian M Madle