By Michael D. Shear
They added that basic maintenance on the transformer, called SGT3, was last performed by National Grid Electricity Transmission, the company that operates the substation, in July 2018.
鈥淓vidence provided to the review revealed that multiple attempts were made to schedule basic maintenance on SGT3, none of which went ahead,鈥 the report said.
The loss of power at Heathrow prompted questions from travelers, airline officials and some of Britain鈥檚 political leaders about the vulnerability of the country鈥檚 electrical grid. Prime Minister Keir Starmer said at the time that he was 鈥渄eeply concerned鈥 about the airport鈥檚 closure, adding that there were 鈥渜uestions that need to be answered in relation to what happened.鈥
The report released on Wednesday also concluded that Heathrow鈥檚 internal power systems, which were disrupted by the fire, were not designed to quickly take advantage of power from two other nearby substations that were not affected. The report said that airport officials had not expected to have to deal with a catastrophic power outage.
鈥淭he loss of supplies from a supply point was not assessed to be a likely scenario鈥 by the airport company, the report said, 鈥渄ue to its expectation of the resilience of the wider network.鈥