A power outage that shut Heathrow Airport earlier this year, causing travel chaos for more than 270,000 passengers, was caused by a “catastrophic failure” of equipment in a nearby substation, according to a new report.
Experts say the fire at the North Hyde Substation, which supplies electricity to Heathrow, started following the failure of a high-voltage electrical insulator known as a bushing – “most likely” caused by moisture entering the equipment – before spreading.
Two chances were missed that could have prevented the failure, according to the report, the first in 2018 when a higher than expected level of moisture was found in oil samples.
Please use Chrome browser for a more accessible video player
Such a reading meant “an imminent fault and that the bushing should be replaced”, the National Grid Electricity Transmission’s relevant guidance said.
However, the report by National Energy System Operator (NESO) says the appropriate responses to such a serious issue were “not actioned”, including in 2022 when basic maintenance was postponed.
“The issue therefore went unaddressed,” the report adds.
Europe’s biggest airport closed for around 16 hours on 21 March following the fire before reopening at about 6pm.
Around 1,300 flights were cancelled and more than 270,000 air passenger journeys were disrupted.
Tens of millions of pounds were lost, thousands of passengers were stranded, and questions were raised about the resilience of the UK’s infrastructure.
More than 71,000 domestic and commercial customers lost power as a result of the fire and the resulting power outage, the report said.
Responding to the report’s findings, a Heathrow spokesperson said: “A combination of outdated regulation, inadequate safety mechanisms, and National Grid’s failure to maintain its infrastructure led to this catastrophic power outage.
“We expect National Grid to be carefully considering what steps they can take to ensure this isn’t repeated.
“Our own Review, led by former Cabinet Minister Ruth Kelly, identified key areas for improvement and work is already underway to implement all 28 recommendations.”
In May, Ms Kelly’s investigation revealed that the airport’s chief executive couldn’t be contacted as the crisis unfolded because his phone was on silent.
Energy Secretary Ed Miliband called the NESO report “deeply concerning”, because “known risks were not addressed by the National Grid Electricity Transmission.
Mr Miliband said energy regulator Ofgem is investigating “possible licence breaches relating to the development and maintenance of its electricity system at North Hyde.
“There are wider lessons to be learned from this incident. My department, working across government, will urgently consider the findings and recommendations set out by NESO and publish a response to the report in due course.”
The Metropolitan Police previously confirmed on 25 March that officers had “found no evidence to suggest that the incident was suspicious in nature”.
Be the first to get Breaking News
Install the Sky News app for free
This breaking news story is being updated and more details will be published shortly.
Please refresh the page for the latest version.
You can receive breaking news alerts on a smartphone or tablet via the Sky News app. You can also follow us on WhatsApp and subscribe to our YouTube channel to keep up with the latest news.
