Nis the digitization of the wagon fleet of European rail freight transport finally picking up speed? After all, a test train started in January in Berlin’s Westhafen, the 24 cars of which are equipped with the Digital Automatic Coupling (DAK). In concrete terms, this involves two variants of the Scharfenberg coupling (Schaku) developed by the manufacturers Dellner (Sweden) and Voith (Germany). Both systems have prevailed in the DAC4EU project, which was financed by the German Federal Ministry for Digital Affairs and Transport with around 13 million euros in four different prototypes. The other two developments followed the Schwab and SA3 coupling principles. The freight railways of Germany, Austria and Switzerland as well as the freight wagon operators Ermewa, GATX Rail Europe and VTG are involved in DAC4EU.
In the coming months, the wagon association is to gain practical experience on the use of this central buffer coupling, which can connect wagons automatically and not only creates the mechanical frictional connection, but also couples the lines for brake air, power and data. In February, for example, tests with coupling and decoupling processes as well as push-off tests in the marshalling yard were on the program in Austria. The ÖBB Rail Cargo Group wants to gain experience for operation in wintry weather conditions and on topographically demanding alpine railway lines. The freight railway in the neighboring country sees the new coupling technology as the key “to future innovations in the field of intelligent freight transport and subsequently to automated operations management”.
At first glance, it may seem surprising that a rather inconspicuous component such as the coupling of a freight car represents such a lever for technical development. However, the solution currently being tested might actually compensate for several structural disadvantages of rail freight transport. Up until now, freight trains have always consisted almost exclusively of wagons with classic screw couplings. And this technology, which dates back to the early 1860s, makes operation very time-consuming, especially before the start of a journey.
Physically demanding work with a high risk of accidents
To couple, a shunting worker has to climb under the side buffers (they absorb the compressive forces) into the “Bern area” between the cars, place a steel bracket weighing around 20 kilograms from one car over the towing hook of the other and finally both vehicles through the Tightening the spindle to connect train. Then it is necessary to couple the brake air line by hand. The work is physically demanding and carries a high risk of accidents. The lengthy procedure is followed by the brake test, among other things.
The train formation with the DAC is different: the wagons are pushed together when shunting, and the central buffer couplings automatically establish the mechanical, pneumatic, electrical and electronic connection. If the wagons equipped with the DAC also have the components for the automatic brake test installed, this step, which is necessary before the train runs, can be shortened by 45 minutes.
