Posts Tagged ‘fire behavior’

In Reading the Fire: How to Improve Your Skills and Fire Behavior Indicators: Building Factors we started the process of developing a personal fire behavior indicators (FBI) concept map. I am working along with you to expand and refine my FBI Concept Map (Version 5.2.1).

Reading the Fire

I regularly post B-SAHF (Building, Smoke, Air Track, Heat, and Flame) Exercises to provide the opportunity to practice reading the fire. However, photos and video clips can also provide a great opportunity to focus in on a single type of indicator (such as building factors). Dig out the work in progress on your FBI concept map and have a look at the following video clips and focus your attention on building factors.

1. What type of construction was involved? How (or did) this factor influence fire behavior?
2. What other building and occupancy characteristics may have had an impact on fire behavior?
3. Are the factors you identified on your concept map? If not, add them to the map or list them in a staging area until you have determined where they might go on the map.

Los Angeles County Commercial Fire

Vancouver BC Apartment Fire

Los Angeles City Commercial Fire

What additions have you made to your FBI concept map? If you found this useful, poke around on YouTube and continue to apply this method to help you develop and refine the building factors (and other elements) of your map.

Step Back and Look at the Entire Picture

I would not want to waste the opportunity to engage with the rest of the B-SAHF indicators. Download and print three copies of the B-SAHF Worksheet. Consider the information provided in each of the short video clips and complete the worksheet for each. First, describe what you observe in terms of the Building, Smoke, Air Track, Heat, and Flame Indicators and then answer the following five standard questions?

1. What additional information would you like to have? How could you obtain it?
2. What stage(s) of development is the fire likely to be in (incipient, growth, fully developed, or decay)?
3. What burning regime is the fire in (fuel controlled or ventilation controlled)?
4. What conditions would you expect to find inside this building?
5. How would you expect the fire to develop over the next two to three minutes

Next Post

I have spent the last several days attending the Florida State Fire College Live Fire Training Instructor (LFTI) course being delivered at the Oregon Public Safety Academy in Salem, Oregon. My next post will provide an overview and critique of this excellent course.

Ed Hartin, MS, EFO, MIFireE, CFO

Unanticipated smoke explosion and building collapse nearly kills three firefighters.

Portsmouth, VA Near-Miss Incident

Firefighter Eric Kirk gives a firsthand account of a near-miss incident involving a smoke explosion in the June 2009 issue of FireRescue magazine. On a December morning in 2007, firefighters in Portsmouth, Virginia responded to a fire in a church. On arrival, the building was well involved and defensive operations were initiated to protect exposures and confine the fire. Over the course of the fire, smoke extended into an attached, three-story, brick building and formed a flammable fuel/air mixture. Subsequent extension of flames from the church to the interior of the exposure resulted in ignition and explosive combustion of this fuel (smoke)/air mixture.

Incident Photos from PilotOnline.com

Smoke Explosion

This post expands on Smoke is Fuel (Hartin, 2009), a sidebar that I wrote for FireRescue that accompanies Eric’s article examining the Portsmouth, VA smoke explosion incident.

Smoke explosions have resulted in three firefighter fatalities in the United States since 2005, two in Wyoming (see NIOSH Report F2005-13) and one last year in Los Angeles California (NIOSH report pending). In addition, there have been a number of near miss incidents including this one in Virginia and another in Durango, Colorado (see NIOSH Report F2008-02)However, many firefighters have not heard of or misunderstand this fire behavior phenomenon.

The terms backdraft and smoke explosion have typically been used to describe explosions resulting results from confined and rapid combustion of pyrolysis and unburnt products of incomplete combustion. Describing a backdraft incident at a Chatham, England Mattress Store in 1975, Croft (1980) states “this is not an entirely new phenomenon, the first formal description of what have been called ‘smoke explosions’ having been given in 1914” (p. 3).

As an explanation of many contradictory statements in reference to explosions that are reported to have occurred in burning buildings, where it is also testified that explosives were non-existent, we may cite so-called “smoke explosions.”

Distinct from, yet closely allied with explosions of inflammable dust, are explosions caused by the ignition of mixtures of air with the minute particles of unconsumed carbon and invisible gaseous matter in smoke from the imperfect combustion of organic substances…

These “smoke explosions” frequently occur in burning buildings and are commonly termed “back draughts” or “hot air explosions” (Steward, 1914).

As discussed in my earlier post, Fires and Explosions, the term Smoke Explosion was a synonym for Backdraft. In fact, if you look up the definition of smoke explosion in the National Fire Protection Association (NFPA) 921 (2008) Guide for Fire and Explosion Investigation, it says “see backdraft” (p. 921-15). However, today it identifies a different, and in many respects more dangerous extreme fire behavior phenomenon. Smoke (or Fire Gas) Explosion is described in fire dynamics textbooks such as Enclosure Fire Dynamics (Karlsson and Quintiere) and An Introduction to Fire Dynamics (Drysdale) and Enclosure Fires (Bengtsson). Of these, the text Enclosure Fires by Swedish Fire Protection Engineer Lars-Göran Bengtsson provides the best explanation of how conditions for a smoke explosion develop. However, this phenomenon is less well known among firefighters and fire officers. In fact many well known fire service authors continue to use backdraft and smoke explosion interchangeably.

A smoke or fire gas explosion occurs when unburned pyrolysis products accumulate and mix with air, forming a flammable mixture and introduction of a source of ignition results in a violent explosion of the pre-mixed fuel gases and air. This phenomenon generally occurs remote from the fire (as in an attached exposure) or after fire control.

Conditions Required for a Smoke Explosion

The risk of a smoke explosion is greatest in compartments or void spaces adjacent to, but not yet involved in fire. Infiltration of smoke through void spaces or other conduits can result in a well mixed volume of smoke (fuel) and air within its flammable range, requiring only a source of ignition.

Smoke explosions create a significant overpressure as the fuel and air are premixed. Several factors influence the violence of this type of explosion:

• The degree of confinement (more confinement results in increased overpressure)
• Mass of premixed fuel and air in the compartment (more premixed fuel results in a larger energy release)
• How close the mixture is to a stoichiometric concentration (the closer to an ideal mixture the faster the deflagration)

For additional information on transient, explosive, fire phenomena see earlier posts: Gas Explosions and Gas Explosions Part 2.

Indicators Smoke Explosion Potential

It is very difficult to predict a smoke explosion. However, the following indicators point to the potential for this phenomenon to occur.

• Ventilation controlled fire (inefficient combustion producing substantial amounts of unburned pyrolysis products and flammable products of incomplete combustion)
• Relatively cool (generally less than 600^o C or 1112^o F) smoke
• Presence of void spaces, particularly if they are interconnected
• Combustible structural elements
• Infiltration of significant amounts of smoke into uninvolved exposures

Mitigating the Hazard

As with recognizing the potential for a smoke explosion, mitigation can also be difficult. The gases are relatively cool, so application of water into the gas layer may have limited effect. Tactical ventilation to remove the smoke is the only way to fully mitigate the hazard and establish a safe zone. However, use care not to create a source of ignition (such as the sparks created when using an abrasive blade on a rotary saw).

The best course of action is to prevent infiltration of smoke into uninvolved spaces using anti-ventilation (confinement) tactics. Anti-ventilation is the planned and systematic confinement of heat, smoke, and fire gases, and exclusion of fresh air (from the fire). In this case, anti-ventilation may involve pressurizing the uninvolved are to prevent the spread and accumulation of smoke.

Ed Hartin, MS, EFO, MIFIreE, CFO

References

Bengtsson, L. (2001). Enclosure fires. Karlstad, Sweden: Räddnings Verket.

Croft, W. (1980) Fires involving explosions-a literature review. Fire Safety Journal, 3(1), 3-24.

Drysdale, D. (1998). An introduction to fire dynamics (2^nd ed.). New York: John Wiley & Sons.

Hartin, E. (2009, June). Smoke is fuel. FireRescue, 27(6), 54.

Karlsson, B. & Quintiere, J. (2000). Enclosure fire dynamics. Boca Raton, LA: CRC Press.

Kirk, E. (2009, June). Sudden blast: Unanticipated smoke explosion & building collapse nearly kills 3 firefighters. FireRescue, 27(6), 52-54.

National Fire Protection Association. (2008). NFPA 921 Guide for fire and explosion investigations. Quincy, MA: Author.

National Institute for Occupational Safety and Health (NIOSH). (2006) Death in the Line of Duty Report F2005-13. Retrieved June 22, 2009 from http://www.cdc.gov/niosh/fire/pdfs/face200513.pdf

National Institute for Occupational Safety and Health (NIOSH). (2009) Death in the Line of Duty Report F2008-02. Retrieved June 22, 2009 from http://www.cdc.gov/niosh/fire/pdfs/face200803.pdf

Steward, P. (1914). Dust and smoke explosions, NFPA Quarterly 7, 424-428.

Fire Behavior Indicators – A Quick Review

The B-SAHF (Building, Smoke, Air Track, Heat, & Flame) organizing scheme for fire behavior indicators provides a sound method for assessment of current and potential fire behavior in compartment fires. The following provides a quick review of each of these indicator types.

Figure 1. B-SAHF

Building: Many aspects of the building (and its contents) are of interest to firefighters. Building construction influences both fire development and potential for collapse. The occupancy and related contents are likely to have a major impact on fire dynamics as well.

Smoke: What does the smoke look like and where is it coming from? This indicator can be extremely useful in determining the location and extent of the fire. Smoke indicators may be visible on the exterior as well as inside the building. Don’t forget that size-up and dynamic risk assessment must continue after you have made entry!

Air Track: Related to smoke, air track is the movement of both smoke (generally out from the fire area) and air (generally in towards the fire area). Observation of air track starts from the exterior but becomes more critical when making entry. What does the air track look like at the door? Air track continues to be significant when you are working on the interior.

Heat: This includes a number of indirect indicators. Heat cannot be observed directly, but you can feel changes in temperature and may observe the effects of heat on the building and its contents. Remember that you are insulated from the fire environment, pay attention to temperature changes, but recognize the time lag between increased temperature and when you notice the difference. Visual clues such as crazing of glass and visible pyrolysis from fuel that has not yet ignited are also useful heat related indicators.

Flame: While one of the most obvious indicators, flame is listed last to reinforce that the other fire behavior indicators can often tell you more about conditions than being drawn to the flames like a moth. However, that said, location and appearance of visible flames can provide useful information which needs to be integrated with the other fire behavior indicators to get a good picture of conditions.

It is important not to focus in on a single indicator, but to look at all of the indicators together. Some will be more important than others under given circumstances.

Getting Started

Considering the wide range of different building types and occupancies, developing a concept map of the factors and interrelationships that influence fire behavior is no simple task. As you begin this process, keep in mind that it is important to move from general concepts to more specific details. For example, you might select construction type, contents, size, ventilation profile, and fire protection systems as the fundamental factors as illustrated in Figure 2. (However, you also might choose to approach this differently!).

Figure 2. Basic Building Factors

Remember that this is simply a draft (as will each successive version of your map)! Don’t get hung up on getting it “right”. The key is to get started and give some thought to what might be important. After adding some detail, you may come back and reorganize the map, identifying another basic element. For example, early versions of this map listed Fire Suppression Systems (e.g., automatic sprinklers) as one of the core concepts. However, after adding some detail, this concept was broadened to Fire Protection Systems (e.g., automatic sprinklers, fire detection, and other types of inbuilt fire protection).

Developing the Detail

Expanding the map requires identification of additional detail for each of the fundamental concepts. If an idea appears to be obviously related to one of the concepts already on the map, go ahead and add it. If you are unsure of where it might go, but it seems important, list it off to the side in a staging area for possible additions. For example, area and height are important concepts related to size. However, compartmentation may be related to size or it may be a construction factor. If you are unsure of where this should appear on the map, place it in the Staging Area for now.

Figure 3. Expanding the Map

Next Steps

Remember that the process of contracting your own map is likely as important as the (never quite) finished product. The following steps may help you expand and refine the building factors segment of the map:

• Look at each of the subcategories individually and brainstorm additional detail. This works best if you collaborate with others.
• Take your partially completed map and notes and visit several different types of buildings. Visualize how a fire might develop and what building features would influence this process.
• Examine the incident profiled in the Remember the Past segment of this post and give some thought to how building factors may have influenced fire behavior and the outcome of this incident.

In addition, I am still posing questions related to B-SAHF using Twitter. Have a look [http://twitter.com/edhartin] and join in by responding to the questions. While this is not a familiar tool to most firefighters, I think that it has great potential.

Thanks

I would also like to thank Senior Instructor Jason Collits of the New South Wales (Australia) Fire Brigades and Lieutenant Matt Leech of Tualatin Valley Fire and Rescue (also an Instructor Trainer with CFBT-US, LLC) for their collaborative efforts on extending and refining our collective understanding of the B-SAHF indicators. Jason and Matt have been using Bubbl.us to develop and share their respective maps and I will be integrating their work into future posts on Fire Behavior Indicators.

Figure 4 Jason Collits and Matt Leech

Remember the Past

Yesterday was the eighth anniversary of a tragic fire in New York City that claimed the lives of three members of FDNY as a result of a backdraft in the basement of a hardware store.

June 17, 2001
Firefighter First Grade John J. Downing, Ladder 163
Firefighter First Grade Brian D. Fahey, Rescue 4
Firefighter First Grade Harry S. Ford, Rescue 3
Fire Department City of New York

Fire companies were dispatched to a report of a fire in a hardware store. The first- arriving engine company, which had been flagged down by civilians in the area prior to the dispatch, reported a working fire with smoke venting from a second-story window.

A bystander brought the company officer from the first-arriving engine company to the rear of the building where smoke was observed venting from around a steel basement door. The first-arriving command officer was also shown the door and ordered an engine company to stretch a line to the rear of the building. A ladder company was ordered to the rear to assist in opening the door; Firefighter Downing was a member of this company. The first-due rescue company, including Firefighters Fahey and Ford, searched the first floor of the hardware store and assisted with forcible entry on the exterior.

The incident commander directed firefighters at the rear of the building to open the rear door and attack the basement fire. Firefighters on the first floor were directed to keep the interior basement stairwell door closed and prevent the fire from extending. The rear basement door was reinforced, and a hydraulic rescue tool was employed to open it. Once the first door was opened, a steel gate was found inside, further delaying fire attack.

Firefighters Downing and Ford were attempting to open basement windows on the side of the building, and Firefighter Fahey was inside of the structure on the first floor.

An explosion occurred and caused major structural damage to the hardware store. Three fire-fighters were trapped under debris from a wall that collapsed on the side of the hardware store; several firefighters were trapped on the second floor; firefighters who were on the roof prior to the explosion were blown upwards with several firefighters riding debris to the street below; and fire-fighters on the street were knocked over by the force of the explosion.

The explosion trapped and killed Firefighters Downing and Ford under the collapsed wall; their deaths were immediate. Firefighter Fahey was blown into the basement of the structure. He called for help on his radio, but firefighters were unable to reach him in time.

The cause of death for Firefighters Downing and Ford was internal trauma, and the cause of death for Firefighter Fahey was listed as asphyxiation. Firefighter Fahey’s carboxyhemoglobin level was found to be 63%.

In addition to the three fatalities, 99 firefighters were injured at this incident. The fire was caused when children – two boys, ages 13 and 15 – knocked over a gasoline can at the rear of the hard-ware store. The gasoline flowed under the rear doorway and was eventually ignited by the pilot flame on a hot water heater.

For additional information on this incident, see the following:

NIOSH Death in the Line of Duty Report F2001-23,

Simulation of the Dynamics of a Fire in the Basement of a Hardware Store

Incident Photos by Steve Spak

Ed Hartin, MS, EFO, MIFireE, CFO

References

Grimwood, P., Hartin, E., McDonough, J., & Raffel, S. (2005). 3D firefighting: Training, techniques, & tactics. Stillwater, OK: Fire Protection Publications.

Hartin, E. (2007) Fire behavior indicators: Building expertise. Retrieved June 17, 2009 from www.firehouse.com.

Hartin, E. (2007) Reading the fire: Building factors. Retrieved June 17, 2009 from www.firehouse.com.

National Institute for Occupational Safety and Health (NIOSH). (2003) Death in the line of duty report F2001-23. Retrieved June 18, 2009 from http://www.cdc.gov/niosh/fire/pdfs/face200123.pdf

Bryner, N. & Kerber, S (2004) Simulation of the dynamics of a fire in the basement of a hardware store – New York, June 17, 2001 NISTR 7137. Retrieved June 18, 2009 from http://www.fire.nist.gov/bfrlpubs/fire06/PDF/f06006.pdf

United States Fire Administration (USFA) Firefighter fatalities in 2001. Retrieved June 18, 2009 from http://www.usfa.dhs.gov/downloads/pdf/publications/fa-237.pdf

In their article Realistic Live Burn Training You Can Afford published in the May 2009 issue of Fire Engineering, Kriss Garcia and Reinhard Kauffmann extolled the advantages of constructing a panelized wood frame structure lined with several layers of 5/8″ sheetrock (see Figure 1) as an alternative to other types of structural live fire training props and facilities. I have to admit; I am intrigued by the potential advantages of this prop for demonstration of the influence of horizontal ventilation (both natural and positive pressure) and tactical training in fire attack operations. However, I am not convinced that this prop is universally superior to other types of purpose built structures used for live fire training. Choice of live fire training facilities needs to consider a range of factors including intended learning outcomes, cost (both initial and life-cycle), and environmental considerations and constraints.

Figure 1. Build and Burn Single Family Dwelling

Photo provided by Kriss Garcia (positivepressureattack.com)

Response to Garcia and Kauffmann

The most important factor to consider in design, selection, and use of live fire training props and facilities is that all live fire training is a simulation. The fire is real, but the fuel load and conditions are managed to create a specific effect (unlike in the “real world”). This does not necessarily mean that the training is ineffective, simply that each evolution is intended to provide the participants with a specific opportunity to learn and develop skills.

Having conducted a substantial number of live fire training exercises in purpose built props and acquired structures, I have found that each has its advantages. Kriss and Reinhard are particularly critical of props constructed from steel containers. They state that these type of props do not provide a realistic context for showing fire development or honing fire tactical skills. I would respectfully disagree with several caveats. 1) A single compartment prop (such as a demonstration or attack cell) is not designed or intended for tactical training. This type of prop is designed to provide a safe and effective environment to demonstrate fundamental fire development in a compartment and the opportunity for learners to practice nozzle technique. 2) Multi-compartment container-based props do provide a reasonable context for tactical training with interior doors, obstructions, potential for varied fire location, etc. However, as with all other types of prop using Class A fuel (including the build and burn structure), the fuel load and configuration is considerably different than in an actual dwelling or commercial structure. Kriss also points to the severe fire conditions and damage to both equipment and participants when working in container based props. This is the result of inappropriate use, not a defect in the type of prop used. Conditions are set and controlled by the instructors.

I have greater agreement with Kriss’s and Reinhard’s observations on high-tech gas fired props in that they often fail to replicate key fire behavior indicators and may not respond appropriately to ventilation and application of water, providing poor feedback to the learners on their performance.

I also agree with many of Kriss’s and Reinhard’s observations on acquired structures. However, their example illustrating “unpredictable fire behavior” due to medium density fiberboard that had been plastered over, resulting in ignition of pyrolysis products behind the attack crew is inaccurate. This fire behavior was entirely predictable, but unanticipated (the big difference here is that unanticipated fire behavior is simply the result of a lack of information on the part of the instructors, not by random action by the fire). Kriss states that when working with acquired structures, you need to strictly adhere to the requirements of NFPA 1403. This may be a bit misleading in that this standard applies to all live fire training (including use of the build and burn structure).

Kriss and Reinhard make a good case for the ideal live fire training structure. However, it is critical to also give some thought to the intended purpose of the building or prop. Single compartment props (regardless of what they are constructed out of) may be a tremendous tool for practicing door entry and nozzle technique much like a putting green or driving range when practicing golf. The putting green and driving range are useful tools in developing specific skills, but they are not the game of golf. The ideal live fire training prop is designed to provide a means to safely, effectively, and efficiently achieve specified learning outcomes. Much the same as there is no single tactic that will solve all problems presented on the fireground, there is no single type of live fire training prop that provides the ideal context for all types of live fire training evolutions. Again, it is critical to remember that all live fire training is a simulation. The key is to provide an adequate degree of physical and functional fidelity (look real enough and behaves real enough) to achieve the intended learning outcomes.

Intended Use and Learning Outcomes

Pilots in the United States Air Force follow an exacting course of study which includes classroom instruction, simulation, and flight instruction in trainer aircraft such as theT6 and T38 before progression to more advanced aircraft such as the F22 Raptor. Each simulator and aircraft used in this progression is intended to provide the pilot with a specific learning context. After transition to high performance aircraft, pilots continue to use simulators to practice skills that may be too high risk to perform in flight.

Figure 2. T6, T38, & F22 Aircraft

The same concept can be applied to live fire training. Observing fire development and the effect of water application may require a somewhat different context than evolutions involving door entry procedures and integration of fire control and tactical ventilation. In an ideal world, fire service agencies would have access to various types of live fire training props, each suited to providing the best context for specific levels of training and learning outcomes. Container based props and burn buildings may be simple or complex dependent on their intended purpose and learning outcomes that they are designed to support (see Figures 3-5)

Figure 3. Split Level Cell, Palm Beach County Fire Rescue

Note: This prop was constructed by Fire Training Structures, LLC and is most effective for demonstrating compartment fire behavior.

Figure 4. Large Volume Container, Swedish Civil Contingencies Agency, Sandö, Sweden

Note: This prop was constructed on site and is designed to demonstrate fire behavior and the impact of tactical operations in large compartments such as found in commercial buildings.

Figure 5. Large Masonry Burn Building, British Fire Service College

Note: This is one of many live fire training facilities at the college (including container based props and other masonry burn buildings). This building provides an industrial context for advanced firefighter training.

However, for most of us it is not a perfect world. Fire departments faced with limited fiscal resources are often limited in their options for live fire training. If they are fortunate, they have or have access to a purpose built structure that provides a safe and effective environment for a variety of types of live fire training. Each of these types of structures has limitations. The major problem encountered is when instructors and learners believe that the purpose built structure is intended to fully replicate a realistic fire environment as encountered during emergency incidents. It cannot, much the same as a flight simulator cannot fully replicate flying a high performance aircraft. However, it can replicate critical elements of context that help develop knowledge, skill, and a high level of proficiency.

Instructors must 1) identify the intended learning outcomes and critical elements of context necessary to develop learner proficiency to ensure participant safety and 2) recognize both the capabilities and limitations of the props and facilities available.

Other Considerations

Fire departments often face a more difficult challenge than determining what type of prop or facility is most effective or how to best use available facilities. The cost of live fire training is a major concern and unfortunately is often a major determining factor in the availability and type of live fire training conducted. The initial cost for purpose built props and facilities can be a large hurdle with simple commercially built props and structures costing from $40,000 to hundreds of thousands of dollars (or even more for a commercial fire simulator as illustrated in Figure 5).  However, initial cost of the prop or facility is the tip of the iceberg. Ongoing costs include fuel, maintenance, as well as instructor and student costs.

While somewhat beyond the scope of this post, environmental considerations and restrictions can also have a significant impact on both design and operation of live fire training facilities and can also have a significant impact on initial and ongoing cost.

The Way Forward

In general, there has not been a concerted and scientifically based effort to determine the critical elements of context required for live fire training. As discussed in Training Fires and Real Fires, live fire training must look real enough (physical fidelity) and react realistically to tactical operations (functional fidelity). However, we have not defined to what extent this is necessary to develop critical skills.

The variety of props, structures, and facilities available for live fire training is substantial, as is the difference in initial, ongoing, and life-cycle cost. While some work has been done comparing these various options, it is often left to individual departments to sort this out without a consistent framework or methodology.

Subsequent posts will examine these two issues in a bit more depth.

Ed Hartin, MS, EFO, MIFireE, CFO

Reference

Garcia, K. & Kaufmann, R. (2009, 2009). Realistic live-burn training you can afford. Fire Engineering, 162(5), 89-93.

Congratulations!

I would like to offer my congratulations to my two friends and colleagues Inspector John McDonough, ASFM of the New South Wales Fire Brigades and Acting Inspector Shan Raffel, CIFireE, EngTech, ASFM of Queensland Fire Rescue on receiving the Australian Fire Service Medal (AFSM) for distinguished service to their nation’s fire service. This is the second accolade for Shan in the last several months as he was recognized as a Companion of the Institution of Fire Engineers (IFE) for his work as national president and his tireless work for IFE Australia. Outstanding work gentlemen, honors well deserved!

Figure 1 ASFM Recpients Shan Raffel (left) and John McDonough (right)

B-SAHF! Master Your Craft

In Reading the Fire: B-SAHF, I introduced the B-SAHF (Building, Smoke, Air Track, Heat, and Flame) conceptual framework for reading the fire and have subsequently provided a series of video clips and photos to provide an opportunity to exercise your skill in reading the fire. While looking at video, photos (and actual incidents) may help build your knowledge and skill, different types of practice and knowledge building can also further your professional development.

Concept Maps

A concept map is a graphic tool for representing knowledge (Novak & Cañas, 2008). The map illustrates concepts and their relationships to one another (similar to an electrical circuit diagram or road map). Concept maps use a hierarchical form (similar to an organizational chart) with general concepts at the top and details further down. Mind maps are a similar tool often used in brainstorming that use a radial hierarchy with a tree-like hierarchy branching out from the center. I draw on both of these approaches in describing fire behavior indicators. A radial hierarchy is used as the foundation, but other relationships are illustrated and concepts can be interconnected in a variety of different ways.

A key step in improving your ability to read the fire is to think about what you should be looking for. Identifying key indicators and thinking about what they mean can be an important step in developing and improving your knowledge and skill. I find that this is an ongoing process as I continue to add to and refine my fire behavior indicators concept map. This map is not a fireground tool or a checklist of things to look for, but serves as a representation of my understanding and learning. While I am willing to share this map (Ed’s B-SAHF Map v5.2.1), it is more useful for you to build your own, representing your own understanding of these indicators and concepts.

Concept maps can be created using a pencil and paper, Post-It notes and an easel pad or white board, or using a computer with drawing software or a program specifically created for concept mapping. At one point or another, I have used each of these tools and find that they all have advantages and disadvantages. The tools you use are not as important as the mental process of collaborating with others and creating your map.

The Starting Point

Without getting bogged down an a long discussion of the educational and psychological foundations for concept mapping, it is important to understand that development of concept maps supports meaningful rather than rote learning. Rote learning often involves simple memorization. Meaningful learning requires three conditions (Ausubel, 1963).

• Concepts must be clear and presented with common language and examples connected to the learner’s prior knowledge.
• The learner must have relevant prior knowledge. Note that the learner does not require expertise, but needs sufficient knowledge to make sense of the concepts involved.
• Most importantly, the learner must choose to learn in a meaningful way.

Many firefighters struggle with creating mind maps (at first) because much of fire service training focuses on rote learning. However, I find that this challenge can easily be overcome if firefighters recognize the value of exploring the key fire behavior indicators and their relationships to one another.

Developing a concept map starts with a focus question that specifies the problem or issue that the map is intended to help resolve. The fire behavior indicators (FBI) concept map starts with the following focus question:

What building, smoke, air track, heat, and flame indicators
provide clues to current and potential fire behavior?

It is important to remember that a concept map is never finished. After you develop the first draft, it is always necessary to revise the map to increase clarity or add important concepts that you discover as work continues. For example, my FBI Concept Map is on Version 5.2.1, indicating five major revisions and 21 minor revisions or additions over seven years!

Knowledge Soup

The best concept maps are not developed in a vacuum. Collaboration with others can help us identify additional information and provides ideas that we may not have thought of on our own. For example, the current version of my FBI concept map started as my collaboration with Shan Raffel. However, it has evolved to include suggestions from hundreds of CFBT course participants.

Propositions or ideas developed by a group of learners may be thought of as ingredients in a kind of “knowledge soup” (Cañas, Ford, Hayes, Brennan, & Reichherzer, 1995, p. 4). The learners share the ingredients and each cook their own variation on the soup by constructing their own understanding. One way to approach this is to brainstorm key concepts and ideas before beginning the process of organizing the information and drawing the map.

Technology and Information Sharing

We have an advantage today that firefighters in previous generations did not have. Technology provides unparalleled opportunity for collaboration and learning. For example, this blog provides me with an opportunity to communicate and share information with firefighters around the world in a matter of minutes. In addition to my twice weekly blog posts, micro-blogging using the CFBT-US Twitter page provides a simple and easy method to rapidly share information on a daily (and in some cases hourly) basis.

Recently I have been reading a series of blog posts titled 31 Days to Build a Better Blog on Problogger. This stimulated my thinking about different ways to leverage technology to share information within the fire service and more particularly the compartment fire behavior community. Twitter may provide a simple means for collecting the ingredients needed for the knowledge soup necessary to develop and improve our respective fire behavior indicators concept maps.

This process could be started posting a question focused on one element of the FBI Concept map such as: What key building factors that impact on fire behavior can be used as indicators of current and predicted fire behavior? Readers can then respond (Tweet Back) with brief statements (no more than 140 characters) that identify the factors. All readers would then have access to this information when constructing the Building Indicators segment of their FBI Concept Map.

Another challenge is actually drawing the concept map (some of us are more graphically inclined or skilled than others). Bubble.us is a simple and easy to learn tool that provides a way to organize information as a concept map and share the work with others by e-mail, on the web, or embedded in a web page.

Figure 2. Bubbl.us Concept Map

Use of this software is free (you simply visit the bubbl.us web page, sign up and start creating your map. You can share your map with others to read or you can give them permission to edit the map. While I have not used this software extensively, it appears to be extremely easy to use and an excellent tool to simplify the process of drawing concept maps.

Where to from Here?

All very interesting, but how does this help us improve our ability to read the fire? Originally I had thought about using the “31 Days” concept to reading the fire. However, it will likely take a bit longer than that.

My next post will propose that we begin with an examination of building factors that influence fire behavior and which may serve as useful indicators in situational assessment. In the mean time, visit the CFBT-US Twitter page and respond to the question about building factors! Follow me for regular updates (you can also subscribe to an RSS Feed to receive information in a feed reader or via e-mail).

Each month I will move to the next element in the B-SAHF organizing scheme for fire behavior indicators until we have completed the entire FBI concept map. However, feel free to work ahead!

Ed Hartin, MS, EFO, MIFireE, CFO

References

Ausubel, D. (1963). The psychology of meaningful verbal learning. New York: Grune and Stratton.

Cañas,A., Ford, K., Hayes, P., Brennan, J., & Reichherzer,T. (1995) Knowledge construction and sharing in Quorum. Retrieved June 7, 2009 from http://www.ihmc.us/users/acanas/Publications/AIinEd/AIinEd.pdf

Novak. J. & Cañas, A. (2008). The theory underlying concept maps and how to construct and use them. Retrieved June 7, 2009 from http://cmap.ihmc.us/Publications/ResearchPapers/TheoryUnderlyingConceptMaps.pdf

Art and Science of Firefighting

NIST has performed a wide range of research that can have a positive impact on the safety and effectiveness of firefighting operations. However, all too often, this information has not made it to front line firefighters. Dan Madrzykowski and Steve Kerber have made a concerted effort to address this issue and increase the day to day impact of NIST fire research. In the video overview of the wind driven fire research, Battalion Chief Jerry Tracy of the FDNY stated that this project was an effort to bridge the gap between the science and art of firefighting and get science to the street.

Research on Wind Driven Fires= Governors Island, New York City

Note: John Freeman Photo from NIST Report TN 1629

Understanding, Surviving, & Fighting Wind Driven Fires

This two DVD training package is based on NIST research conducted at the Building Fire Research Lab (BFRL) in Gaithersburg, MD and on Governors Island in New York city. The package contains:

• Written reports on the laboratory and field experiments
• Multiple videos of the experiments (from standard and thermal imaging video cameras)
• PowerPoint presentation on experimental procedures and results
• Video overview of the research and implications for fireground operations

While the reports and detailed video are tremendous resources, I believe that every firefighter in the United States would benefit from taking 86 minutes to watch the introductory video overview narrated by Battalion Chiefs Peter Van Dorpe (Chicago Fire Department), Jerry Tracy (Fire Department of New York), Dan Madrzykowski (NIST), and Steve Kerber (NIST). The overview presentation is divided into four segments:

1. Introduction and the Chicago Fire Department Experience (BC Peter Van Dorpe)
2. The FDNY Experience (BC Jerry Tracy)
3. Laboratory Experiments (Dan Madrzykowski, PE)
4. Governors Island Experiments (Steve Kerber)
5. Conclusion (BCs Peter Van Dorpe and Jerry Tracy)

This video provides a powerful explanation of the potential danger of wind driven fires (in both high and low-rise structures) and illustrates how scientific research can have a positive impact on the safety and effectiveness of fireground operations. While some may discount the information presented because the research focused (to a large extent) on high-rise buildings, many of the lessons learned have applicability to a much wider range of buildings.

In the summary section of the overview video, BC Peter Van Dorpe made several interesting observations regarding the lessons he learned from this research:

In a high-rise building, you don’t ventilate until you have water on the fire based on potential for a wind driven fire and dramatic influence of wind and ventilation on fire behavior.

Consideration of the concept that the first water on a high-rise fire [in a non-sprinklered building] should be from the exterior based on the dramatic effect of relatively low flow application from the exterior in changing conditions from severe to controllable.

BC Jerry Tracy emphasized the importance of integrating the art and science of firefighting and the need for change. Credibility is critical, both from a scientific and operational perspective. He pointed to the importance of understanding impact of changes in ventilation profile on fire behavior in all types of fires and the potential benefits of alternative strategies and tactics.

How to Order

This two DVD set can be ordered from the United States Fire Administration (USFA) Web Site. However, orders are limited to a single set per organization.

Order Evaluating Firefighting Tactics Under Wind Driven Conditions

Information on this research is also available on the NIST Wind Driven Fire Research web page.

Action Steps

Get a copy of this training package and have a look at the overview video. Ask yourself how this information can be put to work in your environment? What application does this research have beyond high-rise buildings? How can we use this information to increase the safety and effectiveness of firefighting operations in single and multi-family dwellings and in commercial buildings?

CFBT-US on Twitter

In an effort to expand our network, CFBT-US is now on Twitter! Follow Chief Instructor Ed Hartin for information on fire behavior, incident information, photos and video for B-SAHF exercises. Check out the Twitter Portal for an overview video on Twitter and additional information on this social networking tool.

CFBT-US is exploring how to integrate Twitter with the CFBT Blog (and the blog with Twitter). Please share your feedback on the effectiveness and utility of this approach to information sharing.

Ed Hartin, MS, EFO, MIFireE, CFO

My last two posts (Contra Costa County Line of Duty Deaths (LODD) Part 1 & Part 2) examined the conditions and circumstances involved in the incident that took the lives of Captain Matthew Burton and Engineer Scott Desmond while conducting primary search in a small residential structure in San Pablo, California early on the morning of July 21, 2007.

As identified in the Contra Costa County Investigation and NIOSH Death in the Line of Duty Report F2007-28, these line of duty deaths were the result of a complex web of events, circumstances, and actions.

These two reports identify the rapid fire progression that trapped Captain Burton and Engineer Desmond as a fire gas ignition (county and NIOSH reports) or ventilation induced flashover (NIOSH report). Both reports also point to ineffective or inappropriate use of positive pressure ventilation as a contributing factor in the occurrence of extreme fire behavior. However, neither report provides a substantive explanation of how and why this extreme fire behavior occurred.

Investigative Approach

Developing a reasonable explanation of the extreme fire behavior that occurred in this incident involved application of the scientific method as outlined in NFPA 921 Standard on Fire and Explosion Investigations (2008).

The following analysis is based on narrative data and photographic evidence provided in the Contra Costa County Fire Protection District Investigation Report: Michele Drive Line of Duty Deaths and the video taken by the Q76 Firefighter.

In that the district and NIOSH had already collected data, this effort focused on 1) analysis of the data contained in the incident reports, photographs, and video; 2) development of a hypothesis that provided an explanation for what occurred (deductive reasoning), 3) testing this hypothesis (inductive reasoning); 4) revising the hypothesis as necessary; and 5) selecting a final hypothesis.

Figure 1. Fire Development in Bedroom 2

Hypothesis

The fire originated in Bedroom 2, likely on or near the bed. In the growth stage, the fire extended through the hallway into the living room (see Figure 1). The fuel load in the living room and ventilation provided by the open front door permitted the fire to progress through flashover and become fully developed (see Figure 2).

Figure 2. Extension and Fire Development in the Living Room

The extent of fire in the living room consumed the oxygen supplied through the front door, resulting in an extremely ventilation controlled fire in the hallway and bedroom. Unburned flammable products of combustion and pyrolysis products from contents and structural materials accumulated in the upper layer in the bedrooms and hallway.

Figure 3. Fire Control and Development of a Gravity Current

Extinguishment of the fire in the living room allowed development of a gravity current and movement of oxygen through the living room to the hallway and bedrooms allowing flaming combustion in these areas to resume.

Figure 4. Positive Pressure Ventilation

Flaming combustion in the hallway or bedroom resulted in piloted ignition of a substantive accumulation of pyrolysis products and flammable products of incomplete combustion in the upper layer within the hallway and bedrooms. Application of positive pressure at the door on Side A influenced (or speeded up) this phenomena and may have increased the violence of this ignition (due to increased pressure and confinement) but likely aided in limiting the spread of flaming combustion from the hallway into the living room.

Figure 5. Fire Gas Ignition

Supporting Information

Information supporting the preceding hypothesis is divided into three categories: Known, suspected, and assumptions.

Known

The cause and origin  and line of duty death investigation conducted by the Contra Costa Fire Protection District and line of duty death investigation conducted by NIOSH identified and documented a range of data supporting this hypothesis. These data elements include physical evidence, and narrative data obtained from interviews with individuals involved in the incident.

• The fuel load in the bedroom included a bed, dresser, and other contents, exposed wood ceiling, carpet, and carpet pad.
• Fire originated in Bedroom 2 (on or near the bed)
• The female occupant exited the structure prior to making a 911 call to report the fire (via cell phone).
• The female occupant then reentered the building prior to the arrival of the first fire unit in an effort to rescue her husband. [Observations by bystanders included in the report]
• The fire in Bedroom 2 entered the growth stage and extended into the hallway and subsequently the living room. This fire spread was in part due to the combustible wood ceiling. [Information on the cause and origin investigation provided in the report]
• Windows other than the living room window on Side A were substantively intact until the occurrence of the extreme fire behavior event. [Observation by firefighters included in the report]
• E70 knocked down the fire in the living room prior to initiating primary search (without a hoseline). E70 used a left hand search pattern in which they would have moved into the hallway and bedrooms located on Side B of the residence.
• A blower was placed at the front door while E70 and E73 were conducting primary search. Due to the placement of the blower close to the door, it is possible that the air cone did not fully cover the door opening. There is no mention in the report regarding the air track at the door or living room window following placement of the blower. However, E73 reported increased visibility and temperature in the kitchen a short time after the blower was placed, and observed rollover from the hallway leading to the bedrooms.]
• The large window in the living room (if fully cleared of glass) would provide approximately equal area as the door on Side A used as an inlet. Given an equal sized inlet and outlet, efficiency of PPV is likely to be approximately 70%. However, given the location of the exhaust opening next to the inlet, the effectiveness of this ventilation at clearing smoke from compartments beyond the living room and kitchen would have been limited.
• Vertical ventilation was not completed until after the occurrence of the extreme fire behavior phenomena that trapped and killed Captain Burton and Engineer Desmond. The exhaust opening created in the roof had limited impact on interior conditions when it was completed due to the presence of the original roof.
• Fuel load in this compartment was more than sufficient to provide the heat release rate necessary to allow fire development to flashover. [This assessment is based on post-fire photos, room dimensions, and ventilation openings at the time of the ignition].
• Other bedrooms contained a similar fuel load.

Deductions

Several factors supporting the stated hypothesis are not directly supported by physical evidence or narrative data. These elements are deduced based on the design, construction, and configuration of the building and principles of fire dynamics in conjunction with known information.

• The front door remained open after the female occupant reentered. [E70 reported fire and smoke showing from the door and living room window on arrival, but no information provided in the report regarding the position of the door or extent to which the window had failed (fully or partially)]
• Use of the blower is likely to have increased mixing of air and hot, fuel rich fire gases in the hallway, particularly near the opening between the hallway and the living room. Ventilation of smoke from the living room and kitchen through the window on Side A, likely reduced the potential for flaming combustion to have extended from the hallway into the living room.
• Heat conducted through the tongue and groove wood roof/ceiling may have resulted in melting and gasification of asphalt roofing which may have been forced through gaps between the planks to add to the gas phase fuel resulting from pyrolysis and incomplete combustion of contents and structural surfaces within the involved compartments.
• The primary source of air for the fire was through the front door and the living room window. The bottom of the doorway was the lowest opening in the building, likely resulting in a bi-directional air track with smoke exiting out the top of the door and air entering at the bottom. While the sill of the living room window was higher than the door, a bi-directional air track likely developed at this opening as well, with the extreme lower portion of the window opening serving as an inlet while the top of the window functioned as an outlet for flames and smoke [No information about air track at the front door was provided in the report.]
• The fire in the living room reached the fully developed stage after the civilian occupant reentered and prior to the arrival of E70 [This deduction is based on the ability of the female occupant to enter and make her way to the kitchen and the presence of flames exiting the door and living room window on Side A when E70 arrived]

Assumptions

In addition to known and deduced information, the hypothesis is based on the following assumptions.

• The fully developed, ventilation controlled fire in the living room substantively utilized the atmospheric oxygen provided by the air entering through the front door, causing the fire in Bedroom 2 and the hallway to enter ventilation controlled decay. The decay stage fire and heat from the hot gas layer present in the hallway and adjacent rooms continued pyrolysis of fuel packages in this area, resulting in accumulation of a substantial concentration of gas phase fuel in the smoke.
• Control of the fully developed fire in the living room reduced oxygen demand from the fire. The bi-directional air track would have continued and gravity current would have increased air supply to the ventilation controlled decay stage fire in the hallway and bedroom(s).
• Establishment of positive pressure ventilation with the door on Side A serving as the inlet (or inlet and outlet) and the living room window serving as an outlet would have cleared smoke from the living room, but would not have influenced smoke movement from the hallway and bedrooms (as quickly).

Validation

Special thanks to Dr. Stefan Svensson of the Swedish Civil Contingencies Agency and Assistant Professor Greg Gorbett of Eastern Kentucky University for serving as critical friends and providing useful feedback in development of this analysis.

This hypothesis is supported by a range of evidence, deductions and assumptions. However, further validation would require use of other methods such as development of a computational fluid dynamics model and small or full scale fire tests.

More to Follow

My next post will examine the potential influence of positive pressure ventilation (PPV) in this incident as well as a broader look at potential hazards when PPV is used incorrectly or under inappropriate circumstances.

Ed Hartin, MS, EFO, MIFireE, CFO

References

Contra Costa County Fire Protection District.  (2008). Investigation report: Michele drive line of duty deaths. Retrieved February 13, 2009 from http://www.cccfpd.org/press/documents/MICHELE%20LODD%20REPORT%207.17.08.pdf

National Institute for Occupational Safety and Health (2009).  Death in the line of duty report 2007-28. Retrieved May 5, 2009 from http://www.cdc.gov/niosh/fire/pdfs/face200728.pdf.

National Fire Protection Association (NFPA) (2008) NFPA 821 Standard on fire and Explosion Investigations. Quincy, MA: Author.

This post continues examination of the incident that took the lives of Captain Matthew Burton and Engineer Scott Desmond early on the morning of July 21, 2007. Captain Burton and Engineer Desmond died while conducting primary search in a small, one-story, wood frame dwelling with an attached garage at 149 Michele Drive in San Pablo (Contra Costa County), California.

This post focuses on firefighting operations, key fire behavior indicators, and firefighter rescue operations implemented after Captain Burton and Engineer Desmond were discovered after rapid fire progression in the area in which they were searching.

Firefighting Operations

Based on the report of trapped occupants, E70 immediately placed a 150′ preconnected 1-3/4″ (45 m 45 mm) line into service using apparatus tank water. The officer of E70, seeing what he believed to be E74 arriving he passed command to the E74 officer. Unfortunately, the second arriving engine was E73 (using apparatus normally assigned to Station 74 and marked E74).

Note: This incomplete passing of command resulted in loss of command, control, and coordination of tactical operations until the arrival of BC7 at 0202 and formally assumed command at 0205. All tactical operations prior to 0205 were the result of independent action by first alarm companies.

The crew of E70 (officer and firefighter) initiated fire attack through the door on Side A and advanced 3′-5′ (0.9-1.5 m) through the door and quickly knocked down flaming combustion in the living room and through dispatch, requested the first arriving truck to establish vertical ventilation. Retrieving a thermal imaging camera (TIC) from the apparatus, the crew of E70 began a left hand search (towards the bedrooms), but left the hoseline just inside the door on Side A (see Figure 1)

Figure 1. Floor Plan-149 Michelle Drive

E73 hand stretched 200′ of 5″ (127 mm) supply line to a nearby hydrant. As he returned from the hydrant the firefighter from E73 observed a large volume of smoke from Side B. E73 officer tasked E70 engineer with placing a blower at the door on Side A. E73 (officer and firefighter) entered through the door on Side A and began a right hand search (taking the opposite direction from E70). E73 encountered poor visibility, but moderate temperature. While E73 conducted the search, E73 engineer shut off the natural gas service to the house.

E69 arrived at 0157 and prepared to perform vertical ventilation. The officer performed a size-up while the engineer obtained a chain saw and the firefighter placed a 14 ladder to provide access to the roof at the A/D corner. E70 engineer, asked the E69 officer about placing a blower to the front door (as previously ordered by the officer of E73) and he answered in the affirmative. The engineers from E70 and E73 placed a blower into operation 3′ (0.9 m) from the front door due to a half wall that partially enclosed the porch.

Note: No information is provided in the report regarding air track prior to or following pressurization of the building. The only substantive exhaust opening at the time the blower was placed into operation was the window in the living room immediately adjacent to the door on Side A.

E73 located the first civilian casualty, a female occupant in the kitchen (see Figures 2 and 5). As they removed the victim, both visibility and temperature increased dramatically. As they move the victim through the living room, they observed rollover coming from the hallway leading to the bedrooms (see Figures 2 and 5). The E73 officer briefly operated the hoseline left in the living room by E70 to control flaming combustion in the upper layer. The blower was turned 90^o to permit removal of the victim, but was then returned to its original operating position. E69 officer assigned the E69 firefighter to assist E73 with patient care on Side A.

The E69 officer and engineer proceeded to the roof and began making a vertical ventilation opening on Side A roof, over the hallway. At 0159 Q76 arrived and while the officer was donning his breathing apparatus (BA), the window in Bedroom 1 failed suddenly followed by a significant increase in flaming combustion from the windows in Bedroom 1 and 2 on Sides A and B.

The firefighter from E73 who was providing emergency medical care to the civilian fire victim observed that the window in Bedroom 1 which had been cracked with some discharge of smoke, failed violently with glass blowing out onto the lawn and a large volume of flames venting from the window for a period of 10 to 15 seconds (see Figure 2).

Figure 2. Extreme Fire Behavior

Note: Adapted from eight seconds of video was shot by Q76 firefighter from in front of Exposure D, looking towards the A/D corner of the fire building.

Figure 3. Post Fire Photo from in Front of Exposure D

Note: This screenshot from Google Maps Street View is from a similar angle as the video taken by Q76 firefighter and is provided to provide a point of reference and perspective for the video.

The E73 officer reentered the building and initiated fire attack using the hoseline left in the living room. E70 engineer stretched a second 150′ 1-3/4″ (45 m 45 mm) line to the front door. The second line was stretched into the building by Q76. Immediately after entering through the door on Side A, the Q76 met E73 officer who was exiting with low air alarm activation. Q76 took over the initial hoseline and worked their way down the hallway leading to the bedrooms, leaving the second line in the living room (see Figure 2) Q76 encountered poor visibility and high temperature with flames extending out of Bedrooms 1 and 2 and rollover in the hallway.

Shortly after exiting the building E73 officer advised E73 engineer that he was “out of air” [he was likely in a low air condition with low air alarm sounding rather than completely out of air] and expressed concern regarding E70’s air status.

Battalion 7 (BC7) arrived at 0202 and attempted to make face-to-face contact with Command (E70) as he had not heard E70 attempt to pass command to E74. At 0203, BC7 confirmed that a medic unit was responding and requested that the medic upgrade from Code 2 to Code 3. (Code 2 is a non-life threatening medical emergency requiring immediate response without the use of red lights or siren. Code 3 is a a medical emergency requiring immediate response with red lights and siren.) BC7 then attempted to contact E70 on the tactical channel and asked other crews operating at the incident about the status of E70. At 0205, BC7 ordered a second alarm and attempted to contact E70 on non-assigned tactical channels (in the event that their radios were inadvertently on the wrong channel). The second alarm added three engines (E74, E75, and E73) and a battalion chief (BC71) to the incident.

While BC7 was attempting to locate E70, Q76 was operating in the hallway and bedrooms in an effort to control the fire. They knocked the fire down in Bedroom 2 and controlled the rollover extending from Bedroom 1 down the hall. Q76 officer scanned Bedroom 2 with a TIC, but did not observe any victims. Q76 then advanced to Bedroom 1.

E69 completed a 6′ x 6′ (1.8 m x 1.8 m) ventilation opening in the roof on Side A, two thirds of the way from their access point at the A/D corner to Side B. Immediately after making the opening, they observed minimal smoke discharge (and were able to see items stored in the attic and the attic floor (original roof). They attempted to breach the attic floor, but were unable to do so (as it was constructed of 2″ x 6″ (51 mm x 152 mm) tongue and groove planks).

At 0206, after repeated unsuccessful attempts to contact E70, BC7 transmitted a report of a missing firefighter and assumed Command. Command requested an additional engine (E68) be added to the second alarm assignment. Battalion 64 (BC64) added himself to the incident and advised dispatch.

As E69 exited the roof they heard a loud pop and observed flames exiting the roof ventilation opening a distance of 8′-10′ (2.4-3.0 m). After knocking down the fire in Bedroom 1 Q76 moved back to Bedroom 2. Failure of the gypsum board on the wall between Bedrooms 1 and 2 allowed operation of the stream from their hoseline into both bedrooms.

While at the doorway of Bedroom 2, Q76 observed a substantial volume of fire in the attic through a small hole in the hallway ceiling (see Figure 4) and attempted to apply water into the attic. However, their stream was ineffective.

Figure 4. Hallway Ceiling.

Note: Adapted from Contra Costa Fire Protection District Photos, Investigation Report: Michele Drive Line of Duty Deaths. Brightness and contrast adjusted to increase clarity.

After exiting the roof, E69 proceeded counter clockwise around the building to Side C where they removed window screens and broke out several panes of glass, but did not observe an appreciable discharge of smoke. Continuing around the B/C corner, E69 observed flames from the window of Bedroom 2 and the attic.

At 0208 Command (BC7) repeatedly attempted to contact E70 by radio on the tactical channel. Unsuccessful, he requested an additional Code 3 ambulance and advised that the status of the missing firefighters was unknown.

E69 met with Command (BC7) and was assigned to continue primary search for the second reported occupant. E69 firefighter and engineer began the search while the officer replaced his SCBA cylinder. As they entered, they picked up a hoseline (second 1-3/4″ (45 mm) hoseline) and used it to extinguish small areas of fire as they moved towards the kitchen. Q76 handed off their TIC to E69 as they exited the building with low air alarms sounding.

Q76 replaced SCBA cylinders and was tasked with search for E70 on the exterior. While conducting this search, they observed flames 10′-15′ (3.0-4.6 m) in length issuing from the gable vent on Side B.

After E69 officer rejoined his crew in the kitchen, they located the second civilian casualty who was determined to be diseased (see Figure 2). Command (BC7) ordered E69 to defer removing the victim and continue searching for E70.

Firefighter Rescue Operations

E69 walked through the interior of the dwelling looking for E70 and used a hoseline to knock down fire still burning in the closet of Bedroom 2. E69 advised command that E70 was not inside, but was instructed to conduct a second search of the interior.

At 0127, Command (BC7) asked dispatch to conduct a “head count” [personnel accountability report (PAR)]. Second alarm resources arrived between 0218 and 0221.

E69 reentered the building and conducted a thorough search for E70. At 0221, Command (BC7) ordered companies to “evacuate” [withdraw from] the building. Based on the urgency of his assignment to locate E70, E69 officer decided to continue the search into Bedroom 2. At approximately 0222, E69 located Captain Burton (fire service casualty 1) under debris on the right side of the bed (see Figure 2). His facepiece was still in place and his low air alarm was ringing slowly. E69 attempted to remove the Captain, but were only able to move him to the doorway to Bedroom 2 before smoke conditions worsened and visibility decreased. Near exhaustion, one member of the crew experience low air alarm activation and became disoriented requiring assistance to exit to the door on Side A.

Command (BC7) assigned Q76 to assist with the search. As E69 exited, they advised Q76 that they had located one member of E70 in the bedroom. After exiting, E69 advised Command (BC7) that they had located one member of E70 and that he appeared to be diseased and that they were having difficulty in removing him. Q76 quickly located Captain Burton inside the doorway of Bedroom 2 and removed him to Side A at 0228. E73 attempted resuscitation, but quickly determined that the Captain’s injuries were fatal.

BC64 and E76 officer continued the search in Bedroom 2 and located Engineer Desmond (fire service casualty 2) on the left side of the bed (see Figure 2). E72 assisted in controlling the fire in Bedroom 2 and the removal of the second member of E70 on a backboard. Engineer Desmond was removed from the building at approximately 0224. After both members of E70 were removed, crews removed the deceased civilian occupant.

Timeline

Review the Michelle Drive Timeline (PDF format) to gain perspective of sequence and the relationship between tactical operations and fire behavior.

Questions

The following questions focus on fire behavior, influence of tactical operations, and related factors involved in this incident.

1. The E73 officer tasked E70 engineer with placement of a blower at the door on Side A (use of this tactic was reaffirmed by the E69 officer). What air track did this use of positive pressure create and what effect did this have on 1) conditions in the living room and kitchen and 2) in the hallway and bedrooms? Why do you think that this was the case?
2. What type of extreme fire behavior phenomena occurred in this incident? Do you agree with the Contra Costa County Fire Protection District report conclusion that this was a fire gas ignition or do you suspect that some other phenomenon was involved?
3. How did the conditions necessary for this extreme fire behavior event develop (address both the fuel and ventilation sides of the equation)?
4. What was the initiating event(s) that lead to the occurrence of the extreme fire behavior that trapped Captain Burton and Engineer Desmond? How did the use of positive pressure ventilation influence the occurrence of the extreme fire behavior (if in fact it did)?
5. What action could have been taken to reduce the potential for extreme fire behavior and maintain tenable conditions during primary search operations?
6. How did building design and construction impact on fire behavior and tactical operations during this incident?

Ed Hartin, MS, EFO, MIFireE, CFO

References

Contra Costa County Fire Protection District.  (2008). Investigation Report: Michele Drive Line of Duty Deaths. Retrieved February 13, 2009 from http://www.cccfpd.org/press/documents/MICHELE%20LODD%20REPORT%207.17.08.pdf

National Institute for Occupational Safety and Health (2009).  Death in the Line of Duty Report 2007-28. Retrieved May 5, 2009 from http://www.cdc.gov/niosh/fire/pdfs/face200728.pdf.

The theme for the 2009 meeting Institution of Fire Engineers (IFE) Compartment Firefighting Special Interest Group (SIG) in Sydney, Australia was Finding the Common Ground. The 15 participants represented 12 fire service organizations from Australia, New Zealand, Sweden, the UK, Spain, Croatia, China, Canada, and the United States.

Figure 1. 2009 IFE Compartment Firefighting SIG Participants

Understanding & Application

The dominant common theme identified by the participants is the need for firefighters and fire officers to have a solid understanding of fire dynamics and the ability to apply that knowledge in an operational context. Achieving this goal cannot be accomplished simply by delivering a course or training program, it requires a fundamental shift in perspective and ongoing effort to support individual and organizational learning.

Simply achieving knowledge of fire dynamics and skill in task and tactical activity is necessary but not sufficient. Achieving increased safety and effectiveness requires that firefighters and fire officers effectively apply this knowledge on the fireground. Facilitating this transfer from training to operational context is a challenge is a significant challenge.

Dr. Stefan Svensson of the Swedish Civil Contingencies Agency posed the question: How do we get learners to understand the differences between training fires and “real fires”. This is an interesting question in that training conducted in a container, burn building, or acquired structure is in fact a “real fire”, but has considerably different characteristics than a fire occurring in a house, apartment, or commercial building. Improperly designed training may provide the learner with an inaccurate perspective on the fire environment which can lead to disastrous consequences. The challenge is managing risk while developing a realistic understanding of fire behavior.

What is the Difference?

Compartment fires in the training environment differ from those encountered during emergency operations differ on the basis of compartment characteristics, fuel, ventilation profile, heat release rate, and time scale. In addition to differences related to fire dynamics, firefighters and fire officers also encounter psychological stress resulting from a sense of urgency, organizational and community expectations (particularly in situations where persons are reported to be trapped in the building).

Other than acquired buildings, structures used for fire training are generally designed and built for repetitive use and not for regular human habitation. Structural characteristics that make a durable live fire training facility are considerably different than most if not all other structures in the built environment. Density, thermal conductivity, and specific heat of training structures can be considerably different than a dwelling or commercial structure, which has a significant impact on fire behavior.

The ventilation profile of a purpose built prop or burn building is also likely to have significantly different compartmentation and ventilation profile than a typical residential or commercial structure. Live fire training facilities often (but not always) are designed with burn compartments. This speeds fire development and minimizes both initial and ongoing cost. However, fire behavior and the impact of fire control tactics can be considerably different in a large area and/or high ceiling compartment. Many modern structures are designed with open floor plans that are challenging to duplicate in the training environment. Energy efficient structures limit ventilation (air exchange), while training structures are often quite leaky, particularly after extensive use. This can have a significant influence on development of a ventilation controlled burning regime and influence of ventilation on the concentration of gas phase fuel in smoke. Failure of glass windows in ordinary structures should be anticipated, as this changes the ventilation profile and resulting fire behavior. Training structures on the other hand provide a more consistent ventilation profile as durable (e.g., metal) windows do not present the same potential for failure.

While structural characteristics, compartmentation, and ventilation differ between typical structures in the built environment and those used for live fire training, one of the most significant differences lies in the types, quantity, and configuration of fuel.

National Fire Protection Association (NFPA) 1403 Standard on Live Fire Training is fairly explicit regarding fuel characteristics and loading for live fire training evolutions. Most of these provisions can be tied directly to incidents in which participants in live fire training exercises lost their lives. Unfortunately, there are not the same provisions in fire and building codes. Fuel load is considerably higher in most residential and commercial occupancies than is typically used in live fire training, even in advanced tactical evolutions.

Together these differences provide considerably different fire dynamics between the training and operational environments. How much and in what ways does this impact on the effectiveness of compartment fire behavior training (CFBT)?

Fidelity

As discussed, CFBT, even when conducted in an acquired structure does not completely replicate fire conditions encountered in an operational context. All CFBT involves simulation. The extent to which a simulation reflects reality is referred to as fidelity:

The degree to which a model or simulation reproduces the state and behavior of a real world object or the perception of a real world object, feature, condition, or chosen standard in a measurable or perceivable manner; a measure of the realism of a model or simulation; faithfulness… 2. The methods, metrics, and descriptions of models or simulations used to compare those models or simulations to their real world referents or to other simulations in such terms as accuracy, scope, resolution, level of detail, level of abstraction and repeatability. (Northam, n.d.)

CFBT can involve a wide range of simulations, from the use of photos and video, non-fire exercises, small scale props such as doll’s houses, single and multi-compartment props, and burn buildings, and acquired structures. Each provides differing degrees of fidelity.

Fidelity can be described in a number of different ways. One fairly simple approach is to examine physical and functional fidelity (see Figure 2). Physical fidelity is the extent to which the simulation looks and feels real. Functional fidelity is based on the extent to which the simulation works and reacts realistically.

Figure 2. Two-Dimensional Fidelity Matrix

Note: Adapted from Fidelity Versus Cost and its Effect on Modeling & Simulation (Duncan, 2007)

While describing fidelity of a simulation as low, moderate, or high, this is likely to be inadequate. A more useful description of fidelity includes both qualitative and quantitative measures on multiple dimensions. But what measures and what dimension? In a compartment firefighting simulation, key elements of physical fidelity will likely include fire behavior indicators such as Building, Smoke, Air Track, Heat, and Flame (B-SAHF). Important aspects of physical fidelity would include the characteristics of doors and windows (e.g., opening mechanism), hose and nozzles, and influence of tactics such as gas and surface cooling on fire behavior.

On the surface it makes sense that increased fidelity would result in increased effectiveness and transfer of knowledge and skill. However, it is important to remember that “All models are wrong, but some models are useful” (Box & Draper, 1987, p. 424). The importance the various aspects of fidelity depend on the intended learning outcome of the simulation. In fact, a simulation that focuses on critical contextual elements may be more effective than one that more fully replicates reality.

Figure 3. Door Entry Drill

For example, teaching the mechanics and sequence of door entry procedures (see Figure 3) might be more effectively accomplished using a standard door without smoke and flame than under more realistic live fire conditions. On the other hand, reading fire behavior indicators at the door and effectively predicting interior conditions is likely to require substantively different elements of context. However, at this point, we simply have unsupported opinion and in some cases anecdotal evidence of the effectiveness or lack of effectiveness of current training practices. The key to this puzzle is to clearly define the intended learning outcomes and identify the critical elements of context that are required.

Questions Remain

The IFE Compartment Firefighting SIG identified the need for a greater emphasis on fire behavior training at all levels (e.g., entry level firefighters, incumbent firefighters, and fire officer) as well as ongoing professional development and skills maintenance. However, a number of interesting questions remain, including:

• What are the most effective methods of developing firefighters understanding of compartment fire behavior?
• What is necessary to effectively facilitate transfer of this knowledge from training to the operational context?
• What level of fidelity is necessary in live fire training do develop and maintain critical skills?
• How can technological simulation (computer or video based) simulation be used to augment live fire training to maintain proficiency?
• To what extent might non-live fire simulation (e.g., CFBT for the Wii) be used to develop compartment firefighting competencies?

Professor David Morgan of Portland State University observes that “A successful research project requires two things: Meaningful research questions and appropriate means to answer those questions” (Morgan, 2005, p. 1-2). One of the greatest potential benefits resulting from collaboration between members of the IFE Compartment Firefighting SIG is the integration of the skills of academics and practitioners, scientists and firefighters. During the 2009 workshop, SIG member Steve Kerber from Underwriters Laboratory (formerly with the National Institute for Standards and Technology) emphasized the importance of scientists and engineers doing research with, not simply for the fire service. This has the potential to not only identify meaningful questions, but also to provide the knowledge and skills necessary to answer them.

Ed Hartin, MS, EFO, MIFireE, CFO

References

Northam, G. (n.d.). Simulation fidelity – Getting in touch with reality. Retrieved May 2, 2009 from http://www.siaa.asn.au/get/2395365095.pdf

Box, G. & Draper, N. (1987). Empirical model-building and response surfaces. San Francisco: Wiley.

Duncan, J. (2007). Fidelity versus cost and its effect on modeling & simulation. Paper presented at Twelfth International Command and Control Research and Technology Symposium (12^th ICCRTS), 19-21 June 2007, Newport, RI.

Morgan, D. (2005). Introduction [to integrated methods] (Unpublished Manuscript). Portland, OR: Portland State University.

In May 2008 I was fortunate to be one of 12 instructors, fire officers, and fire scientists who met in Revinge, Sweden at the invitation of Dr. Stefan Svensson of Räddnings Verket (Swedish Rescue Services Agency). Stefan was intrigued by the idea of putting a dozen or so leading fire service professionals with an interest in fire behavior, but divergent perspectives on strategies and tactics in the same room. His research question was to “see what would happen”. Stefan invited participants from Sweden, the United Kingdom, Australia, Poland, Germany, Spain, France, and the United States to this unique event.

Figure 1. Participants in the 2008 International Fire Instructors Workshop

What happened was that we found tremendous commonality of interest and commitment to improving firefighter safety and fire protection across the world. Surprisingly, while we often disagreed on technical issues and discussion was at times quite vigorous, we left the workshop with greater understanding and a stronger bond.

Special Interest Group

As an outgrowth of our meeting in Sweden, we formed a special interest group (SIG) under the umbrella of the Institution of Fire Engineers. The Compartment Fire Behavior Special Interest Group serves to construct knowledge by integrating fire behavior research, instruction, and practical application.

The first meeting of this newly formed SIG will be held 27-28 April 2009 in Sydney, Australia with the theme Finding the Common Foundation. Participants from around the world will be examining compartment fire behavior training principles and practices to find common ground and identify best practices. Immediately following the workshop, the participants will be presenting at the International Firefighting Safety Conference in Sydney on 29 April through 1 May and in Perth on 4-5 May 2009.

International Firefighting Safety Conference

The conference theme is Protecting the Protectors with a wide range of presentations on fire science, strategy and tactics, and fire behavior training.

I will be making two presentations in Sydney and one in Perth:

• How Much Science? (Sydney)
• Extreme Fire Behavior: Understanding the Hazard (Sydney)
• Fire Development in a Compartment (Perth)

Additional information and a complete outline of the program is available on the conference web site .

Critical NIOSH Recommendation

On Thursday morning, I will be somewhere over the western Pacific, but use WordPress’ automated publishing feature to upload a post on NIOSH Report F2007-28 on the line-of-duty deaths of Captain Matthew Burton and Engineer Scott Desmond of the Contra Costa Fire Protection District while conducting primary search at a residential fire. In a groundbreaking first, NIOSH has identified the need for improvement in Firefighter and Fire Officer Professional Qualifications Standards in the area of fire behavior knowledge:

Standard setting agencies, states, municipalities, and authorities having jurisdiction should: consider developing more comprehensive training requirements for fire behavior to be required in NFPA 1001 Standard for Fire Fighter Professional Qualifications and NFPA 1021 Standard for Fire Officer Professional Qualifications and states, municipalities, and authorities having jurisdiction should ensure that fire fighters within their district are trained to these requirements.

Following the conference, I will publish a series of posts from a CFBT-US case study on this incident and the potential influence of the ventilation tactics used on the extreme fire behavior phenomena that occured.

Reports from the Workshop and Conference

I will be posting on information presented at the workshop conference over the next two weeks.

Ed Hartin, MS, EFO, MIFireE, CFO