Monday 19 June 2017

Auto-Union Streamliners


Former Zeppelin engineer Paul Jaray was at the forefront of streamlined automobile design in the 1920s. He lodged his first automobile patent in 1921 and the following year he had built a series of test vehicles for Audi, Ley and Dixi. Unfortunately, none of the these radically new vehicles proved practical enough to go into production. In fact the negative reaction to the 'Ugly Ducklings' set back the streamlining movement almost ten years. Despite this failed experiment, Paul Jaray continued working on improving and refining his designs and in 1927 he founded Stromlinien Karosserie Gesellschaft in Switzerland and became a consulting engineer.

After Jaray moved to Switzerland, Baron Reinhard Koenig-Fachsenfeld took over Jaray's German representative office. Koenig-Fachsenfeld had been an active participant in motorcycle racing in the 1920s and understood the practical application of streamlining for motorsport. In 1931 he began working with DKW motorsport division, designing a streamlined aluminum body for a series of  F1 monoposto racers in 1931. Koenig-Fachsenfeld would go on to develop this concept further in the 1933 Mercedes-Benz SSK streamlined racer, effectively creating the template for Germany's legendary 'Silver-Arrows.' https://dkwautounionproject.blogspot.com/2021/01/dkw-set-12-new-international-records-on.html


A Dead End

None of this work however, had a tangible effect on passenger car design. In 1933, in response to the growing interest in rear engine engineering, DKW initiated a rear engine car project, constructing a single research vehicle to test the concept. Powered by a 600cc two cylinder water cooled engine mounted in the rear, the car was highly streamlined in accordance with Jaray's patents, but its performance was poorer than the contemporary DKW F2, so the project was terminated and the test car was eventually sold.
https://dkwautounionproject.blogspot.com/2017/07/dkws-1933-rear-engine-streamliner.html

The experience gained on the car's streamlined wooden bodywork would be applied to the DKW Schwebeklasse of 1935. https://dkwautounionproject.blogspot.com/2017/07/1934-dkw-schwebeklasse-brochure.html

The Influence of Motor Sport
After the foundation of Auto-Union in 1934, the new board of directors sought to promote the company through international motor sport. August Horch's intense interest in motor sport had been a source of conflict at both Horch and Audi, leading ultimately to his dismissal and the withdrawal of both those companies from competitive motor sport. DKW however, was an active participant in motorcycle and car racing, but not at a top tier level. Auto-Union's new managing director, Baron Klaus von Oertzen, created a new motor sport division and hired Dr Ferdinand Porsche, who had just completed a contract with the Wanderer company, to head it. Porsche would design the radical, mid-engined Auto-Union Types A and B racers that would go on to dominate the International Grand Prix circuit from 1937 to 1939.

The Types A and B followed the streamlined body design established by Koenig-Fachsenfeld for DKW in 1931. The light weight streamlined aluminum body of the Auto-Union racers was extremely simple. As Auto-Union expanded its racing program to include in road speed trials, further streamlining studies were conducted. In 1935 Auto-Union claimed the world road speed record of 320 kph in a highly streamlined, fully enclosed Type C. The car's axles were completely fared with streamlined spats behind the front and rear wheels. Driver Hans Stuck sat in a fully enclosed aircraft-like cockpit.


The Influence of the Autobahns

It was the expansion of the autobahns that would have the greatest practical effect on vehicle streamlining. Germany's network of local roads were of such variable quality that speeds over 35-40 miles per hour were rare. Now that highways were beginning to crisscross the country and cars could travel long distances at previously unheard of speeds, improving the speed and fuel efficiency of passenger cars became essential.

In 1934 Audi became involved in a practical demonstration of the benefits of streamlining, but not of their own initiative. Streamlining pioneer, Paul Jaray, had Swiss carosserie Huber & Brühwiler fit a streamlined body over an Audi Front and a Mercedes-Benz 200 chassis. The Audi was fitted out as a two-seater coupe and the Mercedes as a four-seater limousine. Jaray exhibited both cars in the 1934 motor show season and had them perform in speed and fuel economy trials. These trials demonstrated conclusively that a streamlined car was faster and more fuel efficient than a standard bodied car. Jaray would sell the Mercedes-Benz car in the 1940s but he retained the Audi Front as his personal car well into the 1950s. https://heinkelscooter.blogspot.com/2021/04/paul-jarays-mb200-streamliner.html

With the lesson of Jaray's Audi Front before their eyes, Auto-Union embarked on their own project. In 1935 an Audi chassis was bodied with a Jaray patent body and trialed against standard bodied cars. The benefits were conclusive.

In 1935 Hornig-Karosserie 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.


The Cross Country Trials

In 1934 and 35 Auto-Union entered the new Schwebeklasse model in a series of cross-country endurance trials. This exercise did no more than highlight the weaknesses inherent in the car's engine and construction. The V4 engine delivered more power, but was problematic in terms of fuel economy and spark plug wear, while the car's wooden body fractured under the extreme stresses of cross country rallying. This led to the development of a streamlined gelandewagen running on a modified Wanderer chassis, but powered by a tuned V4 sports engine. This engine did not prove up to the task and was replaced by a Wanderer 6 cylinder engine for the 1937 rally season.

At the end of the 1937 season, head of the works sports department, August Momberger, reported to the board "there is a lack of suitable cars for fast sports trials. So far, the DKW cars (special class with 4-cylinder 2-stroke engine) have helped, but which are no longer be capable for the future as the KB 11 [V4 tuned sports] engine is too weak for these events...... international reliability drives have become downright country road races in recent years and therefore require special cars with high top speeds.” Momberger noted that for the forthcoming "Berlin-Rome event, which - with the exception of the Alps - largely takes place on German and Italian motorways, it should be considered whether a streamlined shape for the body should not be developed."

The Wanderers

For the Liege-Rome-Liege endurance race in 1938, Momberger had three open topped streamlined bodies installed on the chassis of the Wanderer W 25 with a two litre W25K Porsche designed engine, The engine, with triple carburetors, but without supercharging, were rated at only 40 horsepower. It was estimated that the lightweight aluminum bodywork gave the cars the performance of a 70 horsepower engine and a top speed of 160 kilometres per hour.

August Momberger (above) personally drove one of the cars in the Liege-Rome-Liege race [17th to 21st August 1938]. Unfortunately the Wanderer's failed to perform as well as expected and breakdowns prevented any of the cars completing the race. The cars performed better the following year with better tuned engines, with one car tying for 4th and another gaining 11th position.

The DKWs

The proposed Berlin-Rome-Berlin race was modeled in the Rome-Liege race and was planned for 27th and 28th September 1938. The majority of the route would be on Germany and Italy's newly constructed highways, so maintaining high speeds over long distances would be critically important. The works sports department prepared a series of light streamlined coupe bodies to be fitted over DKW F8, Wanderer Type W 23, and Audi Type 920 platforms. A single Audi and a single Wanderer example were built but engine and suspension issues meant neither car would be available for the race.

For the DKW streamlined coupes, eight of the new F8 pilot series chassis (numbers 7300 to 7307) were used and at the end of August, the first three of these streamlined coupes were transferred to the works sports department. One of the streamlined coupes had a standard but tuned CA 700 cc two-cylinder series engine which delivered 24 hp, while the other two had the ULS 700 double-piston racing engine with charge pump from the DKW sidecar racers, which had an output of approx. 35 hp.

Extensive driving tests began immediately on the Dresden-Jena autobahn and on the Avus track in Berlin. The cars, which weighed around 800 kilograms, were able to achieve maximum speeds of almost 140 kph with the twin-piston racing engine. However, the racing engine had several practical drawbacks, not the least of which was the deafening noise it caused. The engine lacked both an intake silencer or an exhaust dampener and the noise in the driver's cab was so loud that the driver and navigator could only communicate via hand signals. The tuned CA700 engine could not reach the high speed of the race engine, but was able to maintain consistent average speeds of around 105kph on a timed 136km run. Unfortunately the race coincided with the Sudetenland crisis and was called off at the last moment. Rescheduled for September 1939, the race would again be derailed by the invasion of Poland.

In mid 1939 a tender was placed for the construction of coupe DKW racer based on the Wanderer coupes for the 1940 race, but this project too did not proceed. https://dkwautounionproject.blogspot.com/2020/09/1940-dkw-f9-sportswagen.html

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 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

The body of Auto-Union's DKW F9 Hohnklasse (high class) project was also based on the DKW Wanderer design. In fact the patent for the type's streamlined body referenced both the DKW F9 and Horch 920S. The similarity between the two cars was obvious. The development of the DKW F9 is detailed extensively here: https://dkwautounionproject.blogspot.com/2017/07/1939-dkw-f9-prototype.html


Wanderer W-31

The ultimate aim of the 'Hohnklasse' project was to establish a single Auto-Union type which would have variants across the brands' market segments. The Horch was the luxury brand. The DKW F9 would be the budget, entry level version. A Wanderer version, powered by a Wanderer 4 or 6 cylinder engine, would be offered to the middle class. The car was originally designated the W-31, but was then renamed either the W-4 or W-6, depending on which engine was installed. A four door sedan and two door coupe prototype were built and presented in May 1939, before all further development ceased when all Auto-Union civilian car production shut down in 1940.


The War and its Aftermath
In January 1940 Auto-Union shut down its racing department. The department had 43 vehicles in its inventory including 27 DKW and Wanderer gelandewagens and 8 DKW streamliners. Auto-Union retained only two streamlined Wanderers, two Audis and one DKW. All the remaining cars were put up for public sale. Before the sale, the ULS 700 racing engines were removed from the DKWs and replaced with standard 700cc engines were installed. The DKWs were snapped up very quickly by eager buyers, including the DKW dealer posing with his car in the photograph above. When the war turned against Germany and Auto-Union's factories came under attack, the surviving cars were distributed to more secure locations. Some of the cars, including the DKW F9 pre-production cars were placed in storage in a former spinning mill in Saupersdorf. There they where destroyed in a bombing raid in late 1944. The remains of the sole DKW F9 door pre-production car were removed to Spandau bodyworks after the war for study. The wreckage was assessed by a visitor from the Chemnitz plant in 1946 and described as nothing more than a pile of burnt out junk.

A number of the privately owned DKW and Wanderer streamliners survived the war. Two DKW Rome-Berlin cars have been identified in photographs taken after the war, but all have since disappeared without trace. This car was photographed in Baden-Wurttemberg in the 1950s.
https://dkwautounionproject.blogspot.com/2017/07/auto-union-streamliners.html

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, where it now resides. Between 1948 and 1952 six 930 chassis at the Horch factory were assembled into complete cars from spare and scrounged parts. The cars were distributed to Soviet and East German communist party officials. A single surviving example 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 prewar models.


Only the F9 survived the war to be resurrected as both the DKW F89P in the West and the IFA F9 in the East. Despite the destruction of most of the pre-production cars during the war, at least three examples survived. Two complete cars were found in East Germany. One was handed over to the Soviets for assessment. The car, and a complete set of plans, were shipped to Russia where it disappeared. It would be rediscovered in Estonia in 2016. A second intact car was displayed at the Leipzig International Trade Fair in 1948 where it was unveiled as the IFA F9. DKW in the west were horrified to see that their eastern rivals were able to resurrect construction of the F9 so quickly, unaware that this first IFA F9 was actually built in 1940.

One car, technical director. Dr William Werner's personal car, had been shipped to Hamburg after the war to prevent it being seized by the Soviets. It was instead seized by the British, who later shipped the car to Australia where too disappeared. It would eventually be acquired by Audi Tradition in the 1990s and restored. Auto-Union in Ingolstadt were stuck with the prewar F8 chassis and engine, but by a stroke of good fortune discovered that the Algaier tooling company had manufactured a full set of F9 body panel presses during the war. This allowed Auto-Union to put the F9 body on the F8 chassis, as the F89P. This car set the company back on its feet.

For more information see https://dkwautounionproject.blogspot.com/2017/07/dkw-germanys-post-war-wonder-car.htmlmanys-post-war-wonder-car.html and http://heinkelscooter.blogspot.com/2011/02/veb-sachsenring-east-germanys-peoples.html

1 comment:

  1. Hi, You write fantastic reports about, among other things. DKW's history. I am a member of the Swedish DKW club and would like to publish your DKW reports in our DKW magazine, is it OK with you?
    Regards Conny Welander
    Hobbelego@gmail.com

    ReplyDelete