The latest firefighting technology isn't exactly rocket science: triple-strength dishwashing soap mixed with water and spewed in a shaving cream-like lather of compressed-air foam.
But last week, it was enough to save dozens of homes threatened by wildfires raging across Southern California.
Firefighters foamed house after house in advance of the approaching flames. It was a dramatic demonstration of a tool that has been around for years but is only slowly gaining acceptance.
"The houses would have burned without that foam on it, no doubt about it," said Brea Fire Capt. Gregg Lewis, whose crews were assigned to Simi Valley. "I have been in this business 23 years and I have never seen anything work quite so well."
Less than 5% of all new firetrucks are armed with compressed-air foam systems, which firefighters call CAFS, but the number is rising.
Los Angeles County has 19 engines equipped with the foam, as do several cities in the region, including Alhambra, La Verne and Highland.
Phoenix has 30 foam-equipped engines -- about two-thirds of its fleet -- and expects to convert the rest over the next five years. And in Texas, a state law requires insurance companies to give homeowners a reduced rate if they live in cities protected by departments with CAFS.
"You save people's homes. It's hard to argue," said Bob Khan, assistant fire chief in Phoenix.
"Down the road, it will just become part of the apparatus. You're going to have automatic transmission. You're going to have air-conditioning. You'll have power steering. And you're going to have a CAF system."
The foam is about 99% water and less than 1% of a highly concentrated soap solution. The firetrucks are stocked with a water tank, a water pump, a foam injector and a large air compressor system. The soap concentrate and water are mixed, then air is injected. The foam develops as the soapy water travels through the hose at high velocity, creating tiny bubbles that look like shaving cream.
Compressed-air foam works better than water because it clings to a surface, quickly soaking it, and reflects radiant heat. It also conserves water and can coat a house for about an hour.
Fire officials know it's not a panacea, but under the right conditions it can be used to protect homes under threat of fire and to quickly squelch flames.
Firefighters saved the 500-acre ranch of Kentucky Derby-winning horse trainer Jack Van Berg in San Bernardino County's Summit Valley. The fire came so close, Van Berg said, that he was sure his ranch would be lost, but firefighters coated his barn and a dozen adjacent wood buildings with foam, and all were spared.
In Simi Valley, firefighters used the same "foam and go" technique to protect houses there.
"They foamed my house and the people next door to me, both sides," said Judy Towner of Fillmore. "They're all still standing. They did a great job."
In the mid-1980s, the U.S. Forest Service and other forestry agencies began fighting wild land fires with foam to conserve the amount of water carried, said Tom High, product coordinator for Pierce Manufacturing, one of a few CAFS manufacturers.
"The wild land guys started to think, if it works on wood and grass out in the woods, why wouldn't work on the stuff in a house?" High said.
Since then, foam and firetruck manufacturers have been refining the foam-delivery system, making it less bulky, more reliable and more user-friendly. At the same time, they've been bringing the cost down -- though it can still add $30,000 or $40,000 per fire engine, a price that has deterred many cash-strapped cities from making the switch.
High and Geary Roberts, president of another manufacturer, Pneumax, said one of the biggest challenges is persuading fire departments to consider the new technology.
"The fire service in the United States is very traditional," Roberts said. "They look at any new technology kind of with a jaundiced eye. They want to wait until the fire department next door is the guinea pig. That's why it's taken so long."
In the last three years, though, CAFS sales for Pneumax have doubled. And this year's sales are already up 25% over last year. High said much the same: "Our increase in CAFS sales have just gone through the roof. We sold 125 CAF systems last year. Three years ago, we sold two."
Their growing sales are in cities such as Brea, which buy one or two trucks installed with the system, then decide they want more. The Brea Fire Department will ask the City Council for funding to install the system on more engines.
"We were all impressed," said Lewis, the Brea fire captain. "We knew it would do something, but we didn't realize how well it worked."