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Wisconsin Natural Resources magazine

Wisconsin Natural Resources magazine

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April 2005

Tools of the trade

From planes to Pulaskis

Ron Zalewski

Just as the forest fire hazard varies across the state, so does the equipment used to suppress those fires. Some of the equipment has not dramatically changed over the past century. The reliable backcan pump is still commonly used to suppress many smaller fires.


These backcans can be either galvanized metal or newer soft models that are more comfortable to wear. Both types hold about five gallons of water and, when used in a team approach with three or more individuals attacking a fire, can successfully extinguish smaller, lower intensity fires burning less than a couple of acres. These backcans also are used extensively during mop-up procedures, where hotspots are completely extinguished after initially containing and controlling a fire. Often used in conjunction with hand tools such as a shovel or Pulaski (combination of an ax head for cutting and mattock for digging) these backcans can help ensure that the fire is completely out.

Additional equipment, however, may be needed to fight more intense wildfires. Initial attack DNR Type 7X trucks or fire department brush trucks often provide first response to forest fire reports and can be used effectively where access is available. These four-wheel-drive engines carry 150 to 200 gallons of water and are equipped with mobile radios, emergency lights and sirens, hand tools (shovels, Pulaskis, chainsaws) and other safety equipment. These trucks provide quick response to many fires, helping to keep them small and minimizing destruction. DNR Type 7X engines typically are equipped with foam units for applying a foam-water mixture that provides greater protection than water alone.

The Department of Natural Resources uses larger Type 4 engines on more challenging fires. These engines are outfitted with emergency lights and sirens, carry about 850 gallons of water, and house small and large diameter hoses, hand tools, backcans and safety equipment. They often have foam capability. Not only can these trucks deliver water to a fire, they are able to pump water from lakes, streams and even swimming pools. These engines are often used to suppress wildfires and protect structures. Larger fire department engines vary considerably, but also are commonly used on wildfires along with tanker-type engines.

These engines also pull tractor plows used to control more challenging fires. When combined with a tractor plow unit and trailer, they are referred to as "heavy units." Tractor plow units carry 150 gallons of water primarily used for operator protection. The six-way blade on the front can be used to construct drivable roads around larger fires, separate burning materials from unburned material, push over burning trees and create firelines or fire breaks. The plow in back of the tractor may cut a six-foot-wide mineral soil fireline or fire break.

Fire breaks are effective ways to control small intensely burning fires or larger fires. Inside the fire break, a small fire (drip torch) is used to burn out fuels between the fireline constructed by the tractor plow furrows in an attempt to stop the spread of an advancing fire. Tractor plow units are especially effective in upland areas but can also operate in some wetter areas that pose equipment access problems. These tractor plow units are the backbone of fire suppression activities in Wisconsin.

The Wisconsin Department of Natural Resources also has equipment specifically designed to operate in lowland marsh conditions. ATVs, Muskeg Units and Bombardier units oftentimes can provide the necessary access. These tracked units typically are equipped with water tanks and can suppress fires either by running over the edge of a less intense fire with their tracks and smashing vegetation into wetter fuels or water, or by spraying water on the fire edge. Some of these wet ground units are equipped with a front blade to assist fire suppression. Once the fire is contained and controlled these units help with mop-up actions and provide transportation and water into areas that are not accessible by typical equipment.

Plane patrols

Planes are important tools in detecting and suppressing fires. Oftentimes, smoke spotted by these planes, or air patrols, are actually outdoor burning operations. Since burning is normally only allowed toward evening hours, these aircraft patrols are an extremely effective fire prevention tool, alerting forestry personnel on the ground about illegal burning. Fire towers also are used to detect fires and reports from fire towers are checked by air patrols. Once a wildfire is spotted, planes pinpoint the wildfire location and assist by directing ground forces into the wildfire and providing valuable information on fire size, intensity and spread.

During periods of high fire danger, the Department of Natural Resources contracts aerial suppression planes or helicopters to help control fire.

These planes, called SEATs (single engine air tankers), are usually based in the most hazardous areas of central, northwestern or northeastern Wisconsin. These aircraft can deliver up to 600 gallons of foam or retardant to a fire scene in a short time, hopefully arriving while fires are small. They work in conjunction with resources on the ground to prevent fires from becoming larger and more destructive. Helicopters have the same mission. They typically drop water with a collapsible bucket that hangs from the bottom of the ship and holds just over 100 gallons of water or a water/foam mixture. Larger air tankers that carry up to 2,000 gallons also are available from neighboring states to aggressively attack more intense fires.

Fire prevention

Even before a fire starts, computer programs can predict fire danger and fire behavior. Small hand held instruments gather weather information at the scene, helping fire managers make better decisions on how to safely suppress these fires. Other computer programs help firefighters make attack plans and rally resources to suppress larger fires.

Ron Zalewski has been a DNR forester and ranger for 20 years.