D aimler was very proud of his drive-in lane in 1967 and for the first time allowed journalists to take a look behind the scenes to complete the secret facility . The route is intended to provide important impulses for vehicle development to this day. Regardless of whether it's a car, truck, Unimog, omnibus or racing car, all vehicles have been and will be put through their paces here.
The suggestion for a test track directly at the Untertürkheim plant came from Head of Development Dr. Fritz Nallinger as early as 1953, because the demand for cars during the economic boom grew considerably, the model range had to grow and development had to be made more efficient. In January 1955, Mercedes submitted the building application for the “bottleneck” to the city of Stuttgart, the Board of Management of Daimler-Benz AG gave its approval for the investment a year later, and in 1957 the first expansion phase went into operation. Even back then, this included the well-known sliding plate with the concentric road rings made of different surfaces: blue basalt, concrete, sliding asphalt and large paving stones. The integrated irrigation system allows water tests.
Ten years later, the driveway was completely finished and instead of secret prototypes, journalists were given a glimpse into the driveway with all its details for the first time - and the layout of the system has changed little to this day. The total length of the trial and test routes is 15,460 meters, of which 3,018 meters are designed as high-speed routes. A 100 meter long steep curve with a 90 percent incline connects the two lanes. There are a total of seven other different steep sections with slopes between 5 and 70 percent. The steep face can theoretically be driven at 200 km /h, whereby Mercedes notes that this is the physical strain for the driveris exceeded.
Mercedes completed long-term tests at 150 km /h on the upper wheel of the banked curve. At this speed, no steering impulse is necessary for the banked curve, as no lateral forces are exerted on the tires. At this speed, however, the driver is pressed into the seat with 3.1 g.
But it is not only in the steep bend that the test drivers and engineers reach their load limits. The notorious “Heidestrecke” is also a problem for them and the vehicles. The Schlechtwegeparcours owes its not typically Swabian name to a true-to-scale particularly bad street in the Lüneburg Heath from the early 1950s. They and other washboard, jogging and pothole slopes are intended for endurance testing of vehicles, but the drivers have to take turns every two hours. In addition to these torture stretches, there are also extreme twisting stretches for utility and off-road vehicles as well as a jumping hill to try out extreme spring positions. The influence of crosswinds on the body can also be simulated on a 34 meter long crosswind section with 16 turbines. These fans are good for gusts of up to 100 km /h.
The then head of testing and later Daimler-Benz board member Rudolf Uhlenhaut, responsible for the legendary 300 SL among other things, ran a further test track on the one-way lane a: The frond route. Here, the chassis were initially tested at high speeds and with rapid lane changes, later measuring loops in the ground recorded the data electronically. On the 8.4 hectare area, the test and test tracks are also being adapted to modern conditions. For example, whispered asphalt was laid to carry out noise measurements, and who knows, maybe we journalists will be able to get out on the track again after 50 years.