The fault was reported towards the end of the morning rush hour and affected the railway's Wessex route connecting London with the south and south-west, according to multiple reports. The most-affected operator was South Western Railway (SWR), with services across its entire network facing cancellations, delays of up to 90 minutes, or revisions for the rest of the day. SWR reported major disruption on its routes as far west as Exeter.
Passengers at London Waterloo faced crowded platforms and confusion as departure boards showed widespread delays. Many commuters were left stranded, with some reporting that they had been waiting for over an hour with no clear updates. The radio system failure meant that signallers could not communicate with train drivers, forcing trains to stop at signals and wait for instructions.
This led to a rapid build-up of congestion across the network, with trains backed up outside stations. Network Rail engineers worked to identify and fix the issue, which was traced to a hardware failure in the communication system. The fault was resolved by 11am, but the backlog of trains meant that normal service could not resume immediately.
Due to issues with radio communications, train services in the south-west and south have been subject to some delays this morning. Staff have worked to resolve the fault and train services are now returning to normal. We apologise to passengers for the disruption caused to their journeys this morning.
National Rail's website warned that some services may still be delayed by up to 90 minutes or cancelled while the service recovers, and that major disruption is expected until the end of the day. SWR echoed this, advising passengers to expect disruption, allow more time for journeys, and check before travelling. Other operators were also affected.
Southern said that trains on its Haywards Heath route would be running late or ending at Gatwick until at least 1pm. A number of CrossCountry, Gatwick Express, Great Western Railway, London Overground, and Thameslink trains were disrupted. Passengers have been told they can use their tickets on alternative routes or operators at no additional cost.
A Network Rail spokesperson said: "Due to issues with radio communications, train services in the south-west and south have been subject to some delays this morning. Staff have worked to resolve the fault and train services are now returning to normal. " The cause of the radio system fault remains unknown, and it is unclear how many passengers were affected.
No information has been provided on whether compensation will be offered or what measures are being taken to prevent similar faults in the future.