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 commercial fire.
Commercial Fire
This post examines fire development during a fire in an agricultural facility in Spain. First arriving firefighters observed a small amount of light gray smoke issuing from roof ventilators and doorways with low velocity.
Watch the first 50 seconds (0:50) of the video. First, describe what you observe in terms of the Building, Smoke, Air Track, Heat, and Flame Indicators; then answer the following five standard questions?
What additional information would you like to have? How could you obtain it?
What stage(s) of development is the fire likely to be in (incipient, growth, fully developed, or decay)?
What burning regime is the fire in (fuel controlled or ventilation controlled)?
What conditions would you expect to find inside this building?
How would you expect the fire to develop over the next two to three minutes
Now watch the next 20 seconds (1:10) of the video clip and answer the following questions:
Did fire conditions progress as you anticipated?
What changes in the B-SAHF indicators did you observe?
How do you think that the stage(s) of fire development and burning regime will change over the next few minutes?
What conditions would you expect to find inside this building now?
How would you expect the fire to develop over the next two to three minutes
Watch the remainder of the video. If you were the Incident Commander and had crews working inside the building, what information would you communicate to them as conditions change?
Reading the Fire
See the following posts for more information on reading the fire:
It has been a number of months since the last Reading the Fire post. It is essential to continue the process of deliberate practice in order to continue to improve and refine skill in Reading the Fire.
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
In mid-January 2010, the Gary, Indiana Fire Department was dispatched to a residential fire on Massachusetts Street at East 24th Avenue, on arrival Battalion 4 advised of a working fire in a 2 story dwelling. While the first arriving engine was laying a supply line from a nearby hydrant, the first in truck forced entry.
Watch the first 35 seconds (0:35) of the video. This segment was shot from Side A. First, describe what you observe in terms of the Building, Smoke, Air Track, Heat, and Flame Indicators; then answer the following five standard questions?
What additional information would you like to have? How could you obtain it?
What stage(s) of development is the fire likely to be in (incipient, growth, fully developed, or decay)?
What burning regime is the fire in (fuel controlled or ventilation controlled)?
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?
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:
Did fire conditions progress as you anticipated?
A voice heard in the video states that this was a backdraft. Do you agree? Why or why not?
It is likely that the first in truck company in this incident made entry to search for occupants and to locate the fire. Regardless of your perspective on search with or without a hoseline, this video clip provides lessons.
It is essential to read the fire, recognize the stage(s) of fire development and burning regime(s) in the involved compartments.
In addition to reading current conditions, anticipate likely fire development and potential for extreme fire behavior.
Making entry (and leaving the door fully open) creates a ventilation opening (inlet, exhaust, or both). Recognize the potential influence of changes to the ventilation profile on fire behavior.
To borrow a phrase from a number of National Institute for Occupational Safety and Health Death in the Line of Duty reports; “Ventilation and fire attack must be closely coordinated”. One key element in this coordination is that charged lines must be in place before completion of ventilation openings. This is critical when dealing with a ventilation controlled fire.
The previous post in this series presented a video clip of an incident on the afternoon of February 18, 2010 that injured four Chicago firefighters during operations at a residential fire at 4855 S. Paulina Street.
First arriving companies discovered a fire in the basement of a 1-1/2 story, wood frame, single family dwelling and initiated fire attack and horizontal ventilation of the floors above the fire. Based on news accounts, the company assigned to fire attack was in the stairwell and another firefighter was performing horizontal ventilation of the floors above the fire on Side C when a backdraft or smoke explosion occurred. Two firefighters on the interior, on at the doorway and the firefighter on the ladder on Side C were injured and were transported to local hospitals for burns and possible airway injuries.
In analyzing the video clip shot from inside a nearby building, we have several advantages over the firefighters involved in this incident.
Time: We are not under pressure to make a decision or take action.
Reduced Cognitive Workload: Unlike the firefighters who needed to not only read the fire, but also to attend to their assigned tactics and tasks, our only focus is analysis of the fire behavior indicators to determine what (if any) clues to the potential for extreme fire behavior may have been present.
Repetition: Real life does not have time outs or instant replay. However, our analysis of the video can take advantage of our ability to pause, and replay key segments, or the entire clip as necessary.
Perspective: Since the field of view in the video clip is limited by the window and the fidelity of the recording is less than that seen in real life, it presents a considerably different field of view than that of the firefighters observed in operation and does not allow observation of fire behavior indicators and tactical operations on Sides A, B, and D.
Initial Size-Up
What B-SAHF indicators could be observed on Side C up to the point where firefighters began to force entry and ventilate the basement (approximately 02:05)?
Figure 1. Conditions at 01:57 Minutes Elapsed Time in the Video Clip
Building: The structure is a 1-1/2 story, wood frame, dwelling with a daylight basement. The apparent age of the structure makes balloon frame construction likely, and the half story on the second floor is likely to have knee walls, resulting in significant void spaces on either side and a smaller void space above the ceiling on Floor 2. One window to the left of the door on Side C appears to be covered with plywood (or similar material). Given the location of the door (and door on Side A illustrated in the previous post in this series), it is likely that the stairway to the basement is just inside the door in Side C and a stairway to Floor 2 is just inside the door on Side A.
Smoke: A moderate volume of dark gray smoke is visible from the Basement windows and windows and door on Floor 1 as well as a larger volume from above the roofline on Side B. While dark, smoke on Side C does not appear to be thick (optically dense), possibly due to limited volume and concentration while smoke above the roofline on Side B appears to be thicker. However smoke on Side C thickens as time progresses, particularly in the area of the door on Floor 1. The buoyancy of smoke is somewhat variable with low buoyancy on Side C and greater buoyancy on Side B. However, smoke from the area of the door on Floor 1 Side C intermittently has increased buoyancy.
Air Track: Smoke on Side C appears to have a faintly pulsing air track with low velocity which is masked to some extent by the effects of the wind (swirling smoke due to changes in low level wind conditions). Smoke rising above the roofline on Side B appears to be moving with slightly greater velocity (likely due to buoyancy).
Heat: The only significant heat indicators are limited velocity of smoke discharge and variations in buoyancy of smoke visible from Sides B and C. Low velocity smoke discharge and low buoyancy of the smoke on Side C points to relatively low temperatures inside the building. The greater buoyancy and velocity of smoke observed above the roofline on Side B indicates a higher temperature in the area from where this smoke is discharging (likely a basement window on Side B).
Flame: No flames are visible.
Initial Fire Behavior Prediction
Based on assessment of conditions to this point, what stage(s) of development and burning regime(s) is the fire likely to be in?
Dark smoke with a pulsing air track points to a ventilation controlled, decay stage fire.
What conditions would you expect to find inside the building?
Floors 1 and 2 are likely to be fully smoke logged (ceiling to floor) with fairly low temperature. The basement is likely to have a higher temperature, but is also likely to be fully smoke logged with limited flaming combustion.
How would you expect the fire to develop over the next few minutes?
As ventilation is increased (tactical ventilation and entry for fire control), the fire in the basement will likely remain ventilation controlled, but will return to the growth stage as the heat release rate increases. Smoke thickness and level (to floor level) along with a pulsing air track points to potential for some type of ventilation induced extreme fire behavior such as ventilation induced flashover (most likely) or backdraft (less likely). Another possibility, would be a smoke explosion; ignition of premixed gas phase fuel (smoke) and air that is within its flammable range (less likely than some type of ventilation induced extreme fire behavior)
Ongoing Assessment
What indicators could be observed while the firefighter was forcing entry and ventilating the daylight basement on Side C (02:05-02:49)?
There are few changes to the fire behavior indicators during this segment of the video. Building, Heat, and Flame indicators are essentially unchanged. Smoke above the roofline appears to lighten (at least briefly) and smoke on Side C continues to show limited buoyancy with a slightly pulsing air track at the first floor doorway.
What B-SAHF indicators can be observed at the door on Side C prior to forced entry (02:49-03:13)?
Figure 2. Conditions at 03:06 Minutes Elapsed Time in the Video Clip
Figure 3. Conditions at 03:08 Minutes Elapsed Time in the Video Clip
Building, Smoke, Heat and Flame indicators remain the same, but several more pulsations (03:05-03:13) providing a continuing, and more significant indication of ventilation controlled, decay stage fire conditions.
What indicators can be observed at the door while the firefighter attempts to remove the covering over the window adjacent to the door on Floor 1 (03:13-13:44)?
No significant change in Building, Heat, or Flame Indicators. However, smoke from the doorway has darkened considerably and there is a pronounced pulsation as the firefighter on the ladder climbs to Floor 2 (03:26). It is important to note that some of the smoke movement observed in the video clip is fire induced, but that exterior movement is also significantly influenced by wind.
What B-SHAF indicators do you observe at the window on Floor 2 prior to breaking the glass (03:44)?
Figure 4. Conditions at 03:43 Minutes Elapsed Time in the Video Clip
The window on Floor 2 is intact and appears to be tight as there is no smoke visible on the exterior. It is difficult to tell due to the angle from which the video was shot (and reflection from daylight), but it would be likely that the firefighter on the ladder could observe condensed pyrolizate on the window and smoke logging on Floor 2. It is interesting to note limited smoke discharge from the top of the door and window on Floor 1 in the brief period immediately prior to breaking the window on Floor 2.
What indicators are observed at the window on Floor 2 immediately after breaking the glass (03:44-03:55)?
Figure 5. Conditions at 03:52 Minutes Elapsed Time in the Video Clip
No significant changes in Building, Heat, or Flame indicators. Dark gray smoke with no buoyancy issues from the window on Floor 2 with low to moderate velocity immediately after the window is broken.
What B-SAHF indicators were present after the ventilation of the window on Floor 2 Side C was completed and 04:08 in the video clip (03:44-04:08)?
Buoyancy and velocity both increase and a slight pulsing air track develops within approximately 10 seconds. In addition, the air track at the door on Floor 1 shifts from predominantly outward with slight pulsations to predominantly inward, but with continued pulsation (possibly due to the limited size of the window opening on Floor 2, Side C.
Anticipating Potential Fire Behavior
Unlike the firefighters in Chicago who were operating at this incident, we can hit the pause button and consider the indicators observed to this point. Think about what fire behavior indicators are present (and also consider those that are not!).
Initial observations indicated a ventilation controlled decay stage fire and predicted fire behavior is an increase in heat release rate with potential for some type of extreme fire behavior. Possibilities include ventilation induced flashover (most likely) or backdraft (less likely), or smoke explosion (less likely than some type of ventilation induced extreme fire behavior).
Take a minute to review the indicators of ventilation controlled, decay stage fires as illustrated in Table 1.
Table 1. Key Fire Behavior Indicators-Ventilation Controlled, Decay Stage Fires
Which of these indicators were present on Side C of 4855 S. Paulina Street?
Building: The building appeared to be unremarkable, a typical single family dwelling. However, most residential structures have more than enough of a fuel load to develop the conditions necessary for a variety of extreme fire behavior phenomena.
Smoke: The dark smoke with increasing thickness (optical density) is a reasonably good indicator of ventilation controlled conditions (particularly when combined with air track indicators). Lack of buoyancy indicated fairly low temperature smoke, which could be an indicator of incipient or decay stage conditions or simply distance from the origin of the fire. However, combined with smoke color, thickness, and air track indicators, this lack of buoyancy at all levels on Side C is likely an indicator of dropping temperature under decay stage conditions. This conclusion is reinforced by the increase in buoyancy after ventilation of the window on Floor 2 (increased ventilation precipitated increased heat release rate and increasing temperature).
Air Track: Pulsing air track, while at times quite subtle and masked by swirling smoke as a result of wind, is one of the strongest indications of ventilation controlled decay stage conditions. While often associated with backdraft, this indicator may also be present prior to development of a sufficient concentration of gas phase fuel (smoke) to result in a backdraft.
Heat: Velocity of smoke discharge (air track) and buoyancy (smoke) are the only two heat indicators visible in this video clip. As discussed in conjunction with smoke indicators, low velocity and initial lack of buoyancy which increases after ventilation is indicative of ventilation controlled, decay stage conditions.
Flame: Lack of visible flame is often associated with ventilation controlled decay and backdraft conditions. However, there are a number of incidents in which flames were visible prior to occurrence of a backdraft (in another compartment within the structure). Lack of flames must be considered in conjunction with the rest of the fire behavior indicators. In this incident, lack of visible flames may be related to the stage of fire development, but more likely is a result of the location of the fire, as there is no indication that flames were present on Side C prior to the start of the video clip.
What Happened?
Firefighters had entered the building for fire attack while as illustrated in the video clip, others were ventilating windows on Side C. It is difficult to determine from the video if a window or door at the basement level on Side C was opened, but efforts were made to do so. A window on Floor 2 had been opened and firefighters were in the process of removing the covering (plywood) from a window immediately adjacent to the door on Floor 1. At 04:12, an explosion occurred, injuring two firefighters on the interior as well as the two firefighters engaged in ventilation operations on Side C.
Starting at approximately 03:59, velocity of smoke discharge from the window on Floor 2 Side C increases dramatically. At 04:08 discharge of smoke begins to form a spherical pattern as discharged from the window. This pattern becomes more pronounced as the sphere of smoke is pushed away from the window by increasing velocity of smoke discharge at 04:12, immediately prior to the explosion. Velocity of smoke discharge at the door increases between 03:59 and -4:12 as well, but as the opening is larger, this change is less noticeable. As pressure increases rapidly during the explosion a whooshing sound can be heard. After the explosion, there was no noticeable increase in fire growth.
Figure 6. Conditions at 04:08 Minutes Elapsed Time in the Video Clip
Figure 7. Conditions at 04:09 Minutes Elapsed Time in the Video Clip
Figure 8. Conditions at 04:10 Minutes Elapsed Time in the Video Clip
Figure 9. Conditions at 04:11 Minutes Elapsed Time in the Video Clip
Figure 10. Conditions at 04:12 Minutes Elapsed Time in the Video Clip
Figure 11. Conditions at 04:13 Minutes Elapsed Time in the Video Clip
Based on observation of fire behavior indicators visible in the video clip, we know that a transient extreme fire behavior event occurred while a crew was advancing a hoseline on the interior and ventilation operations were being conducted on Side C. What we don’t know is what firefighting operations were occurring on the other sides of the building or in the interior. In addition, we do not have substantive information from the fire investigation that occurred after the fire was extinguished.
The Ontology of Extreme Fire Behavior presented in an earlier post classifies these types of phenomena on the basis of outcome and conditions. As a transient and explosive event, this was likely a backdraft or smoke explosion. In that this occurred following entry and during ongoing ventilation operations, I am inclined to suspect that it was a backdraft.
Indicators visible on Side C provided a subtle warning of potential for some type of ventilation induced extreme fire behavior, but were likely not substantially different from conditions observed at many fires where extreme fire behavior did not occur.
As the title of the wildland firefighting course S133 states; Look Up, Look Down, Look Around! Anticipation of fire development and extreme fire behavior requires not only recognition of key indicators, but that these indicators be viewed from a holistic perspective. Firefighters and/or officers performing a single task or tactical assignment may only see part of the picture. It is essential that key indicators be communicated to allow a more complete picture of what is occurring and what may occur as incident operations progress.
Updated March 7, 2010 with Longer Video Clip of this Incident
On the afternoon of February 18, 2010, firefighters in Chicago responded to a residential fire at 4855 S. Paulina Street. First arriving companies discovered a fire in the basement of a 1-1/2 story, wood frame, single family dwelling and initiated fire attack and horizontal ventilation of the floors above the fire.
Based on news accounts, the company assigned to fire attack was in the stairwell and another firefighter was performing horizontal ventilation of the floors above the fire on Side C when a backdraft or smoke explosion occurred. Three firefighters on the interior and the firefighter on the ladder on Side C were injured and were transported to local hospitals for burns and possible airway injuries.
Figure 1. Consider Key Fire Behavior Indicators
B-SAHF Indicators
Recognizing subtle fire behavior indicators during incident operations can be difficult and important indicators are often only visible from one location (other than where you are). What Building, Smoke, Heat, and Flame (B-SAHF) indicators would you anticipate seeing if potential backdraft conditions exist (or may develop as the incident progresses)? How would this differ from the indicators that conditions may present risk of a smoke explosion?
For more information on key fire behavior indicators related to ventilation controlled burning regime, decay stage fires, backdraft, and smoke explosion, see the following posts:
A video of the incident at 4855 S. Paulina Street was recently posted on YouTube (a shorter version is posted on Firevideo.net). It appears that the video may have been shot through a window by an occupant of the D2 exposure. The title of this video is “Chicago Smoke Explosion”. After watching the video and answering the questions posed in this post, do you think that this was a backdraft or smoke explosion? Why?
One of the great assets of using video as a learning tool is the ability to stop the action and go back to review key information. Watch the video and stop the action as necessary to answer the following questions”
Pause at 02:05. What B-SAHF indicators could be observed on Side C up to this point in the video clip?
Pause at 02:49. What indicators could be observed while the firefighter was forcing entry and ventilating the daylight basement on Side C?
Pause at 03:13. What B-SAHF indicators can be observed at the door on Side C prior to forced entry?
Pause at 03:35. What indicators can be observed at the door after forcing the outer door (prior to ventilation of the window on Floor 2)?
Pause at 03:44. What B-SHAF indicators do you observe at the window on Floor 2 prior to breaking the glass?
Pause at 03:55. What indicators are observed at the window on Floor 2 immediately after breaking the glass?
Pause at 04:08. What B-SAHF indicators were present after the ventilation of the window on Floor 2 Side C was completed and 04:08 in the video clip?
After answering the questions, watch the complete clip. Do you think that this was a backdraft or smoke explosion? If you thought that this was a backdraft: Did you see potential indicators? If so what were they? If not, why do you think that this was the case? If you think that this was a smoke explosion, what indications lead you to this conclusion? What indicators were present?
You may want to watch this video clip several times and give some thought to what factors were influencing the B-SAHF indicators (particularly smoke, air track, and heat). Were these indicators consistent with your perception of backdraft indicators? Is so, how? If not, what was different? What indicators may have been visible from other vantage points. Remember that the video provides a view from a single perspective (and one that is considerably different than the crews working at this incident).
The next post in this series will take a closer look at the video and key fire behavior indicators.
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
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
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.
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.
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.
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.
NIOSH has investigated a number of incidents in which firefighters trapped by rapid fire progress did not take appropriate survival action. Last September, I was reading NIOSH Report F2007-02, which outlined the circumstances surrounding the death of Firefighter Steven Solomon in Atlanta, Georgia. Firefighter Solomon was severely burned after being caught by rapid fire development while advancing an attack line in a vacant structure (see Figure 1).
Figure 1. Rapid Fire Development
Note: Atlanta Fire Department photo from NIOSH Report F2007-02
Firefighter Solomon was on the nozzle as the first arriving truck removed the plywood covering the front door and thick, black smoke came rolling out the top of the doorway. Firefighter Solomon and the crew of Engine 16 advanced the line into the building as the truck continued horizontal ventilation. After advancing a short distance, fire conditions quickly worsened and the crew attempted to back out, but collided with another company who was advancing a backup line. After exiting the building the crew of Engine 16 realized that Firefighter Solomon was still inside. Crews outside the door on Side A observed the silhouette of a firefighter running through the flames inside the building.
As I read the report, I asked myself how a firefighter on a hoseline that was just a short distance could have been killed by rapid fire development. The NIOSH report identified four contributing factors:
Initial size-up not conducted.
Failure to recognize the signs of an impending flashover/flameover.
Inadequate communication on the fireground.
Possibility of ventilation induced rapid fire progression.
While these factors likely contributed to Firefighter Solomon’s death, I still did not have a solid answer to my question of how a firefighter on a hoseline just a short distance inside the doorway could have died in this type of event.
Predictability
The best way to avoid being injured or killed in an extreme fire behavior event is to read the fire, anticipate likely fire behavior, and control your operating environment. A majority of our effort should be spent on mastering these skills.
There is no unpredictable fire behavior. Under the same conditions, a compartment fire will develop and behave consistently. However, conditions are not always the same! In addition, firefighters operate with limited information, imperfect skill in anticipating likely fire behavior, and often under pressure to take rapid action. When making decisions under pressure, in a complex and dynamic environment, and with limited information, potential for error increases.
Improved understanding of fire dynamics and development of a high level of skill reduces, but does not eliminate your risk of encountering extreme fire behavior. When this occurs it is essential that firefighters understand the fire behavior, their own reactions to stress, and have well practiced (to automaticity) responses to increase the chance of survival.
Training for Survival
What exactly are firefighter survival skills? Firefighters may encounter a number of life threatening problems while operating in the hazardous environment of as structure fire. Threats include breathing apparatus emergencies (e.g., malfunctions, running out of air), becoming disoriented, and being trapped by collapse or rapid fire progress.
A quick survey of survival skills training programs from around the United States shows a fair degree of consistency in curriculum content:
Emergency Communications Procedures (Mayday, Radio Emergency Distress Button)
Personal Alert Safety System (PASS) Activation
Reorientation, Searching for an Exit & Following a Hoseline to Safety
Air Conservation Techniques
Assuming a Horizontal Position to Enhance Thermal Protection and Audibility of the PASS
Escape to a Place of Refuge
Use of Visual and Audible Signals (Flashlight, Tapping with a Tool)
Reduced Profile Maneuvers to Escape Through Small Openings
These techniques may provide useful in dealing with a number of the threats that may be encountered in a structure fire. Taking refuge in an uninvolved compartment (with the door closed) may buy time for firefighters to escape through a window. However, the other elements will have little impact on increasing survival potential when encountering extreme fire behavior phenomena.
What is the missing element in the typical survival skills curriculum? In some cases, firefighters are taught breathing techniques to control their respiratory rate and conserve air, but little emphasis is provided on the psychological and physiological effects of the stress encountered in life threatening situations. This is critical to survival regardless of the nature of the threat. When faced with extreme fire behavior, particularly wind driven flames, flashover, and flash fire, appropriate nozzle technique and immediate tactical withdrawal to a safer area is absolutely critical. However, most survival skills curriculums do not address these critical skills.
When was the last time you practiced withdrawing a hoseline while operating the nozzle in the context of offensive, interior firefighting operations?
Performance Under Stress
There has been little if any research has been done to identify factors influencing firefighters’ performance under the extreme stress of a life threatening situation. However, there has been considerable investigation in other domains, particularly in the military and law enforcement
Increased psychological and physiological arousal prepare the human body for action. As this occurs, the sympathetic nervous system increases heart rate and blood pressure to maximize the body’s physical capacity. However, extreme levels of stress can result in significant deterioration in performance.
In On-Combat: The Psychology and Physiology of Deadly Conflict in War and Peace, LT COL Dave Grossman (2008) identifies five levels of arousal designated Conditions White, Yellow, Red, Grey, and Black. While cautioning against fixing specific heart rate numbers (or other precise physiological measures) to these levels of arousal, heart rate can be used as an indicator (see Figure 2).
Figure 2. Effects of Hormonal or Fear Induced Increases in Heart Rate
Note. Adapted from On-Combat: The Psychology and Physiology of Deadly Conflict in War and Peace (p. 31), by Dave Grossman, 2008, Millstadt, IL: Warrior Science Publications Copyright 2008 by David A. Grossman.
When face with an immediately life threatening situation, the resulting stress can significantly impact an individual’s ability to respond appropriately. In addition to the physiological responses (e.g. increased heart rate, visual and auditory distortion) decreased cognitive processing may delay appropriate response or result in freezing, with the inability to act (Wallenius, Johansson, & Larsson, 2002).
Recently a colleague related the experience of a firefighter who had been trapped by a wind driven fire. The firefighter dropped to the floor, went into the fetal position, said goodby to his wife and children and thought he was dead. Fortunately, the firefighter was rescued, but this illustrates the potentially incapacitating effects of stress in life threatening situations.
What is the answer? Military research points to the need for a highly trained (to automaticity) response. Battle drills integrate these immediate individual actions in the context of small unit operations.
Battle Drill
In a military context, 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.
The battle drill concept has direct applicability to 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.
Unless a barrier (such as a door) is available to block the flow of flames and hot gases towards the firefighters position, attempts to escape without protection from a hoseline are likely to fail as fire can spread far more quickly than you can move.
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.
The next post in this series will return to hose and nozzle drills with development of a battle drill for response to rapid fire progression.
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.
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
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.
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.
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.
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.
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.
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?
What additional information would you like to have? How could you obtain it?
What stage(s) of development is the fire likely to be in (incipient, growth, fully developed, or decay)?
What burning regime is the fire in (fuel controlled or ventilation controlled)?
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?
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:
Did fire conditions progress as you anticipated?
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.
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
Figure 2. Extension of Flames and Ignition of Fuel Overhead
Figure 3. Transition to Flaming Combustion Overhead
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).
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.
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
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).
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.
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.
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.
