A mystery power outage brought large parts of London’s public transport network to a halt today amid continued fears over the vulnerability of UK supplies.
Four Underground lines and the Elizabeth line were suspended while 20 stations were shut after the incident in South West London ahead of the afternoon rush hour.
While the cause of the outage remains a mystery, it comes amid concerns over power supplies in Britain and whether Russian agents could sabotage the network.
A substation serving Heathrow Airport caught fire on March 21, forcing it to close to all flights for many hours and disrupting more than 270,000 air passenger journeys.
Then five weeks later a major blackout on April 28 in Spain and Portugal saw train passengers stranded and millions of people left without phone and internet access.
Just one day later another substation fire in London, this time in the Maida Vale area of the capital, saw around 80 people evacuated from their homes on April 29.
Today, no trains were running on the entire Bakerloo line, while the Jubilee line was axed between London Bridge and Finchley Road with severe delays on the rest of it.
The Northern line was part-suspended between Stockwell and Morden and between Euston and Kennington, and there was no service on the Waterloo & City line.
Passengers being turned away from Elizabeth line services at Paddington this afternoon
Passengers Alison Hendry, 33, and Joseph Richardson, 37, who came on the Heathrow Express to Paddington after flying from Glasgow earlier today, are among those caught up in the chaos
People wait outside Tottenham Court Road station in London today amid the power outage
Meanwhile the Elizabeth line was part-suspended in the central section between Paddington and Abbey Wood, with severe delays on the rest of the line.
National Rail said services across the Elizabeth line may be cancelled, delayed by up to 50 minutes or revised until 5.30pm.
Sources told the Telegraph that a brief power supply ‘blip’ caused the shutdown of signalling-related systems used to control the trains.
They added that the cause is believed to lie within the infrastructure of the National Grid, which sends power to regional organisations called distribution network operators (DNOs).
These organisations then transform the power down to voltages that can be sent out to businesses such as TfL and consumers.
UK Power Networks, which is the DNO, said the ‘blip’ was not caused by its equipment.
Meanwhile some businesses in the Regent Street area of London’s West End also suffered power cuts this afternoon, but it is not yet clear if this is connected to the outage impacting the Tube.
Alison Hendry, 33, and Joseph Richardson, 37, came on the Heathrow Express to Paddington after flying from Glasgow earlier today.
Ms Hendry said: ‘It’s a bit annoying they only told us when we got here. We walked all the way across the station, we have to go all the way back.’
The pair carried suitcases from their travels and hope to reach Walthamstow in time for a comedy show this evening.
Commuters are told to leave Paddington station on the Elizabeth line in London this afternoon
A loss of power to the overhead electric wires at Hackney Central was also impacting Mildmay line trains between Canonbury and Stratford. It was not immediately clear whether this was linked to the main power outage.
Separately, the Suffragette line on the Overground was completely suspended after a lineside fire damaged the overhead equipment at Woodgrange Park.
And another lineside fire between Clapton and Tottenham Hale was also impacting London Overground, Greater Anglia and Stansted Express trains.
Some 20 stations were closed or partially-closed across the TfL network due to the power outage.
These included key interchanges such as Paddington, Liverpool Street and Tottenham Court Road.
Signage on an information board at High Street Kensington station in West London today
Other impacted stops were Baker Street, Charing Cross, Bond Street, Westminster, Embankment, Euston, London Bridge and Farringdon.
Woolwich, Whitechapel, Waterloo, Swiss Cottage, South Kensington, Putney Bridge, Abbey Wood, Canary Wharf and Custom House were also closed or partially closed.
The issue was caused by a power outage in South West London at about 2.30pm which has since been rectified but delays are ongoing.
The Transport for London (TfL) website was struggling to handle traffic this afternoon and began to crash from about 3.15pm.
TfL officials were seen directing passengers with suitcases away from Elizabeth line services at Paddington station, recommending buses across central London.
The Bakerloo line entrance was completely shut at Paddington, and TfL staff said they do not know when the entrance will reopen.
One said: ‘It was a power outage. The lights just went off, we don’t know anything else. It’s been about an hour-and-a-half now. We can’t say when it will be fixed.’
A spokesman for TfL told the PA news agency that there was an outage in South West London for ‘a matter of minutes’ and ‘everything shut down’ due to a ‘National Grid issue’.
He went on: ‘When the power goes out the trains will have stopped, obviously, there’s emergency power on trains and stations so everything wouldn’t have gone completely black, if you were on there, but the trains would have stopped and we would have cleared some stations because there’s no electricity it might not necessarily be safe for them to be open … some people would have probably been stuck in a tunnel for a little bit of time.’
TfL is in the process of ‘getting things back up and running again’.
Muniya Barua, deputy chief executive at the BusinessLDN group, said: ‘This power cut is causing significant disruption for frustrated commuters, visitors and businesses in central London.
‘It’s welcome that power has now been restored but Transport for London and others involved must work quickly to get to the bottom of this outage.
‘This needs to be matched with steps to ensure the capital’s infrastructure is more resilient to minimise the risk of similar disruption in future.’
TSSA general secretary Maryam Eslamdoust added: ‘The loss of power on such a scale is deeply troubling and hugely inconvenient for many people across London’s Tube and other networks.
‘Safety for all is key at this moment, but in due course we will need a proper inquiry into what happened and the lessons to be learned.’
National Grid has been contacted for comment.