By John B. Tippett Jr.
Published Sunday, April 1, 2012
| From the April 2012 Issue of FireRescue
There are a number of factors to evaluate when deciding whether to initiate an interior attack. One critical factor that has gained significant attention over the last several years is smoke conditions. Honing your “reading smoke” skills can prove invaluable when it comes time to assess a fire burning inside a structure. Further, smoke conditions provide a wealth of information that firefighters can use to determine the sequence of steps for initiating (or not initiating) an interior attack. More than any other factor, the smoke coming from the building provides a definitive visual indicator of fire growth, relative toxicity and which direction the fire is traveling through the structure.
Reinforcing the value of reading smoke, numerous fire attack-related near-miss reports note that the lack of reading smoke is often a contributing factor to the near miss. The message is clear: If you’re not reading smoke as part of your pre-entry assessment, you’re setting yourself up for a personal protective equipment (PPE) stress test that you don’t want to be the model for. Let’s now review some near-miss report excerpts related to this issue.
“Dispatched at 1245 HRS to a structure fire. The first-due engine consisted of four personnel and arrived within three minutes of the call. Upon arriving on scene, moderate smoke was visible with no flame. A small amount of fire was showing from Side B near the kitchen area. A handline was ordered into place on Side A, and waited for ventilation to take place. At that time, a window on Side B was ventilated releasing smoke and fire. The attack crew then entered the structure on Side A. Then words came across the radio, ‘We are backing out, too much fire and heat.’ Fire was pushing violently out of Side A as flashover conditions followed.” (Author note: The crews make several additional attempts to ventilate and attack the fire but are driven out of the structure.) We began to see sunlight coming through the windows and smoke and steam exiting out of the ventilated windows as we were knocking down the fire. As we progressed toward the seat of the fire, to our amazement, a huge plume of black smoke again enveloped us with conditions deteriorating fast. We applied water to the ceiling but were met with tremendous heat and smoke.”
“On arrival the first-due engine advised of a single-story residential (wood-frame construction) with no hazards showing (smoke or fire). Command was established, a 1¾" line deployed, and an investigative mode initiated. While searching the interior of the structure, two firefighters encountered, as they described, a light haze of smoke with low heat inside the structure. Upon entering the kitchen area, the members reported brown tan laminar smoke in the kitchen with low heat conditions … continued to search for the origin of the smoke. Prior to entering a bedroom off a narrow hallway, the firefighters decided to leave the hoseline in the hallway outside of the bedroom door. Seconds after entering the bedroom, a fire erupted in size and intensity that I have never seen before.”
“We arrived on the scene of a house fire to find heavy smoke showing and a person standing on the front porch in the smoke, only visible from the knees down. We entered the structure without completing a 360-degree walk-around or visualizing the structure. After trying to locate and fight the fire, we had to back out due to high-heat conditions. We then removed a large window to ventilate the structure and were then able to re-enter and extinguish the fire.”
The lessons learned from all three reports acknowledge the value of reading smoke. In Report #06-204, fire conditions continued to increase despite ventilation efforts, and different smoke presentations accompanied the fire growth. In #09-1033, changing smoke conditions (i.e., light and hazy upon entry followed by brown tan, laminar flow) led to a violent eruption of fire in a back bedroom. The key point here was recognizing changing conditions and being able to interpret what they equated to in the fire-development process. Report #10-319 opened with a description of heavy smoke conditions—conditions that telegraphed a high-heat situation occurring somewhere in the building.
Knowing what various smoke factors (e.g., velocity, pressure, color, and volume) indicate provides firefighters with an invaluable tool for making the “go/no-go” decision on the interior attack. To improve your risk/reward evaluation process:
- Attend a reading smoke seminar. Take good notes and put what you learn into practice at the next available opportunity.
- Remember that smoke is unburned fuel. The hotter the fuel, the closer it is to its ignition point.
- Taking a few extra seconds to assess smoke before plunging blindly into the building. The more you know going in, the more control you have over the situation.
- Review the following video clips. Analyze what the smoke is telling you about the fire conditions. Discuss the smoke conditions with your crew/colleagues. Pay particular attention to velocity, pressure, color and volume at different points in each of the clips.
Prevention & Closing
The interior attack is a mainstay in the American fire service tactical tool box and will be for the foreseeable future. That mainstay status is only guaranteed as long as we in the profession demonstrate that a rational risk-based decision-making process is employed prior to entering the fuel-rich, fire-propagating environment. The tactic is not employed without risk, and it is unreasonable to assume all risk can be eliminated. The successful interior attack is one that is mounted after the completion of a risk assessment that considers many factors—not one that plunges blindly into the smoke, extinguishes the fire and then marvels at how lucky the crew was.
Comment Now: Post Your Thoughts & Comments on This Story