Learn the language of fire so you can make better decisions on the fireground
By Janelle Foskett, managing editor of FireRescue magazine
Here in the United States, we hear a lot about “reading smoke”—an invaluable tactic on the fireground. But what do we know about reading fire
In his FDIC Friday morning session, “Reading the Fire: Learning the Language,” Shan Raffel, acting inspector with the Queensland Fire and Rescue Services in Australia, explained how this tactic allows firefighters to spend more time making fireground decisions based on knowledge and skills, not guesswork and luck.
I was excited to talk to Shan about this topic, particularly because of his work with the International Fire Instructors Workgroup (IFIW), an organization made up of a small yet focused group of scientists, engineers and fire practitioners from nine different countries, all deeply devoted to conducting research about fire behavior so that we can reduce the number of firefighter injuries and fatalities on the fireground. Here’s what Shan had to say:
Janelle Foskett (JF): Why did you determine that firefighters needed more information about “reading fire”? What was missing from the current research and/or practices?
Shan Raffel (SR):
Over the first 10 years of my career, I attended a lot of fires, and there were quite a few occasions when the fire behaved unexpectedly. I asked my colleagues if they could explain these events, and no one could really tell me what the different smoke colors and patterns actually meant. I started looking to authorities in other countries to get the answers. I was very intrigued with reports I had been reading about the approach being taken by the Swedish Fire Service. There seemed to be a sound scientific foundation for the very practical training they were conducting.
Then on Feb. 11, 1994, we experienced the loss of two of our firefighters at a fire in a motorcycle dealership. The coroner’s report identified “some phenomena of fire” that knocked them off the hoseline and caused burns severe enough to render them unconscious. We had lost two of our finest and no one could even identify the fire behavior that caused this tragic event. And just over two years later, two of our firefighters were caught by a rapid and unexpected ignition of smoke in hallway that they were searching at a backpackers’ hostel. Both suffered serious burns and were lucky to survive.
By this stage, my research had put me in contact with people who had a sound understanding of teaching methods that could greatly increase our knowledge of fire behavior and how to recognize the indicators of events, such as flashover and backdraft.
I felt that I had to try to learn more about these techniques and the tactics that were emerging as a result of understanding fire behavior in a more practical way. So in 1997, I submitted a study tour proposal that led me to an intensive study program in the United Kingdom, where many of the practices were being adopted, and then to the home of the radical new approach, Sweden.
JF: Can you briefly describe your acronym SAHF and what each letter stands for? SR:
SAHF stands for Smoke, Air Track, Heat, Flame. In more detail, it’s as follows: Smoke:
Height of neutral plane
Color and thickness (optical density)
Volume and location
Buoyancy and pressure
Velocity and direction
Flow – turbulent or smooth
Blackening of windows and no flame showing
Cracking or crazing of glass
Discolouration of glass
Blistering or discoloration of paintwork
Sudden heat build-up
The order is important. I put flame last because we tend to “see nothing else” when flame is present. When flame is showing, at least we have identified one part of the structure that’s lost and must be cut off if we’re going to prevent further loss of life and property.
Smoke on the other hand has the potential to suddenly become flame when the conditions are right. The movement of air into the involved compartment, and heat indicators, can assist in determining how close we are to those conditions.
JF: At what point do firefighters need to begin evaluating the fire using the SAHF acronym (on first arrival, for example)?
Reading the fire can start as soon as the call is received. Pre-incident plans can tell us a lot about the building construction, contents and occupancy. This helps to set the context for the type of fire development and behavior that is likely to be encountered. En route, we can often get a reasonable indication by looking out for the volume and color of smoke present. At night it can be very difficult to see and accurately identify the smoke indicators. Even when background lighting is present, it can sometimes give a false impression of smoke color. If the fire has broken out of the structure, the orange to red glow is often visible, and this tells us that we may have to focus more on exposure protection.
JF: Who is responsible for this and to whom does it get communicated?SR:
It is very much a team effort. The officer is responsible for reading the fire and determining the correct strategy (offensive or defensive) and then the best tactical approach for each particular incident. The firefighters that have been tasked should be continually conducting a SAHF assessment before entering the structure and monitoring conditions as they progress. Fire crews working outside the structure should also be looking for indicators that could provide a more complete picture of the fire and likely changes. Relaying the internal and external indicators and any changes that occur helps to build a more accurate profile of the fire. SAHF is part of the overall dynamic risk assessment process that continues until the hazard is removed. JF: How does building construction factor into this evaluation?SR:
Through research in some very diverse locations around the world, I have come to realize that building construction not only has an enormous impact on how a fire develops, but it has a profound impact on what indicators are likely to be present. A classic example is the heat indicators. Brisbane has a sub-tropical climate, and our construction focuses on making the most of our mild winters and staying cool in our hot summer months. It is very common for a fire to reveal its location as the heat is transferred through single-glazed windows and lightly insulated walls and doors. It is not uncommon for the fire to self-ventilate when the windows fail or the fire burns through the ceiling and roof. In very cold climates, the buildings are well-insulated and sealed from cold conditions. In this context, many of what we would consider to be early heat indicators may not be visible from the outside.
Emerging energy-efficient construction techniques that make use of composite-engineered building elements are making it more difficult to identify things like that rate of fire spread and time to collapse. I believe that the skill of reading the fire provides us with an advantage but it is critical to realize that it is only complete if we know all of the key factors. For this reason, we should be reading the fire and the changes and continually reassessing the situation as more information becomes available.
JF: Can you briefly explain what a firefighter should be thinking about tactically with regard to SAHF?SR:
The most obvious outcome of reading the fire is to be able to identify the location of the fire and work out where it will go with or without our intervention. I suppose the key factor that I am trying to determine is whether the fire is fuel-controlled or ventilation-controlled. If a high percentage of the structure’s volume is filled with smoke, and the indicators are telling me we have a ventilation-controlled fire, I know that there is a very high potential for rapid and aggressive fire spread when ventilation (planned or even unplanned) occurs. The tactical ventilation plan must anticipate this and include actions that will minimize this potential and deal with it in a controlled manner. This could include actions like deliberately keeping sections of the structure under-ventilated (anti-ventilation), delaying ventilation until hoselines are in place to cut off the potential fire progression, cooling the gases before opening up, etc.
Fuel-controlled fires are less likely to react suddenly after opening up. However, it is still important to have a tactical ventilation plan to remove, confine or dilute this accumulated fuel. Door entry techniques, safe zoning and buffer zoning, PPV and gas-cooling are examples of useful tools and techniques that can be used to advantage in these situations.
Shan Raffel has served as a career firefighter in Brisbane for 28 years. After the line-of-duty death of two colleagues in 1994, and the serious injury of two others from the effects of extreme fire behavior in 1996, he submitted a proposal to study the latest methods for teaching firefighters how to recognize and safely deal with flashover, backdraft and other fire phenomena. As a result of this proposal, he was sent to the United Kingdom and Sweden to study the teaching methods, training facilities and tactical approaches. During the next few years, he gained support and acceptance for these life-saving methods in Australia. After implementing a nationally recognized training program, he went on to work for 12 months with a Swedish Fire Engineer on the design of the carbonaceous fire training structures for the Live Fire Training Academy in Queensland. This provided a fantastic learning opportunity that gave insight into the scientific explanations behind the practical techniques. This foundation has led to ongoing international research and cooperation. Additionally, Raffel is a founding member of the IFIW, which has provided him the opportunity to learn from an incredibly diverse group of international experts who are united by the common goal of using sound scientific research to examine and improve the efficiency and safety of firefighting practices. In 2005, Raffel co-authored “3D Fire Fighting, Training, Tactics and Techniques.” He has lectured at numerous international conferences, and his papers have been translated into several languages, including German, French, Spanish, Malaysian, Croatian and Chinese. In 2010, Raffel was awarded a Churchill Fellowship to study planning, preparation and response to emergencies in tunnels. This 10-week fellowship involved research in the United States, Canada and several locations in Europe.