DAC derailment tests have successfully started in FP5-DACtiVate

June 2025: the first test campaign in FP5-DACtiVate has started! The plan: derailment tests on S-curves to prove the safety of Digital Automatic Couplers (DAC) as middle buffer couplers. Couplers of all four suppliers and project partners Dellner, Knorr-Bremse, Voith and Wabtec are tested in Görlitz, Germany.

Proving coupler safety through derailment tests in curves

Set-up of the derailment tests with pushing locomotives (B), the coupling point (A) and the loaded braked wagons (C)

The safety against derailment of freight wagons with DACs is demonstrated with the derailment tests. For this purpose, two wagons coupled with DACs (A) are pushed from behind by one or more locomotives (B) onto loaded and braked wagons in a curve radius. In this situation, there is an increased risk of derailment due to so-called climbing.

The pushing force is continuously measured in the coupling and the wagons are monitored with special measurement equipment to detect derailment. The derailment test is successfully passed if the coupled wagons withstand a pushing force of 550 kN ten times without derailing.
The tests are carried out with different combination of couplers of all four suppliers proving that the DACs are safe and interchangeable. Successful fulfilment of these tests are one of several preconditions for a later deployment of the couplers in European rail freight.

Coupled DACs of Dellner (left) and Voith (right) with measuring equipement

Cooperation of FP5-DACtiVate project partners for the derailment tests

The derailment tests are a joint effort of several project partners. The DACs are provided by the four suppliers and mounted on wagons provided by wagon keepers under the umbrella of UIP. The derailment tests take place in Görlitz, Germany, at a special facility which is certified to carry out this kind of tests and where the required infrastructure (especially curve radii) is available.

Overview of the test site at the TÜV Süd facility in Görlitz, Germany

The test campaign takes four weeks and afterwards the results will be analysed in order to compile the tests reports. These detailed test reports are expected to be published here on the project homepage towards the end of the year.

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Caption for main photo on top: Coupled DACs by Knorr-Bremse with force measuring equipment

(c) All Photos: FP5-DACtiVate, Dr. Simon Funke (WP 1 Lead)