FIREFIGHTING IN THE PINE BARRENS
As more and more forested lands are developed into suburban communities, the structural firefighter rapidly is becoming the primary responder to brush and forest fires. This is especially true in the East Coast pitch pine and oak forests, known as “pine barrens.” These forests are both fire prone and fire dependent —fire is necessary for their existence.
Pine barrens contain some of the most hazardous types of fuel in the nation. According to the I S. Department of Agriculture National Fire Danger Rating System, pine barren forests present firefighters with risks and perils equal to the high fire hazard areas of the California chaparral.
Knowing how to size up a brush or forest fire; understanding the nature and behavior of wildfires; and know -ing when and how to use the right equipment, manpower, and tactics are the ingredients for successfully fighting these fires.
Suburban firefighters receive considerable training and experience fighting structural fires, vehicular fires, and a host of different fire situations ranging from hazardous materials to natural gas leaks and oil spills. On the other hand, most receive little formal training in brush and forest firefighting techniques. In fact, most structural firefighters are poorly trained in size-up and suppression techniques for these potentially dangerous fires. The best interior firefighter may be ill prepared to handle a large-scale brush fire. All devastating brush and forest fires start small. Our job is to keep them that way effectively and safely, which entails our having the necessary skills, experience, and equipment.
This article briefly discusses fire types, size-up factors, and suppression techniques drawn from my experiences fighting fires on Long Island, where wildland fire suppression is the responsibility of suburban and rural departments and where wildland-urban interface is extensive. Brush and forest fires occur dangerously close to residential housing, schools, and businesses, making it necessary to fight most, if not all. brush and forest fires with direct attacks by brush trucks and stump jumpers. These engines rapidly can access a fire and put dow n a “wet line” for suppression.
The forest and brush fire season on Long Island generally has two peaks: one in early spring and a less severe peak in the fall when the leaves drop. The spring season is aggravated by strong March and April winds and low relative humidity. Long Island’s coastal plain soils are sandy or loamy and dry out quickly. Temperatures above 65°F, dry relative humidity, and high winds can result in favorable fire conditions within one to two days of a substantial rainfall. Several weeks with below-normal rainfall can foster dangerous wildfire conditions.
SIZE-UP
Three major factors must be considered in the initial size-up of brush fires: fuel load and type, weather conditions, and terrain and accessibility. Firefighters should know the existing conditions in their district and should begin the initial size-up right after activation. While you may not remember the fuel types and load in the fire area, you certainly should have a good feeling for what the terrain is like, where the access points are, and what recent weather conditions have been.
Fuel type and load or volume. These factors must be carefully considered before initiating the attack. Forest fuels can release 6,000 to 8,000 Btus per pound and push temperatures up to 2,000°F. The type of fuel and its volume determine the degree of fire hazard. Forest fires are as dangerous an any of the other fires faced by the structural firefighter, and they often are more unpredictable.
Fuels can be classified as light or heavy and can be continuous or patchy. Light fuels include grasses, light brush, and slash. On Long Island, scrub oak, huckleberry, and blueberry are typical and can represent fuel loads of 10 to 20 tons per acre. Fires in these fuels burn rapidly and are very unpredictable when pushed by strong or shifting winds. Small pitch pines growing in dense stands are especially hazardous for firefighters, as are stands of common reed grass. Don’t commit firefighters or equipment to these situations without a thorough size-up and route for safe escape.
Heavy fuels include larger-diameter trees, dead falls, and heavy brush. Fuel loads in the range of 20 to 80 tons per acre are common on Long Island. Areas with large-diameter pitch pines and oaks can surpass 200 tons per acre. Fortunately, fires in heavy fuels are uncommon; however, when they occur, they are extremely dangerous to firefighters and the surrounding communities.
When sizing up fuel conditions, look for patchiness and changes in fuel type. Fires in uniform fuels can spread rapidly and intensify. A fire burning in brush and the crowns of pitch pine may be stopped at a fuel break on an open grass field, but they also can rapidly spread and intensify if burning from the grass into the brush or dense pine.
Weather. Whether fuel loads or the weather is the most important singlefactor for fire behavior is debatable. Obviously, the fuel must be there, and conditions must be right to convert the ignition or heat source into a brush or forest fire. In size-up, firefighters should consider temperature, relative humidity, and wind speed. Also, remember that size-tip is a continuous process, and watch for gradual or sudden changes in weather.
Early morning fires have a tendency to intensify as weather conditions become more favorable for fire spread in the afternoon. Several factors interplay to control fire behavior during the course of a day. As the morning temperatures rise, fuel temperatures also rise and close the gap toward the ignition temperature. But most important, rising fuel temperatures drivedown fuel moistures. A 20°F change in temperature causes a 50 percent tiecrease in relative humidity. The lower the relative humidity, the greater the fire risk. Generally, humidity below 30 percent favors rapid fire spread by lowering the fuel and soil moistures.
Compounding the problems of temperature and humidity is wind speed. Wind seems to be the one allimportant factor for creating dangerous fires. As wind speed increases, so do fire spread and danger. Winds higher than 20 mph can create severe fire conditions when low humidity and high temperature are present. Wind speeds higher than 30 mph are extremely dangerous, and direct attacks on such fires should be carefully considered and planned.
Terrain and accessibility. Terrain or topography relative to fuel load and weather contributes the least to fire spread in the pine barrens. Our biggest concern regarding terrain involves access to the fire area. Steep slopes, marshy areas, and barricaded roads can hamper or prevent brush trucks or stump jumpers from accessing the fire scene.
region.(Photo by author.)
(Photo by Peter Frank.)
Barricading roads with heavy pole gates, highway guard rails, and earthen berms is becoming more common as land-management agencies at the state and local levels try to control illegal access to public lands. Fire officers should discuss their concerns for access to public lands with the appropriate land-management authorities In most cases, these agencies are more than willing to work with their fire departments on presuppression plans. Make sure the landmanagement agency understands your concerns and needs, and be prepared to work with the agency to guarantee access for firefighting.
A good preplan will make size-up easier and faster and allow you to consider other factors. A good map showing access points, fire roads, fire breaks, and w ater sources should be available from the public agency. If it isn’t, consider working w ith the agency to develop something that meets your needs.
FIRE TYPES AND CONDITIONS
Three wildland fires are basic to the pine barrens: crown fires, surface fires, and ground fires. More than likely, any forest or brush fire will involve one or more of these fire types, or the fire may evolve from one type to another.
The most common fires in the Long Island pine barrens are surface fires, which occur in virtually all fires. These fires usually involve lighter fuels including leaf litter, brushy woody vegetation, and small hardwood trees or pitch pines. Under favorable fire conditions, these fires spread rapidly and can intensify to involve some of the heavier fuels. In the initial stages of a surface fire, firefighters usually find slow-moving fires with flame lengths of two to six feet in the leaf litter and low brush.
As the fire intensifies, heavier brushy fuels and small trees become involved, and flame lengths can extend 15 feet or more. Under extreme fire conditions, surface fires can spread to the upper portions of trees to create a crown fire.
Crown fires, or intense fires burning in treetops, clearly are the most dangerous. Almost all large forest fires involve crowning. These fires usually occur under conditions of low relative humidity and high winds. A crown fire working through a pitch pine stand has the characteristic and unforgettable rumbling sound many firefighters say is similar to that of a moving train.
Crown fires usually are followed by intense surface fires. Careful and continuous size-up of fire conditions is needed to safeguard firefighters and equipment in such situations. Look for signs of extreme fire behavior during your size-up. Torching, or the explosive ignition of trees, during a surface fire is a warning sign of extreme fire danger and the potential for crowning.
(Photos by Nancy Annes.)
(Photo by Eric Lahr.)
Intense surface fires may cause spot fires in the surrounding areas. Some of the larger fires can set up strong airconvection currents that can carry hot embers up to a mile from the fire and spot new fires. The incident commander continually must size up the potential for spotting and immediately dispatch units to suppress any spot fires that do develop.
The last, and least common, fire type is the ground fire. Ground fires occur in pine barren areas with thick organic fuels of “duff layers.” They often are slow, smoldering fires that, although not intense, are difficult to suppress. Ground fires usually occur in combination with a surface fire. In fact, ground fires often are responsible for the rekindling of surface fires.
Ground fires are difficult to size up because they involve the burning of nx)ts and decaying organic matter in soils. The usual methods of laying down a wet line may be sufficient to extinguish a surface fire, but wet lines will not do the job on a ground fire. Consider using wetting agents in tank water. If the fire keeps rekindling, you may have to call in heavy equipment, such as a fire plow or dozer, to cut a fire line around the ground fire. The fire line should be down to mineral soil to cut off the fuel supply for the fire.
A few years ago, several Suffolk County, Long Island, fire departments battled a stubborn surface fire at the Edgewood Oak Brush Plains State Forest. nil’s fire repeatedly was suppressed by the volunteer departments and repeatedly rekindled for nearly three weeks, eventually burning several hundred acres. What was happending was that the firefighters were attacking only the surface fire with the traditional application of a wet line. After the surface fire was suppressed, high winds and low moisture levels allowed an incipient ground fire to reignite surface fuels within the black or burned area. This fire then rapidly would spread to surrounding unburned fuels. Fire usually would show itself during the height of the daily fire cycle in the midafternoon. State forest rangers eventually brought in a dozer to cut a fire line around the fire area. 1’he ground fire then was allowed to burn off the remaining ground fuels and extinguish itself.
BRUSH TRUCKS AND STUMP JUMPERS
During the past 20 years the wildland-urban interface greatly has increased the dangers of wildland fire spread to suburban structures. In the suburban and rural portions of the Long Island pine barrens, an aggressive direct attack on brush and forest fires is necessary to prevent the spread of fire to these surrounding developments. Also, keeping fires from intensifying reduces the threat of spot fires in areas adjacent to the fire scene.
To control brush and forest fires in Long Island, we have come to rely on direct attacks with brush trucks. Two basic truck designs are prevalent. The smaller brush trucks usually are ½to ¾-ton 4×4 trucks equipped with a 100to 200-gallon water tank, a gasoline-powered pump, and one or two high-pressure ½to /4-inch lines. The normal crew size is two to four firefighters.
Hand tools consisting of shovels, rakes, council rakes, fire brooms, and hand-pumped water tanks are typical. These trucks are useful for a quick attack on smaller surface fires with ready access from roadways and fire trails.
The stump jumper is the backbone of the direct-attack truck fleet. This type of truck usually is custom built on a 2!/2-ton military chassis modified with heavy skid plates, roll bars, and a wire-enclosed bed for the protection of six to eight firefighters. The standard variety has all-wheel drive on all three axles. Most trucks carry 500 or more gallons of water.
Experience has shown that single tires are more efficient and maneuverable in woodland situations than dual tires. Some departments have stump jumpers with dual rear tires. A few five-ton trucks are in service, but they lack the maneuverability of the smaller trucks.
Most trucks are equipped with a gasoline-powered pump supplying two to four ½to ‘/4-inch high-pressure attack lines. The fuel supply for the pump on gasoline-operated trucks is tied into the truck’s fuel supply system but operates off a separate pump. This ensures the continued operation of the pump independent of the truck’s ignition system.
Stump jumpers are designed for direct access to fires and easily can be driven through dense brush and small trees. The direct attack on the fire usually involves envelopment of the fire by several trucks working under one command and by laying down a wet line on both the burned-out and unburned fuels. The general rule of thumb is to avoid making a direct attack on the head of the fire in heavy fuels or during extreme fire conditions.
(Photos by author.)
Eric Lahr.)
(Photos by author)
The usual tactic is to commit one to two stump jumpers working in tandem on the hot flank and another jumper on the cold flank. Trucks work together, gradually approaching and pinching the head fire. For greatest safety, trucks should operate from the burned-out area upwind of the head fire. The smaller brush trucks and the hand crews should work mopup behind the stump jumpers and quickly suppress any spot fires. Remember, hand crews and small brush trucks never should be working a hot, fastmoving head.
A direct attack on the head of the fire by two stump jumpers is the best tactic for smaller surface fires that are cooler and not seriously wind driven. Trucks should attack the head from the cold flank and then separate to suppress the hot and cold flanks independently. Direct head attacks are not recommended for ground fires or fastmoving surface fires with flame lengths in excess of 10 to 15 feet. Head fires of 500 feet or more in coverage can be intense, fast moving, and unpredictable.
Suppressing a crown fire working in combination with a surface fire repreI sents extreme fire dangers for firefighters and equipment. Direct a stump-jumper attack at the hot flank of these fires. Your first consideration for the fire head should be an indirect attack. Natural boundaries to fire such as changes in fuel types and volume, existing fire breaks, fire roads, and paved roads should be used to control or extinquish the head fire. In cases where these features are absent, a fire plow or dozer could be called to create a fire line some safe distance I downwind of the fire and. secondarily, along the hot flank.
Direct attacks with stump jumpers I on the head of a crown fire arc unnecessary’ and dangerous. A stalled truck, a truck stuck in a hole or between trees, or firefighters working a hand crew certainly would be at risk. Truck officers continually should size up their operations and fire behavior and movement and should avoid these dangerous conditions. Remember, the safety of firefighters is the most important factor.
One of the key reasons for using stump jumpers is to have an adequate water supply. Most fires on Long Island are extinquished with wet lines. This involves having adequate and accessible water supply in close proximity to the fire scene. Fortunately, many areas are served by public water supplies, and hydrants usually are available. If they are not, most departments dispatch tankers to provide a mobile water reservoir to support the stump jumpers. Size-up must include water supplies if stump jumpers are used for direct attacks.
Regardless of the ty pe of fire, continuous size-up is important. As noted, cooler fires that start in midmorning easily could become major and dangerous fires by midafternoon as the temperature rises, relative humidity decreases, and wind speed increases. Also, large fires are self-driven. Rising heat from the fire causes convection currents that increase local wind speeds, preheat fuels, and carry embers that cause spot fires.
Stump jumpers provide the quickest and most aggressive attack on most brush and forest fires in the pine barrens. But stump jumpers alone are not enough to finish the job. Mopping up the fire should involve hand crews to ensure that the fire edge is cold and that any small pockets of fire are cleaned up. Hand crews should look carefully for evidence of ground fire and report any found to the incident commander.
Proper size-up of fire conditions, knowledge of the interplay of fuel types and loads, weather and topography, suppression techniques, and firefighter safety continually must be reinforced in training programs for structural firefighters. Firefighters respect the dangers inherent to structural firefighting, but wildland fires present an entirely different set of dangers. These dangers should be treated with the same respect and approached with the same degree of caution.
