How one fire froze Atlanta airport
Even redundant systems can fail, engineers say
How could one fire knock out the main power to Hartsfield-Jackson Atlanta International — the world’s busiest airport — and at the same time disable the backup power, snarling air travel in the United States during one of the busiest travel times of the year?
This is an airport, after all, that is supposedly among the most secure and locked-down facilities in a world where the threat of terrorism is an everyday reality.
The short answer, according to engineering experts, is nothing is 100% certain when it comes to secure sources of electricity.
“Engineers design systems for the likelihood of something happening,” said Christine Brotz, an engineer who is an instructor in the civil and architectural engineering and construction management department at the Milwaukee School of Engineering.
Her specialty is electrical system design for buildings.
“You can’t design for every eventuality,” Brotz said. “If we designed every system so that it could never, ever fail, it would be too expensive to build. So, there is always some compromise in design as far as the likelihood of something happening.”
What engineers don’t want to happen, known as a single point failure, appears to have occurred in Atlanta.
The head of Georgia Power Co. said the failure occurred because the power feeds from two sources — a redundancy built into the system in case one source failed — came together in one place at the airport.
That one place is where a fire occurred in an underground service tunnel bringing the airport to a standstill for 11 hours. The power outage resulted in 1,100 canceled flights Sunday and Monday, while an estimated 30,000 people were at the airport. Hundreds of people where stranded on aircraft on airport tarmacs for hours.
The airport, which is home to Delta Air Lines’ largest hub, continued to attempt to catch up on Tuesday.
“It could be most of the week” before displaced passengers can reach their destinations, because there aren’t many open seats on other flights in the last week before Christmas, said Robert Mann, an aviation consultant and former American Airlines executive.
Passengers described the scene Sunday at Atlanta’s airport as “a nightmare.”
Hartsfield-Jackson serves an average of 275,000 passengers daily,
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