A software crash left five passenger trains stranded for over five hours and delayed others as signalling systems failed to function across the North Yorkshire strand of the East Coast Main Line.
The fault, which occurred on Saturday, affected all trains on the segment that ran between York and North Allerton, North Yorkshire, halting them in their tracks and causing slowdowns across the network. Problems began at around 1:10pm and service was restored by 6:30pm, according to Network Rail.
The problem emerged after a power supply problem knocked out the main signalling system. A secondary system failed to kick in as expected, leading to a five-hour period of downtime, according to Network Rail.
Because the software that relayed information to rail controllers in the York signalling centre failed to function, their information panels which displayed train locations on the segment were blank. As part of an automatic failsafe, track signals on the section defaulted to red due to a lack of operator input.
"When the signalling system goes down it takes down all the signalling that enables the trains to move in a particular segment of track," a Network Rail spokeswoman told ZDNet UK on Monday. "It did cause a significant impact on the system."
3,000 passengers were delayed by the outage, according to Railnews.
The East Coast Main Line connects London to Edinburgh, passing through eastern hubs Peterborough, York and Newcastle, among others, along its 632km track.
Affected operators included East Coast, CrossCountry, First TransPennine Express, Grand Central and Northern Rail, according to reports.
Technical staff from Network Rail were not available to give further details on the nature of the fault, as they are still working on analysing and fixing the problem, Network Rail told ZDNet UK on Tuesday.