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9-11 sparks new thinking on elevators in emergencies

27 august 2011, 13:52
0
©RIA Novosti
©RIA Novosti
An elevator was a terrifying and deadly place to be on September 11, 2001, but the attacks led to a new push for skyscraper safety and the design of futuristic evacuation systems that could work better in a disaster, AFP reports.

The World Trade Center elevators are believed to have trapped about 200 of the nearly 3,000 people who perished, a glaring exception to an otherwise successful evacuation that saw 99 percent of those below the impact zone get out alive before the towers collapsed.

While the current advice to take the stairs in case of a fire still reigns in most places across the world, a few tall buildings have started to adopt new features to allow for safer, quicker exit by elevator during an emergency.

The modern designs incorporate knowledge of human psychology with safety additions to make elevators that get people out fast and allow emergency responders better access to upper floors in a hurry.

"Very tall buildings have never been designed to be totally evacuated, the idea being that you would get people out of several floors near the fire but everyone else was safe where they were," said fire protection consultant Richard Bukowski.

"Up to 9-11, that theory worked fairly well."

Many of the World Trade Center elevators jammed or malfunctioned, and Harry Waizer, a tax lawyer at Cantor Fitzgerald, was one of the few who was lucky enough to escape on the morning of 9-11.

He was ascending between the 78th and 101st floors of tower one when the plane struck, sending his elevator car plummeting.

A fireball blew in and scorched his head and neck. He inhaled blazing jet fuel, and was badly burned on his arms and legs as he tried to beat back the flames.

The elevator fell to a stop at the 78th floor. The doors opened about a foot (30 centimeters) above the landing, and Waizer was able to jump out and walk down the stairs along with the other evacuees.

"It is not an experience to be repeated," said Waizer, now 60, who was initially given a five percent chance of survival due to the extent of his injuries.

Had the towers been filled to capacity, it would have taken nearly four hours to evacuate them, experts say. But both fell in under two hours, killing 343 firefighters who were attempting to climb to the upper floors to extinguish the fire along with scores of police and other first responders.

"It was that kind of situation that caused us at NIST (National Institute of Standards and Technology) to go to the elevator people and say, 'We have got to figure out a way to make these safe,'" Bukowski said.

After much study and debate, changes to building codes for US high-rises were made in 2009, calling for emergency power sources to operate the elevators if electricity is lost, mandatory sprinkler systems and enclosed lobbies around the elevators to keep out fire and smoke.

Bukowski said changes to the elevator code are still being hammered out and should be done by 2013.

Some key changes will likely include a recognizable symbol to show whether the elevators are safe for exit or not, and improved two-way communication systems from elevators to the Fire Department.

According to sociologist and NIST fire protection engineer Erica Kuligowski, evacuation systems of the future should no longer rely solely on the fire alarm to urge people to leave.

"Just an alarm bell isn't enough. You need to provide them an emergency message that tells them what's going on, and what they need to do about it," she said.

Kuligowski took part in a meeting of experts near the US capital earlier this year to share the latest findings on how to adapt evacuation systems according to human psychology during an emergency.

Panic is not usually a problem because of a phenomenon called normalcy bias, explained Ai Sekiwaza, an expert with Japan's National Research Institute of Fire and Disaster.

"People, including experts, want to underestimate situations even though they feel something wrong is happening," he told AFP while in the United States for the conference.

"When an alarm bell rings, most people think it is a false alarm," he said. "In almost all fatal fire incidents, the bulk of fatalities are from people who neglect to pay attention to the alarm."

Kuligowski said efforts are underway at NIST to improve the delivery of emergency messages in building fires, so that occupants would hear a spoken message over an intercom from a trusted source like a fire chief, who would in urgent tones tell them they need to leave the building immediately.

In addition to improved speeds, elevators in new skyscrapers would be installed next to stairwell exits so that if conditions change, people could go straight to the stairs.

Modern elevator evacuation protocols are already in place in some skycrapers around the world, including the Stratosphere Tower in Las Vegas, the Petronas Towers in Kuala Lumpur, and Taipei 101 in Taiwan.

But one thing that will not change in the United States is the mechanism that keeps elevator doors closed in between floors.

The devices, known as door restrictors, began being installed in the 1980s to keep people from attempting to jump out if their elevator became stuck between floors.

According to government data about 27 people die annually by trying such exits and falling down the elevator shaft. So the door restrictors will stay, said Bukowski, despite efforts by some 9-11 victims' groups to change those regulations.

"The thought that we could have been trapped in that elevator, unable to get out, is just awful," said Waizer, who has returned to work part-time in a new building where he regularly takes an elevator to his office on the seventh floor.

"I would happily never go in one again but they are a very difficult-to-avoid fact of life if you work in Manhattan," he said.


By Kerry Sheridan

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