A fault with the UK’s railway communications systems used between train drivers and signallers caused widespread disruption across the country this morning
According to Network Rail, the issue appears to be a fault with the onboard GSM-R radio system, which is used for emergency communications and is powered by its own contained phone and mast system.
This morning drivers found their radio systems were failing to start up automatically when trains left depots. Although a manual solution was found, trains across the network had to start their journeys later because of the fault, leading to knock-on delays and some cancellations.
The BBC has reported that a new piece of hardware, installed as part of an upgrade to the system at a major telecommunications hub in Stoke, was the source of the problem. Replacement hardware has now been installed and the system rebooted.
While the issue has now been rectified, in London services on the Elizabeth line, Gatwick Express, Great Northern, Northern, ScotRail, Southeastern, Southern, South Western Railway and Thameslink were all affected.
Technical issue’ behind NATS air traffic system leads to aviation chaos
Incident response expert Chris Jones, an analyst at Check Point Software, said that the incident highlighted the risks of misconfiguration during essential system maintenance.
“It’s a challenge we’ve seen before with cloud services and communication platforms. While the GSM-R fault appears technical rather than malicious, it raises questions about whether rigorous testing and rollback plans were in place to prevent widespread delays,” he said.
Jones added that it was crucial for critical systems like GSM-R radio to follow the golden rules of IT maintenance: To test thoroughly, plan cautiously, and ensure rapid recovery options in case something goes wrong.
“When these steps aren’t followed, the impact on infrastructure and daily life can be immense, as today’s rail chaos demonstrates. This should serve as a wake-up call for organisations managing critical services—reliability demands preparation, not just hope.”
