Wildland Firefighter Magazine, March 2006

Wildland Firefighter Magazine, March 2006
Thermal Imaging in Wildland Firefighting
By Gary Simpson
Sidebar by Rebecca Scholer

With training and many years of practice, generations of wildland firefighters have battled fires from the air and on the ground, often in poor visibility and with limited knowledge about burning conditions. Now with the emergence of thermal imaging in several wildland firefighting applications, working conditions on the ground and information gathering from the air can be greatly enhanced.

Used properly, thermal imagers can help crews more effectively monitor the flank and head of the fire, place personnel in key areas to create control lines, enhance safety during firefighting, and improve the control of prescribed burns. Firefighters can also use TIs to enhance their safety when navigating through smoke.

Applications of TI

Thermal imagers are primarily being using in wildland firefighting in five ways.

Monitoring the flank and head of the fire from the air – On the screen of a TI, hotter objects show as white, cooler objects show as black, and objects in between these temperatures are displayed in shades of gray. With a thermal imager, the fire’s location and progress will be evident from an aerial position, regardless of sunlight or the smoke conditions. This enables precise monitoring of fire progress that would not otherwise be possible. The ability to monitor fire progress during low light conditions means that crews can begin operations earlier in the day and end later in the evening, increasing efficiency.

Thermal imaging in action. Left: This photo was taken at a fire in August 2005 on the Payette National Forest. The helitack crew observed the fire in the morning, before the burn period. Viewed through regular sight, the fire does not appear very active. Right: The view through the thermal imager, however, presents a different picture, providing the helitack crew with a clear understanding of how active the fire was. Based on this data, the crew recommended that ground personnel not be used to fight the flames, due to the fire’s movement.

Placing and monitoring personnel – Especially in large operations, the placement of limited personnel is critical to gaining control. With the enhanced visibility that thermal imaging provides, wildland firefighters can be placed in key locations where control lines must be constructed. Proper placement enhances the ability of firefighters to protect exposures, including structures, threatened habitats and critical infrastructure. As ground crews deploy, airborne supervisors can monitor their locations and ensure a coordinated and effective response.

Monitoring dangers and extinguishing hot spots on the ground – With proper training on image interpretation, firefighters can use thermal imagers to monitor fire movement on the ground and in the trees above them. The direction and volume of fire brands can be tracked and monitored with a thermal imager. With practice, firefighters can identify snags, thereby improving safety on the job. During mop up, crews with thermal imagers can scan burned areas to ensure that the fire is out.

Managing prescribed burns – Controlled burns are critical to reducing the fuel load to improve manageability of wildland fires. Using the heat picture on the TI, wildland firefighters involved in prescribed burning can monitor the direction of fire spread and manage mop up more effectively. This provides information that enables them to protect exposures and keep these burns in a controlled state.

Navigation – When firefighters travel by ground during active wildland fires, their vision may be obscured by smoke. Thermal imagers used from a vehicle can assist the driver in navigating safely through thick smoke, avoiding fixed hazards as well as firefighters on foot. Firefighters on foot can use the thermal imager to help identify safer travel routes based on terrain or fire movement. This can help crews move safely and effectively when smoke obscures their vision.

Don’t Forget the Basics

Firefighters should be aware that thermal imaging technology is not a replacement for basic tactics. There may be times in mop up when a thermal imager cannot detect a hidden heat source, such as when the heat exists deep within a tree trunk. There may also be times when the image on the TI appears inconclusive to the user. When the TI is not providing as much information as desired, firefighters should rely on traditional techniques. If there is still doubt after using the TI along with traditional techniques, firefighters should err on the side of caution.

As with any other application of thermal imaging, planning and practice are the keys to effective technology usage. Firefighters must not only understand what they are seeing on the TI, but they must learn how to use this information seamlessly with the topographical and locational information they already employ on the job.

Conclusion

Thermal imagers can be used to improve operations in a wide variety of wildland firefighting operations, from the air and on the ground. While the dangers faced by wildland firefighters are different than those faced by structural firefighters, the thermal imager is a tool that can benefit firefighters in both types of incidents. By first understanding how a TI can be employed during a wildfire response, then practicing with it on a regular basis, firefighters can improve their personal safety as well as team effectiveness. Remember the ten standard firefighting orders are the bible of wildland firefighting, and thermal imagers should only be used to enhance the decision-making process.

SIDEBAR: From the Field

June through October is wildfire season for the Garden Valley Helitack crew at the Boise National Forest. Rick Dunlap, Helicopter Base Manager with Garden Valley Helitack, manages a 12-person crew of aerial delivered firefighters that travels by air to locations on over 1.4 million acres of forest land north of Boise. When the crew is not committed there, it responds to other locations in the Western United States. The Boise National Forest is unique in that none of the area is classified by Congress as wilderness, so burning is carefully controlled.

Dunlap says wildland firefighters have been using thermal imaging to collect information needed to control wildfire activity for years, both from helicopters and on the ground.

Dunlap’s crew begins the day early if there is an IR flight scheduled, starting 30 minutes before sunrise. The operations section provides the game plan, directing crews with specific instructions on the areas they should monitor. The crew then uses digital image capture on the thermal imager, as well as latitudinal and longitudinal measurements to collect imaging data of the areas specified.

When uncontrolled spots or new starts are detected, three members of the crew take suppression action, either landing in the helicopter or rappelling to the ground to attack. With hand tools and saws, they construct control lines and fell trees to bring fires to a halt. The TI operator evaluates fire line security from the air and uses topographical information to determine where new control lines need to be constructed. He then communicates instructions by radio to firefighters on the ground. When necessary, bucket support dumps water to aid suppression efforts.

Dunlap says the large handheld thermal imager used in the helicopter allows the crew to stay more than 400 feet off the ground in a very safe flight profile during fire monitoring and control operations, and it can also be used on the ground as needed. The crew uses a small handheld TI for ground operations, to aid with mop up efforts by evaluating hot spots that remain after initial suppression. When bulldozers are used to gain control of burning, this TI aids incident managers in monitoring progress.

Gary Simpson Bio