The National Grid has said that Heathrow has been reconnected to power on an 'interim basis' as firefighters today gave a major update on the fire that has shuttered the airport for at least 24 hours.
The substation fire in Hayes involved 25,000 litres of cooling oil igniting, the London Fire Brigade (LFB) has said.
'The network has been reconfigured to restore all customers impacted, including the ability to resupply the parts of Heathrow airport that are connected to North Hyde,' a National Grid spokesperson said.
This is an interim solution while we carry out further work at North Hyde to return the substation and our network to normal operation'.
West London residents have described hearing a 'massive explosion' before flames
rose into the air and smoke billowed across the capital's skyline. Around 10% of the substation remains alight.
It came as aerial pictures and footage
showed a deserted Heathrow, with the skies over the capital eerily quiet because almost 1,400 flights in and out are cancelled today.
Speaking at the scene of the blaze in Hayes, two miles from Heathrow, London Fire Brigade deputy commissioner Jonathan Smith said: 'The fire involved a transformer comprising of 25,000 litres of cooling oil fully alight. This created a major hazard due to the still live high-voltage equipment and the nature of the oil-fuelled fire.'
Counter terrorism police are now leading the probe into the electrical substation fire amid claims it could be a Russian sabotage attack linked to Vladimir
Putin's campaign of disruption.
An experienced electrical engineer today blamed the failure of an 'oil-filled transformer' for the devastating sub-station fire which shut down Heathrow Airport and blamed a 'lack of investment'.
Tom Watters, director of Sanguine Impact Investments, told MailOnline: 'I'm a transmission and distribution engineer having worked all over the world. An oil filled transformer has obviously failed and caused the massive fire.
'This looks like a very old transformer and it's surprising that such an old piece of critical equipment was still in service. I assume a lack of investment is the reason.