NIST studies survival in wrecked buildings
- By William Jackson
- Feb 27, 2004
National Institute of Standards and Technology researchers recently wired a New Orleans demolition project for sound, looking for ways to help first responders find survivors of building disasters.
The work, funded by the Justice Department's Office of Law Enforcement Standards, grew out of communications glitches during the Sept. 11, 2001, collapse of the World Trade Center in New York. Emergency personnel outside the buildings could not communicate with those inside.
'We've learned that communications are not 100 percent reliable' during a structural collapse, said Dennis Friday, chief of NIST's Electromagnetics Division in Boulder, Colo. 'People often survive in voids of a building. In 2004, most people have cell phones, and police and firefighters all have walkie-talkies, so the chances of somebody being able to communicate are pretty good.'
But the chances that somebody on the outside will hear them are slimmer. Cell phones probably could not reach a base station through wreckage, and radio signals probably would not be strong enough to penetrate rubble.
The division's 100 researchers study magnetic media for both communications and storage. They worked with police and fire departments during exercises and at the sites of last year's western wildfires to define limits of current radio communications.
'Then came the fun part,' Friday said.
They worked with Dykon Explosive Demolition Co. of Tulsa, Okla., and D.H. Griffin Wrecking Co. Inc. of Greensboro, N.C., to bring down the infamous William J. Fischer public-housing complex in the Algiers section of New Orleans last month.
'We placed 14 transmitters in the building,' Friday said.
The demolition experts suggested locations where victims might survive after a collapse. They programmed transmitters to operate on law enforcement frequencies and packaged them in rugged containers with cooling fans and long-life batteries to keep them working.
The researchers measured signal strength from positions around the complex. Then they imploded the building.
'Of the 14 transmitters, 10 survived,' Friday said. In follow-up measurements, the researchers were surprised that so many transmitters kept working.
'This was the first exploratory research,' Friday said. It could help future first responders detect and locate radio and cell phone signals in wreckage.
'We probably have enough money for two, maybe three of these implosions,' Friday said. A second demolition project is tentatively scheduled for late March.
William Jackson is a Maryland-based freelance writer.