Railways simply explained
16. 04. 2025
Shunting is the birthplace of every train. In this article, you will find out why this is the case, how and where trains are formed and what requirements freight wagons must fulfil in order to roll over the hump yard.
Rail freight transport is complex - much more complex than road transport. Once a truck has been refuelled and the driver has all the necessary documents, the journey can begin. Rail freight transport is different: here, empty freight wagons must first be ordered in good time and made available to the customer. Only after they have been loaded and the transport order has been issued are they collected from various operating centres and put together to form a train.
The shunting department is responsible for these tasks: it ensures the provision, collection, formation and control of freight and passenger wagons. In concrete terms, shunting means loading and unloading, queuing and de-queuing as well as moving individual rail vehicles or entire vehicle groups. Wagons are usually shunted several times on the way to their destination - both at the departure and destination stations and en route. This takes place in so-called marshalling yards or service nodes.
One of the most important locations for shunting is the Vienna-Kledering Zentralverschiebebahnhof (central marshalling yard) - the largest marshalling yard in Austria. Here, individual freight wagons or groups of wagons are pushed up an artificial hill, the so-called hump yard, by a shunting locomotive. They then roll down the incline independently and are automatically guided into one of the 48 directional tracks via a switch system. There they are formed into trains again.
Modern technology and the experience of our employees ensure that every wagon ends up in the right train formation. Braking takes place automatically via braking elements installed in the track. Around 140 trains are separated and reassembled here every day - for their onward journey through Europe and as far as Asia.
When rolling over the hump yard, so-called shunting impacts occur - i.e. massive mechanical forces when wagons run into other wagons. In order to withstand these forces, freight wagons must fulfil certain technical requirements. Wagons that do not fulfil these requirements - for example due to their load or an oversize - are shunted manually.
A classic example: standard container wagons in intermodal transport are not rollable. The weak container spigot, which connects the container and the carrier wagon, would not withstand the impact forces. Such wagons are only handled in terminals. That is why not all freight wagons are the same.
