Predictability and Performance Of Buildings on Fire

When we look at various buildings and occupancies, past operations (good and bad) give us experience that defines and determines how we assess, react and expect similar structures and occupancies to perform at a given alarm. The “art and science of firefighting” is predicated on a fundamental understanding of how fire affects a building and its occupants and the manner in which the fire service engages when called on to combat a structure fire.

We have certain expectations that fire will travel in a defined, predictable manner:

• That the building will react and perform under assumptions of past performance and outcomes

• That fire will hold within a room and compartment for a predictable duration

• That the fire load and related fire flows required will be appropriate for an expected size and severity of fire encountered within a given building, occupancy or structural system

• That we can safely and effectively mitigate a fire in any given building type and occupancy

• That we will have the time to conduct the required tasks identified to be of importance based on identified or assumed indicators

• That the building will conform to the rules of firefighting engagement

Times have changed

Today’s incident demands on the fireground are unlike those of even the recent past. This means incident commanders, commanding and company officers and firefighters alike must have increased technical knowledge of building construction with a heightened sensitivity of fire behavior and fire dynamics, a focus on operational structural stability of the compartment and building envelope and considerations related to occupancy risk versus the occupancy type. Understanding the building – its complexities in terms of anatomy, structural systems, materials, configuration, design, layout, systems, methods of construction, engineering and inherent features, limitations, challenges and risks – is fundamental for operational excellence on the fireground and firefighter safety.

There is an immediate need for emerging and operating command and company officers to increase their knowledge and insights of modern building occupancy, building construction and fire protection engineering and to modify traditional and conventional strategic operating profiles in order to safeguard companies, personnel and team compositions. Strategies and tactics must have the combined adequacy of sufficient staffing, fire flow and tactical patience orchestrated in a manner that identifies with the fire profiling, predictability of the occupancy and the building that accounts for presumptive fire behavior.

We used to discern with a measured degree of predictability how buildings would perform and fail under most fire conditions. Implementing fundamentals of firefighting operations built on decades of time-tested and experience-proven strategies and tactics continues to be the model of suppression operations. These same fundamental strategies continue to drive methodologies and curriculums in current training programs and academy instruction.

The lack of appreciation and the understanding of correlating principles involving buildings, compartments, fire behavior, the fuel package, its rate of heat release and growth stages of compartment fires and their effect within a structure are the defining paths from which the fire service must reexamine operations in order to identify with the predictability of occupancy performance during fire suppression operations, thus increasing suppression effectiveness and firefighter safety.

Our buildings have changed – the structural systems of support, the degree of compartmentation, the characteristics of materials and the magnitude of the fire-loading package. All of our occupancies, new and old, have new operating parameters and considerations that must be identified and assimilated into preparedness, training and operations.

New rules

The predictability of building performance under fire conditions, structural integrity and extreme fire behavior, accelerated growth rate and intensity levels typically encountered in buildings of modern construction during initial and sustained fire suppression have given new meaning to the term “combat fire engagement.” The rules have changed, but no one has told us. It’s no longer just brute force and sheer physical determination that define structural fire suppression operations, although any seasoned command and company officer knows that at times it is what gets the job done under the most demanding circumstances.

From a methodical and disciplined perspective, however, aggressive firefighting must be defined and aligned to the built environment and associated with goal-oriented tactical operations. These are defined by risk-assessed and risk-analyzed strategic processes executed under battle plans that promote safety and survivability.

The dramatic changes in buildings and occupancies over the past 15 years have resulted in inadequate fire suppression methodologies. Fire research and the need to understand fire and its relationship to buildings, systems and firefighting operations are challenging long-held beliefs and encouraging debate, resulting in thought-provoking and insightful theories, position statements and a time of retrospect and critical self-examination that will influence numerous facets of the fire service.

We have assumed that the success of past operations equates with predictability and diminished risk to firefighters. Our current generation of buildings, construction and occupancies is not as predictable as past conventional construction; therefore, risk assessment, strategies and tactics must change to address the new rules.

Executing tactical plans based on faulty or inaccurate strategic insights and indicators has proven to be a common apparent cause in numerous case studies, after-action accounts and firefighter line-of-duty-death reports. Our years of predictable fireground experience have ultimately embedded and clouded our ability to predict, assess, plan and implement Incident Action Plans (IAPs).

The demands of modern firefighting will continue to require the placement of personnel in situations and buildings that carry risk, uncertainty and inherent danger. As a result, risk management must become fluid and integrated with intelligent tactical deployments and operations.

Managing risk

“If you don’t fully understand how a building truly performs or reacts under fire conditions and the variables that can influence its stability and degradation, movement of fire and products of combustion and the resource requirements for smart aggressive fire suppression in terms of staffing, apparatus and required fire flows, then you will be functioning and operating in a reactionary manner that is no longer acceptable within many of our modern building types, occupancies and structures. This places higher risk to your personnel and lessens the likelihood for effective, efficient and safe operations. You’re just not doing your job effectively and you’re at risk. These risks can equate into insurmountable operational challenges and could lead to adverse incident outcomes. Someone could get hurt, someone could die; it’s that simple, it’s that obvious.”

Those are the words of Chief Anthony Aiellos (ret.) of the Hackensack, NJ, Fire Department on the 20th anniversary of the Hackensack Ford dealership fire that killed five firefighters in 1988. Without understanding building-occupancy relationships and integrating fire dynamics and fire behavior, risk, analysis, the art and science of firefighting, safety-conscious work environment concepts and effective and well-informed incident management, company-level supervision and task-level competencies, you are derelict and negligent and everyone may not be going home. Empirical insights and test data must be integrated in emerging fire suppression models and improved firefighting theory.

Conclusion

Our world has evolved. Technological and sociological demands create a continuing element of change in the built environment and our infrastructure. With these changes and demands come the need to assess these vulnerabilities, hazards and threats with effective and dynamic risk management and competent command and control.

Fire suppression tactics must be adjusted for the rapidly changing methods and materials impacting all forms of building construction. n

 

Christopher J. Naum will present “Reading the Building: Predictive Occupancy Profiling” at Firehouse Expo 2012, July 17-21 in Baltimore, MD.

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