Rail passengers across Britain face disruption due to a fault with a radio system used by train drivers and signallers.
Train information website National Rail Enquiries said trains “across the network” are having to start their journeys later because of the failure of the onboard GSM-R system, and “may be subject to cancellations or alterations”.
South Western Railway is among the operators to cancel some services.
It said in a message to passengers: “We have been informed of a national issue with communication systems affecting service this morning.
“This means that trains may be delayed before they start their journey.
⚠️NEW: Disruption to Gatwick Express, Great Northern, Southern and Thameslink services this morning #GTRDisruption
ℹ️More details here:https://t.co/o789IaX8oQ
— National Rail (@nationalrailenq) December 6, 2024
“This is because it is preventing our train drivers from contacting the respective signalling centre this morning and a reset is having to be performed before the train can start its journey.”
Elizabeth line trains serving Reading and Heathrow airport are affected.
ScotRail passengers are being permitted to travel via “any reasonable route” because of the issue.
⚠️A national issue with communication systems is affecting the railway.
Trains may delayed because of this problem.
More information: https://t.co/imkvCCexC2
— SWR Help (@SW_Help) December 6, 2024
Gatwick Express, Great Northern, Southern, Thameslink and Southeastern services are also disrupted.
The failure with the GSM-R system “is currently being investigated”, National Rail Enquiries said.
A Network Rail spokesperson said: “We have discovered a fault with the railway’s radio communication system that is preventing it from automatically ‘logging on’.
“The back-up manual log-in system is being used instead, causing a few minutes of delay at the start of the day.
Our colleagues at Network Rail are experiencing an industry-wide problem with communications systems. Thankfully ScotRail services are operating well, with some minor delays in places. Please check before you travel.
— ScotRail (@ScotRail) December 6, 2024
“Once up and running the system is working normally and the impact for passengers is minimal.”
GSM-R is designed to enable driver and signallers to communicate digitally at all times, including while trains are in areas such as tunnels and deep cuttings where previous analogue systems did not work.
It was rolled out to increase safety and reduce costs by replacing the patchwork of inefficient legacy systems which were expensive to maintain.