The Rail Accident Investigation Branch has warned that shortfalls in track inspection could be far more widespread than just those that led to a derailment at Sheffield on November 11 2020.
A Hope-Dewsbury cement train came off the track at the north end of Sheffield station, due to gauge widening (RAIL 918, 919). As well as damage to the permanent way, the station was partially closed.
“The track gauge had widened because a number of track screws that secured the rails and baseplates to the wooden bearers had broken, allowing the rails to spread apart under the loads from passing trains,” said RAIB in its report published in October.
“The track screws had failed several weeks, or perhaps months, before the derailment. But the failures had not been identified by Network Rail’s maintenance inspection activities.
“Although this was a location with a potentially high risk of derailment, it had not been recognised as such because Network Rail’s guidance for identifying such risk had not been applied. Additional mitigation had therefore not been considered.”
In its report, RAIB said that visual inspection had failed to identify the broken track screws, and that Network Rail’s single Multi-Purpose Vehicle equipped to measure track geometry had not made recording runs at Sheffield since November 2019. It is supposed to visit every three months but had been out of service for overhaul and upgrading.
“The fact that 14 out of 19 MPV runs through the tracks at Sheffield station were not undertaken, for various reasons, strongly suggests that there will be many other such shortfalls throughout the network,” RAIB has warned.
Its recommendations include that NR reviews processes for site-specific derailment risk assessments, reviews arrangements for how safety-critical changes to management of track maintenance are incorporated into processes and procedures, and reviews standards and processes relating to check rails.
Various actions had already been taken by the time of the report’s publication, including NR’s North and East route initiating the fitting of high-tensile track screws at locations identified as having a higher risk of derailment.
Read more in RAIL 942