Heathrow Substation Fire Investigation Leaves Questions Unanswered

Investigators have so far been unable to determine the root cause of the fire that disrupted operations at London’s Heathrow Airport in March. The blaze, which occurred at the North Hyde substation, cut power to the airport, leaving over 1,350 flights grounded and affecting nearly 300,000 passengers. In addition to the chaos at Heathrow, around 67,000 homes in West London were also left without electricity.

A preliminary report released by the National Energy System Operator (Neso) confirmed that suspicious activity had been ruled out as a cause. Despite this, the system operator admitted that the precise cause of the fire remains unknown. The affected substation, which was built 57 years ago, is now under a broader investigation to examine its maintenance history, design, and compliance with legal standards.

The fire impacted two transformers within the substation and exposed vulnerabilities in Heathrow’s private electricity network. Although nearby substations continued to function, it took several hours to restore power to the airport. Flights only resumed after a seven-hour delay following power restoration, resulting in nearly 24 hours of disruption.

Ed Miliband, the Energy Secretary, had previously ordered an urgent investigation into the event. He stated on Thursday that the findings of the full report, expected in June, would provide critical insights into protecting the UK’s energy infrastructure and improving resilience against similar incidents.

A spokesperson for Heathrow Airport indicated that the report prompts significant questions for the substation’s owner, National Grid, and Scottish and Southern Electricity Networks (SSEN), which oversees power distribution in the area. They added that greater clarity regarding the fire and its impacts on the transformers is crucial for building a more robust energy grid in the UK.

Both National Grid and SSEN have pledged to work closely with Neso as the investigation continues. Meanwhile, regulators at Ofgem have launched their own inquiry into investment decisions and regulatory approvals related to the electricity networks involved.

Heathrow has also commissioned its own internal investigation into the incident, led by Ruth Kelly, a former Transport Secretary and board member of the airport. Announcing the review, Heathrow’s CEO, Thomas Woldbye, apologised for the disruption, stating that power outages on such a significant scale were considered highly unlikely. He reiterated that the airport had paid for what was believed to be a resilient energy supply. Parliament’s cross-party Transport Select Committee is also seeking reassurances from airport and energy executives to prevent future disruptions of this magnitude.

The findings from both investigations are expected to drive changes in policy and infrastructure investment, with the aim of safeguarding critical national infrastructure and protecting businesses and consumers.