Decisions need to be made on the development of Network Rail’s Infrastructure Monitoring strategy… and on the rolling stock required. NR’s Asset Information Services Director JASON SAXON discusses the next steps with PHILIP HAIGH
Last year marked the 100th anniversary of track recording on Britain’s main line railways as a way of finding faults for track gangs to fix.
It was in 1922 that the Great Northern Railway imported from France a Hallade track recording machine. Placed on the floor of a passenger carriage, it recorded the bumps and jolts the coach produced as it passed over track. If the track had faults, these jolts became worse. With some analysis, it was possible to find the problem’s position and check more closely.
As a British Transport Film about Hallade recorders said in 1951: “It is the ganger’s job to locate and check the trouble before the gang itself sets out to correct the faulty track.”
Matters became more advanced that same decade, as British Rail introduced Matisa recording trolleys. British Pathé filmed one in action on the Eastern Region in 1959, with the narrator chirping: “The trolley is used for detecting and recording all physical track faults. Any irregularity can be pinpointed to within three or four sleepers, and maintenance gangs can go straight to the seat of the trouble instead of spending time measuring and searching.”
Today, Network Rail’s New Measurement Train (NMT) does a similar job - but at 125mph, rather higher than the 20mph of those initial Matisa machines. With techniques such as Plain Line Pattern Recognition, the NMT can spot faults such as missing track clips as it speeds by.
But to replace those track clips, NR still needs to send out a gang, as it must also do with other discrete faults such as flaws or cracks within a rail that NR’s ultrasonic test trains might detect.
With pressure to keep lines open for revenue traffic, Network Rail doesn’t have time to send gangs out to inspect lines and then again to fix faults. There’s a safety aspect too, with NR banning gangs from working on open lines with lookout protection. It was in similar circumstances that two track workers died near Port Talbot in July 2019, having been hit by a train (RAIL 883).
Work must be done in possessions with no trains running. These possessions are hard to get, so NR is increasingly beholden to its fleet of inspection trains. But the fleet is ageing and becoming harder to maintain.
Take Mentor, for example, which NR uses to inspect overhead line equipment. BR introduced it to service in 1973, with the electrification of the northern half of the West Coast Main Line. But this was its second career, following time as a frontline passenger carriage having been built in 1955 as a Mk 1 Brake Second Corridor (BSK) coach.
It’s not surprising to hear Network Rail Asset
