Digital automatic coupling

The digital automatic coupling (DAC) combines the long overdue automation of wagon coupling with the world of rail 4.0

The future belongs to the intelligent freight train. Its core technology: digital automatic coupling. This advance will shift the industry from manual train preparation and coupling into the digital age. DAC lays the foundation for significantly more efficient processes and clear productivity improvements. Let’s use this opportunity to make goods transport more climate-friendly.

The private wagon keepers of VPI are clearly in favour of introducing the DAC technology and are working with industry committees and research projects on this topic. Our goal: All freight wagons in Europe should be coupled automatically by no later than 2030. Freight trains should be digitally connected from the locomotive to the last wagon.

With integrated power and data bus lines, DAC ensures a reliable supply of power and data communication throughout the entire train. It supports condition-based maintenance and enables automatic train formation and brake testing while also speeding up operating processes. The automated brake testing alone reduces the train dispatching time by up to 45 minutes. The coupling of power lines all down the train enables the use of electropneumatic brake technology and clears a path for faster and longer freight trains.

Automated coupling is also safer and less labour-intensive than the manual coupling procedures still used in Europe. Another weighty argument: DAC opens up the full potential of the European Train Control System (ETCS). It enables digital integrity checks on freight trains, eliminating the need for expensive equipment on the track, such as axle counters and track vacancy detection systems.

The introduction of DAC is a full system upgrade that must be completed throughout Europe within a relatively tight time window. Roughly 450,000 wagons must be outfitted with the new coupling technology. This Herculean effort naturally involves high investment costs. The sector is faced with expenses in the range of six to ten billion euros for upgrading the wagons and locomotives with the new coupling system and automation components as well as power and data lines. Policymakers must provide financial assistance at both the national and European level. Subsidy instruments that reward first movers in the sector could help accelerate the comprehensive rollout of DAC.

The “DAC Charter” presented at the 10th VPI Symposium in 2020 helped launch a process that has since picked up speed considerably. In the meantime, the German Ministry of Transport and Digital Infrastructure has released a study on migration to the new technology, and the demonstration train “DAC4EU” announced at the VPI Symposium has now left the station as well. Brussels is entering into the implementation phase at the EU level with the DAC Delivery Programme (EDDP). VPI and its member companies are also on board.

DAC has become the central project within the European freight sector. The European plan for migration to DAC should be ready in 2022 according to the commitment of Europe’s transportation ministers as laid out in their “Berlin Declaration” on the new coupling technology. One initial hurdle has already been overcome: Based on the results of the field testing of the DAC4EU train, the sector has agreed within the EDDP on a standard coupling type for all of Europe: the Scharfenberg coupling.