The closure of Heathrow, the busiest airport in Europe, on March 21 cost airlines tens of millions of pounds and stranded thousands of passengers. It also raised questions about the resilience of Britain’s infrastructure, Reuters reported.
“This review has seen evidence that a catastrophic failure on one of the transformer’s high voltage bushings at National Grid Electricity Transmission’s 275kV substation caused the transformer to catch fire,” the report by the National Energy System Operator said.
“This was most likely caused by moisture entering the bushing, causing an electrical fault.”
National Grid Electricity Transmission’s controls in place were not effective and failed to identify that action had not been taken in relation to an elevated moisture reading in 2018, the report said, adding that the issue went unaddressed.