Digital automatic coupling
.jpg?lang=en)
Digital automatic coupling (DAC) is a type of railway coupling developed in the 2020s to replace the English buffers and chain couplings, initially in Europe.
It resembles the Scharfenberg coupler with extra contacts to join electrical circuits (power, detection and control) and air hoses.[1]
The DAC project is backed by Europe's Rail, a body of the European Union[2]. The system is among several innovations being developed within European working groups to harmonize the rail network and aims to boost freight traffic by 2030[3]. Although not a member of the European Union, Switzerland is associated with the project and wants to subsidize the transition to digital automatic coupling on its territory. [4]
Advantages
[edit]- Longer trains up to 750 m.
- Brakes remotely controlled like electronically controlled pneumatic brakes.
- Monitoring of train and wagon performance.
- Safety. No need for shunter to climb between buffers.
Function levels
[edit]
.jpg?lang=en)
Automatic couplers are categorized into five different levels in general.
- no automation
- Level 1: automated mechanic coupling (air pipes manual coupling)
- Level 2: Level 1 plus automatic coupling of air pipes (partial uncoupling with a lever)
- Level 3: Level 2 plus automatic coupling of power cables (allows uncoupling with switch)
- Level 4: Level 3 plus automatic coupling of data cables (allows uncoupling at a signal)
- Level 5: Level 4 plus remote automatic uncoupling
For the DAC the function levels are narrowed down to specific functions. The function level DAK-3 must connect the electronically controlled pneumatic brakes. The function level DAK-4 must connect the e-coupler including electric supply (400 V) and digital sockets. The function level DAK-5 must allow for remote uncoupling using an electric motor (the DAK does not use uncoupling air pipes as defined in EN 16019 for high-speed trains). Rollout plans may use function level DAK-4 when prepared for an update to DAK-5.[5]
Safe remote uncoupling
[edit]In addition to uncoupling from the driver's cab, the DAC must also enable uncoupling while moving on the shunting hump. In addition to a mechanical device using a cable pull/uncoupling lever, the demonstrator also had an electrical device with switches on a control panel attached to the side of the car. Further development should enable electrical uncoupling both from the train and from a tablet or hump computer. This is essentially software development with high safety requirements.[6]
Other systems
[edit]Couplings based on AAR and SA3 already have automated mechanical couplings, so some of the advantageous features of DAC are lessened. These have a maximum draw gear load well in excess of that possible with the DAC, say 1800 m instead of 750 m.
Makers
[edit]See also
[edit]References
[edit]- ^ DAC DAC
- ^ "Digital Automatic Coupling (DAC) – the backbone for full digital rail freight train operations in Europe". Europe's Rail. February 28, 2022. Retrieved April 11, 2023..
- ^ "L'attelage automatique digital de fret (DAC)". SNCF (in French). March 30, 2023. Retrieved April 12, 2023..
- ^ Pierre Cormon (April 25, 2024). "Des centaines de millions pour le fret ferroviaire suisse" (in French). Entreprise romande. Retrieved November 5, 2025.
- ^ "Part I: What is Digital Automatic Coupling and what are its levels?". DAC Question & Answer. Rail Cargo Group. 2021-01-20.
- ^ Wolf-Dieter Deuschle (2022-10-24). "Konzeptbericht - Automatisierung im Schienengüterverkehr der Schweiz, beginnend mit der Migration zur digitalen automatischen Kupplung" (PDF). Bundesamt für Verkehr BAV (Schweiz).
- ^ Dellner
- ^ Knorr-Bremse
External links
[edit]- "Digital Automatic Coupling". YouTube. 6 September 2021.
- DAC4EU Digital Automatic Coupling for Europe (2022-01-13). DAC4EU - Operational Tests. Retrieved 2025-05-07 – via YouTube.
{{cite AV media}}: CS1 maint: numeric names: authors list (link)
 | This rail-transport related article is a stub. You can help Wikipedia by expanding it. |