AFRL tests new firefighting technology

  • Published
  • By 2nd Lt. William Powell
  • 325th Fighter Wing Public Affairs
TYNDALL AIR FORCE BASE, Fla. (AFPN) --  A new method of extinguishing fires is currently being tested and may revolutionize the way the Air Force and the nation fight fires.

The Air Force Research Laboratory’s deployed base systems branch here has been developing new firefighting technology for nearly two years. Dubbed the ultra-high pressure system, the experiment combines high pressure with water and aqueous film-forming foam.

"We were looking at ways to combine carbon dioxide with water to make a more effective firefighting agent. High pressure is required to keep the carbon dioxide liquid, and we had to design a system that would allow us to operate at high pressures," said Dr. Doug Dierdorf, fire research group lead scientist.

The scientists found that water with the foam solution under ultra-high pressure is extremely effective at putting out fires, he said.

Normal firetrucks deliver firefighting agents, including water, at pressures ranging 100 to 250 pounds per square inch. Firetrucks retrofitted with the ultra-high pressure system deliver firefighting agents at 1,500 ppsi.

"Current firefighting systems use lower pressure and a higher flow of firefighting agent, as much as 500 to 700 gallons per minute," said 2nd Lt. Bob Johnson, fire research group project officer. "What we're offering is higher pressure and a lower flow, which uses only 200 gpm."

Ultimately, smaller amounts of water required to extinguish fires could result in smaller firetrucks; and light, lean and lethal vehicles are especially important in today's rapid globally mobile Air Force.

"This was a very timely discovery because during preparations for Operation Iraqi Freedom, the lab had been asked to try and help develop an air-droppable firefighting system," Dr. Dierdorf said. "We went into a high-speed development mode where we took an (ultra-high pressure system) and mounted it on an air-drop certified, six-wheeled all-terrain vehicle. The system was then immediately put into deployment mode in February 2003. It successfully fought a fire at Baghdad International Airport with only 50 gallons of water shortly after our first forces moved in to occupy the area."

The success of the specially equipped ATV motivated researchers to design a larger scale version as a primary firefighting tool for two reasons.

"First, our current deployable vehicle, the 1,000-gallon capacity P-19, basically fills a C-130 [Hercules]," Dr. Dierdorf said. "With 500 gallons and (the system), we are able to put out as much fire as we would with 1,500 gallons using a conventional firefighting system. This 3-to-1 advantage (could) give us a fire truck half the size of the P-19. Our goal is to put two vehicles on one C-130."

The other driving force behind the program is the collateral damage and high cost involved with applying the foam to large aircraft engines, which are very expensive to repair, Dr. Dierdorf said.

"The high-bypass turbofan engines on the C-17 [Globemaster III] cost roughly $14 million apiece; and a rebuild of one engine, if it's been exposed to (the foam), results in a bill of about $4 million," he said. "It turns out the high-pressure water gives us better penetration, better dispersion of water and helps us attack fires on the large-scale engines.”

While pure water and high pressure are not enough to suppress these fires, researchers found that adding two or three pounds of a gaseous clean agent will do the final extinguishing. The agent evaporates and avoids collateral damage to the engine during firefighting operations, he said.

The ultra-high pressure also changes the physical dynamics of the firefighting agent, further increasing its effectiveness.

"The (ultra-high pressure system) atomizes the agent into very fine droplets, which increases the agent's ability to absorb heat, thus improving its effectiveness," said Donald Warner, Air Force Fire and Emergency Services chief. "Efficiency is increased because less agent is required, which is very important in areas where water is scarce."

Additionally, smaller hoses should dramatically reduce the work effort for firefighters on the ground, who currently must fight fires while carrying very heavy hoses, Mr. Warner said.

All it takes to retrofit a vehicle are the new hoses, a special pump and a new nozzle, roughly one-tenth the size of existing nozzles.

"This technology is very exciting for those among us who worry about getting firetrucks anywhere in the world, rapidly," Mr. Warner said. "I believe this ultra-high pressure technology, though now in its infancy, will dramatically change the face of firefighting in the Air Force and perhaps the nation." (Courtesy of Air Education and Training Command News Service)