The speeding ghosts of Sindelfingen take on their concrete form in David Douglas Duncan's photographs on the following pages. This is Mercedes today: the bright and gleaming sports cars which go through the final body assembly at the Sindelfingen plant, the 300SLs, the 190SLs, the magic come true. The fact that they exist at all is, in itself, remarkable.
In 1945, when the war ended, five Mercedes plants—in Untert�rkheim, Sindelfingen, Gaggenau, Mannheim and West Berlin—lay in ruins. By the end of 1946 Mercedes had produced 214 cars. By 1948 it had risen to 3,812. Two years later, in 1950, workers rolled 33,960 units of all kinds off the production line. Two years after that, in 1952, Mercedes was back in the races again.
A seasoned band of professionals was in charge of the racing team. Dr. Fritz Nallinger was its boss and chief engineer. Dr. Rudolf Uhlenhaut, British-born, was its technical wizard in the development of the racing cars. And on the track, in his old capacity of manager of the drivers and mechanics, was Alfred Neubauer, the colorful martinet whose pear-shaped form had been as familiar on Europe's prewar raceways as the ringed star itself.
The first Mercedes to race again was a sports car. Fritz Nallinger concluded that existing designs for the supercharged prewar racers were unsuited for further development under the new Grand Prix formula. But in the sports car field, most of the necessary equipment was already at hand, and it was Rudolf Uhlenhaut who put it to use and scored the first great successes for the ringed star again.
Using the Mercedes 300S model with its six-cylinder, 150-hp engine as a point of departure, Uhlenhaut produced a light, three-dimensional tubular frame, canted the 300S engine on its side to permit a lower hoodline and stepped up its output to nearly 200 hp. A new aluminum racing brake drum was added, with a cast-iron rim and radial cooling fins, and from wind tunnel work came an enclosed aluminum body of aerodynamic efficiency.
The finished car was named the 300SL (Super Light), and its appearance in 1952 signaled the ascendancy of the Mercedes star once more. Second and fourth in Italy's tortuous Mille Miglia, it took first and second places in the grueling 24-hour test at Le Mans and repeated that performance in Mexico's car-killing Pan-American Road Race.
After that campaign Mercedes quit racing again, partly to start the 300SL toward the assembly line at Sindelfingen, but chiefly to concentrate its efforts on the arduous task of developing a new Grand Prix winner.
Carburetors were discarded and fuel injection adopted as a superior means of supplying the engine. Daimler-Benz had helped design fuel-injection systems for the engines of the Messerschmitt and Focke-Wulf World War II fighters and the Heinkel bombers; before that the firm had had a long acquaintance with the diesel engines. A knottier problem was the design of a new valve system for the Grand Prix car. The goal was to employ the largest possible valves to produce maximum engine breathing. For a year a team of engineers worked on nothing else. They soon realized that the conventional valve-closing spring had to be done away with—there would be no place for a spring of the strength needed. So they brought up to date an old principle that was tested inconclusively by Mercedes in 1912 and used with indifferent success on a French sports car of the 1920s—the "desmodromic" valve system, in which the valve is coupled directly with its operating mechanism.
The problem was chiefly one of metallurgy and of designing a camshaft lobe correctly timed to push the valve shut. In solving it with the right alloys and the proper camshaft contour, the engineers achieved all they had hoped for and more.
Opponents on the racing circuits were run ragged by the cars on which the valves appeared. Developing 300 hp from a 2�-liter fuel-injection engine—50 more than the long-standing ideal of 100 hp per liter—the Mercedes W196 Grand Prix car carried Juan Fangio to two world championships, sweeping five of six major events in the 1955 season.