Investigators have combed the burnt remains of an electrical substation near the London Heathrow airport on Friday, seeking the cause of a spectacular fire that closed the most frequented travel center in Europe for a large part and raised wider questions about British energy infrastructure.
Energy officials and experts said that a fault in a transformer with 275,000 volts that crossed it probably sparked a solid oil fire which cut the airport and tens of thousands of houses neighboring the electricity network. The systems designed to prevent such a fire has apparently failed, and the size of the fire seemed to prevent a second transformer close to restoring electricity.
But the mystery of what caused this fault in the first place remained far from being resolved at the end of the day on Friday, even though the flights resumed in Heathrow.
London metropolitan police said that specialists in the fight against terrorism had taken care of the investigation: “Given the site of the substation and the impact that this incident had on critical national infrastructures.” At the same time, political leaders and industry experts said that it most likely seemed that the fire was an accident.
The two possibilities left residents of Great Britain and the world’s shaken travelers.
If a malicious adversary can so considerably disrupted world trips by causing a fire in a power plant in the neighborhood, he raises new concerns concerning the capacity of open companies such as Great Britain to protect himself against such non-traditional attacks.
And if the fire was the result of an unteashed weakness in the basic infrastructure of the British electrical network, the scope of chaos that has been triggered could undermine confidence in the country’s ability to fix the ruin systems at a time when finances are already tense.
Prime Minister Keir Starmer and Sadiq Khan, the mayor of London, sought to reassure residents and travelers on Friday, with Mr. Khan saying to Sky News in an interview that despite the participation of officers to fight terrorism in the investigation, there was “no reason for anyone who was concerned or alarmed”.
Friday, London police also played the possibility of an unfair game, affirming in a press release that after an initial assessment, they “do not deal with this incident as a suspect, although the surveys remain underway”.
However, neither the Prime Minister nor the Mayor has offered answers to some of the urgent questions posed by frustrated travelers, nervous neighbors of the airport and political leaders across the country.
Why did the airport not have enough electric backups? Didn’t electrical utility provide for the possibility of such a fire, either from sabotage or technical dysfunction? Do the main airports generally have backup systems that can feed the entire operation, or are they based on a main energy source?
John McDonnell, a legislator who represents Hayes, the area where the fire broke out, said that any investigation undertaken in the coming days will have to examine “why the safeguard arrangements had not worked”.
“There are lessons that must be learned here,” he told journalists on Friday afternoon.
At the beginning of the afternoon Friday, the British national network said that the North Hyde sub-station network, where the fire occurred, had been reconfigured to restore energy to the airport and the neighborhood, calling it a “provisional solution” during repairs. National GRID officials did not respond to an email requesting information on the incident.
This announcement paved the way for a partial opening of the airport, where the first flights started to land by the evening.
“We are now going to work with airlines to repatriate passengers who have been diverted to other European airports,” airport officials said in a statement. “We hope to perform a complete operation tomorrow.”
But even if Heathrow tries to return to normal operations, a feeling of uncertainty remains.
Ed Miliband, British energy secretary, said in an interview early Friday with Sky News that the fire of the electric sub-station which paralyzed Heathrow airport also withdrawn at least one of the main backup systems designed to maintain electricity on the move.
“There was a safeguard generator, but it was also affected by the fire, which gives an idea of ​​how it was unusual, unprecedented,” said Miliband.
Transformers convert the current from one voltage to another and are often filled with oil which acts both as insulation and coolant. The types of oil used can withstand high temperatures, but they can ignite if they become hot enough.
In the case of the transformer near Heathrow, the experts said that he would have transformed 275,000 volts into 66,000 volts when he apparently failed. Jonathan Smith, the deputy commissioner of the London Fire-Brigade, said that the fire involved “a transformer comprising 25,000 liters of cooling oil which was completely lit” to the substation.
The failure of at least one backup system to quickly restore electricity after such a major breakdown is likely to be at the center of the reliability of the British infrastructure following the fire and the airport closure.
The British National Infrastructure Commission, which makes recommendations to the government on the main infrastructure, said that the fire highlighted the need for better preparation for shocks and operators to strengthen resilience in their systems and carry out regular stress tests.
“We have been clear that the national resilience standards of the United Kingdom for our transport, digital, energy and water infrastructure,” said commission president John Armitt in a statement. “These will give clarity to operators and users on the service levels they should expect in the face of short and long-term disturbances, and ensure that regulators have a clear criterion against which they can guarantee that sufficient investments in resilience are made.”
In an article on social networks, Willie Walsh, Managing Director of International Air Transport Association, a global association of airlines, wrote: “How is the critical infrastructure – of national and global importance – depends completely on a single source of power without an alternative.”
“If this is the case-as it seems,” he added, “then it is a clear failure of the airport planning.”
In a press release, Heathrow’s airport said that the installation had “several energy sources” but that there was no backup which would provide enough electricity to exploit the whole airport, which, according to him, “uses as much energy as a small town”.
The press release indicates that rescue diesel generators and without interruption supplies have made a kick that would have allowed planes to land and passengers to disembark. But they would not have been sufficient to allow the airport to work fully.
Simon Gallagher, a former senior executive of the largest British electricity supplier, said that he thought that the under-station near Heathrow had been designed so that if the first transformer had a problem, a second could enter quickly. “Basically, we have designed things so that something could fail,” and the system can continue to work, he said.
But, he said, a certain number of things had to go wrong, apparently allowing the fire of rage through the prevention systems and to damage the two transformers.
It is very unusual, said Mr. Gallagher, who is now Managing Director of UK Networks Services, who advises customers on the resilience of their electricity networks.
Gallagher said that the emergency generator systems mentioned in the Heathrow Declaration have been designed to maintain track lights and control tower systems, even during an incident like the one that took place on Friday.
But it said that it would have been impossible to continue to land the planes, to jump an emergency, because there would have been no electricity to move the luggage, to turn on the terminals, to operate the doors and more. By its estimate, doing all this would require at least 20 massive diesel generators the size of 40 -foot shipping containers, each capable of generating a megawatt of power.
Heathrow does not have such a system, which would have been able to keep the energy at the whole airport flowing for about six hours before having to be supplied, he said. But he added that other large energy customers, such as data centers, had installed major backup generators to ensure energy in an emergency.
“I think things will change,” said Gallagher. “I think Heathrow and other airports will install the backup generation.”
