Brigitte Hafner
is a communicator in the Rail Cargo Group
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Railways simply explained: Route class

Did you know that railway routes are divided into route classes? And why freight wagons must not exceed the maximum payload limit? The following article explains what route classes are and how they are related to the maximum permissible axle load.

In 2017, 43 domestic and foreign railway undertakings covered 149 million train kilometres on the Austrian rail network. That is ten orbits a day. The rail network must therefore be able to withstand a lot when freight or passenger trains weighing several tonnes roll over the rails at high speed. But not all trains are allowed to run unrestrictedly on all lines. In the rail world, certain conditions apply in order to guarantee safe rail freight traffic.

Freight transport by rail keeps the roads free of trucks. But it has to meet a few more requirements than road freight transport. © ÖBB_David Payr

Each freight wagon has its route class

An essential prerequisite for a sustainable train service is the construction and maintenance of a modern rail infrastructure. For example, the rail network itself, i.e. the substructure and superstructure, must be designed accordingly for both high-speed passenger traffic and heavy freight traffic. To this end, railway routes are divided into route classes according to their load capacity. The route class determines the maximum permissible wheelset load and metre load of a line. The wheelset load or load limit provides information on the maximum weight per axle or the maximum permissible weight up to which a wagon may be loaded for the individual route classes. This is because the weight of the wagons and thus of a freight train depends on the load-bearing capacity of the superstructure and substructure of the respective section of track. The wheelset load of a wagon is the sum of the wagon’s own weight and the weight of the load divided by the number of wheelsets. In Austria, there are four line classes, ranging from class A with 16 tonnes axle load to class D with 22.5 tonnes axle load. Virtually all major routes in Europe correspond to Class D, while secondary routes are usually Class C. Classes A and B, on the other hand, hardly play a role any more.

The metre load, on the other hand, is determined by the load capacity of the bridges. It is the sum of the dead weight of the wagon and the weight of the load divided by the length of the wagon in metres.

Lightweight construction enables more transport volume

In the case of freight wagons, the possible payload thus depends on the route class, the load capacity of the wagon, the travel speed and its own weight. If the tare weight of freight wagons or wagon undercarriages, such as our TransANT  – the revolutionary platform wagon that sets new standards in rail logistics – is lower, more payload is possible. Thanks to the special lightweight construction and topology optimization of the TransANT, we can achieve up to four tons more transport volume per wagon with a wagon underframe that is 20% lighter. This means that even more goods can be transported by rail in an environmentally friendly manner.

Practically all major routes in Europe correspond to route class D with 22.5 tonnes axle load. © ÖBB_David Payr