Thursday, August 1, 2013

Auto-Union Streamliners

Aeronautical engineer Paul Jaray was at the forefront of streamlined automobile design in the 1920s. Within a year of his first patent in 1921 prototype vehicles had been produced by Audi, Ley and Dixi. Unfortunately, none of the these radically new vehicles proved practical enough to go into production. Despite this failed experiment, Paul Jaray continued working on improving and refining his designs and in 1927 he founded Stromlinien Karosserie Gesellschaft in order to promote and improve his designs.

Paul Jaray's early streamlined car designs were clearly influenced by his work at Zeppelin and were generally tall and front engined. Figure 8 highlights the major flaw of the design - cramped seating and poor use of interior space.

The Audi Type K streamliner was one of the three Jaray built 'ugly ducklings.' The three cars, built by Ley, Audi and DIXI (who would later become BMW) were very experimental and not particularly successful. It would be almost ten years before anyone would seriously revisit the streamlined concept.

By the 1930s the automotive streamlining concept had begun to general gain acceptance and numerous car companies were working on their own projects. Auto Union, the Saxon automotive conglomerate was again in the forefront of developments, initiating several interesting projects based on Paul Jaray patents.  By this time Jaray had begun actively promoting rear-engined, teardrop shaped design concepts. Dozens of companies attempted it, but the engineering proved extremely challenging. DKW attempted to build a Jaray rear-engined car in 1933 but it too proved unsatisfactory. Lessons from its testing however were incorporated into DKW's new, semi-streamlined schwebeklasse model of 1934.

Jaray's rear-engined, low centre of gravity design tempted dozens of companies but proved technically difficult to achieve. Only Tatra and Volkswagen really succeeded making the design work. and

DKW made much of the streamlined quality of the wooden bodied schweberklasse, but it was at heart quite a conventional car.

Although DKW's rear-engined car project was not a success, the concept was picked up by Auto Union's racing program. Auto Union's chairman Baron Klaus Von Ouertzen had recently secured a 500,000 Reich Mark grant from the Nazi government to support the company's racing program. This much needed injection of capital allowed the company to undertake ambitious design projects - as long as they could deliver results on the track. The ambitious designer Ferdinand Porsche was engaged as technical director of the Auto Union race department and given a free hand in design. The result was Auto Union's famous 'Silver Arrows', which between 1935 and 1939 dominated the world's Grand Prix circuits.

Hermann Muller hurls his Auto Union Type D around the track during the Swiss Grand Prix on 21 August 1938. These monstrous beasts were powered by a mid-engined V16 engine generating some 550 horsepower. Porsche trialled his torsion rear suspension on the cars, which contributed to their massive over-steer problems. To say they were challenging to handle would be an understatement. In fact, Bernd Rosemeyer, probably the best Silver Arrow driver, was a motorcycle racer without without experience of conventional front-engined racers.

This streamlined Auto Union Type C was driven by Hans Stuck to set a 199 kilometre per hour world speed record in 1936.

The AVUS Type C world record car of 1937 was the pinnacle of aerodynamic streamlining.

A German documentary about the Auto Union racing team. It also features some interesting footage of car construction at the DKW factory.

The Silver Arrows were the cutting edge of automotive streamlining, but it wasn't easy applying this technology to a successful passenger vehicle. In 1935 DKW took the lead and fitted a Jaray patented streamlined body to an F5 Sonderklasse. The result was a handsome, modern looking vehicle with fully enclosed wheel arches and headlights.

Drawings of the DKW sonderklasse from the Chemnitz archive.

The 1935 DKW Stromliner. The body was built by Hornig-Karosserie

The F5 Stromliner concept was also trialled successfully by Audi. A replica of this car was recently built for a new Audi advertising campaign.

The Wanderers

With a successful concept in hand, Auto Union returned to motorsport in order to develop the design further. For the 1938 Liege-Rome-Liege endurance race, Wanderer constructed three streamlined racers. The cars were something of a hybrid, combining Wanderer's W-24 chassis, mounting a DKW schwebeklasse floating axle and powered by a 2 litre W-25K engine with triple carburetors. The engines were not supercharged however and rated only 40 horsepower, but the aerodynamic effect of the lightweight aluminum bodywork delivered the cars the performance equivalent of 70 horsepower. Although the cars had a top speed of 160 kilometres per hour breakdowns prevented any of the cars completing the race.

The three Wanderers, followed by a DKW overlander jeep. While the Wanderers' failed to complete the race, the DKW overlander did - dead last.

The cars performed better the following year with better tuned engines. One car tying for 4th and another gaining 11th position.

The DKWs

For the 1938 Berlin to Rome endurance race chief DKW designer William Werner fielded three streamliners based on the Wanderer design. The cars were fitted with 700cc four-cylinder twin-V engines with priming cylinders. Strikingly, these little engines delivered 40 horsepower - the equivalent power output of Wanderer's 2 litre engines - and could push the cars along at 140kph.

For the 1939 Berlin to Rome race the DKW team trialled different engines in the cars, including a tuned two-cylinder 700cc two stroke from the contemporary F7, the four-cylinder 1000cc engine of the DKW Schweberklasse and their new three cylinder 900cc engine. Further improvements were planned for 1940, but were put on hold by the war.

This DKW Rome-Berlin stromliner was photographed in Baden-Wurttemberg after the war but then disappeared. Perhaps it will be rediscovered one day, like the Volkswagen Rome-Berlin racer that now resides in the Prototyp Museum in Hamburg.

Production Vehicles
Auto Union's central design team in Chemnitz took the lessons learned on its streamlined endurance racers to develop a series of modern, streamlined passenger vehicles. The result was three exceptional machines, two of which never really made it passed the prototype stage and one that went on to become the foundation of DKW's post-war success.

Horch 930S

Horch unveiled its new luxury limousine, the 930S, at the Berlin Auto Show in 1939. Designed by Günter Mickwausch, Georg Böhm and John Hufnagel, the chassis was based on the 930V of 1935 and mounted a V-8 3.9 litre engine. The hand crafted bodywork was closely modeled on the DKW-Wanderer endurance streamliners of 1938. The car was a sensation, with all the luxury fittings, such as a fold out washbasin behind the front wheel, that were the trademark of the Horch brand. Performance tests on the Dessau racetrack clocked the 2300 kilogram car at 178 kilometres per hour. Only three cars were built before the war intervened.

DKW F9 Hohnklasse

Meanwhile, over at DKW, William Werner's design team were working on a budget version of the design. The F9 Hohnklasse (high class) was also based on the DKW-Wanderer design and featured the new three-cylinder two-stroke engine. The car shared styling with the Horch 930S, which is especially apparent when the vehicles are viewed from the rear quarter. Ten pre-production examples were built before the war.

Wanderer W-31

Wanderer also built their own version of the DKW F9 but powered by a Wanderer 6 cylinder engine. The car was originally designated the W-31, but was then renamed either the W-4 or W-6, depending on whether a four cylinder or six cylinder engine was installed. The car barely made it past prototype stage. A four door sedan and two door coupe prototype were built and presented in May 1939, before all further development ceased and the Wanderer brand was was shut down in 1940.

The War and its Aftermath
In 1940 Auto Union shut down its racing department and placed all the cars in storage. Amongst the horde were all six DKW and Wanderer streamline endurance racers, the Silver Arrows, and the AVUS record breaking car. When the war turned against Germany and Auto Union's factories came under attack, the collection was distributed to more secure locations. Some cars were moved west, while others were hidden in underground bunkers and mines. Despite this the cars were found and seized by the Soviets after the end of the war and shipped back to Russia for study. Unfortunately the Soviets the massive Type C & D racer engines were incredibly complex and required the attention of an experienced engineering staff to run. Unable to capitalise on the technology, the Soviets were determined that these symbols of Nazism should be destroyed and ordered all the machines to be scrapped. A couple of Silver Arrows that had been sent to Czechoslovakia and Latvia as part of an exhibition escaped destruction. After the Fall of Communism they disappeared in mysterious circumstances before eventually re-emerging and were recovered by Audi Tradition, who spared no expense restoring these extraordinary machines.

The Wanderer W-31 and the endurance racers, along with all plans and blueprints were destroyed during the war. A handful of photographs are all that remain. Audi Tradition decided to recreated the trio of Wanderer endurance racers as exhibition vehicles. Without blueprints or documentation for the original cars, these cars were modeled off original photographs with modern running gear underneath.

A single Horch 930S escaped destruction in hands of race driver Tazio Nuvolari, who took it to Switzerland. The car was returned to Germany after the war and was preserved by Audi Tradition in Ingolstadt. It now resides at the Audi Museum. The Soviets found six 930S chassis at the Horch factory at the end of the war and between 1948 and 1952 complete cars were constructed using spare and scrounged parts. The cars were distributed to Soviet and East German communist party officials, who were so pleased with the results that VEB, the East German automotive collective, officially commissioned Horch to build limousines. These were known as the Sachsenring P240 and the unique Horch 950S. One of each of these cars is on display at the August Horch Museum in Zwickau.

The surviving 1948 Horch 930S was found in Riga, Latvia and restored for the August Horch museum in Zwickau. The post-war 930S' had a different front end to the pre-war models.

Only the F9 survived the war to be resurrected as both the DKW F89 in the West and the IFA F9. Although most of the car's blueprints were lost during the war, three examples survived. One complete car was found in Leipzig and became the template for the IFA F9. A body shell was found in Spandau and shipped to Ingolstadt where it became the template for the DKW F89. DKW however did not have complete car or engine, so the new DKW car used a modified F8 chassis and 700cc engine. The third car escaped intact, was commandeered by the British and later shipped to Australia, where it was later recovered by Audi Tradition. The F9, in all its guises, proved to be an outstanding success, both in the West and in the East. For more information see and

The first post war F9 is unveiled at the Leipzig Motor Show in 1949 by IFA.

A DKW F9 and IFA F9 parked side by side highlights both their similarities and differences.

No comments:

Post a Comment