London’s transport network disrupted by power outage

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London’s underground transport network was heavily disrupted on Monday afternoon after a “fault” on the electricity grid led to a power cut, underscoring the vulnerability of Britain’s national infrastructure. 

Thousands of passengers in the capital city were affected as several tube lines, including Jubilee and Waterloo & City, were delayed or suspended during Monday afternoon’s rush hour. 

The disruption comes less than two months after a fire at a substation in Hayes, west London, led to the closure of Heathrow airport for a day, triggering scrutiny of the resilience of Britain’s transport hubs.

Claire Mann, chief operating officer of Transport for London, said several lines had lost power because of a “brief interruption of the power supply to our network”. London Overground and Elizabeth Line rail services were also disrupted.

The short power outage caused the severe disruption because many of TfL’s IT systems are ageing and crash if they are not shut down properly, one person familiar with the matter said.

Signalling systems are also not designed to be turned off, so they needed to be tested before trains restarted, they added.

National Grid, the FTSE 100 company that owns the high-voltage electricity transmission network in England and Wales, said on Monday afternoon that an unspecified fault on its network was resolved “within seconds”. 

It added that the fault “did not interrupt supply from our network, but a consequent voltage dip may have briefly affected power supplies on the low-voltage distribution network in the area.”

UK Power Networks, which runs London’s distribution networks, said it had restored supply to customers including TfL in “less than a minute” and had offered further assistance.

TfL was still reporting severe delays on the Bakerloo and District lines and one Overground service on Monday evening, according to its website.

National Grid said the cable fault caused a “small, contained fire” at a substation in Aberdeen Place, north-west London, which had been brought under control by firefighters. 

“We apologise for any inconvenience and ongoing travel disruption,” it added.