Asset integrity
Ensuring that railway assets perform as a whole system and meet future demand, effectively, safely, and at an acceptable cost
Asset integrity means ensuring that the assets, such as tracks, bridges, tunnels, signalling systems, and rolling stock, that make up the railway are safe and reliable.
Over the last 20 years, the train accident risk as tracked by the PIM has reduced substantially (see Figure 6). However, there has been relatively little change in the metric over the last 5 years. Much of the change in the PIM over this period has been driven by infrastructure failures. These are highly dependent on extreme weather such as heavy rainfall and are therefore at risk with a changing climate.
RSSB’s decision support tool PRIMA (proportionate risk response when implementing mitigating speeds to assets) uses data modelling techniques and analytics to give rail operators more insight into the safety risks associated with rain. They can then use this intelligence to plan how to respond in a proportionate way.
PRIMA has been trialled on two routes in the North West and Central region, and 4 routes in Scotland. Work is currently ongoing to model the risk from falling trees caused by high winds. The risk from falling trees was highlighted by RAIB’s investigation into the train strike at Broughty Ferry published in December 2024. RSSB are working with Network Rail to roll out PRIMA to new areas.
Maintenance of assets is still an area of focus with an emphasis on good quality asset information and data sharing. This year RAIB published its report into the derailment of a passenger train at Grange-over-sands. The train derailed because a void had opened in the embankment on which the train was travelling, caused by a leaking water pipe beneath the railway.
Incidents such as this highlight how the railway needs to understand its assets and their condition. Effectively operating an asset management system requires high-quality datasets. Systems such as the National Defect Recording, Analysis, and Corrective Action System (DRACAS) will allow for the sharing of high quality failure and fault information between organisations, ensuring that proactive action can be taken.
The risks associated with assets at boundary interfaces have also been highlighted this year and they further support the need to focus on asset information. In February 2025, RAIB published its report into the derailment of a train at Roudham Heath caused by a tree falling onto the railway from an adjacent property. The railway needs to understand the risks presented to the assets by the operations at boundary interfaces.
The Precursor Indicator Model shows that the risk from structure failures has reached its lowest level in over 5 years, mainly due to a reduction in the risk from rail bridge failures.
