Posts Tagged ‘reading the fire’

Battle Drill Part 3

Sunday, February 21st, 2010

A Quick Review

As discussed in the previous posts in this series, military battle drills are an immediate response to enemy contact that requires fire and maneuver in order to succeed. Battle drills are initiated with minimal commands from the unit leader. Soldiers or marines execute preplanned, sequential actions in response to enemy contact (see Figure 1).

Figure 1. Battle Drill

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Battle Drill Part 2 addressed the appropriate reaction of a team of firefighters on a primary hoseline when confronted with rapidly worsening fire conditions that are not readily controllable once they occur (e.g., flashover, wind driven fire conditions). As when a military unit is ambushed, the fire and maneuver of battle drill involves more than one weapon. This post will address the role and reaction of backup lines in the extreme fire behavior battle drill.

Backup Lines

Once a hoseline has been deployed for fire attack it is good practice to stretch a backup line. Klaene and Sanders (2008) observe that backup lines are needed to protect the crew on the initial attack line and to provide additional flow if needed (p. 216). Unfortunately, many firefighters see the backup line as simply another attack line and miss the first and primary function of this hoseline to protect crews on primary hoselines.

The first priority in fire attack operations is to get a hoseline in position to apply water effectively to the fire. To this end, hoselines are deployed in series (attack line first, then backup line) not in parallel, where both lines are attempting to advance and maneuver in the same space. The crew of the backup line can often assist in pulling up additional hose for the attack line (particularly when crews are lightly staffed). As illustrated in Figure 2, the backup line is positioned to protect the means of egress and if necessary support fire attack.

Figure 2. Attack and Backup Line Placement

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Extreme Fire Behavior Battle Drill

As discussed in Battle Drill Part 2, the thermal insult experienced in an extreme fire behavior event is dependent on temperature (of gases and compartment linings) and flow of hot gases. The higher the temperature and faster the speed of gas flow, the higher the heat flux. Survival requires that crews on hoselines extinguish or block the flames, cool hot gases, and maneuver out of the flow path to a point of egress or area of safer refuge.

Crews engaged in fire attack or search are often first to encounter rapidly deteriorating fire conditions. Hose Handling and Nozzle Technique Drill 8 outlined the immediate actions that should be taken to support a tactical withdrawal under severe fire conditions. In these circumstances, the crew staffing the backup line has a critical role in supporting withdrawing crews.

Fire conditions that are beyond the capability of a single hoseline may be controlled by the higher flow rate from multiple lines. As noted by Klaene and Sanders (2008) one of the functions of backup lines is to provide additional flow if needed (p. 216). The attack line and backup line operating in a coordinated manner may be able to control fire conditions and allow continuation of fire attack. If this is the case, these lines should be reinforced by deployment of one or more additional backup lines.

If fire conditions cannot be controlled, and the attack line must be withdrawn while maintaining water application to protect the crew, the crew on the backup line can aid in withdrawal of attack and/or search hoselines. If the hoseline is not withdrawn as the firefighter on the nozzle retreats, the hose may kink or become exposed to flames (either of which may result in loss of water supply to the nozzle).

While the attack or search crew is likely to be first to encounter worsening fire conditions, this is not always the case. Depending on fire location and building configuration, fire spread may cut off the attack or search line from behind. In this situation, the backup line becomes the primary means of defense for operating crews.

Regardless of how deteriorating conditions develop, safe and effective tactical withdrawal requires a coordinated effort between interior crews and as soon as possible, report of conditions to Command and if necessary transmit a Mayday message.

Drill 9-Extreme Fire Behavior Battle Drill-The Backup Line: Key hose handling and nozzle techniques when faced with extreme fire behavior are the ability to apply long pulses of water fog or maintaining a continuous flow rate while maneuvering backwards. However, the backup line may initially need to advance to support fire attack, and then if necessary cover and support other crews as they withdraw.

Hose Handling & Nozzle Technique Drill 9 Instructional Plan

Skill in operation and maneuver of a single hoseline is a foundational firefighting skill. However, in the extreme fire behavior battle drill, coordinated operation of the attack and backup line is essential, making Hose Handling & Nozzle Technique Drill 9 an important step in skill development.

References

Klaene, B. & Sanders, R. (2008) Structural Firefighting Strategy and Tactics (2nd ed.). Sudbury, MA: Jones & Bartlett.

Battle Drill Part 2

Thursday, February 11th, 2010

A Quick Review

As discussed in the last post in this series, military battle drills are an immediate response to enemy contact that requires fire and maneuver in order to succeed. Battle drills are initiated with minimal commands from the unit leader. Soldiers or marines execute preplanned, sequential actions in response to enemy contact.

This post discusses application of the battle drill concept in training firefighters to react appropriately on contact with our enemy (the fire) which requires fire (application of water) and maneuver (movement to a safer location) in order to succeed.

Remember: The key elements of a battle drill are fire and maneuver! This requires the ability to operate and maintain control of the hoseline while moving backward.

Working Without a Hoseline

In the United States, it is common for some companies working on the fireground to operate inside burning buildings without a hoseline (particularly when performing search). While common, this practice places firefighters at considerable risk when faced with extreme fire behavior. Without a hoseline your only defense against rapid fire progress is recognition of developing conditions and immediate reaction to escape to a safer location (see video below); which is not always possible. In some cases, firefighters fail to recognize developing conditions or the speed with which conditions will change. In other cases, firefighters are unable to escape or take refuge outside the flow path of hot gases and flames quickly enough.

Cl

If your department’s operational doctrine includes companies working on the interior without a hoseline (or without being directly supported by a hoseline), it is essential that firefighters are trained to 1) recognize early indicators of potential for extreme fire behavior and 2) maintain a high level of awareness regarding locations which may provide an area of refuge. When confronted by rapidly worsening conditions, action to escape must be immediate and without hesitation.

Extreme Fire Behavior Battle Drill

Regardless of their assignment (e.g., fire attack, primary search), firefighters with a hoseline have a solid means of maintaining orientation, a defined primary escape route, and the ability to actively control the fire environment through application of water. However, as always, safe and effective operation in the fire environment is dependent on a solid size-up, dynamic risk assessment, maintenance of a high level of situational awareness, and proactively controlling the fire environment. The best way to deal with extreme fire behavior is to avoid it or prevent it from occurring. For more information on reading the fire and key fire behavior indicators related to potential for extreme fire behavior, see:

In situations where you were unable to recognize potential for extreme fire behavior or you have been unable to control the fire environment, immediate action is required!

This is my nozzle, there are many like it but this one is mine. My nozzle is my best friend. It is my life. I must master it as I master my life. Without me it is useless, without my nozzle I am useless.

I will use my nozzle effectively and efficiently to put water where it is needed. I will learn its weaknesses, its strengths, its parts, and its care. I will guard it against damage, keep it clean and ready. This I swear.

As stated in the first paragraph of this adaptation of the United States Marine Corps Riflemans’ Creed, Without my nozzle I am useless.

The extent of thermal insult experienced in an extreme fire behavior event is dependent on both radiant and convective heat flux. Total radiant heat flux is dependent on temperature (of gases and compartment linings) and flow of hot gases. The higher the temperature and faster the speed of gas flow, the higher the heat flux. These scientific concepts drive the key elements of the extreme fire behavior battle drill. Extinguish or block the flames, cool hot gases, and maneuver out of the flow path to a point of egress or area of safer refuge.

Drill 8-Extreme Fire Behavior Battle Drill: Key hose handling and nozzle techniques when faced with extreme fire behavior are the ability to apply long pulses of water fog or maintaining a continuous flow rate while maneuvering backwards. This requires a coordinated effort on the part of the nozzle operator, backup firefighter, and potentially other firefighters working on the hoseline or at the point of entry.

Hose Handling & Nozzle Technique Drill 8 Instructional Plan

While this drill focuses on single company operations, it is important to extend this training to include crews operating backup lines. The importance, function, and operation of the backup line will be the focus of the next post in this series.

Not all That is Learned is Taught

When training to operate in a hazardous environment, avoid the mindset that it’s only a drill. As often observed, you will play the way that you practice. Extreme stress can activate inappropriate routine responses. For example, a Swedish army officer suddenly stood up while his unit was under fire while engaged in peacekeeping efforts in Bosnia. When asked about this response, he explained that in training, he often stood up while leading exercises (Wallenius, Johansson, & Larsson, 2002).

“A simple set of skills , combined with an emphasis on actions requiring complex and gross motor muscle operations (as opposed to fine motor control), all extensively rehearsed, allows for extraordinary performance levels under stress” (Grossman, 2008, p. 38).

When developing skill in nozzle technique and hose handline, and in particular the critical skills required to effectively perform this extreme fire behavior battle drill, it is essential to maintain critical elements of context such as appropriate use of personal protective equipment, position, and technique.

Ed Hartin, MS, EFO, MIFireE, CFO

References

Grossman, D. (2008). On-combat: The psychology and physiology of deadly conflict in war and peace. Millstadt, IL: Warrior Science Publications.

Wallenius, C. Johansson, C. & Larsson, G. (2002). Reactions and performance of Swedish peacekeepers in life-threatening situations. International Peacekeeping, 9(1), 133-152.

2010 Congreso Internacional Fuego y Rescate

Saturday, January 30th, 2010

At a formal dinner on 23 January 2010, Chief Ed Hartin was recognized as an honorary member of Company 1 “Germania” of the Valdivia, Chile Fire Department. In addition, he was awarded a commendation for supporting the ongoing professional development of the members of Company 1 “Germania” of the Valdivia, Chile Fire Department and encouraging them in their efforts to share their knowledge with Chile’s fire service.

Commendation for Support of Company 1 “Germania”

commendation

Left to Right: Teniente Juan Esteban Kunstmann, Chief Ed Hartin, Capitán Francisco Silva V.

On 24-27 January 2007, the Company 1 “Germania” of the Valdivia, Chile Fire Department hosted the first international fire service congress to be held in South America. Participants included over 150 firefighters and officers from Chile, Peru, Argentina, and the United States. The congress provided an opportunity to participate in both classroom and hands-on workshops on a wide range of fire service topics including fire behavior, ventilation, search, rapid intervention, technical rescue, and extrication. While topical areas were diverse, the congress had a substantive emphasis on compartment fire behavior with lectures presented by CFBT-US Chief Instructor Ed Hartin and Geraldo Crespo of Contraincendio in Buenos Aires, Argentina and practical training sessions conducted by Ed Hartin and Juan Esteban Kunstmann of the Valdivia Company 1 “Germania”.

Lecture Presentation

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Lecture presentations by CFBT-US Chief Instructor Ed Hartin included (click on the links for a copies of the presentations):

CFBT practical skills sessions were held at the Valdivia Fire Department’s training center and focused on developing basic skill in nozzle technique and understanding fire development in a compartment.

This is My Nozzle! There are many like it, but this one is mine…

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Center: Ed Hartin

Practicing Nozzle Techniques

juan_cl_practical

Right: Teniente Juan Esteban Kunstmann

International Collaboration

giancarlo_cl_practical

Left to Right: Battalion Chief Danny Sheridan, FDNY and Capitán Giancarlo Passalacqua Cognoro, Lima, Pe?u Cuerpo General de Bomberos Voluntarios

Congratulations to the members of Company 1 “Germania” for their success with the first Congreso Internacional Fuego y Rescate! I look forward to working with these outstanding fire service professionals in their ongoing efforts to learn and share knowledge with the fire service throughout Chile, Latin America, and the World.

Ed Hartin, MS, EFO, MIFireE, CFO

Recent Extreme Fire Behavior

Tuesday, January 19th, 2010

Two recent events in Baltimore, Maryland and Gary, Indiana point to the criticality of recognizing key fire behavior indicators and understanding practical fire dynamics.

Five Firefighters Injured in Baltimore

Early on the morning of Friday, January 15, 2010, the Baltimore City Fire Department was dispatched to a residential fire Southeast Baltimore. First arriving companies observed a row house of ordinary construction with a large volume of smoke and flames issuing from the basement and extending to the first floor.

According to a department spokesperson, the first engine took a line through the front door to the rear kitchen area where crew had some trouble finding the basement stairs. Another engine company went to the rear with a line to the outside stairwell leading to the basement and was just starting down the stairs. The first truck vented some skylights on the roof as well as the front basement windows. As crews were attempting to access the fire, some type of transient extreme fire behavior resulted in flames blowing through the unit and out the front door, rear stairwell, second floor windows, and skylights. The firefighter from the first arriving truck assigned to the roof described the sound of a freight train coming through.

Five firefighters injured as a result of this explosive fire behavior phenomenon were transported to area hospitals. The officer of the first in engine company was admitted to the Bayview Burn Center, where he is listed in stable condition


Find more videos like this on firevideo.net

What Happened?

As always when a video of an incident involving extreme fire behavior is posted to the web, there is ongoing debate about what happened. Was it a backdraft? Was it a flashover? An interesting debate, but the value is not so much in being “right”, but in understanding how these phenomena occur, what might have happened in this incident, key indicators that may (or may not) be visible in the video, and most importantly how to prevent this from happening to us and the firefighters that we work with!

Flashover: sudden transition to fully developed fire. This phenomenon involves a rapid transition to a state of total surface involvement of all combustible material within the compartment.

Given adequate fuel and ventilation, a compartment fire may reach flashover as it develops from the growth to fully developed stage. However, when fire development is limited by the ventilation profile of the compartment, changes in ventilation will directly influence fire behavior.

For many years firefighters have been taught that ventilation reduces the potential for flashover. However, when a fire is ventilation controlled, heat release rate is limited by the available oxygen. Under these conditions; increasing air supply by creating opening results in increased heat release rate. This increased heat release rate may result in flashover.

If a fire is sufficiently ventilation controlled and a high concentration of excess pyrolizate and unburned flammable products of combustion accumulate in a compartment, the outcome of increased ventilation may be different.

Backdraft: Deflagration of unburned pyrolyzate and combustion products following introduction of air to a ventilation controlled compartment fire and ignition of the fuel/air mixture. This deflagration results in a rapid increase in pressure within the compartment and extension of flaming combustion through compartment openings. Occurrence of this phenomenon requires an atmosphere in which the fuel concentration is too high to deflagrate without introduction of additional oxygen.

As introduced in Extreme Fire Behavior: An Organizational Scheme, extreme fire behavior phenomena can be classified on the basis of outcome and conditions (see Figure 1)

Figure 1. Extreme Fire Behavior Classification.

extreme_fire_behavior_sr

Use of this approach may aid in making sense of what may have occurred in the Baltimore incident. But, it is often difficult to classify extreme fire behavior phenomena into discrete, black and white categories. What is the dividing line between a ventilation induced flashover and a backdraft. One key difference may be the speed with which heat release rate increases, but where is the dividing line (see Figure 2)?

Figure 2. The Gray Area.

gray_area

Keep in mind that while being right is great, it is more important to work through the process of figuring things out to improve your understanding.

Near Miss in Gary

Monday morning January 18, 2010 firefighters in Gary, Indiana were operating at a residential fire at 24th and Massachusetts when they experienced a near miss involving rapid fire progression. Have a look at video of this incident and give some thought to what influenced fire behavior. Also look at the similarities and differences between the extreme fire behavior that occurred in the Baltimore and Gary incidents.

Master Your Craft

Back on Task!

I have been extremely busy working on a project for the National Institute for Occupational Safety and Health and preparing for the International Fire & Rescue Congress in Valdivia, Chile. Next week’s post will provide a quick update on training conducted at the Congress.

After returning from Chile, I will be back on task with examination of the concept of battle drills to develop effective reaction to worsening fire conditions while operating in an offensive mode.

Ed Hartin, MS, EFO, MIFireE, CFO

Reading the Fire 13

Thursday, January 7th, 2010

As we start the New Year it is a good time to reaffirm our commitment to mastering our craft. Developing and maintaining proficiency in reading the Fire using the B-SAHF (Building, Smoke, Air Track, Heat, and Flame) organizing scheme for fire behavior indicators, requires practice. This post provides an opportunity to exercise your skills using a video segment shot during a residential fire.

Residential Fire

Early on the morning of December 23, 2009, the Cheektowaga Police department was dispatched to 305 Highland Drive in Cheektowaga to investigate a 911 call for an unknown type problem. The female caller was screaming, but the dispatcher was unable to determine the nature of the emergency. The first arriving police unit discovered a residential fire with persons trapped, and requested fire response. The police officers rescued a male victim from just inside the door, but fire and smoke conditions prevented them from assisting the other occupants.

The Hy-View Volunteer Fire Company responded with a first alarm assignment and observed flames showing on Side C.

Download and the B-SAHF Worksheet.

Watch the first 1 minute 10 seconds (1:10) of the video. This segment was shot from Side B at the B/C Corner.  First, describe what you observe in terms of the Building, Smoke, Air Track, Heat, and Flame Indicators; 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? If presented with persons reported (as the first arriving companies were) how would you assess potential for victim survival?
  5. How would you expect the fire to develop over the next two to three minutes

Now watch the remainder of the video clip and answer the following questions:

  1. Did fire conditions progress as you anticipated?
  2. A voice heard in the video states that this was a backdraft. Do you agree? Why or why not?

Hy-View Volunteer Fire Company personnel recovered two female civilian victims from the residents. However, all three victims died as a result of smoke inhalation.

Master Your Craft

Ed Hartin, MS, EFO, MIFIreE, CFO

Nozzle Techniques & Hose Handling: Part 4

Thursday, December 10th, 2009

The previous posts in this series, examined the importance of proficiency in use of the firefighters’ primary weapon in offensive firefighting operations, and outlined several drills that can be used to develop proficiency in basic nozzle operation and hose handling.

This post extends this examination of how to develop proficiency in nozzle operation and hose handling, presenting method or developing skill in working under conditions with poor visibility and application of indirect attack as an offensive firefighting tactic.

This is my nozzle, there are many like it but this one is mine. My nozzle is my best friend. It is my life. I must master it as I master my life. Without me it is useless, without my nozzle I am useless.

I will use my nozzle effectively and efficiently to put water where it is needed. I will learn its weaknesses, its strengths, its parts, and its care. I will guard it against damage, keep it clean and ready. This I swear [adapted from the Rifleman’s Creed, United States Marine Corps].

Operating Without Visual Reference

Drills to this point have been under conditions of good visibility where firefighters can observe nozzle pattern and fire stream effects. However, on the fireground it is critical that these skills can be used effectively under conditions of low or no visibility.

Sometimes it is necessary to go backward in order to move forward. One way to begin the process of developing the ability to work effectively with limited visibility is to go back to Nozzle Technique and Hose Handling Drills 1 & 2 and repeat these exercises with the firefighter’s breathing apparatus facepieces covered (unlike working in the dark, this makes it much easier for the instructors to observe and provide feedback). While this seems like an extremely slow and incremental process, it is likely to build a higher level of skill and require less time to develop proficiency than simply fumbling about in the dark!

Door Entry and Gas Cooling

In Nozzle Technique and Hose Handling: Part 3, door entry was illustrated at an exterior door. However, this method should be used anytime that firefighters encounter a closed door that may have hot gases or fire behind it. This becomes even more important when operating in a smoke (fuel) filled environment.

Smoke is fuel! The upper (hot gas) layer may contain a substantial mass of fuel that is ready to ignite. Flames exiting from a compartment door can ignite this fuel, resulting in rapid fire progression through the upper layer and into adjacent compartments. This phenomenon is demonstrated by CFBT-US Senior Instructor Trainer Matt Leech (LT Tualatin Valley Fire & Rescue) in Figures 1 through 3. While this demonstration involves use of a single compartment doll’s house and “porch roof”, the same phenomena can occur on a larger scale in any type of structure.

Figure 1. Accumulation of Fuel Overhead

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Figure 2. Extension of Flames and Ignition of Fuel Overhead

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Figure 3. Transition to Flaming Combustion Overhead

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This simple demonstration illustrates the hazards presented by smoke overhead, the importance of gas cooling, and good door entry technique. While often overlooked, recognition of this hazard is not new. “Smoke contains unburned fuel and when mixed with air in the proper proportion becomes a flammable mixture” (Layman, 1955).

When working under conditions of limited visibility, other sensory feedback becomes even more important to the nozzle operator. It is essential that firefighters become familiar with audible indicators of stream performance. Think about the sound of a straight stream hitting the ceiling or a wall versus the sound of a fog pattern applied into the hot gas layer (without significant contact with compartment linings). Would you be attuned to the difference in sound? This is important when you can’t see the pattern being discharged. Changes in temperature can also be an important indicator. However, it is important to remember that perceived temperature is also influenced by moisture. Excess steam production (from water hitting hot compartment linings) may make it seem like the temperature is rising, when this is due to increased moisture content in the smoke and air. If it seems like it is getting hotter, it is important to recognize if this is due to worsening fire conditions, or inappropriate water application.

Drill 6-Operating Without Visual Reference: This drill integrates door entry, hose handling, and nozzle techniques (pulsing and painting) under conditions with limited visibility. The drill can be conducted with the facepiece covered, in darkness, or using cold smoke (e.g., from a smoke machine). Learners should begin by using good door entry technique on an exterior door and then move through several compartments (preferably of different sizes), encountering several doors (some of which should be closed) along the way to the seat of the “fire”. Alternately, this drill can be used to practice hose handling and nozzle technique in the context of primary search with a hoseline (or in support of crews performing search).

Hose Handling & Nozzle Technique Drill 6 Instructional Plan

Indirect Attack

Indirect attack is a commonly misunderstood firefighting tactic. Common misconceptions include:

  • Indirect attack is only performed from the exterior of the building.
  • Indirect attack will push fire throughout the building.
  • Indirect attack involves banking water off the ceiling to reach burning fuel that is inaccessible to direct application of water (see Figure 4).
  • Indirect attack and gas cooling is the same thing.

These statements are absolutely incorrect!

Figure 4. What Indirect Attack is NOT.

bank_shot

Several years ago I had a company officer that I worked with tell me that he had learned about a “new” fire control technique called the indirect attack at strategies and tactics class. I loaned him a small blue book titled Attacking and Extinguishing Interior Fires (Layman, 1955) and observed that this was not exactly a “new” idea.

The concept of the indirect attack was an outgrowth of extensive study of fuel oil fires within confined spaces conducted by the instructor staff of the US Coast Guard Firefighting School at Fort McHenry in Baltimore, Maryland during World War II (Layman, 1955). The term indirect, referred to application of water into a hot compartment, but not directly onto the burning fuel. Conversion of water to steam absorbed a tremendous amount of energy and the expansion of steam filled the compartment (and potentially adjacent compartments which may also have been involved in fire).

In 1947, Lloyd Layman completed his service with the US Coast Guard and returned to duty as Fire Chief with the Parkersburg West Virginia Fire Department. Over the next two years, Layman and the members of his department worked to implement the concept of indirect attack for structural firefighting. In 1950 Chief Layman delivered a presentation titled Little Drops of Water (Layman, 1950) which outlined the adaptation of indirect attack for structural firefighting. In 1952 he completed Attacking and Extinguishing Interior Fires (Layman, 1955), a textbook that provided a more comprehensive look at indirect attack including several case studies based on incidents in Parkersburg where this approach had been used successfully in dealing with both residential and commercial fires.

As presented by Layman, the indirect attack was generally performed from the exterior of the building. However, it is important to recognize historical context. In the late 1940’s respiratory protection (when it was used) was often limited to All Service Masks, which used a filter mechanism to remove toxic products of combustion (to some extent), but could not be used in significantly oxygen deficient atmospheres.

Layman’s Error: Chief Layman made a number of extremely important and astute observations, particularly with regards to the tremendous cooling capacity of water when it is not only heated to its boiling point, but also converted to steam. However, one of the major assumptions related to indirect attack was in error. Layman states: “The injection of water into a highly heated atmosphere results in rapid generation of steam…[increasing] the atmospheric pressure within the space (p. 36-37). This points to the Chief’s assumption that steam produced as water was evaporated in the hot gas layer added to the total volume of gas and vapor within the space (i.e., the volume of steam was added to the volume of smoke and hot gases in the compartment). As discussed in Estimating Required Fire Flow: The Iowa Formula [LINK]; this is incorrect, water vaporized as it passes through the hot gas layer actually reduces total volume (due to cooling of the hot gases). On the other hand, water that is vaporized in contact with hot surfaces (that did not significantly cool the gases as it passed through the hot gas layer) adds to total volume as expanding steam is added to the volume of hot gases within the compartment. The difference between indirect attack and gas cooling will be explored in detail in my next post on Fire Stream Effectiveness and Efficiency.

Figure 5. Indirect Attack

indirect_attack

Drill 7-Indirect Attack from the Door: When faced with a fully developed fire in an enclosed area or a severely ventilation controlled fire (decay phase) that presents potential for a ventilation induced flashover or backdraft. Indirect attack may be an effective option for fire control. However, this tactic is not limited to exterior operations. Indirect attack can be initiated as part of the door entry procedure (exterior or interior doorway). If dynamic risk assessment indicates that entry is not viable due to fire conditions, the nozzle operator can use long pulses from the doorway (while the other member of the hose team controls the door) to apply water to hot surfaces, producing steam to gain control of conditions within the compartment prior to entry. This fire control method should be integrated with effective tactical ventilation (think planned, systematic, and coordinated).

Hose Handling & Nozzle Technique Drill 7 Instructional Plan

This approach can be extremely useful when the door to the fire compartment can be controlled and the hose team is presented with multiple priorities (persons reported and the need to control the fire to maintain the safety of interior operations). Figure 6 illustrates an example of how an indirect attack may be used when operating from the interior. In this scenario, the first arriving engine observes a fully developed fire in the bedroom on the A/D corner of a single family dwelling and receives information that an occupant is in the bedroom on the C/D corner. Rapidly developing fire conditions require immediate fire control. The crew makes entry from Side A, cools the hot gases overhead as they proceed to the fire compartment. As it is necessary to control the fire before proceeding past the involved compartment, they control the door, implement an indirect attack, and then extend an oriented search to locate the occupant while the nozzle operator protects the means of egress and maintains orientation for the firefighter performing the search in the adjacent compartments.

Figure 6. Application of Interior Indirect Attack.

indirect_bedroom_fire

While there are other tactical approaches that could be taken in this situation, use of an indirect attack allows the hose team to address both life safety (firefighters and occupants) and fire control tactical priorities.

Master Your Craft

Ed Hartin, MS, EFO, MIFIreE, CFO

References

Layman, L. (1955). Attacking and extinguishing interior fires. Boston, MA: National Fire Protection Association.

Layman, L. (1950). Little drops of water. Unpublished paper, presented at the Fire Department Instructors Conference (FDIC), Memphis, TN.

Reading the Fire 12

Wednesday, December 2nd, 2009

As discussed in prior Reading the Fire posts and the ongoing series examining fire behavior indicators (FBI), using the B-SAHF (Building, Smoke, Air Track, Heat, and Flame) organizing scheme, developing proficiency requires practice. This post provides an opportunity to exercise your skills using three video segments shot during an apartment fire.

Apartment Fire

At 2235 hours on November 19th the Bethlehem, PA fire department dispatched Engines 6, 9, 7, Ladder 2 & Chief 205 for an apartment fire with persons reported at 1992 Gatewood Lane. On arrival Engine 6 reported a working fire in an end-of-row unit. Tower Ladder (TL) 2 made two vertical ventilation (exhaust( openings in the roof above the fire. Chief 205 requested a second and then third alarm as the fire extended rapidly into the trussloft.

Download and the B-SAHF Worksheet.

The video segment was shot after TL 2 opened the roof.  First, describe what you observe in terms of the Building, Smoke, Air Track, Heat, and Flame Indicators; 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 (on floor 2 and in the attic)?
  5. How would you expect the fire to develop over the next two to three minutes

Crews use a combination of exterior attack (from the tower ladder and the roof) and interior attack from the second floor to control the fire.

  1. Did fire conditions progress as you anticipated?
  2. What concerns would you have about working on the top floor or roof in the involved area?
  3. How did vertical ventilation influence the fire in the trussloft (think about positives and negatives)?
  4. What alternatives to vertical ventilation of this lightweight roof system could be used to control the fire and prevent extension over uninvolved units?

While this incident had a positive outcome, it is important to recognize the potential for collapse of lightweight, engineered structural systems such as truss roof assemblies. Tactical success in one incident is not necessarily a predictor of future success should conditions be different (e.g., duration of fire impingement on structural members prior to arrival, burning regime, changes to the ventilation profile, etc.).

Master Your Craft

Remember the Past

Line of duty deaths involving extreme fire behavior has a significant impact on the family of the firefighter or firefighters involved as well as their department. Department investigative reports and NIOSH Death in the Line of Duty reports point out lessons learned from these tragic events. However, as time passes, these events fade from the memory of those not intimately connected with the individuals involved. It is important that we remember the lessons of the past as we continue our study of fire behavior and work to improve firefighter safety and effectiveness on the fireground.

November 23, 2006
Firefighter Steven Mitchell Solomon
Atlanta Fire Department, Georgia

Firefighter Solomon was working a 24-hour shift on Thanksgiving Day. Shortly after 2000hrs, Atlanta Fire-Rescue dispatched a full first-alarm assignment for a reported fire in an abandoned house. On arrival, companies encountered heavy smoke showing from a boarded-up single-story brick structure. As other crews removed plywood window coverings and forced entry through the front door, the crew of Engine 16 prepared to advance a 1-3/4inch attack line into the house. Firefighter Solomon was on the nozzle as the line was advanced inside. The attack team immediately encountered high temperature and zero-visibility conditions. Within seconds after they entered, the battalion chief arrived, assumed command, and ordered the companies to operate in a defensive strategy. Before the line could be backed out, the interior became enveloped in flames and the 3 firefighters from Engine 16 lost track of each other. Two of the firefighters managed to escape through the front door. Firefighters who were outside saw the silhouette of a firefighter, enveloped in flames, running past the front door and moving toward the rear of the house. The fire was quickly knocked down and crews made entry from both the front and rear to conduct a search. Firefighter Solomon was located almost immediately by a member who was using a thermal imaging camera and several firefighters quickly removed him from the dwelling. He was unconscious and critically burned. When he was found, Firefighter Solomon had removed his helmet, hood, and SCBA facepiece. One boot was also missing. Although he received immediate treatment from firefighter/paramedics on the scene and was transported within minutes to a level-one trauma center and regional burn unit, Firefighter Solomon died 6 days later without regaining consciousness.

Ed Hartin, MS, EFO, MIFIreE, CFO

Nozzle Techniques & Hose Handling: Part 3

Thursday, November 19th, 2009

The previous posts in this series, examined the importance of proficiency in use of the firefighters’ primary weapon in offensive firefighting operations, and outlined several drills that can be used to develop proficiency in basic nozzle operation and hose handling.

Developing proficiency in nozzle use is somewhat like building skill with a rifle. Understanding what end of the rifle the bullet comes out of and that the rifle is fired by pulling the trigger is the easy part, learning to consistently hit what you are aiming at over varied distances requires considerably more effort.

This is my nozzle, there are many like it but this one is mine. My nozzle is my best friend. It is my life. I must master it as I master my life. Without me it is useless, without my nozzle I am useless.

I will use my nozzle effectively and efficiently to put water where it is needed. I will learn its weaknesses, its strengths, its parts, and its care. I will guard it against damage, keep it clean and ready. This I swear [adapted from the Rifleman’s Creed, United States Marine Corps].

In the first three nozzle drills learners develop basic proficiency in basic nozzle use (fixed position), integrating nozzle use while moving a hoseline forward and back, and use of the nozzle while moving the hoseline through varied size compartments. This post will provide an overview of door entry procedures.

Door Entry Concepts

For many firefighters, door entry is simply a process of remembering to “try before you pry” and then figuring out how to force the door if it is locked. For others it is simply kicking the door in! Often overlooked is the fact that the entry point is a ventilation opening; sometimes an inlet, sometimes an outlet, and often both. When the fire is ventilation controlled, opening the door and increasing air flow to the fire will result in increased heat release rate. Depending on the stage of fire development and conditions within the compartment or structure, this may result in extreme fire behavior such as a ventilation induced flashover or backdraft (see Fuel & Ventilation).

As illustrated in Figure 1, firefighters often encounter rapidly changing conditions after making entry. In this incident, flashover occurred less than 60 seconds after firefighters opened the door and made entry (see Situational Awareness is Critical for additional information on this incident)

Figure 1. Rapidly Changing Conditions

pg_before_after

Note: Photos by Probationary Firefighter Tony George, Prince Georges County Fire Department.

Safe and effective firefighting operations depend on effectively reading the fire and recognizing potential stages of fire development and burning regime (see previous posts on Reading the Fire) and effective tactical operations to take control of the fire environment. Door entry is an important element in this process.

Door Entry Procedure

As you review this door entry procedure, you may find that it makes sense to you exactly as presented. On the other hand, you may find that some elements (e.g., size-up and dynamic risk assessment) make sense, but other components (e.g., cooling overhead prior to opening the door) require a bit more of a leap. The elements of the door entry process reinforce one another, adopt the elements that make sense to you, but consider the value of the procedure as an integrated process. The process outlined is not followed in a lock-step manner, it is important for the hose team to take action based on observed conditions.

Size-Up: Door entry begins with a focused size-up as you approach the building. Assessment of conditions is not only the incident commander or officer’s job. Each member entering the building should perform a personal size-up and predict likely conditions. When making entry, size-up becomes more closely focused on conditions observed at or near the door and includes an assessment of potential forcible entry requirements as well as B-SAHF (Building-Smoke, Air Track, Heat, and Flame) indicators. If available, a thermal imaging camera (TIC) can be useful, but remember that temperature conditions may be masked by the thermal characteristics of the building. If a thermal imaging camera is not available, application of a small amount of water to the door may indicate temperature and the level of the hot gas layer (water will vaporize on contact with a hot door).

Size-up begins as you exit the apparatus and approach the building, but continues at the door and after you make entry!

At the door, pay close attention to air track and heat (door temperature) indicators as these can provide important clues to conditions immediately inside the building!

Control the Door: If the door is open, close it. If it is closed, don’t open it until you are ready. Heat release requires oxygen, controlling the air supply to the fire controls heat release rate. If you force the door in preparation for making entry, make sure you maintain control of it.

Gas Cool Above the Door and Assess, and Control Interior Conditions: When you open the door to assess conditions inside, hot smoke will likely exit at the top of the door. If it is hot enough it may auto-ignite. The hazard presented by the exiting smoke can be reduced by applying two short pulses above the door just as it is opened (the firefighter controlling the door should crack the door as the first pulse is applied).

The door should be opened sufficiently to allow the nozzle operator to visualize interior conditions, but not so much that a large amount of air is introduced (no magic number on how far to open, “it depends”). If hot smoke is present, the nozzle operator should cool the gases inside the compartment from the doorway. This may involve a short pulse or two or it may involve a longer pulse, depending on the size of the compartment and conditions (again, this requires the nozzle operator to think!).

Close the Door: While there is often a sense of urgency to make entry (due to developing fire conditions, persons reported, etc.), this step is important as it provides an opportunity for a focused risk assessment.

Risk Assessment: Is it safe to make entry (or to make entry through this opening)? Fully developed fire conditions inside the door or a pulsing air track (indicating potential for vent induced flashover or backdraft) may indicate a need to consider alternative tactics).

Entry: If it is safe to make entry, the process of cooling above the door as it is opened is repeated and hot gases inside the compartment are cooled as the hose team makes entry.

Figure 2. Door Entry Procedure

door_entry_multi-panel

Note: Adapted from video clip 00000010 on the 3D Firefighting: Training, Techniques and Tactics Resource DVD.

Remember: The purpose of door entry procedures is to reduce risk of extreme fire behavior during and immediately after entry! Door entry procedures should be used any time that hot smoke or flames may be on the other side of the door. These procedures are used at exterior doors when making entry and on closed doors encountered inside the building.

Drill 4-Door Entry-Inward Opening Doors: Many doors (particularly interior and exterior residential) open inward (away from the nozzle team), door entry requires that the hose team integrate forcible entry, door control, and nozzle operation. Practicing door entry procedures with a variety of inward opening door configurations (location of the door in relation to walls and with varied size compartments) is critical in developing proficiency.

Drill 5-Door Entry-Outward Opening Doors: Commercial doors (and some interior doors) will open outward (towards the hose team). Outward opening doors require a somewhat different position when performing door entry. Firefighters must develop skill in performing door entry with both inward and outward opening doors.

Hose Handling & Nozzle Technique Drill 4 & 5 Instructional Plan

These two drills can be conducted using any door where water can be applied. However, a free-standing door entry prop (see Figure 3) provides a simple and effective aid to developing door entry proficiency.

Figure 3. Door Entry Prop

door_entry_prop

Note: Photo by Inspector John McDonough, ASFM, New South Wales Fire Brigades.

Alternately, a forcible entry prop could be used to integrate the forcible entry component of the door entry process.

Drills

As discussed in Nozzle Techniques and Hose Handling: Part 2 [LINK], it is essential for firefighters to have the ability to react immediately to deteriorating conditions. While battle drills will be discussed in depth in a subsequent post, consider how this concept might apply during door entry. What action should the hose team take if they encounter strong indicators of backdraft conditions at the doorway (e.g. pulsing air track, thick (optically dense) smoke)? How should the hose team react if, despite following good practice, conditions worsen immediately after entry?

Ed Hartin, MS, EFO, MIFireE, CFO

References

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

Moving Day!

Monday, November 9th, 2009

This morning I begin the process of relocation to beautiful Whidbey Island, Washington. Later this week I begin my new job as Fire Chief with Central Whidbey Island Fire & Rescue.

Coupeville Harbor at Sunrise

coupeville_harbor

As I have been packing and preparing for my move all weekend, I have not had time to develop an in-depth Monday morning post. However, I did run across an interesting video clip a few weeks ago that ties in well with our ongoing effort to develop skill in reading the fire.

R-Fire

On March 27, 2009 the Emerson and Red Oak Fire Departments were dispatched for a residential fire at 901 Lowell Ave in Emerson, IA. First arriving companies observed a fire on Floor 1 and smoke throughout the structure.

The following video clip appears to have been shot early in incident operations as positive pressure ventilation is being implemented.

Download the B-SAHF Worksheet to use as a reminder while watching the video clip.

As you view the video clip, what do the fire behavior indicators (particularly smoke and air track) tell you about the stage of fire development, burning regime, and effectiveness of tactical operations?

Questions

In addition to your general observations of B-SAHF indicators while you watched the video the first time, consider the following questions:

  • Watch the video clip again and examine conditions at the inlet between 0:21 and 0:25. What does the presence of smoke (and particularly dark smoke) pushing from the inlet indicate?
  • Continue the video and examine conditions between 1:02 and 1:10. What do you observe at this point? What do smoke and air track conditions indicate now?
  • Continue on and examine conditions closely between 2:28 and 2:48. What does the variation in smoke and air track indicators at different points on the exterior of the structure tell you?

Back on Schedule!

I plan to be back on track with the next post in the series examining nozzle techniques on Thursday, November 12. I have been having an e-mail conversation BC Mike Walker of the Oklahoma City Fire Department regarding nozzle techniques and flashover. Mike is working on a research project regarding “right for reach and left for life”. Interestingly, when I received Mike’s first e-mail, I was in the process of outlining an upcoming blog post on the concept of “Battle Drills” to deal with or escape from conditions such as those resulting from unplanned changes in ventilation (window failure, wind, etc.).

Ed Hartin, MS, EFO, MIFireE, CFO

Decay Stage Fires:
Key Fire Behavior Indicators

Thursday, October 29th, 2009

As discussed in Flashover and Fully Developed Fires: Key Fire Behavior Indicators, providing additional oxygen to a ventilation controlled fire will result in a corresponding increase in heat release rate (HRR). This occurs because oxygen is required to release the chemical potential energy in fuel. The energy released per unit of mass of oxygen is remarkably consistent for both natural and synthetic organic (carbon containing) fuels.

Thornton’s Rule specifies that one kilogram (1 kg) of oxygen is required to release 13.1 mega joules (MJ) of energy. Multiplying 13.1 MJ/kg of oxygen by 21% (the concentration of oxygen in air) provides a value of 2.751 MJ/kg of air. The Society of Fire Protection Engineering (SFPE) Handbook of Fire Protection Engineering (SFPE, 2002) rounds this value to 3.0 MJ/kg of air. For a more detailed discussion of Thornton’s Rule and the relationship between fuel, oxygen, and energy release, see Fuel and Ventilation.

Decay Stage

A compartment fire may enter the decay stage as the available fuel is consumed or due to limited oxygen. As discussed in relation to flashover, a fuel package that does not contain sufficient energy or does not have a sufficient heat release rate to bring a compartment to flashover, will pass through each of the stages of fire development (but may not extend to other fuel packages). On a larger scale, without intervention an entire structure may reach full involvement and as fuel is consumed move into the decay stage. However, there is another, more problematic way for the fire to move into the decay stage. When the ventilation profile of the compartment or building does not provide sufficient oxygen, the fire may move into the decay stage. Heat release rate decreases as oxygen concentration drops. While temperature follows heat release rate, the temperature in decay stage fire may remain high for some time (particularly in well insulated, energy efficient buildings). This presents a significant threat as solid fuel packages continue to pyrolize and the involved compartment(s) may contain a high concentration of hot, pyrolized fuel, and flammable gaseous products of incomplete combustion.

Ventilation Controlled Fires

Under ventilation controlled conditions excess pyrolizate and flammable products of combustion present in smoke are a significant hazard to firefighters. Let’s go back to the fire triangle to examine the nature of this threat. While fuel, heat, and oxygen are present in proportion to support combustion where the fire is burning, the heat of the fire is pyrolyzing more fuel vapor than the fire can consume. In addition, incomplete combustion results in production of flammable gases such as carbon monoxide. The speed of fire development is limited by the availability of atmospheric oxygen provided by the current ventilation profile of the compartment or building.

In his presentation, Fire Dynamics for the Fire Service, Dan Madrzykowski of the National Institute of Standards and Technology (NIST) discussed the increased potential for ventilation controlled, decay stage fires in today’s modern, energy efficient structures. Dan presented the time temperature curve illustrated in Figure 1 to describe modern fire development and the potential influence of firefighting tactics.

Figure 1. Fire Development in the Modern Environment

modern_fire_development

Note: Adapted from National Institute of Standards and Technology (NIST) Fire Dynamics for the Fire Service, D. Madryzkowski.

The data in Figure 1 could be presented as HRR over time as well, but as HRR cannot be measured outside the lab, temperature is often used to describe fire development in full-scale tests. When the fire is burning in a ventilation controlled state, any increase in the supply of oxygen to the fire will result in an increase in heat release rate. Increase in ventilation may result from firefighters making entry into the building (the access point is a ventilation opening), tactical ventilation (performed by firefighters), or unplanned ventilation (e.g., failure of window glazing due to elevated temperature).

It is essential to recognize when the fire is, or may be ventilation controlled and the influence of planned and unplanned changes in ventilation profile. Most compartment fires that progress into the growth stage are ventilation controlled when the fire department arrives. A bi-directional air track (smoke out the top and air in the bottom) is often a significant indicator of a ventilation controlled fire, but what about before the door is open?

Figure 2. Assessment of Conditions at the Door

door_questions

As combustion becomes more incomplete, smoke production increases, color darkens, and optical density increases. However, these indicators may be subtle when observing fire conditions from the exterior. Assessment of conditions must continue after making entry. Smoke and air track indicators can be particularly useful in addressing the stage of fire development and burning regime when working inside. In addition, flames moving through the hot gas layer are a strong indicator of a ventilation controlled fire (as well as a threat to your safety which should be dealt with immediately).

Ventilation Induced Extreme Fire Behavior

When the fire is ventilation controlled, increased air supply to the fire will result in increased heat release rate and depending on conditions may result in extreme fire behavior such as flashover or backdraft. While both phenomena result from an increase in ventilation, vent induced flashover and backdraft are different phenomena. The conditions required for a ventilation induced flashover are 1) a compartment fire which has an insufficient HRR to reach flashover due to ventilation controlled combustion, and 2) insufficient concentration of excess pyrolizate and unburned products of incomplete combustion to result in a backdraft. While complex, the key determinant in the occurrence of a backdraft is likely to be the concentration of gas phase fuel within the compartment.

While these phenomena are different, both present a significant threat to firefighters. Rapid fire progress due to ventilation induced flashover or backdraft is not an instantaneous process. Depending on a number of variables such as the location of the fire, current level of involvement, temperature of the smoke (hot gas) layer, and extent of the increase in ventilation these rapid fire progress phenomenon may take some time to occur. However, when it does, fire development will be extremely rapid! Firefighters entering a compartment or building containing an under ventilated fire must be aware of and manage the hazards presented by the potential for rapid fire progress. Remember, many if not most fires that have progressed beyond the incipient stage before firefighters arrival are ventilation controlled and present the potential for rapid fire progress with increased ventilation (see Situational Awareness is Critical).

Figure 3 lists the fire behavior indicators related to ventilation controlled decay stage conditions and the potential for ventilation induced extreme fire behavior. It is important to note that there are not always clear distinctions in the visual indicators for vent induced flashover and backdraft.

Figure 3.  FBI: Decay Stage

decay_indicators

Be Wary

Decay stage indicators can sometimes be subtle and conditions may not look too bad (maybe like an incipient or early growth stage fire if you are not paying close attention and consider the possibilities).

It is often assumed (incorrectly) that ventilation induced extreme fire behavior (flashover or backdraft) will occur immediately after an increase in ventilation. Depending on fire conditions and building configuration there may be a significant time lag between ventilation and resulting changes in fire behavior. When ventilation controlled decay conditions are indicated (or suspected), firefighters should move cautiously and take action to change conditions inside the building or compartment (e.g., gas cooling, ventilation).

You have responded to a fire in a one-story single family dwelling of wood frame construction. A fire which started in a bedroom on the Alpha Bravo corner of the structure has gone from fully developed to the decay stage due to a lack of oxygen as building openings (doors and windows) remain closed and intact.

  • What conditions would you expect to see from the exterior of the structure?
  • What indicators may be visible from the front door as you make entry?

A fire in the decay stage (particularly when this is due to limited oxygen) still presents a significant threat as conditions can change rapidly.

  • If the door at your entry point remains fully open, how will this influence fire behavior (assuming no other ventilation has been performed)?
  • How would fire behavior be influenced if a window (or windows) in the fire compartment are opened along with the door at your entry point?
  • What indicators would you anticipate observing as you traveled through the living room to the hallway leading to the bedroom?
  • What conditions would you find in the hallway outside the fire compartment?

After making entry, consider if conditions are different than you anticipated?

  • Why might this be the case?
  • What differences in conditions would be cause for concern?

Late Breaking News

I have been selected to serve as Fire Chief with the Central Whidbey Island Fire District in Washington and anticipate starting in my new position by mid November.

Over the next year I will also be serving on an advisory panel to assist Underwriters Laboratory with a research project on to examine the impact of ventilation on fire behavior in legacy and contemporary construction. Output from this project will include a formal technical report, articles in fire service publications, presentation to the fire service community, and a stand-alone web-based training module.

References

Society of Fire Protection Engineers (SFPE). (2002). The SFPE handbook of fire protection engineering (3rd ed.). Quincy, MA: National Fire Protection Association.

Madrzykowski, D. Fire dynamics for the fire service [PowerPoint Presentation], Gaithersburg, MD: National Institute of Standards and Technology.