Larger fire-fighting crews save lives, limit damage in high-rise fires
concluded that smaller crews end up facing larger fires because of the additional time required to complete tasks.
A three-person crew, for example, would battle a medium-growing blaze that is almost 60 percent larger than the fire faced by a six-member crew, which would start extinguishing a fire roughly three-and-one-half minutes earlier. In an office building, this difference is equivalent to four employee cubicles on fire for a three-person crew versus two cubicles for a six-person crew.
Comparing the performances of different-sized crews, the researchers found that adding two members to three- and four-person teams would result in the largest improvements in starting and completing critical tasks, such as advancing the water hose to the fire location and beginning search and rescue. Improvements ranged from one minute to twenty-five minutes, depending on the task.
The research team also evaluated whether dispatching more three or four-member crews to a high rise fire — accomplished by sounding a higher initial alarm — would be as effective as sending a low first alarm contingent of engines and trucks staffed by more firefighters. They found that a “low-alarm response with crews of size four or five outperforms a high-alarm response with crew sizes smaller by one firefighter.”
“Prior to this experiment, some fire departments attempted to deploy with smaller crews on each piece of apparatus,” explains Lori Moore-Merrell of the International Association of Fire Fighters, a co-principal investigator for the study. “The logic suggested that, if the fire is big enough, just send more units, but it ignores the fact that larger crews have tactical advantages that reduce risk exposure to people and firefighters. Crews of six and even five can carry out crucial tasks in parallel rather than in series. Saving time can save occupant lives and prevent firefighter injuries and property damage.”
The National Fire Protection Association (NFPA) defines high-rises as buildings that are seven stories or taller, the height that exceeds most types of fire service ladders. In most U.S. communities, new high-rises are required to have automated sprinkler systems, which are designed to control the spread of fires, not to extinguish them.
According to the NFPA, however, 41 percent of U.S. high-rise office buildings, 45 percent of high-rise hotels, and 54 percent of high-rise apartment buildings are not equipped with sprinklers, as compared with 25 percent of hospitals and related facilities. Moreover, sprinkler systems fail in about one in fourteen fires.
As a result, Averill says, “fire departments should be prepared to manage the risks associated with unsprinklered high-rise fires regardless of whether a building is actually sprinklered.”
The release notes that high-rise buildings now dot the U.S. urban, suburban and even rural landscapes. While concentrated in large cities, such as New York with 6,543 skyscrapers and buildings seven stories or taller, Chicago with more than 2,300, and Phoenix with about 175, high-rises are also common in smaller metropolitan areas, according to the building inventory maintained by Emporis. For example, Omaha has about 70 buildings seven stories or taller, Fargo, North Dakota, has twenty-two, and Gulf Shores, Alabama, has about sixty-five.
While much less frequent than house fires, about forty-three high-rise fires occur in the United States every day. Between 2005 and 2009, according to the NFPA, high-rise structure fires averaged 15,700 annually. Average annual losses totaled 53 civilian deaths, 546 civilian injuries, and $235 million in property damage.
The new study on responding to high-rise fires complements a 2010 study from the same research team that looked at staffing levels and arrival times in the context of fighting residential fires.
“Rather than providing a one-size-fits-all answer, our study provides a scientific basis for discussions in communities as they consider matching resources deployed to their particular risk levels.” says Averill.
“Until now, high-rise staffing, deployment and even operational decisions have been based on decades of applying trial and error strategy and tactics,” says NFPA’s Russell Sanders, a retired Louisville, Kentucky, fire chief. “Tragically, the fire department standard operating procedures and industry standards that we have today have, in many cases, been established at the high cost of civilian and firefighter lives: the science to prove these policies, procedures and standards as the best practice has been absent.”
Sanders says NFPA consensus committees will use the results of the new study as they update safety and best-practice standards for firefighters.
— Read more in J. D. Averill et al., Report on High-Rise Fireground Field Experiment (NIST Technical Note 1797, April 2013); and Jason D. Averill et al., Residential Fireground Field Experiments (NIST, 27 April 2010)
