Mercedes Benz

OFFICIAL PRESS RELEASE

Stuttgart, Germany, Feb 18, 2009

Unimog, a child with many fathers

* 1945: First plans and drafts

* 1946: Testing of the first chassis

* 1948: Launch and production start-up

* 1950: Project taken over by Daimler-Benz

The legendary Unimog got off to a start that was as adventurous as the time during which this extraordinary vehicle was designed. Its inventor was Albert Friedrich, previously head of Aeroengine Design at Daimler-Benz AG. Friedrich began as early as during World War II to occupy himself with the design of a compact tractor – and started developing the Unimog in 1945, immediately after the war. It was conceived as an agricultural vehicle but was to differ substantially from conventional tractors. Among the partners Friedrich was able to win over for his project was his former colleague, Heinrich Rößler, who had also worked in Daimler-Benz engine development before the war. Rößler had been making ends meet as an agricultural worker after the war and so was able to contribute a lot of valuable experience.


Originally an agricultural working machine

Friedrich's first drawings showed an "engine-powered universally applicable machine for agriculture" – the name Unimog had not yet been coined. The plain vehicle featured all-wheel drive and four equal-sized wheels and was conceived as an agricultural tractor, implement carrier, stationary working machine and delivery vehicle with an output of 25 hp – at the time, nobody thought of the Unimog's diversified range of applications in later years. Six speeds up to 50 km/h were planned, as well as a power take-off for agricultural implements at the front, a towing coupling at the rear and a load platform behind the cab. All features together resulted in a simple but nonetheless extraordinary and unique concept that differed substantially from conventional tractors.

Friedrich established contacts with the American occupying forces at the time and obtained one of the rare "production orders" – a manufacturing permit, in other words. His partner in development and production was Messrs. Erhard & Sons in Schwäbisch Gmünd, a factory producing gold and silverware. Development progressed rapidly. Their drawings soon showed a modified, highly efficient design: identical sheet metal components for the front and rear axle housings, identical hub drive assemblies with brakes for the front and rear axles and no more than four drive joints.

A concept differing substantially from conventional tractors

The engineers thought along practical lines: the track width of 1,270 millimetres corresponded to two rows of potatoes. Numerous features gave this new vehicle a unique character, among them the comparatively high road speed, axles with coil springs and dampers, all-wheel drive with differential locks front and rear, a frame design comparable to trucks and cars, implement attachment points at the front, centre and rear as well as power take-offs at the front, centre and rear.

First test vehicle as early as 1946

With its angled front section, cab with soft-top and load platform behind the cab, the first test vehicle set up in late 1946 already largely corresponds to the production model at a later stage. It was also during this time that the vehicle was given its name: the designation "Universal-Motor-Gerät" (universally applicable motorised machine) was shortened to Unimog. Its engineers presented their creation for the first time in the spring of 1947 – but they still had not found a suitable diesel engine. That same year, however, Daimler-Benz began working towards the new OM 636 diesel engine, developed on the basis of the 170 V engine (M 136) by former sports boat marine engine designer Julius Witzky. At the time nothing had been decided about production, but Friedrich's team placed its faith in the brand with the three-pointed star and even ensured a temporary solution involving the M 136 petrol engine for the first prototype vehicles, should the worst come to the worst with the new diesel design – they were, after all, on intimate terms. Soon, nothing stood in the way of production any more – the only problem was that the right production partner hadn't been found yet. Messrs. Erhard had shown great commitment in development but weren't the right partners for production. Several motor manufacturers were not interested but finally, the machine tool producer Boehringer in Göppingen agreed to produce the Unimog in 1947.

Material for large-scale production had to be procured – not an easy undertaking at that time. The Unimog development team also had to occupy themselves with the appropriate tyres and the urgently required implements for attachment to the Unimog. This was far from being easy since tractors already existed in the market, so why adjust everything to the differently designed Unimog? In spite of all these difficulties, the Unimog moved into the public limelight shortly afterwards, at the German agricultural trade fair in Frankfurt in 1948.

Production start-up in 1948

Finally, large-scale production of the Unimog began at Boehringer in August 1948. However, Boehringer was not a motor manufacturer, and Albert Friedrich's team consisted of development engineers. It was therefore a question of creating a new sales organisation out of the blue and in next to no time while production got underway. The new vehicle attracted the interest not only of farmers but also of authorities, the latter requiring standardised attachment implements. From these early beginnings, very close and fruitful cooperation with implement producers has developed.

Move from Boehringer to Daimler-Benz

Boehringer produced some 600 Unimogs until the summer of 1950, their trademark being a stylised ox head with U-shaped horns. However, larger production volumes required too high investments, which Boehringer was unable to raise. So things developed as they had to develop given the development team's professional background: the entire project, complete with patents, development team and newly established sales organisation, was taken over by Daimler-Benz in the autumn of 1950. The Unimog moved to Gaggenau which has been its home ever since and which at the time was the location of the company's truck plant.