Many European railway lines need to increase the capacity of their lines, which are very busy. New lines and tracks can be built and added but it is quiet expensive and it will not allow to fulfill the future capacity requirements. The concept of virtual coupling can be then introduced to allow more flexible train operation and better utilization of existing railway infrastructure and will be part of the Shift2Rail work program.
The concept of virtual coupling relies on the exploration and demonstration of Virtually-Coupled Train Sets (VCTS). It allows to operate physical trains much closer to one another (inside the absolute braking distance) and to modify dynamically the composition of the trains. The convoy of virtually coupled trains is then linked by a ultra-reliable hard real-time communications radio, sharing the same data (speed, braking commands, etc.) . The concept is basically to reduce the headway and then to increase the capacity on the lines. It can be seen as the extreme limit of the concept of moving block, removing the “one block, one train” limitation. The functionality relies on board environment in addition to new features in the wayside signalling and supervision systems.
The application of the virtual coupling concept involves several steps, such as the analysis of radio aspects, related to the direct radio communications within the
VCTS, through external network and what radio systems are available and the related functionality.