Search-and-Rescue Robots Tested at New York Disaster Site

Bijal P. Trivedi
for National Geographic Today
September 14, 2001
Three experimental robots, each about the size of a shoebox, are being used to search for victims in the mountain of rubble that was once the World Trade Center in New York City.

Researcher Robin Murphy and three of her graduate students have been clambering over the jagged piles of debris—powdered concrete and twisted steel—with the camera-carrying robots, lowering them into voids that are inaccessible to people, dogs, and other cameras involved in the search for bodies.

"So far the robots haven't found a survivor," said engineering professor Robin Murphy of the University of South Florida, who is developing the robots specifically for urban search and rescue missions.

"We've only seen body parts and bloody splotches," said Murphy. "At this point we don't have much hope. We are trying to find remains so that they can be handled with dignity."

Urgent Response

All of the robots have microphones to detect voices or other sounds of possible human presence within the ruins. Some of the robots carry thermal cameras that can detect body heat; others have cameras that search for colors distinctive from the gray dust that has blanketed the debris.

"Everything is gray and computers are really good at looking for color," said Murphy. "A tiny dot of red, whether it is fabric or blood, can be easily identified and used to alert a rescue team."

Murphy said that in most cases, rescue workers need to retrieve victims within about 48 hours. "After that it is pretty much a recovery mission," she said. In this disaster, she added, many hours passed before large numbers of human rescuers were able to begin searching for victims.

That situation, Murphy explained, illustrates why there is a need for search-and-rescue robots that are small, cheap, and light. Hundreds of them could be released immediately after a disaster in which the conditions are too dangerous for people and dogs to begin searching for victims.

Limited Use So Far

When Murphy and her students drove up from Florida—an 18-hour drive—just hours after word of the attacks in New York City, they carried about eight different robot models with them.

The researchers found that most of the robots were not yet sophisticated enough to roam the rubble. Some were too big and heavy to maneuver the terrain. The "hot zone" of the rubble is in vertical piles, which the robots are not capable of climbing, Murphy noted.

In this disaster, officials have found that even dogs trained for search and rescue have not been able to climb across much of the debris, and the dust-laden air has diminished the dogs' keen sense of smell.

The experimental robots that did prove useful in New York look like mini-tanks with treads. Using a device similar to a joystick, Murphy can direct the small machines to wiggle, crawl, and travel into voids as deep as 30 feet (10 meters).

Murphy said the experimental robots have had "no real impact" on the rescue mission in part because there are so few of them. "It's like one guy showing up to a construction site with six nail guns. You need everybody to have a nail gun to make an impact," she said. "This is truly like finding needles in a haystack."

Instead, the simplest kind of technology—"bucket brigades"—has been one of the most effective search techniques at the World Trade Center site. Hundreds of rescue workers are removing rubble by passing buckets of it from hand to hand.

The experience in New York, however, gives Murphy and other engineers insights that can help them design search-and-rescue robots that are smarter, faster, and more independent, which is critical in most disasters.

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