DACIO - Digital Automatic Coupling in Infrastucture Operations

The nationally funded DACIO Project joins eight research institutes and companies from Austria. Its research focus is the effects of an introduction of a Digital Automatic Coupling (DAC) on shunting processes. We support the DAC development with a focus on Austrian specifics. Special emphasis is placed on train formation and train preparation in the main shunting nodes using hump shunting as well as a single person operation for flat-yard shunting and last mile.

Dacio Project Structure
Project structure
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DAC Coupling (Voith)
Courtesy of ERJU / FP5TRANS4M-R


Automatic coupling is used by rail operators around the world but not in Europe. In the last century there were efforts to introduce them in the 60’s, 70’s and 90’s. They all failed. Europe is the last continent without an automatic coupling in rail freight operations. However, it could become the first one with a Digital Automatic Coupling (DAC).

Increasing transport demand and the requirements for climate protection create considerable pressure for the rail freight sector to become more competitive, efficient and sustainable. The Digital Automatic Coupling paves the way for a modern and digital European rail freight sector.

The decision to introduce the DAC until 2030 is one of the central innovations enabling a a digital and automated rail freight sector in Europe. Once introduced the screw coupling used since the 19th century in all railcars for freight transport will be history. Back then it was an innovation today it is a relic producing a lot of suffering by the European Rail freight sector.

A screw coupling works purely mechanically, and everything has to be connected manually. A chain link is put over the towing hook of the following wagon and tightened by turning the release screw. The air pipe for the pneumatic brakes has to be connected manually as well. Not only are these processes time consuming, but they are also dangerous. Plus, it is increasingly difficult to find people who want to do this physically challenging and risky jobs.

A Digital Automatic Coupling will produce the necessary connection between rail freight wagons automatically and connects the air pipes for the brakes as well as electrical power and data lines. All that occurs automatically without risking staff. This automation step secures sufficient energy supply for telematic applications as well as a secure and safe data communication for the whole length of a train. It also covers the train integrity and train length information which are critical to automatic train operation.

Thus, the DAC is a key component to achieve the necessary increase in efficiency and transparency of the European rail freight sector. It use will also lead to an increase in infrastructure capacity leading to positive effects regarding achieving the European climate objectives.


The DACIO consortium is coordinated by ÖBB Infrastructure. It comprises eight partners – research institutes and private companies – united by the aim to introduce the DAC. Processes are viewed through the lens of an DAC Level 5 being available which may be remotely de-coupled contrary to DACs of Level 4. Thereby offering the highest value added.

Besides ÖBB Infrastructure who manage the overall project, DACIO includes two university research institutes of the Technical University of Graz and of the University of Applied sciences St. Pölten in Lower Austria as well as a research group from the University of Applied Sciences Upper Austria and joins them with the Austrian Institute of Technology, a leading extramural institution as well as three private companies, PJ Monitoring, Ulbrich Mechanical Engineering and m.ZERO.

Our Research is organized in six Work Packages (WP) which are designed to generate synergies by permanent exchange and cooperation.

The Institute of Engineering and Business Informatics at the Technical University of Graz is involved in two WPs. Its work is focused on process steps in shunting at the major hump shunting nodes in Austria. In addition, it analyzes the DAC ‘s influence onto the brake system of the wagons and elaborates a possible future production system of rail freight transport based on the DAC in Austria. Possible migration scenarios of the DAC is studied via monitoring and consideration of by the European projects responsible for it.

The “Carl Ritter von Ghega Institute for Integrated Mobility Research” of the University of Applied Sciences St. Pölten focuses on the shunting of trains and its processes, which will be significantly influenced by the introduction of DAC. Particular consideration is given to the operational processes in flatyard and last mile shunting and the effects of the DAC on personnel.

The Railway Automation and Traffic Telematics Research Group of the Upper Austria University of Applied Sciences (FH OOE) in Wels is also involved in two WPs. It provides crucial support for the test implementation of the DAC and develops infrastructure-side automation solutions to achieve a fully automated marshalling yard.

The Austrian Institute of Technology (AIT), together with the University of Applied Sciences St. Pölten, converts simulations of predefined shunting target processes in selected stations into models using special software, which are then linked to the simulations of the Graz University of Technology.

PJ Monitoring GmbH examines automatic decoupling in a requirements analysis and prepares an expertise in the field of automatic brake testing in connection with automatic coupling.

m.ZERO OG deals with those technical upgrades that are required in addition to the DAC on the vehicle level for automated shunting in marshalling yards. It also supports the overall project management in website editing, among other things.

ULBRICH Maschinenbau- und Export-Import Betriebsg.m.b.H. contributes its expertise in testing and trial facilities for railroad components and supports the developments of the FH OOE regarding robotics solutions.


In order to achieve the goals set by the DACIO project, comprehensive analyses, tests and surveys are already taking place.

This way, the effects of DAC on the processes in the marshalling yard and in flatyard shunting and last mile operations are investigated from the point of view of the infrastructure operator and shunting service provider.

The DACIO team provides its expertise to scientifically support the EDDP’s DAC test program. The program tests and analyzes shunting processes in the station and on the ground.

In the search for possible solutions for additional automation steps in the shunting yard, we are developing functional models and laboratory demonstrators on the topics of uncoupling at the hump yard, brake handling (venting and refilling the brakes), carrying out an automatic brake test and securing the wagons and track ends.

Wagons will also need further automation, e.g. the introduction of new types of braking systems for rail freight transport and are conducting research in the area of wagon-integrated perception systems.

Last but not least, we are investigating the potential impact of the DAC introduction on the structure and scope of the shunting infrastructure. Our goal is to sustainably increase the efficiency and, above all, the effectiveness of rail freight transport through re-dimensioning.

Thus, the DACIO project provides an important contribution to the EDDP and, on its basis, will also provide concrete proposals for the piloting of more advanced automation solutions, for example in the context of ERJU.

Justifications for the Research Work

The leap from a screw coupler to a DAC represents a far-reaching paradigm shift in many parts of rail operations and will initially require more technical, operational and financial effort. However, a complex development and migration strategy has been agreed upon in Europe that will ultimately support the automation of rail processes to the highest degree with DAC and the systems it enables. Several critical, preparatory developments must therefore take place in parallel with the development of the core technology – another essential mission of DACIO.

Remote-controlled automatic uncoupling with simultaneous disconnection of the brake lines is a critical safety issue and potentially vulnerable to cyber manipulation. For the first time, freight cars are being supplied with electrical power on a large scale and connected via data links to the locomotive. This means data connectivity will extend into rail operations automation and planning levels. This will lead to new role assignments. For example, the question will arise as to who will be authorized to carry out decoupling and by what means?

Current production models and simulations must be adapted to the new processes or completely rethought and re-generated to be able to fully analyze the effects on the system and the people operating in it and create an intelligent freight train based on digitally connected wagons.

Photo credit slider:

  1. Voith DAC Type 4 Coupled / Courtesy of ERJU / FP5TRANS4M-R
  2. Presentation Demo-Train DAC4EU / ÖBB-Infrastruktur AG
  3. Voith DAC Type 2 (DB Polska) / Courtesy of ERJU / FP5TRANS4M-R
  4. View from Shunting Hump at the Central Shunting Station Wien-Kledering / M. Reichmann, Institute of Engineering and Business Informatics (EBI) at Graz University of Technology
  5. Sequence from Sensor Tests with VIS/FLIR Sensor / m.ZERO OG
  6. Concept Design of HMI of a Yard Automation and Management System (YAMS) App / Institute of Engineering and Business Informatics (EBI) at Graz University of Technology
  7. PJM Smart-Train / PJM Smart-Train
  8. UIC 530 Installation Space / Courtesy of ERJU / FP5TRANS4M-R
  9. Preliminary Housing (VIS/FLIR) / m.ZERO OG
  10. Automated Break Test System – Design Version in Track / University of Applied Sciences Upper Austria – Research Group Rail Automation and Telematics
  11. DAC Coupling (Voith) / Courtesy of ERJU / FP5TRANS4M-R
  12. Sequence from Sensor Tests with VIS/FLIR Sensor / m.ZERO OG
  13. DAC Hybrid Coupler as used by SBB / m.ZERO OG
  14. Excerpt from Presentation Matthias Reichmann at SFT in Graz
    / Matthias Reichmann
  15. Presentation Demo-Train DAC4EU / ÖBB-Infrastruktur AG
  16. Screenshot AIT Simulation Suite Open Track / Austrian Institute of Technology (AIT)
  17. Automated Break Test System – Design Version Parallel to Track / University of Applied Sciences Upper Austria – Research Group Rail Automation and Telematics
  18. m.ZERO OG
  19. Preliminary Housing (VIS/FLIR) / m.ZERO OG
  20. Voith DAC 4 New Design / Courtesy of ERJU / FP5TRANS4M-R