Hans Gustav Röhr (10 February 1895 – 10 August 1937) was a German aviation pioneer. After the First World War international treaty obligations imposed on Germany made this impossible and he applied his talents to automobiles. In 1926 he founded his own automobile manufacturing business, but this succumbed to bankruptcy in 1931. After that he worked for Adler. Here his responsibilities included design and development of new models. One of the cars he designed and developed, launched in 1932, was the Adler Trumpf which was both technologically innovative and successful commercially. He moved, as Technical Director, to Daimler-Benz in 1935, but his career was cut short by Pneumonia to which he succumbed, according to at least one report, after a drive in an open-topped car, and as a result of which he died.
Biography Provenance and early years Hans Gustav Röhr was born at Uerdingen near Krefeld (into which it has subsequently been subsumed), close to the River Rhine. His father owned a lead rolling mill in the town. His father hoped that he would, in due course, take over the family business, and with that in mind Hans Gustav attended the (lower secondary school) in Uerdingen between 1905 and 1911. By the time he left school, however, it was clear that he had little enthusiasm for producing lead coils. By contrast, the aviation business – still in its infancy – had completely grabbed his enthusiasm.
Aviation In 1911, still aged only 17, he accepted a two-year internship at Düsseldorf-Oberkassel with "Rheinischen Aerowerke GmbH", which he had been offered through the mediation of his friend Joseph Dauben (1889–1960) who was already employed as an engineer by the company. During 1912, Röhr and Dauben, who would remain friends for life, were able to use the facilities at the factory to construct a curiously futuristic airplane to Röhr's design. It was fitted with a five-cylinder radial engine which he constructed himself, using motorcycle cylinders, at a time when many aircraft designs were still using inline engines, and it featured a rod-supported single main wing plane while others believed that the future belonged to the biplanes. Another innovation was a closed cabin to protect the pilot from the weather. Sources differ as to the level of direct financial support he received from his family. One records that his father became progressively more alarmed by his son's obsession with so dangerous a hobby, meaning that the younger Röhr was obliged to accept "help from strangers". Even the Uedringer casino donated a few barrels of petrol to the dare-devil pioneer. The maiden flight of Röhr's monoplane took place in November 1913, vigorously applauded by onlookers and, in print, by the "Uerdinger Anzeiger" (local newspaper).
In 1914, Gustav Röhr senior, the father of Hans Gustav Röhr, died. All four of his sons inherited the leadership responsibilities for the lead mill. This suited Hans Gustav who was still left with plenty of time for his "hobby". In July/August 1914, war broke out and he reported to the flying corps ("Luftstreitkräfte") with his airplane. The advanced design failed to impress the military authorities, however, and the craft was sent back to Uerdingen.
Röhr himself volunteered to serve in the war as a fighter pilot. He received his flight training at the “Griesheimer Sand” airfield near Darmstadt. As a fighter pilot her served in Flanders and achieved two "kills", before himself being shot down in a "Dogfight". While he was recovering in a military hospital the military high command revisited the details of the airplane he had presented at the outset of the war: when he was ready to leave hospital, instead of being sent back to the front, he was mandated to develop a 600 PS airplane engine incorporating 21 cylinders, configured radially and fitted with a five-stage compressor. While retaining the military rank of flight-lieutenant, He now teamed up again with his friend Joseph Dauben.
Under wartime conditions many car factories and workshops were switched to production of airplanes and their components. The contract for the new engine was to be implemented at the Priamus Automobile Factory in Cologne-Sülz. In 1918 Röhr also took a financial interest in the (financially precarious) Priamus business, and between 1919 and 1921 he served as its chief executive ("Geschäftsführer"). For the wartime airplane engine, an ambitious power-to-weight target was set of one kilogramme per one unit of horse power. In November 1918, however, as a prototype engine was being made ready for the test-rig, news came through of the German military collapse on the western front. A condition of the armistice signed by the governments on 11 November was the military occupation of the Rhineland by the French and their allies, and in the chaos of those times, as a result of an indiscretion by one of the factory workers, the French military became aware of the existence of the advanced engines. Röhr had no choice but, with heavy heart, to arrange for their immediate destruction.
Automobiles Under the terms of the Treaty of Versailles aircraft construction in Germany was forbidden. Röhr and Dauben switched their focus to automobile development. From the start they were keen to apply their experience of aviation to their work on motorcars. In the words of one source, they wanted to build the aircraft for the high road. That was the philosophy behind several prototypes that they constructed between 1919 and 1924. The elements of Röhr's later designs could already be seen in these prototypes, combining lightweight construction techniques in a car intended to appeal to the masses and to be priced accordingly, while incorporating the quality standards normally associated with the luxury end of the market. During 1919 and 1920 they progressed their work at the Priamus Factory in Sülz, but with the financial collapse of Priamus imminent Röhr resigned his directorship and they moved over to Berlin where they continued their development work at the Charlottenburg premises of the car and engine factory. (Carl Bolle (1893–1955) was both a successful businessman and, like Hans Gustav Röhr, a former wartime fighter pilot.) The result of their endeavours was a futuristic underslung chassis frame ("Tiefbettrahmen") using sheet steel and incorporating independent suspension, lightweight construction and, by the time they built their second prototype after moving to Berlin in 1920, hydraulically controlled brakes on all four wheels. The brakes proved problematic, however. As Germany lurched from sustained economic crisis to mere acute austerity, they were unable to find any automobile producer sufficiently adventurous to produce the Röhr design.
Röhr Auto AG The alternative was to produce the car himself. Somehow Röhr persuaded Hugo Greffenius (1876–1954), the principal shareholder in MIAG, to support his plans. Backed by the deep pockets of his new investor, including an immediate cash injection of 500,000 Marks, on 30 October 1926 a new company, , was established. Further funding came from Hirsch & Co., a Frankfurt bank. That same year the new company took over the site hitherto occupied by the insolvent in Ober-Ramstadt (near Darmstadt).
It quickly became apparent that the factory space at the Ober-Ramstadt was not suitable for high volume production, so Röhr sent his chief construction engineer Joseph Dauben back to the drawing board to adapt their existing prototype as an eight-cylinder car that could be produced in relatively small quantities. The result was the . The design reflected the experience gained from the prototype vehicles already built, and featured light weight construction using an underslung chassis frame formed from sheet steel. It had, in consequence, an unusually low centre of gravity by the standards of the time. The independent suspension at both ends of the car was also innovative as was the rack and pinion steering. The Röhr 8/40 was much admired for unparalleled driving qualities. One more recent source refers to its "stunning roadability". Deliveries began during the middle part of 1927. Along with the excellent driving characteristics, the car won plaudits for its exceptionally smooth and well-balanced engine. Nevertheless, the eight cylinders had only a combined capacity of 1,980 cc; with a claimed output of just , the first Röhr 8 was short of power. During 1927 and 1928 fewer than 100 were produced.
In March 1928 the annual German Motor Show returned from Leipzig to Berlin and Röhr took a stand which the company adorned with he slogan Der sicherste Wagen der Welt ("The securest car in the world"). The car itself now appeared with a 2,246 cc engine. Both the bore and the stroke of the combustion chambers in the cylinders had been increased, as had the advertised power output which now stood at . The claimed maximum speed increased from 90 km/h to 100 km/h. Apart from the enlargement of the engine and a small adjustment to the bottom gear ratio the car was virtually unchanged. Nevertheless, this Röhr 8 9/50 became the company's first commercial success. Between 1928 and 1930 almost 1,000 were produced. Although its exterior was not particularly remarkable, some of the more astute visitors to the 1928 show stand were impressed by the unusual nature of the chassis, and the design also caught the attention of overseas pundits. Others were dismissive of what they saw as a gratuitously gimmicky approach. While some admired the novel configuration of the rear swing-axle, more conservative elements simply complained that the car was missing a "proper" (beam) axle at the back. The car was widely discussed in specialist journals and in the general press. After the 1928 motor show the "Odenwälder Nachrichten" (newspaper) was reporting that the company had finished the show with orders for 2,200 cars. Even if the number was an exaggeration, the exposure at the Berlin show and appearances at other international motor shows over the next couple of years supported a healthy level of demand. In 1929 the Röhr factory at Ober-Ramstadt was employing around 800 people, producing approximately six cars per day.