Restart after the Second World War
Innovative methods in bus design
By 1960: Europe’s largest commercial vehicle plant
Mannheim was the first plant of Daimler-Benz AG to be occupied by the Allies at the end of the Second World War. The plant, one quarter of which was destroyed, was taken by the Americans on March 23, 1945. The US Army commandeered a part of the southern end of the plant for their own needs, and only gave up their occupation of the area in 1955.
Production of the three-ton L 701 truck started again at the Mannheim plant in June 1945, making Mannheim the first plant belonging to Daimler-Benz AG to resume activities after the war. At the same time as building this version of the Opel Blitz under license, work began on reconstructing the plant. One measure introduced to help employees during this period was to grow vegetables on the premises to feed the workforce. But the war had taken its toll: “The core of the plant is still functioning. It may be badly damaged, but the engineering department and assembly shops are still intact,” reported Rhein-Neckar-Zeitung in 1946.
Return to the company’s program
Demand was high for the initial output of 20 trucks a day. Commercial vehicles were urgently required, because it was not possible to supply towns and cities with food and other necessities by railroad or shipping routes. Mercedes-Benz had intended to return to the production of models in Mannheim it had developed itself. But the years of shortages after the Second World War made production and new development difficult. In particular there were serious shortages of coal and electricity from late November 1946 until late February 1947. For this reason, production of the licensed Opel model continued for the time being.
Then summer 1949 witnessed the debut of the new Mercedes-Benz L 3250 truck – an event that laid the foundations for the development of the modern Mercedes-Benz commercial vehicles program. Many saw the L 3250 as the vehicle that inspired the rise of Mercedes-Benz to its position as European market leader for medium-duty trucks.
Since production in Mannheim resumed very soon after the war, revenues at the plant recovered faster than those of Daimler-Benz AG as a whole. This fact was clearly reflected in the relative figures: from May 1945 until 1948, Mannheim was responsible for around one quarter of the total sales of Daimler-Benz AG. And even the absolute figures were indicative of a rapid recovery: by 1949 the Mannheim plant (48 million marks) was already well above the figure for 1936 (27 million reichsmarks), whereas total sales for Daimler-Benz AG was just 199 million marks as compared with 295 million reichsmarks.
First bus of the post-war era
It was a most unusual Christmas present: the first bus built at Mannheim in the post-war era – an O 3500 model – left production on December 24, 1949. From now on Mannheim took over some of the responsibility for bus production from Sindelfingen. The bus’s engine, an OM 312, belonged to the new series of engines launched in Mannheim that same year.
In May 1949, the new bus was presented as the O 3250, since it was based on the corresponding truck model. Adopting the traditional approach, the bus body was mounted onto a truck chassis. Then in 1950 the bus was launched under the designation O 3500.
Mercedes-Benz eventually concentrated its entire bus production at Mannheim in March 1951. Construction of the O 5000 was discontinued in Sindelfingen, and production of the O 6600 was switched to Mannheim. But Mannheim also continued to build medium-duty trucks, including the L 4500, which made its debut in 1953 at the International Motor Show (IAA) in Frankfurt. This 4.5-tonner was a useful addition to the Mannheimers’ truck range alongside the popular 3.5-ton L 3500.
In a report published in 1953, Frankfurter Allgemeine Zeitung gave a detailed description of the commercial vehicle production process in Mannheim – the use of oil sand in the core shop, the polishing shop with its soot and metal dust, but also the enormous, spotless assembly shops: “How small the human being seems in this giant workshop, filled with the incessant scraping, squealing and whirring of machinery.”
New approaches to bus design
Mannheim was responsible for the first bus to be built according to an entirely new design in 1954, the O 321 H. This vehicle featured a frame floor assembly welded to the body to form a self-supporting entity – in common with passenger car design. Tribute was paid to this approach by the designers in Hans Pohl’s biography of Mercedes-Benz buses, where he referred to it as “an emancipation from the truck”. In contrast to the old method of combining chassis and bus body, this so-called semi-integral design approach, involving a highly rigid frame floor unit and welded body, offered greater stability and increased space.
That year also saw the introduction at Mannheim of a plant suggestions scheme. After Sindelfingen, the plant beside the river Neckar was the second Mercedes-Benz facility in Germany to give employees this kind of opportunity to express their opinions and innovative ideas.
By 1955, Mannheim was already Europe’s largest bus plant. During this period around 8,500 employees were engaged in the production of buses, trucks and engines. The focus of vehicle design was therefore shifting ever further towards the bus. Mercedes-Benz finally decided to abandon truck production at Mannheim in 1965 and to move it completely to Wörth. Back in 1960, Daimler-Benz AG had purchased industrial premises covering an area of 1.5 million square meters at Wörth near Karlsruhe, with a view to building the new truck assembly plant there. Construction work got under way in 1962, and the first truck – an LP 608 – came off the production line in July 1965.
The launch of the first modern large-capacity bus by Mercedes-Benz also played a part in the Mannheim bus success story. The O 317 made its debut at the 1957 IAA, and production of the 12-meter-long vehicle began in 1958. The O 317 had room for 120 passengers and was designed specifically for regular service use. From 1958 onward, the O 317 also became the basis for the Mercedes-Benz articulated bus. This was the designers’ answer to the ban on bus operators using tractors and trailers.
The largest commercial vehicle plant on the continent
50 years after the official opening of the plant at Mannheim-Waldhof, the Benz factory became an international center of competence for commercial vehicles. This fact was highlighted in a press release produced by Daimler-Benz AG in 1960 to mark the delivery of the 200,000th truck to be built there since 1949. Mannheim was by now the “largest commercial vehicle plant on the continent.” The production shops covered an area of approximately 200,000 square meters, and from the early 1960s they were turning out trucks and buses that were regarded all over the world as high-quality, efficient and reliable carriers of people and goods.
A new component of this model plant was the foundry, opened by Mercedes-Benz in Mannheim in 1965. Construction work had begun on this facility in 1962, and when it was opened the foundry was considered the most advanced facility of its kind in Europe. With a daily casting capacity of 300 tons, Mannheim was able to produce crankcases and cylinder heads for commercial vehicle engines, as well as meeting some of the engine requirements for Untertürkheim.