Drives & Controls Magazine June 2023

31 www.drivesncontrols.com June 2023 COMMUNICATIONS AND SECURITY n Wi-Fi keeps world’s steepest cogwheel train on track Switzerland’s Pilatus-Bahnen railway, built more than 130 years ago, is still the world’s steepest cogwheel railway. It takes about 30 minutes to cover the 4.6km climb from Alpnachstad to Pilatus Kulm, 1,635m higher, with gradients of up to 48%. The railway is one of Switzerland's biggest tourist attractions. Because of the large number of passengers wanting to use the service, it was decided that larger and faster vehicles equipped with modern technology were needed. The original control system was based on mechanical and electromechanical elements. For the new larger, faster trains, a modern electronic control system from Actemium Schweiz was chosen. To establish a connection between trackside control boxes and the moving trains, the PbS (positionbased signalling) system needed reliable wireless communications. Based on a redundant Ethernet ring architecture, the network consists of wireless and wired devices designed for maximum reliability. The network had to balance demanding technical requirements against affordable costs. Network security also played a significant role in the planning. The Swiss government's cyber-security recommendations for critical infrastructures were taken into account. It was important to include network security from the outset and to implement it gradually. An encrypted data network with several security zones, monitoring and surveillance systems was created. Redundancy was achieved using Westermo’s FRNT (fast recovery network topology) ring protocol for high-availability Ethernet networks. In the unlikely event of a device or network link failing, the ring architecture ensures data transfer via other paths. Furthermore, to ensure that the network can be operated securely and is protected from the outside, security functions such as data encryption, port security and active firewalls were implemented. WLAN connection to the train vehicles are provided via Westermo Ibex-RT-370 infrastructure access points installed next to the track, along with redundant routing switches with firewall functions in the stations. The network on board the trains is based on Westermo Viper-212A managed routing switches and Ibex-RT-320 wireless clients that communicate via Wi-Fi with the trackside access points. This ensures reliable communications between the trains and the control system. A collision warning system between the trains was also implemented using wireless technology. As two vehicles approach each other, a WLAN connection is established automatically between them. This allows the steering systems to exchange data, enabling them to travel in tandem and avoid collisions. In winter, there is often more than 10m of snow on the Pilatus summit. To protect the infrastructure, it will be partially dismantled in the autumn and reassembled in the spring. To simplify and streamline this process, a special trackside radio equipment (TRE) box was developed, containing WLAN access points, antennae and power splitters. These boxes were delivered fully wired, tested and configured, cutting costs and time during the installation and commissioning. The boxes can be dismantled easily in the autumn and reassembled in the spring. This ensures that the antennas mounted on the TRE boxes are correctly aligned after reassembly. The railway reopened with its new vehicles this month. It is now carrying up to 368 passengers an hour at speeds of up to 15km/h. At its highest point, Mount Pilatus is more than 2km above sea level and is exposed to extreme conditions. Occasionally, work on the upgrade could not be carried out as planned due to geological or weather conditions, requiring a high degree of collaboration and flexibility between the organisations involved in the installation. “A project like this one has never been built before and is essentially a prototype,”says Patrick Blaser, operations manager and a member of the railway’s executive board. “To be able to accomplish this project, we needed partners like Westermo who actively contribute their know-how and support us with planning.” n The world’s steepest cogwheel railway re-opened this month after a major upgrade including new vehicles and control systems. The Pilatus-Bahnen railway in Switzerland now relies on sophisticated wireless communications to ensure reliability and safety. The spectacular Pilatus-Bahnen cogwheel railway has reopened this month after a major upgrade, including the installation of wireless communications

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