Asset integrity
Ensuring that railway assets continue to perform as a whole system, effectively, safely, and at an acceptable cost
Asset integrity means ensuring that the infrastructure assets such as tracks, bridges, tunnels, signalling systems, and rolling stock that make up the railway are safe and reliable.
Climate change is putting railway assets under increasing stress. Extreme weather in 2023/24 has likely contributed to RSSB’s Precursor Indicator Model (PIM) showing an increase in the risk due to earthwork failures since the end of 2022. Although, it remains below its peak in 2020. This partly reflects the substantial investment Network Rail has made to both improve the condition of earthworks and manage the risk from them failing. RSSB continue to work with Network Rail to trial the PRIMA tool which helps the railway develop proportional responses to extreme rainfall. Maintenance of assets continues to be an area of focus, particularly in relation to wrong side signal failures. This year RAIB published its report into the wrongside signal failure and SPAD at South Wingfield. The investigation found that track engineering works the previous night had introduced a wire cross which had not been identified in testing.
RAIB made five recommendations. Two related to improving non-technical skills among staff and three aimed at the testing process. These were to ensure that testers have enough time to complete their test, can record their test steps, and there are better measures to assure that the tests have been completed. There is a line here that can be drawn from South Wingfield, back through the Dalwhinnie derailment of April 2021, the collision at Waterloo in August 2017, the signalling irregularity at Cardiff East in December 2016 to the multi-train, multi-fatality accident at Clapham in December 1988. This point was also made by RAIB in a Summary of Learning, published in May 2024.
Historically, track faults and structural failures have caused high-consequence accidents. RSSB’s PIM risk metric for track and structures is at its lowest for five years. It will be important to ensure that these and other assets continue to be safely maintained during a period of cost constraint. These continue to be monitored by the Asset Integrity Group (AIG). The PIM shows that the overall risk from rolling stock failures has reached the lowest level in five years. AIG continues to collaborate with stakeholders to improve the quality of data feeding a number of precursors. This includes those relating to rolling stock failures.
