Firefighting goes high-tech

Science World, March 21, 1997 by Emily Costello

The emergency call rings at the Bethesda-Chavey Chase Rescue Squad. A house on Lindale Drive in Bethesda is on fire. Flames are leaping through the windows. A man may be trapped inside.

Jeff Hearle and his fellow fire-fighters grab their equipment, climb into the truck, and race to the scene. By the time they arrive, the house is filled with blinding black smoke. Hearle sums on his equipment and heads into the fire....

Fire kills someone in the United States about once every two hours. And last Year, almost 100 firefighters were killed on the job. But new firefighting gear -- high-tech clothing, ropes, hoses, and helmets -- is making firefighting safer and more successful. Here's a look at some of the gadgets that might help firefighters save your life -- and theirs.

WHERE THERE'S SMOKE...

Firefighter Jeff Hearle was lucky that January day. Traditionally firefighters locate victims in heavy smoke by blindly sweeping their hands along the floor. But that method is slow and dangerous. Instead, Hearle was outfitted with a new high-tech, vision-enhancing helmet: the Cairns Infrared Imaging System (IRIS).

The IRIS consists of a flip-down display that fits over a firefighter's eyes, and a small black-and-white camera attached to one side of the helmet. Instead of recording visible light, this camera records low-energy infrared rays -- light waves too long to be seen bY the human eye. In other words, the camera records images of heat.

The infrared camera can "see" differences in temperature as small as half a degree. Fire looks white on the video screen; people stand out as relatively "cool" dark outlines. That makes it easy for firefighters to see -- and save -- people hidden by smoke.

"The IRIS gives firefighters their vision back," says George Bachelor, who works for the company that developed the system. While wearing the IRIS, firefighter Hearle was able to spot 40-year-old Guy Tayrien, who had passed out on his kitchen floor. Hearle and his crew carried Tayrien to safety.

FIREFIGHTER FASHION

Even with the latest "heat-imaging" helmets, walking into a fire is dangerous. So firefighters suit up in pants and jackets made from Nomex fiber. This "super yam" won't burst into flame, even in temperatures up to 371 [degrees] C (700 [degrees] F).

The material's resistance to heat, however, has created a new problem. Suited-up firefighters have a tough time telling when they're exposed to life-threatening heat. The result: More firefighters than ever are suffering from bum injuries.

So firefighters nationwide may soon be donning SmartCoats, coats rigged to warn firefighters when a fire is getting too hot, says John Cole of SunnyCor Inc., based in Washington, Connecticut. Here's how the "smart coats" work:

Each coat has silicone-capped sensors in the chest upper arms, and upper back. Every five seconds, each sensor sends a signal to a microprocessor (computer chip) tucked away in the coat's lining. The microprocessor calculates how fast the temperature inside the coat is rising. When the temperature approaches 65[degrees] C (150 [degrees] F) -- slight'y below the temperature that would cause blistering second-degree burns -- the microprocessor sounds an alarm. That gives firefighters time to get out of the fire safely.

LET THEM BE . . . ROPE?

Getting out of a smoke-filled building isn't easy. Firefighters usually use fire-resistant nylon or Kevlar rope to mark the path they've taken into a fire. That way they can retrace the path to safety. One problem: Drop the rope and you may never find it again ... unless the rope glows.

That's why engineers at FlexLight in Edison, New Jersey, designed LiteLine -- a kind of long, skinny flexible flashlight. The "rope" is made of a series of tiny bulbs covered in tough, see-through plastic. The light can withstand immersion in water, and it won't melt, even in temperatures up to 232 [degrees] C (450 [degrees] F). And if flame does melt through the rope, the rope stays lit from the melting point back to the power source.

For firefighters, "it's like bread crumbs in the forest," says Paul Manley, Flexlite's president. Talk about bright ideas!

TARGETED SPLASH

Soon, firefighters may not have to enter burning buildings at all, Scott Kelly, a spokesperson for Charge Injection in Monmouth Junction, New Jersey. His company is designing a new nozzle that win enable firefighters to douse flames from as far as nine meters (30 feet).

The high-tech nozzle is called the Spraytron Gun. It shoots water that's been exposed to a stream of negatively charged electrons, Kelly says. The electrons attach themselves to the water and give it a negative charge. The negatively charged water droplets repel one another and break up into a fine mist.

The charge also makes water from the Spraytron gun home in on fire -- even under tables and in hard-to-reach places. Like an electric current, the charged water droplets seek out the ground, or any object -- like fire -- attached to it. So fire-fighters don't have to crawl into a burning room and aim the spray. Instead, they can slip the nozzle into the fire -- and wait while it does the hard work!