By now, it’s no surprise that as development continues to increase in the wildland/urban interface (WUI), more and more structural fire departments have to learn and train on wildland firefighting tactics. Although structural and wildland fire suppression strategies may contain some similarities, the tactics are quite different. In this article, we’ll provide a basic overview of wildland firefighting tactics for the structural firefighter.
The Safety Toolbox
Before you step foot onto any WUI fire incident, your WUI “safety toolbox” should contain information on the 10 Standard Fire Orders, the 18 Watchout Situations, the 12 WUI Watchout Situations (see sidebar on p. 72 for complete list) and Lookouts, Communication, Escape Routes and Safety Zones (LCES). If proper LCES is maintained, the Standard Orders and Watchouts won’t be compromised. Note: For a complete list of the 10 Standard Fire Orders and the 18 Watchout Situations, visit http://www.fs.fed.us/fire/safety/10_18/10_18.html.
Whether you’re a firefighter or an incident commander (IC), your safety toolbox should also contain the risk management process, which
consists of the five following steps:
- Maintain situational awareness. On a WUI fire, keep in mind that your surroundings aren’t confined to four walls. The fire could spread across hundreds of acres, burn through entire neighborhoods and jump highways. Gather information–such as current fire behavior, wind patterns and weather forecasts–from various sources to gain a complete understanding of the fire and how it may change and grow.
- Assess existing and potential hazards. Determine fuel characteristics, fuel moisture, temperature and terrain.
- Control any known hazards. Has LCES been established? If not, do so immediately. If you don’t, you might not be able to control any hazards because you might not know they exist.
- Make clear and concise decisions. Are controls in place for identified hazards? Are selected tactics based on expected fire behavior? Have instructions been given and understood? If the answer is no to any of these questions, stop and reassess the situation.
- Throughout the incident, evaluate firefighters’ experience level, as well as their fatigue and stress levels, and their attitude.
- Other factors, such as exposures and the environmental value of the area (such as a watershed or timber region) should also be factored into your decision on how to fight the fire.
3 Attack Methods
To determine which tactics to employ on a wildland/WUI fire, you must first determine what the fire is doing. Fire growth and behavior are based on several factors, including response time, weather conditions, topography and fuel types. If your initial size-up indicates that the fire can be safely attacked, there are three basic fire-attack methods that you can use either by themselves or in combination with each other. The objective: to control the head, flanks and heel of the fire.
Method 1: Direct Attack
When performing a direct attack on a WUI fire, personnel and equipment start from a common anchor point, which include well-used roads; the banks of a creek, river, or pond; a rock scree (debris at the base of a slope); or a previously burned area that contains “good black.”
Working close to the fire’s edge, firefighters cut line and/or deploy hoselines to create a control line around the fire. This tactic is also known as “working with one foot in the black.”
There are many advantages to performing a direct attack, the biggest being that firefighters can usually escape into the burned area if fire behavior suddenly changes and threatens firefighters’ positions. There’s also no need to attempt backfiring, which minimizes the area burned.
There are three different ways to perform a direct attack on a WUI fire: the flank attack, the pincer action and envelopment. During a flank attack, firefighters work along the side or hot flank of the fire, attempting to envelope the head of the fire and continue around until they reach the black area of the cold flank. Once they reach the cold flank, they can construct a control line back to the anchor point.
As the name implies, the pincer action allows fire crews to “pinch off” the head of the fire. To perform this maneuver, fire crews start out at a common anchor point, but then split into two separate groups that work both flanks of the fire simultaneously, attempting to reduce the head of the fire.
When attempting to envelope the fire, personnel operate from multiple anchor points and work the head of the fire and the cold flank.
Method 2: Indirect Attack
In some situations, the fire behavior, fuel types and lack of on-scene resources preclude an aggressive direct attack. In these situations, natural barriers can be used while additional resources are gathered. These natural barriers can include fuel breaks, such as streams, lakes, ponds, rock slides and any other areas that contain sparse fuels. They can also consist of constructed barriers such as roads or irrigation canals.
The indirect attack is accomplished by constructing fireline at a distance from the edge of the fire. Backfiring will be necessary to remove the unburned fuel between the edge of the fire and the fireline, which increases the safety risk to firefighters because more area will be burned than in a direct attack. Firefighters operating at a distance from the fire may also not have a good visual on the fire and its behavior.
Method 3: Parallel Attack
Like the indirect attack, hand crews and bulldozers perform parallel attacks when a direct attack isn’t practical. Crews and/or dozers can work anywhere from 5 to 50 feet off the hot flank, allowing fuel to burn out up to the control line. But this can be a risky tactic, as it allows for unburned fuel to be between personnel working on the control line and the fire. This method should only be used when winds are in your favor.
A Word about Backfiring
Both indirect and parallel attacks may employ backfiring or burning out; however, if you haven’t been trained in the use of these tactics, backfiring falls into the “high risk/low frequency” category. If the wind changes, the timing is off or the sequence and speed of the firing is off, backfiring can put firefighters’ lives at risk and create additional exposures. Due to the complexity of these tactics, only experienced firefighters trained in how to use firing devices and how to determine whether conditions are favorable for these operations should performing backfiring.
Conclusion
If your response area includes WUI or wildland areas, it’s imperative that you train for WUI/wildland fires. If your department hasn’t implemented WUI training, start by developing scenarios that can be used for tabletop or sandbox exercises, incorporating the three attack methods in this article. Preplan neighborhoods in the WUI, become familiar with the typical weather patterns in your area and always remember to maintain situational awareness.
The 12 WUI Watchouts
- Poor access and one-way roads
- Bridge load limits
- Wooden construction and wood shake roofs
- Power lines, propane tanks and hazmat threats
- Inadequate water supply
- Natural fuels that are 30 feet or closer to structures
- Structures in chimneys, box canyons, narrow canyons or on steep slopes (30 percent or greater)
- Extreme fire behavior
- Strong winds
- Evacuation of public
- Parking under power lines
- Applying a straight stream to power lines
