Part II: Why do we need electricity and data connections on the wagon?

24. 03. 2021

We’ve answered the most important questions about the journey from screw coupling and automatic coupling right through to Digital Automatic Coupling in the second part of our series.

You can see on the map that we’re the only ones who still don’t have automatic coupling. Why do we need to carry out coupling tests when it’s already being used everywhere else?

The automatic coupling systems that are used outside Europe don’t have any electricity or data connections that are directly integrated into the coupling mechanism. This combination is a first for rail freight transport and that’s why it needs to be rigorously tested. Besides, Europe’s geography makes things interesting too. Coupling needs to function perfectly in both the iciest deep winters of Sweden and in the dry, windy and sandy Pannonian Steppe in Hungary – the Pustza. On top of that, every country in Europe needs to agree on one coupling design, because the different types that are already being used all over the world aren’t compatible with each other.

Why do we need electricity and data connections on the wagon?

A reliable electricity supply and safe data transmission on the freight wagon will help drive forward more automation and digitalisation efforts in rail freight transport. They make it possible for us to work on new digital and automatic solutions – train integrity monitoring, for example, which is essential for the ETCS Level 3 train protection system. This system is part of the future uniform European Railway Traffic Management System (ERTMS).

Right now, the technologies are deployed using energy self-sufficient systems like batteries. However, we’re seeing the limitations of these systems more and more. Electricity and safe data cables open up a ream of new possibilities.

Why do we not use automatic coupling mechanisms from passenger transport?

On a fundamental level, they do function in a similar way. They can’t be used however, because passenger transport operates under different parameters, which means it has different requirements. On one hand, passenger carriages are not coupled as much and whenever they’re coupled, it’s done under different conditions. This means there’s much less wear and tear on the mechanisms. Passenger transport coupling doesn’t need to be able to go over a marshalling hump, while that’s an essential part of freight transport. The wagons put more pressure on the coupling mechanism when pushing, so they need to be more robust. What’s more, there’s more single wagonload transport in European freight transport. The type of coupling has to be the same all over Europe because all the wagons need to be compatible with each other. Introducing DAC4 would give Europe a standard basis for the first time that we could build on.

As part of the funded TARO project – funded by the Federal Ministry Republic of Austria Climate Action, Environment, Energy, Mobility, Innovation and Technology (BMK) and the Austrian Research Promotion Agency (FFG) – the RCG is working on getting “DAC ready”.

In the next part, you’ll find out more about the differences between screw coupling and DAC!