Smoke and fire gases are highly flammable materials.
Last month, we took a look at the first of seven common factors that contribute to the majority of deaths and injuries in the Fire Service. This month we will look at the second factor of location and will discuss the concept of ‘Big Exiting’ as it contributes to operational planning.
Location
When we consider location as a factor in injury and death, we need to develop a view of a ‘location’ as two separate issues.
We need to assess the location of the fire in relation to building egress, and we need to evaluate the location of firefighters in relation to the fire.
The failure to provide, improve and protect access and exit points in structure fires has been a factor associated with a number of fatality events.
Two significant issues arise in relation to a failure to plan for access and egress from structural fires as part of the operational plan.
· The first occurs when firefighters working as part of an interior fire team are cut off from their exit.
· The second event occurs when there is an over dependence upon a single access point for crews engaged in interior operations.
The over extension, or advancement of interior hose lines past uncontrolled fires and deployment of firefighters into environments that indicate imminent and rapid fire development are two situations where hose teams have been cut off from their escape routes. In both situations, the fire environment has not been controlled to the point where the safe withdrawal of firefighters has been assured.
Firefighters should extinguish bodies of fires as they advance into the structure. Many firefighters have been trapped when small fires have flared up behind them, cutting off their escape. Bypassing bodies of fire without knocking them out should be discouraged.
Experienced fire crews recognize the importance of controlling their environment and will not routinely bypass fires during their advance into a building fire. What may be viewed as a nuisance fire on the way in could kill you a few minutes later.
Firefighters and Fire Officers should have a fundamental understanding of how fire and fire gases behave in enclosed environments. Controlling the interior environment increases the likelihood of a successful evolution. Failure to control that environment can lead to rapid and uncontrolled fire behavior.
Common fire events that have the greatest impact on the safety of personnel include back draft and flashover phenomena.
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| Smoke and fire gases are highly flammable materials. |
Controlled depressurization and the channeling of smoke and fire gasses out of the structure through the proper application of ventilation techniques can reduce the impact of rapid fire development and reduce the risk of being caught in a back draft or flashover.
Ventilation efforts should be directed toward reducing interior pressure while attempting to control the airflow into a structure. The goal is to draw heated gases and smoke away from our customers, our crews and the pathways of escape.
If you accept the fact that smoke and fire gases are a mixture of highly flammable materials, needing only proper fuel to air ratios to ignite, then you will be able to understand why is important to get control of these fuels.
The ignition of fire gases within an enclosed environment is one factor related to the deaths of three firefighters in a commercial fire earlier this year.
Understanding the effect of pressure produced by fire and the risk of being caught in a negative pressure situation should also be part of the fire officer’s assessment. The negative pressure situation exists where the fire compartment that has a higher internal pressure than the place from which the attack takes place.
There have been a number of instances where firefighters, working from an area of lower pressure, such as a stairwell, or hallway, have been trapped by the explosive force of fire gasses issuing out of the fire compartment. A plan that incorporates manual or mechanical venting to outside of the building or over pressuring a stairwell prior to opening interior doors will help alleviate this effect.
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| A plan that incorporates manual or mechanical venting will help reduce the potential for backdraft and flashover. |
The over use of single entry points as a means of accessing fire structures has also been identified as an important mortality issue. More often than not, it is the initial access point that represents the focal point of entry for later arriving units.
In a virtual re-enactment of the “moth to candle” dance, one crew after another is sent into the front door without regard to the fact that these same crews will, in an emergency, come out that same door.
Over use of a single entry points is unwittingly encouraged in a culture that sees extinguishing fire as a competitive activity that pits one Engine Company against the skills and speed of another. That competitiveness on the fire ground can work against us. Harnessing and directing that energy towards team directed control of fires includes the development of multiple access and egress in a burning structure.
Most overuse of a single access point has occurred because arriving units are attempting to speed up access into the structure. The intent is to provide necessary resources to perform search and rescue, fire suppression and overhaul inside of the building as rapidly as possible. In most cases, the first door opened happens to be the only door opened. If all goes well and the fire is extinguished, as many routinely are, the issue of a single access or egress point is not a big deal. But, if the situation within the structure deteriorates and necessitates a rapid withdrawal, the escape plan may be delayed much to the detriment to the last person in line.
It wasn’t too many years ago that there occurred a large fire in multi-story masonry building in one large West Coast City. Multiple companies operating at the top of a narrow stairway were alerted to the warning signs of impending building failure. As these Companies attempted to funnel down to the street, major portion of the building collapsed. A popular fire Captain, the last man in line, was crushed under tons of brick. Among the issues that may have contributed to his death are certainly issues related to construction, age, fire damage and so on and on. That said, the number of firefighters that had to exit the single steep stairway hampered an organized withdrawal from the structure.
| The larger the footprint of the building, the more complex the fire problem, the larger the number of interior fire teams, the more important it is to provide multiple access into and out of the building. |
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Looking for opportunities to develop multiple access points into a building should be a part of the initial size-up of any structural fire. The practice of providing multiple access points into a fire structure, as a means of providing alternatives for firefighters’ escape when the building condition deteriorates, is a sound plan.
Consider the need to provide multiple access points whenever the situation requires more than two companies to “work” hose lines inside of a structure.
Three on a match or three in the door could be bad luck.
The larger the footprint of the building, the more complex the fire problem, the larger the number of interior fire teams, the more important it is to provide multiple access into and out of the building.
An important thing to remember is when considering the use of multiple access points; it is crucial to firefighter safety to avoid placing hose teams into situations where opposing hose streams are in operation.
"Big Exiting" is the practice of developing alternative access and egress points at structural fires. Big exiting should be given prudent consideration at every structural fire where personnel are committed to interior operations.
Big Exiting is the process by which a structure is prepared for the self-rescue.
This type of preparation gives interior crews and roof ventilation crews the ability to withdraw on their own when they have become disoriented, when interior conditions deteriorate, or when they simply feel the need to get out.
The likelihood of safe extraction will increase if a crew can self-extract when they become aware that it is ‘time to go’. The importance of training crews to recognize the triggers that indicate that it is no longer safe to operate inside of a structure cannot be understated.
The “Big Exiting” is a six-step process that includes:
1. The establishment of RIT/RIC or Stand-by Teams.
2. The routine placement of secondary ladders to roofs and at windows.
3. Avoidance of openings below facades, marquees, and mezzanines.
4. Making sure hose lines inside of buildings are pulled straight.
5. Making use of ropes and roof bags when operating without hose lines.
6. Providing lighting at entry points to show the way out.
The initial steps of “Big Exiting” involve:
- A detailed 360-degree survey of the structure. Completed after initial reconnaissance, this exercise is looking for more than location of fire and people waving from windows. It is a calculated attempt to minimize the impacts of building emergencies by providing a way outside prior to an emergency. It is the basis of an “escape plan”.
It focuses on the details of the building construction, configuration of components and changes in elevation of a structure that may be missed during the rapid assessment that occur just prior to initiating interior operations. Often, when decisions need to be made quickly, it is easy to overlook trivial details that will haunt you later. Therefore, the secondary survey is an important task taken to reassess the structure.
- The removal of bars and other window obstructions that would hamper self-extraction. There are any numbers of stories of lost and trapped firefighters found behind barred and boarded windows, locked and barricaded doors. These obstructions to escape must be removed.
- The positioning of secondary roof egress for ventilation crews. Placement of secondary escape or providing some other means of retreat for crews operating on top of roofs have been part of fire operations for generations. Yet today this is still an oft-neglected facet of firefighter safety.
- The placement of ladders to windows at and above the fire floor for interior teams performing ventilation, victim search, and fire control. A lost practice in many cities, the placement of exterior ladders at windows and balconies is critical for safe interior operations.
- The unlocking and disabling of doors and access points so that crews on the interior may get themselves out in an emergency. The near death of the young Captain in Phoenix some years ago underscores the importance of disabling locked doors. Exterior openings in buildings are sought out by lost and trapped firefighters.
- The communication of exit locations, access problems and building configuration issues that will impact the safety of personnel engaged in suppression and rescue activities. Interior firefighting operations are impacted by time. The time that it takes to remove obstructions preventing initial entry into a building must be communicated.
Access points that are secured for access and egress should be announced to crews working inside of the structure. The larger the building the greater the importance of announcing the location of access points as well as the location of exits that are not usable.
Care must be taken to evaluate whether opening doors and windows during this process will adversely impact the people working inside. Opening doors and windows may adversely impact ventilation efforts and increase the risk to interior crews. The goal is to disable the opening so that it can be opened from the inside though there will be situations where ‘more vent holes are good vent holes’.
Next Month: Pro-active R.I.T = Pro-active Rescue
