What may appear to many of us to be a marvel of connectivity, with trains rolling across European borders, enabling routes such as Amsterdam to Paris and London, Cologne to Brussels and more, is apparently not as simple as it looks: At least three different power systems are in use, and they're starting to get in the way.
The high-speed lines such as HSL 3 that carry, among others, Thalys and ICE Intercity Express trains run on 25,000 V power, while Germany's Deutsche Bahn operates on 15kV. And, just to make it more complicated, sizable portions of Belgium, including a 20km stretch that connects Aachen, Germany to the line to Brussels run on 3kV.
Europe has a program to 'harmonize' its rail power, but it's far from completed yet. Each time a locomotive reaches a change point, it has to safely come off one power system and connect to the next, a potential cause of delay.
While French and German power units are able to operate on both of the high voltages once they are switched over, some Belgian locomotives are not equipped for the high voltage services and must be swapped for other engines. Belgium's rail operator has now ordered 50 new Alstom engines capable of operating on all three voltage levels.