Shifting freight transport from road to rail is a key component of the transportation transition in Germany and across Europe. The introduction of digital automatic coupling (DAC) is expected to significantly enhance the competitiveness of rail freight. DAC technology will simplify and speed up shunting operations as well as enabling longer and heavier freight trains to be used.

The FP5-DACtiVate project brings together 21 European partners committed to advancing the digitalization of rail freight transport. A key goal is to enable the preliminary commissioning of pilot trains equipped with DAC and to carry out the necessary safety tests. TÜV SÜD’s Görlitz test facility offers the ideal conditions for doing so. Extending over approximately 50,000 square meters, it features specialized track configurations as well as test rigs for rail vehicles and individual components.

Derailment safety and interoperability put to the test
Tests performed in June and July 2025 focused on derailment safety of the DAC. Several cars connected using DACs were repeatedly shunted at increasing force into a loaded and braked row of cars on a curved section of track (S-curve) considered particularly hazardous for flange climb derailment. In each test, the DACs were mounted on an unloaded car in the middle of the train formation and subjected to a horizontal compressive force of up to 550 kN per trial. The aim was to simulate a realistic scenario with a high risk of derailment, but without actually triggering that event. DACs from different manufacturers were tested in various combinations to assess both safety and interoperability.

The results from the FP5-DACtiVate project and the corresponding reports will form part of the technical documentation that is required to get the DAC approved for European rail freight operations. “The DAC has not yet been included in the Technical Specifications for Interoperability (TSI),” points out Dr. Stefan Soltysiak, responsible site manager at TÜV SÜD Rail GmbH. “For this reason, rail operators still currently need to carry out their own risk assessments for DAC deployment.”

All the infrastructure and expertise needed for the full array of required DAC tests
“Here in Görlitz, we can carry out the complex and safety-critical tests required for the introduction and approval of new technologies,” says Dr. Soltysiak. For the current DAC test runs, the existing tracks were completely renewed over a length of 200 meters. “This was crucial for tests involving long train formations and high forces, where longitudinal compressive forces of up to 550 kilonewtons (kN) can occur—more than twice the usual level,” explains Felix Bührdel, Lead Test Engineer at TÜV SÜD Rail.

In addition to having the necessary infrastructure for conducting practical tests, the TÜV SÜD experts in Görlitz contribute hands-on experience from numerous DAC projects in recent years. TÜV SÜD can also provide the expertise required to support the entire approval process.

TÜV SÜD Rolling Stock Test Center
TÜV SÜD offers a comprehensive range of test services for rail vehicles and their components. The company operates its own test facilities at sites in Görlitz, Halle/Saale, Berlin, and Winterthur (Switzerland) for the purpose. The Görlitz test facility covers an area of around 50,000 square meters. Speeds of up to approximately 40 kilometers per hour can be achieved there, enabling a variety of test scenarios to be run. At its other locations, the company’s rail experts also carry out on-track tests for running performance, braking systems, fatigue strength, and pantographs. Testing is performed on both public railway networks and non-public test infrastructures

Further information on the rail vehicle testing center and DAC testing is available at: tuvsud.com/en/rolling-stock-testing and tuvsud.com/en/industries/rail/rolling-stock-testing/digital-automatic-coupling.