Knowing about fire is not enough; some skillful and knowledgeable firefighters are now accident statistics. WHY?
When fire intensities are increasing, firefighters tend to become very busy trying to “win the fight.” Instead of assessing the potential of the fire, they turn their attention toward gaining another foot of fire line or holding what fire line they’ve built. Neglecting to predict the obvious change in fire behavior because of the distraction of firefighting is what I call The Distraction Factor.
The Distraction Factor
When your crew is felling trees, cutting fire line, or burning out, it is easy to become totally distracted from the signs that foretell the future. When trees seem to be torching with more frequency, the flames are higher and the control more difficult, the supervisor must not become distracted from the responsibility of adjusting the tactics to match the near-future condition of the fire. Recognizing the big picture is part of the job. The fire is hissing its message to all who will be observant, “I’m about to crown and run the slope. I want that terrain.”
I remember the infamous fires that snuffed out the lives of my peers. The Decker, the Loop, the Elizabeth, the Romero, the Steward, the Inaja and the Dude Fires burned over 28 firefighters. Others who lived through them were forever changed in some way. I know I was. How many victims were there? More than the deceased, some could not go on as firefighters.
These fires and others reveal a deadly commonality: The fatal fire behavior was not predicted in time to get out of the way. How can a firefighter obey the standard firefighting order to “Initiate all action based on current and expected fire behavior” if he cannot predict change?
Attacking a fire and loosing should be considered an error rather than a brave action
This chapter isolates some of the key elements that will allow fire behavior predictions while engaged in the battle of fire suppression.
Awareness of Flammability Peaks
When working on a fire under conditions of significant fuel temperature/flammability differences, firefighters and supervisors need to maintain an awareness of the time period when the exposure peaks in flammability.
As you’ve already learned, this is the time of day that the area will be at its extreme high point, the peak of the flammability curve. During this time, the fuel is at its highest temperature. This is the most dangerous time to be in the path of the fire, this is time to become defensive in tactics selection.
Maintain an awareness of where you and the exposure are on the flammability curve. If that point is not the bottom or the peak, note whether the fire behavior is ascending or descending the curve. Ask yourself and others, “Is the topography becoming more or less flammable with the passage of time?” If the answer indicates that fuel flammability is increasing, we need to select appropriate tactics for that condition. If the fuel flammability is receding or getting better, we may select more offensive tactics.
I cannot imagine working on fire without this crucial information upon which to base tactics. You should learn to be mentally ahead of the potential. The observed fire will tell you its current state; you need to mentally place the fire in it’s new time, condition or position and then determine the fire’s near-term potential. To accomplish this, you need to compare the conditions of the future with current observed conditions. If the conditions are such that advantage is given to the fire, then the prediction of deteriorating (extreme) fire behavior is obvious. We must read the signs available to us and predict the ebb and flow of the fire’s behavior.
Many Burnovers Occur Near the Peak of the Flammability Curve
Whenever I read about a burn over situation, I have made it a habit to ask, “Where was the exposure on the flammability curve when the incident occurred?”
Many times I read in the reports that the signs of changing behavior were there. For this I offer some rather handy rules:
- Tactics must match conditions
- Firefighters must predict to be ahead of the event and create the lead time necessary to provide for safety
- We need to change our tactics based upon our predictions
- We need to communicate in prediction language
Tactics that may be successfully used when the fuel flammability is low on the curve can be dangerous near the peak of the flammability curve. Tactics need to be adjusted as conditions change.
Review tactics as the fuel flammability changes during the day or night. Good tacticians should be able to put a timetable on potentially dangerous tactics. “Indirect, secondary, parallel, and burnouts “are all potentially dangerous and should have time tags. Time tag is a phrase I used to describe the time period that a tactic is safe. The time period is determined by the point at which the fire behavior crosses the threshold from “workable” to “out of control” or beyond the capacity of firefighters. It is an educated guess, but one that must be made.
Sometimes only you will be aware of the changing conditions because you have received instructions to observe conditions. At other times, changing conditions can be of general notice as in the case of a weather condition change like a thunderstorm.
To illustrate the point, I’ll describe a situation that is not unusual for many wild land firefighters.
A hand crew was assigned a division on the fire with instructions to construct a hand line until relieved or until they tied the line into another division’s line. The morning was spent cutting a direct hand line along the fire’s edge. The fire had many fingers, and the line was crooked as it progressed over the topography. The day was hot and dry. During the daytime, the crew crossed many aspects and topographic features: gullies, canyons, up- and down-slopes. The weather forecast predicted afternoon thunderstorms.
About noon, the crew found themselves on a southwest aspect with thunderheads building above. As the afternoon bore on, the fire behavior seemed to be increasing and the thunderheads looked ominous. Adverse fire conditions were being stacked up to a potentially over threshold situation. The situation should be reassessed because conditions are forecast to change from a topography fire to a wind-driven fire compounded by changing wind directions.
The crew is on a hot slope near the peak of the fuel flammability curve. The thunderheads contain potential for violent downdrafts, when change direction as the cloud passes over. If the crew’s position is at all vulnerable to a fire run caused by downdrafts, it is time for action. The safe position of the crew should be the highest priority.
With fire conditions changing for the worse, the correct language to use in this case might be: “The forces creating extreme fire behavior are present and will not decrease for three or more hours. The tactics that were appropriate in the morning hours have now become hazardous and unsafe.”
If this practical Campbell Fire Prediction System were adopted for future use, the assignment of the crew would include consideration of the afternoon thunderstorm prediction stacked on top of the peak burning period, compounded by potential downdrafts from the thunderstorm. The assignment would identify the peak fire intensity period for the Division and a safety message to those assigned to be aggressive early and late, but defensive in tactics selected when the fire and conditions dictate.
The time frame for defensive tactics would depend upon the time of peak flammability of the exposure aspects, the alignment of forces of wind and slope, and the position of the fire in relation to the crew. Weather forecasters should be asked the time down drafts might be expected to occur.
The Operations Chief should prepare to stage crews out of harms way while the potential is at its maximum, then re-engage the fire when danger has passed. The supervisors on the line need to ask, “What would a wind from a thunderhead do to the fire” and “Will the crew be threatened?” This is maintaining control of your men; it is what I mean when I say tactics need time tags.
Fire Behavior Survival Rules
- When time or topography change and you find yourself headed into hot fuel, recognize the increased fire behavior potential. Don’t bet your life on the wind being consistent; decrease your exposure.
- When the fire runs into cold fuel, recognize that an opportunity for control is enhanced.
- Look at the differences in fire behavior while on the fire. Identify what forces and alignments created those differences. Base your fire behavior predictions on these observations.
- Know the time and conditions that the fire behavior potential will be at its worst. Assure that your selection of a suppression tactic does not put you and your firefighters in danger during that time or at that location.
- When an attack fails, consider it a failure of prediction of the fire’s behavior or your estimated suppression capability. If you predict fire behavior and the ability of the suppression force correctly, the attack should succeed.
- Always try to explain the causes for the predicted fire behavior change. Encourage others to do the same. This increases everyone’s understanding of the basis for the fire line prediction, and communicates the logic of the predictor. If you can recognize and communicate factors that are the precursors of change, it is easier to convince others of the need to change a tactic.
- Continually ask yourself: What forces are changing that will change the fire behavior is it the time, the topography, or the atmospheric conditions?
Copyright © 1991, 2016 by Doug Campbell.