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A panel at the side of a railway line, for instance, requires equipment that can operate at extreme temperatures, cope with shock and vibrations, and operate reliably in an area with high electromagnetic fields.
A resilient data networking solution that could meet these challenges was required to help ensure the timely and successful completion of a major Network Rail project in Cornwall. The purpose of the Cornwall Capacity Enabling Scheme (CCES) was to increase the number of automatic block signalling sections on the Great Western Main Line running through the county, so that the length of each individual section could be reduced. To ensure safe operation, only one train at a time can pass within each signalling section, and the length of these blocks was restricting the frequency of services.
The project’s first phase, completed in May 2018, saw 20 intermediate block signals introduced. As well as improving safety and journey reliability, the extra signalling enables one extra train per hour to run in each direction between Plymouth and Penzance from the start of the new timetable in December 2018.
CCES was divided into east and west areas, with rail infrastructure specialist Amey plc awarded the design and build contract for the east area segment from St Germans to Lostwithiel. This part of the project included a new signal section at Menheniot, with the signals controlled by a Westplex vital transmission system and axle-counters used to detect passing trains. About 50km of new communications cable was laid, and the FTN fibre network provided digital access to certain trackside locations.
Data communications plays a critical role in ensuring the safety, reliability and availability of railway operations. It was therefore vital for Amey to ensure a resilient and secure data networking solution for the new signalling section, and it selected Westermo to provide its robust and compact industrial switches for installation at trackside to securely manage the network’s data flow. Network redundancy is provided via networking with a ring structure and Westermo’s patented FRNT protocol. This enables fast recovery in the event of a fault at any point in the network.
Westermo’s Lynx L110-F2G Managed Ethernet Switches, which were chosen for the new signalling section, are well proven in rail applications. The Lynx range has Network Rail acceptance and meets the requirements of the EN 50121-4 standard for trackside use, where typical challenges include wide temperature variations, vibration, shock and exposure to electromagnetic interference.
The signalling architecture required the transmission of several functions over the FTN network, including axle-counter transmission of remote heads that could not be directly fed with paired cable, and transmission of vital Westplex functions between signalling buildings. The transmission of these functions was designed using IP technology. This required Amey’s design team to provide an IP network from the trackside Signalling Relocatable Equipment Buildings (REB) to the nearest FTN transmission nodes. The use of fibre optic cables between the nodes and the REBs provided a path for routing the IP circuits over the FTN network to each of the other Signalling REBs and trackside assets within the project boundary.
Various switching technologies to provide the IP networking connectivity for the signalling circuits were evaluated by Amey, with Westermo’s chosen because of its proven robustness, high reliability, ease of configuration and long service life. Once the network design was approved by Network Rail, the Lynx switches were successfully tested to prove that their IP circuits would work across the Westermo equipment and across optical fibre connections. A point-to-point test was also successfully completed over an FTN Keymile testing rig, proving connectivity over the new FTN Keymile transmission equipment. The switches were then installed at each of the Signalling REBs at St Germans, Menheniot, Bodmin and Liskeard. Using the Lynx switches and fibre optic cables enabled the FTN layer 2 interfaces to be extended out to existing and new Signalling REBs. The IP network was then commissioned in April 2018.
The one-year timeframe for completing this section of CCES was extremely challenging. Therefore, as well as the data networking technology having to be extremely reliable, it was also important to use equipment that would reduce complexity and help ensure the project’s on-time completion.
Valuable project time was saved in device and network configuration. Traditionally, this would require a great deal of programming and coding, which would be both complex and time-consuming. However, Westermo’s WeConfig network configuration management tool made network configuration more simple, efficient and reliable, saving many hours of work on initial installation of the network. Increasing reliability, WeConfig automates time-consuming routine configuration, minimising the risk of misconfiguration caused by human error, and reduces maintenance requirements. As well as supplying products and technology, Westermo also provided Amey with expert application advice and technical support throughout the project, helping to ensure that the section was finished on time.
Reducing the risk of unauthorised access to the network, WeConfig enabled the simple deployment of system-wide security features, while its security analysis functionality allows any network vulnerabilities to be found and fixed. After the Westermo devices had been configured and the network commissioned, WeConfig enabled a manual or periodic back-up of all the device configuration files to be easily made and stored. Lynx switches provide a long service life, with a mean time between failures of 630,000 hours, but in the event of a switch needing to be replaced in service, a rapid download of the saved configuration file onto a new device will result in a fast network repair.
For more information, visit www.westermo.com
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