A massive fire brought Heathrow Airport to a standstill earlier this year, with 1,300 flights cancelled and thousands stranded in London. An official report released on Wednesday revealed that the incident had been caused by a ‘preventable’ technical fault that was identified almost seven years earlier. British energy watchdog Ofgem has since opened an enforcement investigation into the National Grid Electricity Transmission.
The report by the National Energy System Operator said that an “elevated moisture reading” had been found in oil samples at the substation in west London in July 2018. It further stated that no action was taken to replace electrical insulators known as bushings. The report concluded that the March 20 fire was triggered by a “catastrophic failure” within one of the transformers, “most likely caused by moisture entering the bushing, causing a short circuit,” which then ignited the oil.
The airport, despite being the busiest in Europe, was shut down for about 18 hours and disrupted more than 200,000 passengers’ journeys on March 21.
Initially, counterterrorism police led the investigation, amidst heightened concerns across Europe regarding potential sabotage. However, authorities quickly ruled out vandalism or sabotage backed by Russia, and shifted focus to the resilience of Britain’s critical energy infrastructure.
Energy Secretary Ed Miliband described the findings as “deeply concerning.” He announced that Ofgem, the energy industry regulator, has launched its own investigation into whether National Grid Electricity Transmission, the substation’s operator, breached its license conditions. The government had previously ordered a broader inquiry into “any wider lessons to be learned on energy resilience for critical national infrastructure” following the significant impact of the fire.
The fallout from the substation fire was extensive, resulting in the loss of tens of millions of pounds, stranding thousands of passengers, and prompting serious questions about the overall resilience of the UK’s critical infrastructure. Beyond the airport, the blaze and subsequent power outage left over 71,000 domestic and commercial customers without electricity, according to the report.
