By Paul Shapiro

Dividing this flow by the two handlines means that each line should be able to flow 150 gpm. Is your department currently meeting this standard? What would you say if I told you that it is possible for that initial 1¾-inch attack line to flow up to 240 gpm with two firefighters and is no harder to use than a 150-gpm attack line with a 100-pound-per-square-inch (psi) nozzle pressure (NP)?

Over the past several years there has been a push to lower the NP on handlines to make them more user-friendly for firefighters. The main focus has been on 100-psi combination nozzles and their nozzle reaction, especially with higher flows. Some departments that use 100-psi nozzles actually keep the flows as low as 100 gpm to make the handlines more manageable. Doing this corrects the handling issues. However, it comes at a cost by creating inferior flows. Remember-the minimum flow is 150 gpm. This article is going to show how a low-pressure nozzle in conjunction with proper hose-handling techniques can allow for an increased flow of 240 gpm using a 1¾-inch handline with an increase in nozzle reaction by no more than five pounds over nozzles flowing 150 gpm with 100-psi NP.

Before I cover how to accomplish this feat, consider the four main characteristics an interior attack line must possess: hose performance, nozzle performance, kink resistance, maneuverability.

Hose Performance

1 There are basically two types of 1¾-inch hose: that which specs out to exactly 1¾ inches and one that is slightly larger at 17⁄8 inches. Shown here, with 1¾-inch on the left and 17⁄8-inch on the right, they look almost identical. However, the 17⁄8-inch hoseline's friction loss is 20 psi less than 1¾-inch hose. (Photos by author.)

When 1¾-inch hose was first introduced back in the 1970s, its claim to fame by the hose peddlers was that it could take the place of 2½-inch hose in terms of handline flow capabilities. In those days, most 2½-inch handlines were only flowing 250 gpm, and folks were told that the 1¾-inch hose would also flow 250 gpm. What they neglected to tell firefighters was that the pump discharge pressure had to be high to move the 250 gpm with the smaller hose.

Here's an example of what firefighters saw when they tried to flow 250 gpm through the 1¾-inch hose. With their 2½-inch lines, the average pump pressures were between 80 and 150 psi, depending on the length of the line and the type of nozzle they used. When they tried to pump 250 gpm through their 1¾-inch lines, they were developing pressures easily greater than 200 psi and sometimes pushing 250 psi. This was the trade-off for using the smaller-diameter hose.

Fire hose manufacturing has come a long way since the 1970s in improving hose quality, which in turn has lowered the friction loss (FL) numbers. So, what is the FL now?

There are two basic types of 1¾-inch hose in the industry. The first specs out to a true 1¾-inch-diameter dimension. Based on a 240-gpm flow, FL in this hose is between 60 and 70 psi per 100 feet. Keep in mind that these numbers are only approximate. To come up with exact numbers, it is important to do flow tests on the hose your department uses. Based on a 200-foot hand-line flowing 240 gpm, its FL

Grady North

Although there are several firefighting methods unique to ARFF situations, there are also many similarities. Here is an overview of ARFF fire suppression techniques, many of which apply equally well to municipal or wildland tactics.

History

In 1962, the Federal Aviation Administration (FAA), then known as the National Aviation Facility and Experimental Center, and the Naval Research Lab at China Lake conducted extensive research. The tests established the turret performance standards of the National Fire Protection Association (NFPA), the FAA, and the International Civil Aviation Organization that are still in use today. At the time of the tests, protein foam and manually operated air-aspirated turrets were the technology of the day.

Even though turret technology and foam agents have changed, techniques developed in the 1960s' testing are often used today. Rain drop is a term used to describe raining foam down on the fire from a distance. The protein foams of the time dictated this technique. Protein foam has very little burn-back resistance. If the foam cover breaks, the exposed fuel can quickly reignite. The rain drop technique allows firefighters to build up a thick foam blanket on the fuel without disturbing the surface.

AFFF Foam

In the mid 1960s, the United States Navy developed aqueous film forming foam (AFFF). This synthetic foam has a low viscosity and spreads rapidly across the surface of most hydrocarbon fuels. A water film forms beneath the foam and cools the liquid fuel, which stops the formation of flammable vapors. This provides dramatic fire knockdown, an important factor in crash rescue firefighting. As a result, techniques in firefighting are changing, with more emphasis on low attack-bumper turrets and ground sweep nozzles-that can spread the foam across the fire's surface at a low angle instead of with the rain drop technique. The advantages of AFFF are that it is readily available around the world, and proportioning systems are inexpensive and simple to operate. The disadvantage is that it is recognized as environmentally unfriendly. There can be restrictions placed on performance testing, although closed-loop foam testing systems have been recently developed.

Compressed Air Foam

The forestry service initially developed compressed air foam systems (CAFS) as a method to provide maximum coverage of the fire area with a minimum amount of water. CAFS uses pressurized air injected into a water and foam solution to expand the foam many times more than a conventional AFFF nozzle, which relies on mechanically mixing ambient air with the water and foam solution at the nozzle. As a result, compressed air foam (CAF) has more of a shaving cream consistency than conventional AFFF. This characteristic allows the foam to cling to vertical surfaces to provide a long-lasting insulating effect. Foam blankets typically have very long drain-back times, keeping fuel vapors in check for extended time periods. Because of the higher expansion ratios, personnel need less water than they need to create an equivalent amount of AFFF. The pressurized air source can be supplied by stored air (pressurized air cylinders) or by air compressors.

The advantages of CAF include a superior foam blanket with low amounts of water. Handlines are very lightweight as the hose is full of expanded foam instead of liquid. Air injection provides energy to the foam solution, resulting in excellent discharge distances at relatively low liquid flow rates.

Disadvantages include the need fo

By Alan M. Petrillo

Changing Designs

1 Oshkosh's latest ARFF product is the Striker, which has an electronic foam proportioning system and is available with a Snozzle 501 HRET with a piercing nozzle. (Photo courtesy of Oshkosh.)

Marty Huffman, Rosenbauer's ARFF regional manager, says Rosenbauer has made substantial improvements and modifications to its signature Panther ARFF truck, which is made in 4x4, 6x6, and 8x8 versions. "While the basic structure of the Panther has remained the same, we have made improvements in the cab and its layout, instrumentation, and control systems like our Logic control system that can be used to integrate chassis and pump controls into one easy-to-use box," Huffman says.

The Panther models use Rosenbauer's R600 1,850-gallon-per-minute (gpm) pump, which has a stainless steel pump shaft borne by triple roller bearings where the main bearings run in an oil bath in the gear box to make them maintenance-free. The Panther also uses the RVMA500 mechanical, automatic around-the-pump foam proportioning system and is available with three different turret configurations.

Steve Schwartz, director of customer support for Oshkosh, says his company completed a redesign of its Striker ARFF unit in 2001 to meet both high-pressure water discharge and ultra-high-pressure (UHP) water discharge requirements, as well as to support stored air compressed air foam systems (CAFS).

Adam Graves, ARFF product manager for KME, says his company has redesigned and reengineered its Legacy ARFF product "going back to our own design of an aluminum cab and body. There also are internal changes to the vehicle where we've updated it, so it can be modern and still be tough." Graves notes the aluminum cab and body make the vehicle lighter and more maneuverable.

2 The Burbank-Glendale-Pasadena (CA) Airport Authority purchased this Rosenbauer Panther 4x4 ARFF truck that carries a 1,500-gallon water tank and is set up to run a CAFS that uses stored air cylinders instead of an air compressor. (Photo courtesy of Burbank-Glendale-Pasadena Airport Authority.)

Compressed Air Foam

CAFS are finding uses on ARFF vehicles, Huffman says. Rosenbauer has built ARFF units for the Ottawa International Airport that have compressed air foam available through their turrets. "It's FlashCAFS technology-a stored energy system and not your typical CAFS compressor on a vehicle," Huffman points out. "You have stored air bottles that are able to make three percent or six percent compressed air foam with a certain number of gallons of water."

Rosenbauer also built a Panther 4x4 ARFF truck for Burbank-Glendale-Pasadena (CA) Airport Authority, according to Marc Domingo, a fire captain with the Airport Authority. "We were the first department to put CAFS on an ARFF truck for an Index C airport in California," Domingo says. "We have it on our 2012 Panther with a 1,500-gallon water tan

Chris McLoone

It was built between 1898 and 1900 by P.A.B. Widener to house three generations of his family and what is now a priceless art collection under one roof. The greater than 30-acre tract has a second, smaller mansion; a gate house; and the 110-room monster, which has fallen into disrepair through the years as it has sat vacant with a sole caretaker trying to maintain the grounds. The owner finally put the complex up for sale recently for $20 million.

I've been fascinated by this house for many years, and when it went up for sale, I visited the realtor's Web site hoping to get a glimpse of the inside through online images. There were only three exterior shots but also a video captured by a drone. I thought that was a pretty cool application for the drones that are now on the market, especially for a 34-acre tract of land to give potential buyers an idea of the scope of their purchase.

What the above example means, however, is that drones are becoming more accessible to civilians. Seen more as a toy probably than anything else, these units are probably not as sophisticated as the ones we have seen around the trade show circuit in recent years, but they are available, and citizens are using them for any number of reasons-some good and some probably not so good.

Regardless of the intent, we need to be aware that they are available to a much wider group of people than in the recent past and their use will impact our fireground operations. In recent years, we've had to adapt to the smartphone proliferation and how instantly people can share what's happening anywhere at any time. It's not so easy to put up yellow caution tape in the sky, however, to keep bystanders back behind the lines. Drone use is so new, it is hard to establish procedures. We were really just figuring out how to integrate their use into our own operations. Wildfires are a good application, as well as industrial fires. But, what happens when someone else wants to get a bird's-eye view? There's actually a case in point for that.

In California recently, a bystander using a drone to get a better view of a wildfire almost hampered firefighting efforts. Luckily, personnel spotted the unmanned aircraft and directed its owner to stop using it before it posed a danger to firefighting planes. Moving forward, we all must keep the potential for these aircraft in the back of our minds. It's not hard to imagine a department using its drone at an industrial fire only to have a civilian-operated unit crash into it. We're used to listening for helicopters. Now we need to keep our ears open for the sound of drones in the sky.

The California example isn't the only one. A bystander used one in New York a few months ago after an explosion and fire until the police department told him to stop. There is also footage from a Detroit, Michigan, fire captured by a drone and available on Internet video services.

Do our jurisdictions have any ordinances regarding using these? We need to look into it. Controlling civilian use is one aspect, but we need to make sure we are not violating any local ordinances if we decide to purchase them to add to our firefighting arsenal. My guess is there aren't many municipalities that have enacted anything. So, we are in uncharted waters. It used to be that we worried more about people on the ground with cell phones recording and instantly sharing incidents via social media or sending immediately to news outlets. It's gotten almost comical in some respects as we wonder aloud why people are recordi