A fire that shut down London Heathrow Airport in March has been linked to poor maintenance of an electricity substation.
The incident occurred on March 21, when a fire broke out in an electrical transformer station, paralyzing operations at Heathrow—one of the world’s busiest airports—and triggering widespread disruptions to global air traffic. Hundreds of flights were canceled or diverted.
An investigation report released on Wednesday July, 2nd identified National Grid, the private operator of the UK’s electricity transmission network, as the likely cause.
According to the National Energy System Operator (Neso), the blaze was “probably” sparked by a short circuit, possibly caused by moisture or another contaminant infiltrating a high-voltage insulating component on the transformer.
There were numerous opportunities to rectify moisture affecting electrical parts at the North Hyde substation, but maintenance was repeatedly deferred, the report said.
Elevated moisture had been detected in July 2018 and that under National Grid’s guidance, such readings indicate “an imminent fault and that the bushing should be replaced”.
More than 270,000 journeys were affected by Heathrow’s shut down.
