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Landmark Residential Fire Study Shows
How Crew Sizes and Arrival Times Influence Saving
Lives and Property
National Institute of Standards and Technology
For Immediate Release: April 28, 2010
WASHINGTON D.C. – A landmark study issued today by
the U.S. Department of Commerce's National Institute
of Standards and Technology (NIST) shows that the
size of firefighting crews has a substantial effect
on the fire service's ability to protect lives and
property in residential fires.
Performed by a broad coalition in the scientific,
firefighting and public-safety communities, the
study found that four-person firefighting crews were
able to complete 22 essential firefighting and
rescue tasks in a typical residential structure 30
percent faster than two-person crews and 25 percent
faster than three-person crews.
The report is the first to quantify the effects of
crew sizes and arrival times on the fire service's
lifesaving and firefighting operations for
residential fires. Until now, little scientific data
have been available.
"The results from this rigorous scientific study on
the most common and deadly fires in the
country—those in single-family residences—provide
quantitative data to fire chiefs and public
officials responsible for determining safe staffing
levels, station locations and appropriate funding
for community and firefighter safety," said NIST's
Jason Averill, one of the study's principal
investigators.
The four-person crews were able to deliver water to
a similar-sized fire 15 percent faster than the
two-person crews and 6 percent faster than
three-person crews, steps that help to reduce
property damage and lower danger to the
firefighters.
"Fire risks grow exponentially. Each minute of delay
is critical to the safety of the occupants and
firefighters, and is directly related to property
damage," said Averill, who leads NIST's Engineered
Fire Safety Group within its Building and Fire
Research Laboratory.
"Our experiments directly address two primary
objectives of the fire service: extinguishing the
fire and rescuing occupants," said Lori
Moore-Merrell of the International Association of
Fire Fighters (IAFF) and a principal investigator on
the study.
The four-person crews were able to complete search
and rescue 30 percent faster than two-person crews
and 5 percent faster than three-person crews,
Moore-Merrell explained. Five-person crews were
faster than four-person crews in several key tasks.
The benefits of five-person crews have also been
documented by other researchers for fires in medium-
and high-hazard structures, such as high-rise
buildings, commercial properties, factories and
warehouses.
This study explored fires in a residential
structure, where the vast majority of fatal fires
occur. The researchers built a "low-hazard"
structure as described in National Fire Protection
Association Standard 1710 (NFPA 1710), a consensus
standard that provides guidance on the deployment of
career firefighters. The two-story, 2000-square-foot
test facility was constructed at the Montgomery
County Public Safety Training Academy in Rockville,
Md.Fire crews from Montgomery County, Md., and
Fairfax County, Va., responded to live fires within
this facility.
NIST researchers and their collaborators conducted
more than 60 controlled fire experiments to
determine the relative effects of crew size, the
arrival time of the first fire crews, and the
"stagger," or spacing, between the arrivals of
successive waves of fire-fighting apparatus
(vehicles and equipment). The stagger time simulates
the typically later arrival of crews from more
distant stations as compared to crews from more
nearby stations.
Crews of two, three, four and five firefighters were
timed as they performed 22 standard firefighting and
rescue tasks to extinguish a live fire in the test
facility. Those standard tasks included occupant
search and rescue, time to put water on fire, and
laddering and ventilation. Apparatus arrival time,
the stagger between apparatus, and crew sizes were
varied.
The United States Fire Administration reported that
403,000 residential structure fires killed close to
3,000 people in 2008—accounting for approximately 84
percent of all fire deaths—and injured about 13,500.
Direct costs from these fires were about $8.5
billion. Annually, firefighter deaths have remained
steady at around 100, while tens of thousands more
are injured.
Researchers also performed simulations using NIST's
Fire Dynamic Simulator to examine how the interior
conditions change for trapped occupants and the
firefighters if the fire develops more slowly or
more rapidly than observed in the actual
experiments. The fire modeling simulations
demonstrated that two-person, late-arriving crews
can face a fire that is twice the intensity of the
fire faced by five-person, early arriving crews.
Additionally, the modeling demonstrated that trapped
occupants receive less exposure to toxic combustion
products—such as carbon monoxide and carbon
dioxide—if the firefighters arrive earlier and
involve three or more persons per crew.
"The results of the field experiments apply only to
fires in low-hazard residential structures as
described in the NFPA Standard 1710, but it provides
a strong starting point," said Moore-Merrell. Future
research could extend the findings of the report to
quantify the effects of crew size and apparatus
arrival times in medium- and high-hazard structures,
she said.
The next step for this research team is to develop a
training package for firefighters and public
officials that would enable them to have both
quantitative and qualitative understanding of the
research, a project also funded by FEMA's Assistance
to Firefighters Grant Program.
The study's principal investigators were Averill,
Moore-Merrell and Kathy Notarianni of Worcester
Polytechnic Institute. Other organizations
participating in this research include the
International Association of Fire Chiefs, the
Commission on Fire Accreditation International-RISK
and the Urban Institute.
The report was funded by the U.S. Department of
Homeland Security, Federal Emergency Management
Agency's (FEMA) Assistance to Firefighters Grant
Program and released today in Washington, D.C.,
before the start of the annual Congressional Fire
Services Institute meeting that draws top fire
safety officials from across the nation.
The Report on Residential Fireground Field
Experiments, NIST Technical Note 1661, can be
downloaded
here. (22.1 MB
PDF)
Founded in 1901, NIST is a nonregulatory agency of
the Commerce Department that promotes U.S.
innovation and industrial competitiveness by
advancing measurement science, standards and
technology in ways that enhance economic security
and improve our quality of life. |
