Heathrow fire caused by substation maintenance deficiencies

The fire that paralyzed London's Heathrow Airport in March, stranding thousands of people, was caused by inadequate maintenance at an electrical substation. According to an official report published Wednesday, the problem that caused the fire was identified seven years ago but failed to be addressed by the electricity network operator National Grid. Energy regulator Ofgem called it an "avoidable technical error."

The energy regulator also launched an investigation into National Grid, which operates the high-voltage network in England and Wales. Energy Secretary Ed Miliband described the findings as "deeply worrying."

Operations were suspended for 18 hours

Europe's busiest airport was forced to shut down for 18 hours at the end of March after a fire at a nearby substation disrupted power. More than 200,000 passengers were stranded, airlines suffered millions in losses, and the disruption raised questions about the resilience of Britain's infrastructure.

The report states that a "catastrophic failure" in one of the transformer's high-voltage bushings at the substation caused the transformer to catch fire. This was most likely due to moisture ingress into the bushing. Although elevated moisture levels were detected in 2018—an indication of an impending failure—the affected component was not replaced. Even a maintenance opportunity in 2022 remained unused. Instead, National Grid postponed essential maintenance work.

Infrastructure maintenance and review program launched

Ofgem now intends to investigate whether National Grid has violated legal requirements or licensing conditions and has announced an independent audit of the network operator's facilities. A National Grid spokesperson stated that the company has a comprehensive infrastructure maintenance and inspection program in place and has taken additional measures following the incident.

In its own statement, Heathrow Airport blamed the incident on a "combination of outdated regulations, inadequate security mechanisms, and failures by National Grid." An internal investigation by the airport concluded in May that the response to the power outage was appropriate, and that alternative measures would have had little impact on the outcome.

APA/Reuters