Enhanced Effectiveness of Fire Fighting Tactics Project

Firefighting is hazardous. In 2010, the fire departments in the United States responded to more than 480,000^[1] structure fires. These fires resulted in approximately 3,120 civilian fatalities, 17,720 injuries and property losses in excess of $12 billion dollars. In addition, almost 33,000^[2] fire fighters were injured on the fire ground^[3]. This project will demonstrate through the use of measurement science the dynamics of fire behavior in a structure and provide guidance on non-traditional means to mitigate the fire hazard in the structure in a manner that provides optimum safety and effectiveness for the fire fighter. The project has three key focus areas; ventilation, suppression and technology transfer to the fire service.

 

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[1] Karter, M.J., Jr., Fire Loss in the United States During 2010, National Fire Protection Association, Quincy, MA 02169-7471, September 2011, www.nfpa.org

[2] Karter, M.J., Jr, and Molis, J.L., Firefighter Injuries in the United States, National Fire Protection Association, Quincy, MA 02169-7471, October 2011, www.nfpa.org

[3] In 2010, fire fighter injuries totaled 71,875 of which 32,675 or 45.4% occurred on the fire ground.

 

Objective: Improve the safety and effectiveness of firefighters through measurement science to advance ventilation strategies and non-traditional means of fire suppression and transfer of the results to the fire service  by 2014.

What is the new technical idea?  The three main objectives of a firefighting operation are life safety, fire extinguishment and property protection.  Most fire departments have standard operating guidelines for achieving these objectives, which vary from department to department because they are based on the experience of the department leadership, the organization of the department, and the resources that each department has to respond to a fire.  As a result, the actions of the fire fighters may not be driven by fire science but by tradition and experience.

As an example, currently fire suppression operations are termed “offensive,” if the fire fighters advance a hose line into a building to attack the fire, while a “defensive” operation would be to apply water streams into the building from a safe distance away from the building.  A recent study on wind driven fires in structures, conducted by NIST in cooperation with the Fire Department of New York City, the Chicago Fire Department, the Fire Protection Research Foundation and New York University Polytechnic, demonstrated alternate means of reducing the fire hazard for both firefighters and building occupants by using new tools to control the fire from the floor above or the floor below the fire floor.  Hence a good defensive operation became a great offensive operation.  This study has made the fire service aware that the traditional approaches that have been taught over the years may not be the most effective or the safest tactics,  nor necessarily lead to the best outcome.

While fire science has made significant improvements in both measurement and prediction, much of the work has focused on the fire behavior in a single compartment, not a series of compartments linked in a structure.  Measurements are needed to determine the capabilities and limitations of fire fighting techniques in actual structures to provide a basis for evaluating operational tools on the fire ground and to provide firefighters with the knowledge to predict the outcome of their tactics.

What is the research plan?  The project has three key focus areas; ventilation, suppression and technology transfer to the fire service.  The fire service defines ventilation as the removal of heat and smoke from a burning structure while introducing cooler, cleaner air.  Traditionally this would be done with vertical ventilation - by making an exhaust vent in the roof and providing air inlets by opening doors or breaking windows.  Another method is horizontal ventilation, where only windows are vented.  Given the fuel rich environment found in structures, these actions may actually enable the fire to reach flashover at a faster rate, increasing the hazard.  Therefore, a study documenting the fundamentals of natural ventilation in a real scale residential structure is required.  The objective of the task is to examine the exhaust and inlet vent sizes needed to safely cool and raise the hot gas layer interface height within the structure.  The initial phase will be conducted with natural gas burners.  These experiments will then be modeled with FDS/Smokeview.  Once validated for these experiments, the model will be used to assist in the design of the second phase of ventilation experiments with real furnishings as fuel.  The results will be used to provide guidance to fire fighters on their ability to ventilate a structure with a favorable outcome.  For example, the exhaust vent size required based on the volume of the building and the volume of the building filled with smoke.  Other factors which fire fighters need to take to account prior to venting a building include smoke color, speed, wind conditions, fire location and fire size.

Suppression operations have been conducted from the interior of the structure as a means to reduce water damage and limit fire damage to structures.  These operations must be coordinated with the ventilation operations.  Previous research and examinations of line of duty deaths has shown that ventilation events occurring with fire fighters in the structure prior to suppression have led to tragic results.  One means of eliminating the possibilities of this occurrence would be a transitional attack, in which water is directed into the structure from the exterior to cool the fire gases and reduce the heat release rate of the fire, prior to the fire fighters entering the building.  The major concern with this type of operation is the potential harm that might occur to people trapped in the structure or the amount of water damage to the structure.  Therefore, measurements are needed to document the changes of the thermal environment within the structure and the impact on the viability of people, who might be trapped in the structure.

As this new information is documented, a significant task is to share the information with the fire service across the nation.  Mechanisms include NIST reports and videos on the fire.gov website, journal articles, firefighting trade magazine articles, conferences, webinars, web-based training programs, podcasts and the integration of the new knowledge into standards, guides and training materials.  NIST works with a variety of organizations that have established communications networks with fire departments in order to transfer technology efficiently.  These organizations include: the North American Fire Training Directors, the International Association of Arson Investigators, the International Fire Service Training Association, The International Society of Fire Service Instructors, National Fallen Firefighters Foundation, National Fire Protection Association, the International Association of Fire Fighters, the Internationa Assocaition of Fire Chiefs and the U.S. Fire Administration’s Training Resources and Data Exchange (TRADE) group.  Through their state and local networks these groups reach both rural and metro fire departments of all sizes.  In addition, NIST works directly with a number of large metro departments as these departments in turn impact the surrounding regions.

Recent Results: 

Outputs:

Fire Modeling and the Fire Service, Fire Rescue Magazine, Barowy, A. and Madrzykowski, D., November 2011.

Simulation of the Dynamics of a Wind-Driven Fire in a Ranch-Style House – Texas, Barowy, A. and Madrzykowski, D., National Institute of Standards and Technology, Gaithersburg, MD., NIST TN 1729, January 2012.

Completed a series of gas –fueled vertical ventilation experiments in collaboration with UL in Northbrook, IL.

NIST collaborated with UL to complete series of experiments  on Basement Fires.  http://www.ul.com/fireservice.

Analysis of a Fatal Wind-Driven Fire in a Single-Story House, Fire Engineering, Barowy, A. and Madrzykowski, D., May 2012.

How Hot is Hot?  How Heat Release Rates Can Help Us Gauge Thermal Hazards., Bshifter, Madrzykowski, D., Spring 2012.  www.bshifter.com/magazine/B_Shifter_Spring_2012.pdf.

Hazard Assessment of Fire Service Training Fires, NFPA Fire Protection Research Foundation Webinar, February 16, 2012. http://www.nfpa.org/itemDetail.asp?categoryID=2355&itemID=54901&URL=Training/Webinars/Sponsored%20webinars.

Week in Review with Bobby Halton: Interview on ventilation and wind driven fires. http://www.fireengineering.com/topics/m/video/53487817/week-in-review-dan-madrzykowski-interview.htm. February 22, 2012.

In FY12, researchers provided 20 presentations transferring NIST research results on fire behavior and control in structures at national and regional meetings of fire service personnel, providing 88 hours of direct instruction to more than 2300 firefighters.

Experimental and Computational Characterziation of Strong Vent Flow Enclosure Fires. Weinschenk, C., Ph.D. Dissertation, University of Texas at Austin, August 2011. (funded through a NIST Fire Grant)

Outcomes:

Draft sections of  Fire Fighting Essentials, 6th edition, incorporating new material based on NIST research results on fire behavior and control in  fire fighter training guidance in collaboration with the International Fire Service Training Association. 

A foundation of materials on fire dynamics and thermal hazard in training fires was incorporated in NFPA 1403, Standard on Live Fire Training.

Standards and Codes: 

This project is fully engaged in standards activities and the project team are members or participating in several standards as listed below:

• NFPA 921, Guide for Fire and Explosion Investigations
• NFPA 1001, Std for Fire Fighter Professional Qualifications
• NFPA 1021, Std for Fire Officer Professional Qualifications
• NFPA 1041, Std for Fire Service Instructor Professional Qualifications
• NFPA 1403, Std for Live Fire Training Evolutions
• NFPA 1404, Std for Fire Service Respiratory Training
• NFPA 1408, Proposed Std on Thermal Imaging Training
• NFPA 1410, Std on Training for Initial Emergency Scene Ops