Engineers remain baffled by a signalling fault on London Underground’s Northern line that has caused severe delays since Sunday, with disruption potentially extending into next week. Transport for London (TfL) is considering cancelling the weekend night tube service to allow for extensive investigations if the problem is not resolved by Thursday night.
The fault, located in signals at Stockwell, has slowed journeys and led to station closures due to overcrowding. Although trains continue to run, controllers are manually guiding drivers through the affected section. TfL believes the fault is unprecedented and has ruled out cyber-attack or sabotage.
The Northern line, once known as the “misery line,” had become more reliable since upgraded signalling was introduced over a decade ago. This week’s issues are a setback for the busiest line on the network. A separate signal failure at Tooting on Tuesday was repaired the same day.
Passengers are advised to avoid the Northern line where possible and use alternative routes. Bus services along the route are also affected by increased road traffic and diverted passengers. TfL’s director of customer operations, Nick Dent, apologised and said engineers are working hard to restore a good service.
Meanwhile, industrial action on the tube may be avoided as London Underground has offered a three-year pay deal linked to RPI inflation. Aslef has recommended the offer, and the RMT union has yet to reject it.
