By Richard Marinucci

It has been said that a chain is only as strong as its weakest link. Today's fire apparatus continue to evolve into more diverse vehicles with more parts and functions.

Having reliable components in all aspects of fire apparatus is extremely important for a variety of reasons. Most obvious is the need to keep vehicles in service to deliver the services expected by the taxpayers and public. As vehicles have more functions, parts, and components, the chances of something not working as intended increase. Departments need to do more to learn how these items interact and what is needed to keep them operating. Regardless of which component is not functioning properly, anything that takes a vehicle out of service affects performance.

Reliability

Consider everything that goes into a modern piece of fire apparatus. There are the obvious parts of the chassis such as brakes, transmissions, engines, and everything else contributing to moving the vehicle down the road. Like most vehicles today, not just those designed for the fire service, fire apparatus are not quite as easy to work on as those from years gone. I think today's vehicles are so much better and reliable than those in the past, are much easier to operate, and do more.

Reliability is directly related to maintenance and following a manufacturer's instructions. Preventive maintenance is critical-not just for the core components of a vehicle but for anything that requires attention. Maintaining a vehicle is more than performing a lube, oil, and filter change. Pay attention to all critical components. The supplier will have suggestions regarding this. Failure to follow this guidance can void a warranty as well as lead to premature failure of a part. There are also recommendations within National Fire Protection Association (NFPA) standards that offer minimum maintenance requirements.

Case in Point

I recently attended a seminar presented by the deputy commissioner of the Detroit (MI) Fire Department. He related problems created by failing to follow NFPA recommendations regarding ladder and elevated platform testing. Because of many issues within the department, including extreme financial challenges, it did not perform much of this routine maintenance and testing. The result was that almost all of the ladder trucks were forced out of service until the department could complete the preventive maintenance. This placed an incredible strain on the organization's response capabilities. In this case, the old saying that "you can pay me now or pay me later" rang true. The department, no doubt, has faced and faces some significant financial challenges, but neglecting core responsibilities ended up costing more than just money. It impacted service for a period of time.

It is easy to dismiss this as just one of the byproducts of a city in deep distress. But in talking to others, there are many more departments that don't meet their obligations regarding components maintenance compared to the manufacturer's recommendations or NFPA standards. It could be for a variety of reasons-mostly financial-but it could also be time or having personnel capable of doing it. Regardless, failure to stay up on the maintenance of the entire vehicle and its components could prove detrimental.

Although not always possible, departments should consider required maintenance when specifying components for vehicles. If something requires time and money above the norm, then perhaps consider a part that requires less. Being maintenance-free has its advantages but may not be realistic. But, ease of routine and minimum required preventive maintenance also have their value.

Responsibility

In every organization, one individual should be assigned ultimate responsibility for vehicle maintenance-including components. Who will do it will vary by the size and budge

By Alan M. Petrillo

Almost every first-due apparatus carries a ventilation fan of some sort on the rig, and often fire departments have special compartments designed on their pumpers, aerials, and rescues to accommodate an assortment of ventilation equipment.

The types of ventilation fans available today range from gasoline- and electric-powered units to hydraulically powered blowers that use the water flow from a hoseline to move volumes of air.

From Ejector to Positive Pressure

Roger Weinmeister, president of Super Vac, says since the mid 1990s there has been a strong push among fire departments toward using positive-pressure ventilation (PPV) equipment and away from traditional smoke ejectors. "That trend reached a high point about 10 years ago and now is moving more toward electric-powered fans with big motors," he says. "Gasoline-powered fans require a lot of maintenance," he notes, which is one of the chief reasons for the swing toward electric motors on positive-pressure fans, along with a movement toward variable speed motors. "The nice thing about a variable speed fan is that it can fake out normal 60-cycle electricity and make the fan run faster on its variable speed, which gives the fan a little bit more push and makes for a higher-capacity fan," Weinmeister points out. He maintains that variable speed fans make up the bulk of the electrical positive-pressure fan market today.

A firefighter sets up a Super Vac electric PPV fan at the entrance to a building. (Photo courtesy of Super Vac.)

Weinmeister estimates that a variable speed fan can increase the fan's capacity by 30 to 40 percent. "A typical motor runs at 1,700 revolutions per minute (rpm), but with a variable-speed motor, you can get up to 2,400 rpm for the same size motor," he notes. "The higher speed gets you better performance."

Super Vac's most popular electric positive-pressure ventilation fan is its VR3. Its biggest seller has a 6½-horsepower (hp) Honda motor with an 18-inch fan that displaces 15,500 cubic feet per meter (cfm) of air. Its next most popular fan is a 20-inch-blade model with the same horsepower motor but a larger shroud that can push up to 18,500 cfm.

Smoke ejectors are still used by a lot of fire departments, Weinmeister says, and are the right way to go in a lot of situations, especially where there is limited egress. "A smoke ejector used the right way to vent can pull fresh air from all over a building and exhaust it where the seat of the fire was located," he observes.

Weinmeister recommends that fire departments choose the largest fan that will fit easily into a compartment. "You want to move the most air possible," he notes.

He says that his company has battery-powered ventilation fans that it is excited about. "They give firefighters the ability set up a vent without a generator or power cords and will push almost as much air as a gasoline-driven fan," he says. "They'll run about 20 minutes, then can be supplied off a cord from the fire vehicle."

Allowing for Entry

James Neils, chief executive officer of Ventry Solutions Inc., notes his company makes both gasoline and electric PPV fans that can be used for aggressive attack to remove smoke from a structure to allow fire crews to make entry. "Our fans allow firefighters to set up about 10 feet outside of a building and shoot air into the structure to clear the air," Neils says. "We make eight gas-powered models a

By Robert Tutterow

This year's "Kill the Flashover" (KTF) project was once again held at the South Carolina Fire Training Academy.

Regrettably, the February 10-14 dates coincided directly with the worst winter storm in more than 10 years for the region. Three inches of sleet followed by a quarter inch of freezing rain prohibited completing all the scheduled burns. However, there was valid information from the completed burns, as well as from the classroom presentations and intense networking.

KTF is a research project for gaining a better understanding of fire behavior. Under the leadership of Joe Starnes and Shawn Oke, it is based on the premise that much of the conventional wisdom on fire extinguishment is flawed. The objective is to learn to control extreme fire behavior through:

1. Air management.
2. Enhanced water streams.
3. Thermal data.

This year's event brought leading edge fire behavior experts from across the nation as well as Canada, Germany, and Sweden.

This was the fourth consecutive year of live test fires for KTF. During the opening session, there was a panel discussion with one pertinent question: "What have we learned from the past three years?" The immediate response from all the panelists was simple: "Don't ever delay the application of water!" Or, as one panelist emphasized, don't delay the application of "enhanced" water-i.e., water with an agent that breaks down the surface tension of water.

A key part of the KTF test fires is the captured data. There are multiple thermal couplers, thermal imagers, and video cameras documenting every second of the tests. So far, all the tests indicate that the best chance for occupant survival is to apply water as soon as possible, even if that means an exterior attack.

Air Track Managment

Air track management is one of three components of understanding fire behavior at KTF. A key tool in managing air movement is using a portable door or portable air curtain. The concept is to install a fabric cloth in openings to manage the movement of air. This is not necessarily limited to exterior door openings but also to openings within the structure. This includes openings such as hallways and other openings within a structure that do not have doors installed. At least two United States manufacturers have added air curtains to their product lines. A benefit of using fabric is that it indicates if the air flow is moving in or out of the structure or confined room. Dr. Michael Reick, a firefighter and fire researcher from Germany, reports that several German fire departments are users of fire curtains at all openings.

Another outcome from fire tests during the past three years is discovering that vertical ventilation is not nearly as effective as conventional wisdom suggests. For occupant survivability and firefighter safety, quickly applying enhanced water and isolating the fire room by closing doors and using air curtains are far better than the time spent performing vertical ventilation.

Thermal Imager Use

The success of the KTF fire tests is directly dependent on the data captured. In addition to thermal couplers and video cameras, using thermal imagers is mission critical. KTF staff members are adamant about using a thermal imager while performing a 360-degree size-up. In addition, the fire attack crew must use a thermal imager.

There has been a lot written about leadership and change that states we should make every attempt to make the "unknown known." Thermal imagers help us know what would otherwise be unknown.

Buyers, beware when purchasing a thermal imager. There are companies aggressively touting units that are inexpensive-and they are. But, they will not perform as needed in the fire environment. Always purchase National Fire Protection Association (

By Alan M. Petrillo

Fire departments tend to be traditional in many ways yet often take time to embrace new technologies.

But when it comes to sirens-audible warning devices for fire apparatus-a mix of old and new technology can be found on many fire vehicles. It's not unusual, for instance, to see a new first-due pumper outfitted with both electromechanical and electronic siren systems.

Electromechanical Sirens

Vic Hilbert, owner of Eagle Sirens Inc., makes traditional electromechanical sirens that he says use a forward projection of sound instead of a wall of noise. "We focused the sound from our sirens to send it forward," Hilbert says, "and also off on a 55-degree angle to each side to get great penetration at intersections. A lot of other sirens put up that wall of sound, which puts the noise out front but also has a backwash that penetrates backward into the cab of the fire truck."

Eagle Sirens Inc. makes the Screaming Eagle electromechanical siren, shown here pedestal-mounted on an extended bumper. The siren also can be flange-mounted and nested in a hidden mount. (Photo courtesy of Eagle Sirens Inc.)

Hilbert's company makes the Screaming Eagle siren in one model available in three mountings: a pedestal mount (for apparatus with extended bumpers), a flange mount, and a hidden mount where the siren is nested behind a vehicle's bumper.

Hilbert points out that Eagle Sirens uses a pure silicone formula for all of the noncontact sealed bearings in its sirens. "The silicone makes the siren run much quieter and longer, and it has an anti-vibration effect," he says.

Kevin O'Connell, owner of B&M Siren Manufacturing Co., says B&M has five models of electromechanical sirens in its line: two direct-driven Super Chief versions and three Siro-Drift models. O'Connell maintains that electromechanical sirens move traffic better than electronic sirens. The electromechanical signal sent by a siren depends on the number of ports it has and how fast the air is moving through the ports, he notes. "The faster you run the siren, the more it sounds like you're stepping on a cat's tail," he says.

O'Connell says a siren's spinning rotor is very similar to that of a centrifugal pump. It draws air in at the front of the siren; compresses it slightly; and, as the air escapes out of the ports, the siren pops with sound.

One of the advantages of a mechanical siren over an electronic one, he points out, is that the mechanical siren emits a lower-frequency signal, which travels much farther. "The lower the frequency, the farther the sound travels, which is why air raid sirens operate at a low frequency," he says. "There's no beating a mechanical siren for attracting attention down the road," O'Connell says.

Code 3 has developed the Banshee, an electronic device that can be attached to any siren in the industry to produce attention- getting low-frequency tones among its 25 tone combinations. (Photo courtesy of Code 3.)

Timberwolf Siren Technology also builds an electromechanical siren-the Timberwolf 45, which develops a 123-decibel sound level from a 12-volt, 28-amp power source. The Timberwolf 45 uses an angle-designed rotor that the company says won't lose acoustic energy because the sound is d