Could it be that residential tactics won’t or don’t necessarily work at nonresidential fires?
BY JOHN A. REARDON
Engine 22 was returning from its third fire of the day. Each dwelling was effectively attacked with a 11/2-inch handline-nothing unusual for this busy inner city fire company located in a district primarily comprised of single-family dwellings.
Before returning to quarters, Engine 22 receives a radio run. “Engine 22, fire is reported in a commercial building.” On arrival, the company radios back, “Engine 22 is on the scene, stretching on a one-story concrete block commercial building 25 by 40.”
The pump operator stops in front of the building as firefighters disembark from their running seats and move to the rear of the apparatus. The officer disembarks grabbing his SCBA as the firefighters, following routine, pull a 11/2-inch handline. From the rear they signal the driver to go for the hydrant using a reverse lay.
(1) A firefighter (left) waits for water on a 11/2-inch handline at a well-involved commercial building fire. A 21/2-inch line would provide for better reach and penetration, resulting in a quicker knockdown. (Photos by Bill Eisner.)
Soon water surges through the line, making a popping sound as the pressure builds and blows out the kinks. By this time, the firefighters have donned facepieces and are ready for the attack. They advance toward the front of the building where flames leap freely from the broken front window. Suddenly, the advance stalls.
Engine 36, the second engine on the “box,” arrives a couple of minutes later and reverse lays a 21/2-inch line. Once charged, the crew advances and the fire is knocked down. Soon, the incident commander radios dispatch that the fire is under control.
Luckily, the building was a concrete block building built years ago, not a modern lightweight wood building that could suffer a quick collapse. The older construction allowed time for a slower knockdown procedure. Yet, had a 21/2-inch been pulled initially, the fire would have been controlled without Engine 36’s need to stretch. A quick knockdown stops the fire from doing further damage to the structural members of the building. It makes the overhaul operations safer. A rapid knockdown allows the incident command to state, “Dispatch, this fire is under control.”
Quick math tells the story. Use the National Fire Academy’s (NFA) fire flow formula for initial attack: Length times width divided by three equals the flow for 100 percent involvement for one floor.1 For the scenario: 40 x 25 = 1,000; divided by 3 = 333 gpm.
Engine 22 was probably flowing less than 150 gpm from its 11/2-inch line-not nearly enough. Additionally, it lacked the reach and penetration provided by a 21/2-inch line. The heat of the fire ate up the relatively small-caliber stream.
RAPID DECISION MAKING
In June 1988, the U.S. Army Research Institute for the Behavioral and Social Sciences published a study, Rapid Decision Making on the Fire Ground, prepared by Klein Associates, Inc., which stated:
In more than 80 percent of the cases (incidents studied), the strategy was for the FGCs (Fire Ground Commanders) to use their experience to directly identify the situation as typical of a standard prototype ….”2
|Type of structure||1999 structure fires4||1994-1998 firefighter deaths per 100,000 structure fires5|
|Stores and offices||5.5 %||15.2 %|
|Note: Per 100,000 structure fires, 96.1% of firefighter deaths occurred in other than residential structures.|
Figure 1. Firefighter Deaths for Selected Structures
“Their ability to handle decision points appeared to depend on their skill at recognizing situations as typical, as instances of general prototypes that they had developed through experience.” (2, 17; emphasis added)
Engine 22 fell victim to this thinking. Having had successful experiences with 11/2-inch lines deployed on the majority of the fires it encountered (dwelling fires), the crew automatically stretched a 11/2-inch line on a commercial building fire. The “routine” fire has set the stage for the “Well, it worked before” mindset without considering that this was not a routine fire.
Had they initially stretched a 21/2-inch line with a 11/4-inch smooth-bore tip, personnel could have provided a flow of 329 gpm at 50 psi nozzle pressure. A solid stream would have penetrated the flames and heat to actually apply water on the material burning. Barring interior shelves or walls, they could expect a quick knockdown.
“The most important effect on a fire in ordinary combustibles is that of direct wetting and cooling of the burning combustibles themselves so as to extinguish the fire. In addition, the water spray can also wet the surfaces of unburned materials just outside of the fire zone preventing or at least delaying ignition of the exposed material.”3 If this is recognized for sprinklers, shouldn’t this be our practice as well?
FIREFIGHTER DEATHS IN STRUCTURES
Most firefighters die during residential structure firefighting simply because that is the most common structure fire we fight. Yet, when we look at firefighter fatalities per 100,000 structure fires, we see our greatest risk is in other than residential structure fires, what might be termed “nonroutine” structure fires.
Of an estimated 523,000 structure fires in 1999, 383,000 or 73 percent occurred in residential occupancies.4 Twenty-seven percent occurred in other than residential structures. Nonresidential structure fires accounted for 96.1 percent of firefighter deaths from 1994 to 1998.5 A firefighter’s chance of dying is in a nonresidential building.
Based on the U.S. Army’s study, we base our decisions on our past experiences. Could it be that we lack experience and training in nonresidential, nonroutine-type fires? Could it be that our tactics for nonresidential buildings are those we use at residential fires? Could it be that residential tactics won’t or don’t necessarily work at nonresidential fires?
RECOGNIZING THE DIFFERENCE
When we attack a residential fire in a one-story dwelling, we generally fight it one room at a time and a 11/2– or 13/4-inch line is more than adequate. Industrial and commercial buildings often have larger open floor plans; we now need the reach and penetration provided from a larger caliber stream.
The reach of the stream provides us with a relative degree of safety. Consider that an open plan usually involves an open or larger roof span. Residential buildings have interior support and partition walls that can minimize or localize collapse. Many nonresidential buildings don’t provide for a localized collapse scenario. Francis Brannigan explains the collapse hazards of trusses and the fact that large sections of a roof may collapse when a truss fails.6 If for no other reason, use larger caliber streams for reach.
In the U.S Army’s study of rapid decision making, it states, “In the RPD (recognition primed decision) model of time-pressured decision making, situational awareness becomes very important. We are claiming that most decision points can be handled without deliberation by applying an ‘if x … then y’ strategy.” (2, 21; emphasis added) We call it size-up, not situational awareness, but it means basically the same thing.
Officers and firefighters need to recognize that they are at a nonroutine fire situation when encountering a commercial or industrial building fire. Regardless of how many commercial or industrial fires we encounter, they may all differ dramatically because of operations, processes, and products involved. Regardless of how routine it may be to pull a 11/2– or 13/4-inch line for a dwelling fire, a judgment call has to be made for nonresidential building structures.
One problem is that of having a well-oiled energetic crew. Efforts made to deploy lines quickly, as they do at routine fires, set the stage-good or bad. The automatic reflex of a crew may result in pulling an inadequate size line before the officer can make the call. The crew needs to recognize nonroutine fires and have the discipline to await the officer’s decision.
The most effective use of the NFA’s fire flow formula is not when at the scene but in the preincident planning of the building. The NFA did an excellent job of taking the required fire flow and extending it into a staffing requirement formula. It’s simple: Figure for every 25 to 50 gpm of flow, one firefighter needs to be involved in active suppression activities. (1) (My experience shows it to be closer to 35 gpm per firefighter.)
It also developed a simple, easy-to-read, one-sided form that can capture this and other information. The reverse side of the form can be used to sketch the building’s site: identifying access points, stairs, and utilities locations.
Training should include instilling discipline in firefighters to await a fire officer’s judgment call at nonroutine fires. Fire officers, themselves, should be trained at making these calls. The scenario in this article could be a starting point. Magazines that document incidents can provide case studies.
Training should include basic refreshment in placing and advancing a 21/2-inch hoseline. Properly done, two firefighters can advance a 21/2-inch line as easily as two firefighters can each advance 13/4-inch lines. Remember, our effort is aimed at quick knockdown. Once accomplished, the 21/2-inch line can be reduced to a smaller, more maneuverable line.
Critique your fires, especially those that are nonroutine. How effective was your attack? Did your attack stall? Why? Don’t use the critique to point fingers. Effective firefighting is accomplished through a team effort. When we fail, we fail as a team. Look for operational deficiencies.
Decisions on the fire scene will be based on experience, as the Army’s study verifies. However, we need to realize when we exceed that experience level, we need to understand that years of fighting dwelling fires may not be the experience needed for a nonresidential-type structure fire. For these fires, we can generally use a simple rule of thumb in selecting the proper stream size.
SELECTING A STREAM
For interior attack, select a hoseline and nozzle size so you can place a straight or solid stream of water into the far corner of the room from the doorway. If you can hit that corner, you can wet everything in that room. Don’t be deceived by the amount of steam created when using a fog stream. Remember the principle of the sprinkler system-wet burning combustibles and wet surrounding combustibles below their vaporization temperatures. Do the same thing with a fire stream.
Those who argue for a fog stream application and against solid streams usually base their case on excessive water damage. Trained firefighters know when to shut down the nozzle, thus preventing excessive water damage. As I once heard at the National Fire Academy, “Everything dries; nothing unburns.”
Fog streams striking a formidable wall of flames may produce a significant amount of steam right in front of you, deluding you into thinking you’re doing one heck of a job. Meanwhile, the fire burns in the farthest corner, eventually attacking the building’s structural components. What is needed is knockdown-control-now!
Consider our history. We used fog on large structures, such as barns, creating plenty of steam while the building usually burned down. In our effort to prevent water damage, we scalded plenty of firefighters. How much damage from the fire occurs while we try to prevent water damage? How many injuries are incurred? How much additional risk is posed to the operating firefighters?
SELECTING THE SIZE
Referring again to the NFA’s fire flow formula, consider a one-story dwelling measuring 30 by 40 feet. On arrival, the living room (20 by 15 feet) is involved. Using the formula, 30 2 40 = 1,200 feet, divided by 3, equals 400 gpm, for a total floor involvement. One would estimate 25 percent involvement and would be correct-the formula states that 100-gpm flow is required for knockdown. (Interestingly enough, using this formula for the room itself equals the same.) Surely, a 11/2– or 13/4-inch line would handle this fire. Both the 11/2– and 13/4-inch lines could handle this fire even if the dwelling were 100-percent involved, because we would attack it one room at a time.
However, if the building were a commercial structure of the same size and fully involved, we would need the reach and penetration of a larger stream. Knockdown is critical and must be timely. With an open floor space, we might take the advantage of using a master stream for accomplishing this. This fire is not a “one room at a time” venture. Go for the knockdown. The longer knockdown is delayed, the greater the potential for collapse.
Although the Army’s research concluded that in 80 percent of the cases, past experience was the basis for decision making, what about the remaining 20 percent? Could it be that we are better students of success than failure? “Success is a valuable teacher, providing you don’t get lulled into complacency by her succulent fruit.”7
Our success in fighting routine dwelling fires may be our undoing when fighting nonresidential fires-those in commercial, industrial, and storage buildings. As creatures of habit, we need to recognize that these nonroutine fires require a second or two of thought. If we mentally flag these incidents, we may take another approach, which may mean using different size fire streams and tactics. Our strategy, if life safety is not an issue, must be for quick stabilization-a knockdown. To accomplish this, we need to overpower the enemy. Don’t take a knife to a gunfight!
The U.S. Army study basically states that our successful experiences lead us into an “if x, then y” mentality for rapid decision making. When we have a loss, if our routine didn’t quite work or it worked but with difficulty, then we should ask, “If x, then why?”
- Managing Company Tactical Operations: Preparation. National Fire Academy course.
- Klein, Gary, Robert Calderwood, Anne Clinton-Cirocco. Rapid Decision Making on the Fire Ground. Klein Associates, Inc., June 1988, vii.
- Norman J. Thompson, Fire Behavior and Sprinklers. National Fire Protection Association, Feb. 1978.
- Michael J. Karter Jr., “1999 U.S. Fire Loss Report,” NFPA Journal, Sept./Oct. 2000, 83.
- Faby, Rita F. and Paul R. LeBlanc, “1999 U.S. Fire Fatality Report,” NFPA Journal, July/August 2000, 51.
- Brannigan, Francis L. Building Construction for the Fire Service, Third Edition. National Fire Protection Association, Quincy, Mass. 1992, 522-523.li>Belasco, James A., and Ralph C. Stayer. Flight of the Buffalo. (Warner Books, New York, NY, 1994;), 81.
JOHN A. REARDON is chief of the Tri-City (MI) Fire Department serving Orchard Lake, Keego Harbor, and Sylvan Lake. He retired as a lieutenant from the Detroit (MI) Fire Department after 25 years of service and remains active in many statewide fire training activities.