Airport officers mentioned the closure was as a result of time it took to change to the opposite substations and make security checks.
“A whole lot of vital techniques throughout the airport have been required to be safely powered down after which safely and systematically rebooted,” a Heathrow Airport spokesperson mentioned.
“Given Heathrow’s dimension and operational complexity, safely restarting operations after a disruption of this magnitude was a major problem.”
Heathrow chief government Thomas Woldbye had mentioned a backup transformer failed, which means techniques needed to be closed so energy provides might be restructured from the 2 different substations.
The federal government has ordered a six-week investigation into the shutdown.
About 1,350 flights have been affected by Friday’s closure, in line with the Flightradar24 monitoring web site. Round 120 Heathrow-bound planes have been within the air when the closure was introduced and needed to be diverted.
Hearth officers have mentioned the blaze, which broke out on Thursday night time, was “believed to be non-suspicious” and that enquiries would “give attention to {the electrical} distribution gear”.
Requested on Monday about the way in which airport bosses dealt with the occasions, transport secretary Heidi Alexander mentioned: “I am not going to justify selections that Heathrow management did or did not take.”