OVERVIEW
In 2017, KeolisAmey Metrolink (KAM) took over the operations and maintenance of Manchester’s Metrolink. Owned by TfGM, Metrolink is the largest tram system in the UK. In July that year, a fault with the Gigabyte Ethernet Network (GBE) was reported to the Trafford Control Centre.
Over the following 10 hours, one by one the systems failed, including the complete loss of communication to the Thales Tram Management System (TMS). The radio system failed which meant the control room at Trafford lost the ability to speak directly to the tram drivers. As a safety critical failure, the Metrolink service was suspended for 14 hours.
APPROACH
We identified the root cause of the failure and worked with the TMS supplier to identify recommendations that would not impact the operation of the TMS. We submitted a Network Outage Report with a list of recommendations with the aim of improving network performance and resilience.
BENEFITS
- We identified and corrected the root cause of the previous four failures. The Virtual Routing Protocols (VRRP) were configured incorrectly, resulting in the network constantly switching routing between the control centres.
- The GBE Change Control Board received full buy-in from all stakeholders and daily backups of all network switches are now automated.
- KAM has procured the spares identified in the report to ensure the network can be maintained for the next two years until the replacement programme finishes.
- KAM has not had a disruptive failure of the same scale as the GBE failure since 2017 and has kept Greater Manchester moving.