London Fire Brigade has confirmed the fire in a high-voltage substation near Heathrow Airport, which began on the evening of 20 March, has been fully extinguished.
The fire was brought under control at 06:28 on 21 March. However, because of its complexity, crews remained on-site to manage remaining hotspots within the electrical equipment.
The incident involved a transformer containing insulating oil which was fully alight. This created a significant hazard due to being within a substation containing high-voltage equipment and the challenges of an oil-fuelled fire.
Extinguishing the fire
To combat this technically complex fire, crews initially deployed foam to suppress the flames. The foam works by smothering the fire and cutting off its fuel source, preventing reignition.
Firefighters also used a firefighting technique called ‘indirect cooling’ where they use a misting jet to reduce the heat being produced by the transformer where they are unable to directly tackle the fire.
The Brigade’s 32-metre turntable ladders were on hand to apply foam and water and the drone team attended to provide incident commanders with a 360-degree view of the fire ground.
Since the 21 March, crews were waiting for the transformer to cool to required levels before cutting through the steel casing to reach and extinguish pockets of fire that were inaccessible.
After working closely with scientific advisors, the Brigade has confirmed that as a result of the fire, oil levels were either very low or completely gone. This allowed crews to adopt a more aggressive firefighting approach rather than further intermittent cooling.
Meanwhile, a waste management company was working alongside partners to dispose of oil and water to minimise any environmental impact.
To better understand where the remaining fires were, the Brigade’s drone team was redeployed to help assess the situation through the use of both video and thermal imaging from above.
Crews then strategically set up ground monitors and branches, allowing water to be directed exactly where it was needed to fully extinguish the fire on Wednesday, 26 March.
Further investigation
London Fire Brigade Fire Investigation Officers have worked closely with the Metropolitan Police Service to investigate the cause of the fire, who confirmed they are not treating the fire as suspicious. The Brigade is leading the fire investigation and this will focus on the electrical equipment.
To support the fire investigation, firefighters will maintain a presence at the scene throughout the investigation process.
Additionally, the Brigade is the enforcing authority for the Regulatory Reform (Fire Safety) Order 2005 and has therefore had Fire Safety Officers at the scene to follow up various lines of enquiry.
Deputy Commissioner, London Fire Brigade, Jonathan Smith’s statement
Commenting on the incident, London Fire Brigade Deputy Commissioner Jonathan Smith said: “At 23:23 on the evening of 20 March, London Fire Brigade received the first of 212 calls to a fire in a high voltage substation near Heathrow Airport.
“The first appliance was on scene within five minutes of mobilisation. The Brigade was in close contact with blue light partners overnight, and at 00:42 the Metropolitan Police declared a major incident.
“Ten fire engines, two Bulk Foam Units and one High Volume Pump were on scene at the peak of the incident – this equates to approximately 70 London Fire Brigade personnel.
“Our firefighters worked tirelessly in challenging and hazardous conditions overnight to bring the fire under control as swiftly as possible.
“Firefighters safely evacuated 29 people from neighbouring properties, and as a precaution, a 200-metre cordon was established. Working with the Met police, around 150 people were evacuated. There were no reports of any injuries.
“I would like to take this opportunity to thank firefighters, Control officers and staff for their courage and professionalism in bringing this incident under control in what were very challenging circumstances.”
The London Fire Brigade has announced that the electrical substation fire in Hayes is fully extinguished: Summary
The fire in a high-voltage substation near Heathrow Airport, which began on the evening of 20 March, has been fully extinguished, announce the London Fire Brigade.