Roslagsbanan

Roslagsbanan was Sweden’s first electric railway. It travels a route of nearly 70 km, and it has a narrow-gauge track. In the process of being closed down, its owner, SL (Stockholm Transit), decided to go for a major upgrade of the trains, a renovation of the stations, and new tracks and ties. In connection with this, the 30-year-old automation system was also traded in for the latest technology.

In the early 1990s, Cactus Automation was entrusted with the task of supplying a new traffic management system. Due to the ongoing improvements of the track, such as new interlocking systems, Cactus has been able to demonstrate their flexibility and resourcefulness.

A single location
Supervision takes place from a control room located at Östra Station. Six display screens grouped together make up an overview of the entire line.
Each station has a direct line to the central system at Östra Station. At each station there is either a PLC and a relay interlocking system, or stations will be equipped with an electronic interlocking system. In total, around 3,700 indications and 2,300 commands are processed.

A system beyond the ordinary
The base of the system consists of conventional remote interlocking features, i.e. the remote control and re-indication of all stations.

But the system is capable of a great deal more as well:

• Timetable tracking and reporting. Arrivals and departures are logged, and are compared to the pertinent timetables. Delays (as well as early departures) are indicted in the log and are shown in the display.
• Automatic routing. With reference to timetables and the actual traffic situation, the system will issue the appropriate remote control commands for the train in question. Naturally, dispatchers are able to switch to manual control whenever they deem this necessary.
• Reconstruction in the event of operational failure. Practically every move the system makes is logged automatically. In the event of an incident, the sequence of event can be replayed. Events can be replayed sequence by sequence, making it possible to review every aspect of the incident on screen and in the log.