Alan M. Petrillo
It’s not unusual these days to see a rescue vehicle carrying water and a pump, often called a rescue-pumper or a wet rescue. But frequently, such rescues have begun to be outfitted with compressed air foam systems (CAFS). It’s part of a developing trend that is seeing wider use of CAFS not only on rescue-pumpers but on traditional pumpers, urban interface vehicles, and wildland units.
Dan White, national sales manager for Spartan ERV’s Classic series, says that although most of the growth in CAFS use has been on wildland style units, it also is growing on the structural side of the fire apparatus industry. “CAFS is becoming more and more popular,” White says. “We’re seeing CAFS on about 40 percent of our wildland units, when three years ago that figure was about 25 percent. CAFS is becoming a required tool instead of something that’s simply a ‘want to have.’ “
(1) Darley’s family of CAFS products includes the EMBC, a two-
Spartan ERV has built traditional pumpers, rescue-pumpers, and even tankers with CAFS units, White maintains, and has a version of CAFS for its traditional rescues. “We built a compressor with a 100-gallon per minute (gpm) PTO-driven pump that can run one handline off of a 100-gallon water tank and a five-gallon foam tank. It doesn’t take up a lot of room on the truck body and if the rescue is first on the scene of a vehicle fire, for instance, it can do a quick knockdown on the fire if necessary.”
White points out that the typical Rapid CAFS unit that Spartan ERV builds is set up to handle any discharge that is plumbed as foam-capable. “Our standard 140-cubic feet per minute (cfm) compressor can generally handle two 1¾-inch discharges,” he notes. “We also make 200-cfm and 250-cfm CAFS units. You essentially can add one 1¾-inch line for each step up in a typical setup.”
The Rapid CAFS unit was developed, White says, to make the system easy to use. “We wanted it to be as simple as possible and not complicated at all,” he says. “Once you’re pumping water through a handline on the truck, it truly is a one-touch system.”
Effects on Design
Chad Trinkner, director of product development for aerials, pumpers, and fire suppression at Pierce Manufacturing Inc., says that between 20 and 25 percent of the various types of pumpers Pierce makes-traditional, rescue, and industrial-have a CAFS unit on them. “There’s a pretty good mix of the kinds of CAFS units going onto the vehicles,” Trinkner points out. “It’s about 50-50 of PTO to hydraulically driven units.”
(2) Hale Products has introduced its Smart
Pierce first started installing Hercules CAFS units on pumpers in 1999, Trinkner notes, with a 200-cfm PTO-driven unit located in the pump house. In 2002, Pierce developed a 140-cfm hydraulically driven CAFS unit located in the pumper’s dunnage area over the pump house, and in 2011 it came out with a 165-cfm PTO-driven unit located in the pump house. Locating a CAFS unit in the pump house, Trinkner points out, has one drawback. “A PTO-driven CAFS unit in the pump house increases the vehicle’s wheelbase by about four inches,” he says.
But Trinkner says that advocates of CAFS say the advantages outweigh the added cost and additional training needed to use CAFS. “A CAFS handline is much lighter to carry; there’s less stress on the firefighter, especially when used on multilevel structures; and the knockdown capabilities of CAFS are so much better than plain water,” Trinkner says.
Trinkner adds that Pierce will install CAFS units made by other manufacturers as well as its own proprietary system that it mates with its Husky foam system. “For instance, the Honolulu (HI) Fire Department is a huge advocate of CAFS for structural work,” Trinkner says. “All of their pumpers use Waterous pumps and Waterous CAFS on either Pierce Arrow XT or Pierce Quantum pumpers.”
Tradition or One Button?
Gregg Geske, product manager for foam and CAFS at Waterous, says his company makes both a traditional CAFS unit and a One Step CAFS. “With the traditional system, we balance air to water pressure, as do most traditional CAFS,” Geske says, “so you always are concerned about incoming water pressure to your engine pressure. With the One Step system, we keep the air pressure consistent and reduce the water pressure in relation to the air pressure through a pressure-release valve. Because the water pressure is reduced to all CAFS discharges, you don’t have to worry about different incoming water pressures.”
The Waterous One Step CAFS is available in 150- and 200-cfm units, with the larger output models generally used when CAFS is piped to a deck gun or other monitor. The standard CAFS offering by Waterous can provide for three handline discharges.
The traditional CAFS units Waterous builds, all PTO-driven systems, are available in 80-, 140-, and 200-cfm models. “In the last few years we’ve seen a downturn in CAFS use, mostly because of tightened budgets,” Geske observes. “CAFS and foam systems seem to be the first things cut, but CAFS will come back as budgets get bigger. Some people haven’t been using CAFS because of the ease-of-use issue, but we addressed those things with the One Step system where you press one button for wet foam or another for dry foam.”
(3) Waterous makes the One Step CAFS in 150- and
Geske notes the One Step CAFS is controlled by a touch screen panel, which Waterous intends to eventually use on its traditional CAFS units as well. “CAFS can be safer to use on structure fires,” Geske points out. “You can use an exterior attack to knock down the fire and then make entry when the visibility is better. Also, you get farther reach with CAFS and better penetration.”
Brian McKinney, chief of the Dallas Fort Worth (TX) International Airport Fire Department, points out that because his department protects not only aircraft but also numerous structures, CAFS is carried on all the aircraft rescue and firefighting (ARFF) vehicles and all structural pumpers. The department has six stations, four primarily ARFF, but with a combination of structural and ARFF vehicles, and two primarily structural and EMS stations.
For structural responses, the Dallas Fort Worth Airport has three Pierce pumpers, two Pierce 105-foot quints, and two Pierce 100-foot aerial platforms. All of the vehicles except the two platforms are fitted with Pierce’s 140-cfm Hercules CAFS units. Each carries 20 gallons of Class A foam and 30 gallons of Class B foam. The pumpers carry Pierce Darley 1,500-gpm pumps and 750-gallon water tanks; the quints, Hale Q-MAX 2,250-gpm pumps and 500-gallon water tanks; and the platforms, Hale Q-MAX 2,250-gpm pumps and 300-gallon water tanks.
Mark Jack, a Dallas Fort Worth Airport firefighter, says department firefighters like using CAFS. “It’s safer for the firefighter, the hose is lighter, and we use one-third less water,” Jack says. “We can put out a car fire without connecting to a hydrant or having another engine lay a line to us. The cooling effect of CAFS is better than straight water, and it has greater surface tension, more reach, and greater penetration.”
On structure fires, Jack notes that using CAFS “clears the smoke better and cools down the temperature more quickly to allow you to get to the seat of the fire.”
McKinney says Dallas Fort Worth Airport has a new fire training and research center that was commissioned in March of this year. “We will be testing CAFS and researching its use at the center,” he says, “and we’ll be investigating both Class A and Class B foams with its use.”
(4) The Dallas Fort Worth (TX) International Airport Fire
Troy Carothers, Darley’s CAFS product manager, says Darley’s Auto CAFS units are used “on many different fire apparatus applications-from traditional pumpers to rescue-pumpers to wildland to urban interface trucks.” He notes that besides the Auto CAFS where the vehicle pump is the driving force for the air compressor, Darley also makes PTO-driven pump and compressor systems typically used in wildland pump-and-roll applications.”
Darley makes the LDMBC pump, an L model midship pump with a double impeller that can be rated to 1,750 gpm while having a 220-cfm rotary screw air compressor. “That’s our flagship model that we’ve sold since 2002 and have mounted it on a variety of pumpers over the years,” Carothers says. “More recently we developed the EMBC, a two-stage 2,000-gpm stationery pump with a 220-cfm air compressor similar to the L pump with its own belt drive system off of an extended impeller.”
Darley’s family of CAFS products ranges from 500- to 2,000-gpm midship units as well as its PTO-driven wildland CAFS units.
Carothers points out that the Apopka (FL) Fire Department bought two Rosenbauer pumpers earlier this year fitted with three-stage Darley EMHBC pumps. “They will pump 2,000 gpm at 150 psi; 500 gpm at 600 psi; and, using the third stage, up to 150 gpm at 800 psi,” he says. “The CAFS is plumbed to five discharges that are capable up to 600 psi, and a booster pump can produce 800 psi to two hose reels.”
He notes that 90 to 95 percent of the fire departments that buy Darley CAFS units are specifically seeking to reduce the amount of water used fighting fires. “They’re using CAFS for structures, vehicle fires, and wildland,” Carothers says. “Using CAFS reduces the total flow of water to reach the target, so water damage reduction is very common.”
Michael A. Laskaris, P.E., director of engineering for Hale Products, says the premium part of Hale’s CAFS line is the CAFSPro, which has been produced for about the past ten years. The CAFSPro unit is the only system in the world that uses a closed-loop-flow air-proportioned measuring system, according to Laskaris, where both the air and the chemical mixed with the water are proportioned.
He notes, “We’ve now introduced Smart CAFS to the United States, made on the DSD and Q-MAX pumps, and all of them are midship products available in 210 cfm.” Smart CAFS has 50- and 210-cfm compressors under the Godiva Prima brand owned by Hale and under the Hale-branded DSD pump at 750 through 1,500 gpm. Both Smart CAFS and CAFSPro are available on the Q-MAX pump at 1,000 through 2,250 gpm.
“Typically we see both CAFSPro and Smart CAFS used on urban interface vehicles, structural pumpers, and industrial pumpers,” Laskaris says. “With CAFS, the chief benefits are the fire goes out quicker, firefighters use less water, there is less water damage, and there is enhanced firefighter safety because personnel spend less time in a hazardous environment.”
ALAN M. PETRILLO is a Tucson, Arizona-based freelance writer and is a member of the Fire Apparatus & Emergency Equipment editorial advisory board. He served 22 years with the Verdoy (NY) Fire Department, including in the position of chief.