By Catherine Koele, Wisconsin DNR Field Fire Prevention Specialist
Wildfire activities in Wisconsin are increasing – we are currently reaching the peak of the fire season in northern Wisconsin. The DNR responded to nearly 70 veld fires over the weekend, and more are expected this week as the increased fire danger continues. Strong gusts, warmer temperatures, low humidity and very dry vegetation provide challenging firefighting conditions.
So, what happens when a wildfire occurs? The DNR has several suppression tools to combat these unwanted human-caused wildfires.
The primary purpose of the fire suppression program is to pre-position fire resources and quickly attack these fires from the ground to minimize fire growth. Teams are also working to contain the blaze to protect lives, property and natural resources from any damage.
When a wildfire is reported, the DNR’s fire control dispatch office is notified. The office will alert area firefighters immediately. When a fire is reported, the response times to a fire average ten to fifteen minutes.

The Type 6 engine is typically the first unit to arrive at the scene of a DNR wildfire. (Wisconsin DNR photo)
A Forester Ranger probably comes on the scene first and drives a custom 4 × 4 called a Type 6 or 7 engine. This engine serves as the primary source of transportation for patrol, initial attack, smoke control and law enforcement. The unit effectively navigates off-road driving, carries about 150 gallons of water, pumps, drafts and applies water or foam. The DNR currently has 115 Type 6 and Type 7 engines in its fleet.
The DNR also uses a tractor plow, or a “bulldozer”, which suppresses veld fires. This is mainly for larger fires or smaller intense fires in hard to reach places. The reassembled plow creates a 6-foot-wide mineral soil fire escape. These firebreaks, also called furrows, contain the fire and prevent it from growing. The front blade burns burning debris, creates fire lines and builds roads.

Three tractor plows digging furrows in tandem along the perimeter of a fire. (Wisconsin DNR photo)
In areas with larger timber, tractor plows can move along the perimeter of the fire in tandem to create wider furrows to reinforce the line of fire. The unit also carries 150 liters of water for operator protection and to suppress small fires with a mounted hose. The DNR currently has 77 tractor plows in its fleet.

The Type 4 Heavy Unit is used to tow the tractor plow on a tilting bed trailer and for fire suppression. (Wisconsin DNR photo)
A heavy unit, also called a type 4 engine, is a larger fire truck that tows the tractor plow on a tilt bed trailer. This unit suppresses veld fires, especially larger fires where the tractor plow is needed. The unit carries 850 liters of water and uses a pump to apply and draw water from lakes, rivers, swimming pools, etc. The pump also has foaming ability, which prevents water from evaporating quickly and can be used to help protected structures. The DNR currently has 82 heavy units in its fleet.
Low-ground units are another tool used by the DNR. It comes in many shapes and sizes, but all serve the same purpose of being able to work on soft ground in wetlands and swamps.

Lowland units are intended for combating fires on soft soils or wetlands. (Wisconsin DNR photo)
This unit is equipped with a 260 liter water tank, pump, hose reel, winch and a foam system. This slow but powerful piece of equipment has a 3-speed gearbox and 4-cylinder diesel engine and reaches 16 mph. The steel rails that support the rig are covered with rubber for extra grip and durability and often have a blade. The DNR currently has five low-ground units in its fleet.
The DNR not only fights fires from the ground. Air sources also play an important role. Airborne aircraft fly patrol routes and assist firefighters in detecting smoke, identifying hazards, guiding ground resources to a fire, and monitoring fire behavior.

Single-engine air tank makes a trap to slow down the spread of a wildfire. (Wisconsin DNR photo)
Single-engine air tankers (SEATs) combat wildfires from the air. They drop water to slow the progress of the fire and reduce fire intensity until land units arrive on the scene. The tank holds 800 gallons of foam, water or fire retardant and can release a droplet to cover an area 100 feet wide by 400 feet long. The aircraft’s top speed is 185 mph. The DNR contracts for SEATs in the spring through private companies and places them in advance according to fire hazard throughout the state.
The DNR also has access to helicopters with bucket capacity to drop 150 liters of water on a fire. There are also larger air tankers from partners in Minnesota and Ontario that can scoop up water from nearby lakes and drop up to 2,000 gallons.
Fire management personnel look at each situation from case to case. They make informed decisions about the best strategies for the site, fire conditions and unique conditions for each reported wildfire, using all the tools at their disposal.
As the fire season continues, the DNR will monitor and respond to the changing situation on a daily basis. Want to see where wildfires are actively burning in the state? Check out the DNR’s Fire Management Dashboard.
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