Rail E-ssentials

On behalf of DLR, the Goerlitz test centre for rolling stock performed a first-time realistic crash test for an innovative crash concept. The test was successfully completed – the tubes of the crash structure worked as expected. The successful test represents the next step towards the development of the “Next Generation Train (NGT)”.

On behalf of the German Aerospace Centre (Deutsche Luft- und Raumfahrt, DLR), the Goerlitz test centre for rolling stock performed a first-time realistic crash test for an innovative crash concept. While a controlled collision of two rail vehicles is nothing special at the Goerlitz test centre, in this new crash concept the kinetic energy caused by the impact was to be absorbed by special crash elements integrated into the vehicle's structure. The new concept will thereby make the complex installation of additional heavy crash elements at the ends of rail vehicles unnecessary. The experts chose a modern, high-strength yet ductile steel for their design of the lightweight energy-absorption elements that offered the required features. All measures together result in a significant lightweight construction, saving on materials and weight. This in turn has positive impacts, such as higher transport capacity and lower energy consumption. (New crash concept of the German Aerospace Centre (Deutsches Zentrum für Luft- und Raumfahrt, DLR).

Relying on their long-standing experience in the design and development of new test methods and performance of all types of crash tests, the scientists at DLR commissioned the Goerlitz test centre for rolling stock to carry out a full-scale test on rails. More than a week before the crash test, our colleagues at TÜV SÜD Rail began to apply strain gauges to the side of the crash structure to be connected to the vehicle (demonstrator  – a simplified replication of the future vehicle structure). They then installed the crash structure on the adapter frame of a 80-tonne tank wagon.

The cooperation between TÜV SÜD Rail and DLR was characterised by mutual trust and support, both during crash-test preparation and implementation. One day before the actual test, the test engineers installed the crash tubes and the front frame. Furthermore the positions of the displacement sensors were defined  necessary adjustments were made and required welding was carried out.

The test centre owns a variety of rail vehicles. These vehicles can carry variable loads between 10 and 90 tonnes and can be flexibly combined to meet all of the customer's requirements for collision and crash tests. The test was performed with two special tank wagons with reinforced structures. The wagons had buffers on the ends facing each other and were filled with concrete to bring them up to a weight of 80 tonnes each. 

Force sensors located between the adapter frame and the buffer of the stationary wagon measured the forces arising during the crash.

In combination with the values measured by the displacement sensors on the crash structure and the relative displacement between the wagons, this approach allows the forces involved to be measured and the energy absorbed to be calculated – exactly what the DLR scientists need for final validation of their model calculation.

On the day of the test, almost all the employees at the Goerlitz test centre were busy helping to carry out the crash test successfully and according to plan. In addition to installing and monitoring the measurement instruments, a large number of cameras, including high-speed cameras, had to be positioned.

After a last check of all test components by test manager Olaf Schüßler, the wagon which was to run into the other wagon was accelerated to 18 km/h. Everybody involved in the test grew tense as the wagon approached the crash structure. There was a loud bang, braking was initiated automatically and both wagons came to a standstill after a few metres. The test was successful; the crash tubes had worked as expected, as later analysis of the test data confirmed. The DLR scientists were very satisfied at the result, which represented the next step towards developing the “Next Generation Train (NGT)”.

Timing of the crash test:

2016-03-17 – Start of preparations and strain gauge application

2016-03-22 – Installation of the on-board part of the crash structure to the adapter frame of the tank wagon as a preparatory measure.

2016-03-23 – Installation of the energy-absorption elements to the part of the frame that faces the vehicle, installation of the front frame and application of displacement sensors

2016-03-24 – Provision of the fully equipped wagon on track 4,  installation and adjustment of sensors, measurement instruments and camera systems, plus subsequent crash test at 18.5 km/h

If you have any questions related to the crash test, please contact [email protected]