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The chief executive of the National Grid has confirmed power was available to keep Heathrow open throughout Friday’s shutdown.<\/p>\n
In an interview with the Financial Times, John Pettigrew said the fire that knocked out a substation was a “unique event”, but that two other substations remained operational and capable of powering the airport in west London.<\/p>\n
Heathrow chief executive Thomas Woldbye had said on Friday that the shutdown was not caused by a lack of power, but was due to the time it took to switch from the damaged substation to the other two.<\/p>\n
The airport is under pressure from airlines to explain why flights were suspended for 18 hours after the fire in the early hours of Friday morning.<\/p>\n<\/div>\n
The fire started in a transformer within the electrical substation in Hayes north of Heathrow around midnight.<\/p>\n
The airport has emergency back-up power supplies, which use diesel generators and batteries, but these only keep crucial safety systems running, such as landing equipment and runway lights.<\/p>\n
A separate biomass power generator also provides heat and electricity to Terminal Two.<\/p>\n
However, the National Grid is the main source of power for Heathrow.<\/p>\n
Mr Pettigrew told the Financial Times said he couldn’t remember a transformer failing to such an extent in his 30-year career in the industry.<\/p>\n
“Losing a substation is a unique event but there were two others available. That is a level of resilience.”<\/p>\n<\/div>\n
A Heathrow spokeswoman said that Mr Pettigrew’s comments “confirms that this was an unprecedented incident and that it would not have been possible for Heathrow to operate uninterrupted. <\/p>\n
“Hundreds of critical systems across the airport were required to be safely powered down and then safely and systematically rebooted,” she said.<\/p>\n
“Given Heathrow’s size and operational complexity, safely restarting operations after a disruption of this magnitude was a significant challenge.”<\/p>\n
On Friday, Heathrow managers decided to close the airport on the grounds of safety while they switched to the alternative National Grid supplies.<\/p>\n