The new building for the technology centre for vehicle safety (TFS) was a major construction project. The challenges included the stipulation that no pillars were allowed in the large crash test hall, and that the floor of the crash tracks had to be perfectly level. The structural features also include temperature control using the waste heat from the adjacent climatic wind tunnels.
The sheer dimensions and materials used when constructing the TFS are impressive: for example, the unsupported crash hall measuring 90 x 90 metres is much larger in area than an international football pitch. More than 7000 tonnes of steel were used. And the 36,000 cubic metres of concrete used may be visualised as an approx. 40-kilometre long queue of concrete mixer trucks.
The longest approach track from crash block to crash block measures more than 200 metres. An extremely level floor is necessary for precise test procedures. The tolerance along a ±4-metre strip along the middle of the crash tracks is ±2 mm/m, and ±5 mm/100 m for the track as a whole. The floor slab rests on approx. 500 concrete pillars driven up to 18 m into the ground. It is temperature-controlled like an underfloor heating system, so as to maintain the necessary constant temperature in the hall.
Designed to meet the requirements of crash tests, great precision was needed during the construction phase. The temperature on the day had to be taken into account to install the large steel cross-members of the unsupported hall correctly. This was very important owing to thermal expansion of the steel.For reasons of accessibility, helicopters were used to carry the ventilation outlets onto the 23-metre high roof for installation.
The crash test vehicles are accelerated to impact speed by a cable pulley system powered by DC electric motors with a rated output of over 600 kW. This output can also be boosted considerably higher for a short period. Acceleration in both directions is possible thanks to an innovative redirection system.
The so-called Microtrack system is used on the crash tracks. The advantages of this compact underfloor rail system include precise guidance of the test vehicles to the point of impact and a very narrow track width of 70 mm. This allows a particularly good view of the vehicle underbodies from the five-metre deep video pits located at the impact points of the crash tracks. Incidentally, the glass covers have a thickness of eleven centimetres to withstand the weight of trucks as well.
To conduct Car2Car crash tests with impact angles from 0° to 180°, a variable above-ground rail system is installed in the floor of the angled track for attachment of the steel cables. Increments of 15 degrees are pre-configured, but any desired angle is possible. If the cable powering system is not needed it can be removed, creating a large, level surface for e.g. braking or skid tests.
The waste heat from the adjacent climatic wind tunnels is used to control the temperature in the TFS. Energy is also saved by using all-LED lighting in the building. The bright crash lighting is also provided by LED spotlights, which radiate less heat and therefore no longer heat up the dummies. This has improved the lighting compared to the previous halogen metal-hydride gas discharge (HMI) lamps, as the light source has greater coverage than HMI.
Extensive new construction project in the Sindelfingen location
Daimler AG has invested a three-digit sum in millions of euros in the complete facility. The new TFS allows even closer integration between research, development, planning and production at the Sindelfingen site. Located in the direct vicinity, a new driving simulator, new climatic wind tunnels and a new aeroacoustics wind tunnel were taken into service in 2010, 2011 and 2013, respectively.
The most important construction phases for the TFS:
- Start of construction and ground-breaking: Autumn 2013
- Foundations: April 2014
- Topping-out ceremony: 12 May 2015
- Start of structural steel work: November 2015
- First productive crash test: 30 September 2016