SAFETY AT STUMP JUMPER OPERATIONS
BY FRANK M. PANEK
Suppressing brush and forest fires in the pine barrens is hard, demanding work that involves recognizing fire behavior and knowing how to deploy safe and effective firefighting tactics. As is true for all kinds of fires, training and experience are vital to acquiring these skills. Strategies and tactics must be appropriate to conditions, fire behavior, risks, and available personnel.
Proper size-up and initial tactics ensure the greatest chance for successfully suppressing any fire, including the wildland fire. To gain control of a brush fire, personnel and equipment must be appropriately deployed within the first 15 minutes. Factors such as the season of the year, the time of day, past and present weather conditions, the type of terrain and its accessibility, and fuel types and loads must be continually assessed by every firefighter engaged in fighting the fire. Chief officers of fire districts with high incidences of wildland fires should maintain contact with state forestry officials and receive updated reports on current fire danger ratings, especially during the peak fire season. In most instances, being familiar with the fire district and the fire area helps to more accurately predict fire behavior. Chief officers and incident commanders should be trained in fire behavior and in the fire danger rating system used in their areas. These basic skills provide the basis for interpreting forestry reports and implementing tactical operations.
THE FIRE TRIANGLE
To control and suppress any fire, the tactics used must break one of the legs of the fire triangle. In Long Island, New York, most brush fires are suppressed by applying wetlines to reduce the heat leg of the triangle. This involves using brush trucks and stump jumpers for rapid access to the fire edge. Stump jumpers are rugged, direct-attack engines usually custom built on a 212-ton military chassis. The trucks are modified for woodland firefighting by adding heavy skid plates, roll bars, and a wire-enclosed bed to protect firefighters and their equipment. Most trucks carry 500 gallons or more of water and can operate several handlines. Similar equipment used by rural departments in the New Jersey and Massachusetts pine barrens are referred to as brush breakers.
Secondary tactics may include using fire control lines, fire roads, and other manmade or natural barriers to reduce the fuel leg of the triangle. Heavy equipment such as dozers and loaders usually are called in from state or town highway departments to work under the direction of the incident commander or chief fire officer. Tractors with fire plows may be available from federal or state forestry offices. Heavy equipment can effectively contain most fires by creating fire breaks and control lines in advance of fast-moving fire fronts.
WEATHER FACTORS
Changing weather conditions often complicate the task of suppressing brush fires. This is especially true for larger fires occurring in heavy fuels during the height of the fire season. Understanding how daily weather patterns influence fire behavior helps firefighters choose the appropriate tactics for the prevailing fire conditions. It also makes for safer firefighting. Abrupt changes in local weather conditions, such as sudden wind shifts, can turn a controlled fire into a wildfire requiring redeployment of firefighters and equipment. Unwary firefighters also may become trapped by blocked escape routes or disoriented by changing fire behavior.
Size-up and successful tactical operations depend on reliable weather reports and an understanding of how local weather conditions interact with fire behavior. High air temperatures, low relative humidities, and increases in wind speed help reduce fuel moistures and create favorable fire conditions. Fire officers can receive reliable fire weather reports from the National Weather Service through a network of more than 1,000 fire weather observation stations across the country. Fire weather forecasters provide daily and long-term forecasts to federal and state forestry offices; these reports usually are available to chief fire officers. Monitoring these reports during the fire season and knowing the current fire danger rating enable fire officers to predict fire behavior during the size-up.
Low relative humidities and high winds typically result in high fire danger ratings and dangerous fire behavior. Relative humidity–the amount of moisture in the air as a percentage of the maximum amount that could be held by an air mass at a given temperature and barometric pressure–probably is the single major long-term and daily weather determinant of fire risks and behavior. As moist air cools, its capacity to retain moisture decreases until it reaches its dew point. Dew forms when temperatures fall below the dew point and air moisture begins to condense. Serious fires under these conditions are unlikely. Conversely, as air warms, its capacity to retain moisture decreases. Fire conditions worsen into the mid-afternoon as temperatures rise, humidities fall, and local winds increase. Prolonged periods of low relative humidity dry forest fuels and increase fire dangers.
Wind, an important factor in any fire situation, significantly influences firefighting safety. Surface winds help dry fuels, provide a continuous supply of air to support combustion, and drive flame fronts. Firefighters must be especially cautious when fighting wind-driven fires. These fires usually have longer flame lengths and a much wider burning zone than fires occurring on windless days. The convection heat of wind-driven fires is pushed downwind of the advancing flame front, accelerating the preheating of fuels in advance of the flame front and intensifying the fire. Such fires often move into the upper fuel layers, causing crown fires. Deploying stump jumpers for direct attacks on crown fires produces safety risks that could greatly outweigh immediate fire suppression benefits. Crown fires are best fought by containing the fire with indirect attack methods.
On Long Island and in other coastal areas, local surface wind conditions are influenced by convective air circulations known as sea and land breezes. As land masses warm during the daytime, air rises and brings in cooler air masses from off-shore. The reverse occurs in the evening. The intensity of these surface winds is determined by the degree of differential heating of the land and water masses and the ability of these masses to absorb heat. Firefighters in such areas should expect local wind directions to shift in the late morning and again several hours after dusk. Responders should observe smoke conditions during their size-up. Keeping a careful eye on smoke columns often makes it possible to predict fire behavior and changes in local wind conditions.
SAFETY ISSUES IN STUMP-JUMPER OPERATIONS
Most Long Island departments responsible for protecting large tracts of pine barrens forests or with significant urban-wildland interfaces have one or more stump jumpers. It is not uncommon for several departments to dispatch stump jumpers to provide mutual aid for large fires. Regardless of the size of the fire or number of trucks operating, safe operation of the apparatus is essential to protect firefighters and equipment.
Safe operation begins with the driver and the truck officer understanding the abilities and limitations of the apparatus and knowing their destinations and how they will get to them safely. The driver is responsible for making sure the truck is operating properly and the crew is safely aboard before leaving the fire station. Firefighters should be in the truck`s cab or a safe crew compartment for over-the-road response to the fire scene. The officer should know the fire area, the location of the fire roads, and the fire gates and their access points and should remain in contact with the incident commander or chief officer.
Among the initial decisions to be made at the fire scene are which methods of attack to use, how many units are needed, and how the units will be deployed to work the fire. On Long Island, most stump jumpers work off-road to apply wetlines to the fire flank or head. This means putting the truck and its crew in the woods in areas with limited visibility, smoke, and intense flames.
Operating stump jumpers in dense brush with fire and heavy smoke is dangerous. Trucks should operate from the black or burned area and, if possible, approach the fire from the cool, upwind side. The black area always serves as a safe refuge if problems develop. Working downwind of a rapidly moving surface fire or a crown fire is dangerous and should be avoided when possible. Serious problems can arise when stump jumpers work uphill of a fire front. Trucks never should be put in this position. Fires tend to intensify and move rapidly up slopes and may entrap the truck and its crew. In general, the rate of fire spread doubles for each 10-percent increase in slope. Slopes of 10 to 30 percent are common in the rolling hills of Long Island`s pine barrens.
Stump jumpers should work in pairs. By working together, the trucks can suppress flank and head fires more efficiently while providing mutual protection. Also, truck-to-truck communications are enhanced and visual contact can be maintained.
Crews working on stump jumpers must be trained to operate them and to learn their limitations and the dangers of working in a heavy vehicle moving through dense brush. Under no circumstances, for example, should crew members extend their hoseline nozzles or arms, legs, or head outside the brush truck`s protective structure while it is moving. Tree trunks or branches scraping along the side of a stump jumper can crush limbs and break bones.
Drivers must take special precautions to avoid injuries and accidents associated with woodland driving. The most common injury to drivers involves broken and dislocated thumb fingers. Steering wheels on stump jumpers are difficult to hold onto and control during off-road use. When a truck hits a stump, log, rock, or depression, the steering wheel rapidly and forcefully spins as the tires are forced in a new and unexpected direction. Some drivers wear a glove or tape down their thumbs in a way that prevents the thumb from grasping the wheel. In that way, the wheel`s rapid movement does not jam the spokes into the thumb. Drivers should also wear a seat belt, which not only protects them while on the road but also gives more control while in rough terrain. Drivers and truck officers should use seat belts to minimize injuries should roll-over occur.
Firefighters must wear protective clothing and headgear. Several Long Island departments have discontinued using structural firefighting headgear in favor of headgear that gives greater protection to the head and face. Appropriate headgear should include a visor that protects the entire face from potentially impaling twigs and branches. Lightweight fire retardant fire clothing and a pair of good safety-tipped boots should be worn. Heavy structural firefighting turnout gear may cause overheating, which could lead to heat exhaustion or heat stroke. Wearing lighter fire clothing provides greater mobility for wildland firefighters, reduces fatigue, and extends the fire crew`s safe and effective working time. This is particularly true on the hot, dry afternoons that are typical of the worst fire season in the pine barrens.
WOODLAND HAZARDS
Woodland operations present hazards in addition to those associated with attacking the flame front and suppressing the fire. Most of these hazards can be avoided. Drivers should avoid rugged terrain, dense brush, and areas with large trees. They should try to keep the trucks on forest roads, trails, and fire breaks as much as possible. Operating the trucks in dense brush puts a significant amount of wear and tear on the apparatus and can cause extensive damage to the forest. Stump jumpers can cause severe soil compaction, which leads to erosion. The uprooting of and damage done to forest vegetation can lead to temporary or long-lasting scars on the landscape.
While stump jumpers are designed to and are capable of felling six- to eight-inch oaks and pines, doing so may damage the equipment or injure the crew. In areas where forest fires occur often, many of the larger trees are dead and may be weakened by fire damage or decay. If a stump jumper plows into such a pine tree, a large top section of the tree could snap and fall into the crew compartment. Firefighters operating from stump jumpers may have a false sense of security and confidence. This attitude is foolish. Drivers should always give themselves a safe way out. They should never drive into a situation from which they can`t walk out.
Trucks should be kept out of dense smoke whenever possible. Smoke limits visibility and makes it more difficult to avoid hazards. Smoke also exposes the crew to unnecessary health risks. Exposure to carbon monoxide may make firefighters working the fire edge for more than an hour or two nauseated and dizzy. Continued exposure could cause disorientation, poor judgment, and accidents. Burning forest fuels also may release airborne skin and lung irritants from poison ivy, oak, or sumac. Smoke problems usually can be avoided by operating from the black zone and staying upwind of the fire.
Power line rights-of-way are often encountered during brush fire operations. Avoid working under or near power lines. Since the areas containing them are usually cleared of brush, crews often mistake them for safe areas and use them for rest or staging equipment. Never assume power lines to be deenergized, and always be on the alert for downed wires.
In addition to power lines, watch out for other types of wires and cables. Telephone and cable television wires are easily identified and should be avoided. In many areas of Long Island, landowners have strung 14- to 38-inch steel cable to define property boundaries or to create cable gates across forest roadways. These cables are difficult to see from a moving vehicle and have injured firefighters and damaged equipment. Ironically, these hazards seem most common on public recreational lands. Chief officers should work with public authorities to identify and remove these hazards. The best way to operate safely is to remain aware of your surroundings and avoid hazards.
KNOW WHAT`S BURNING
Not all that burns in brush fires are forest fuels. Wildland firefighters increasingly are being exposed to potentially hazardous substances as a result of illegal or improper disposal of solid and chemical wastes. The heavy dark smoke columns resulting from burning automobile tires, garbage, and construction demolition debris can appear similar to that produced by incomplete combustion of forest fuels. The objective is to avoid working in smoke. Report nonforest fuels or potentially hazardous materials encountered to the incident commander. Drivers operating stump jumpers off-road must be on the lookout for propane bottles, agricultural chemical containers, gasoline cans, or other unidentified containers as well as abandoned cars that may be in the brush along fire roads. These vehicles can complicate firefighting efforts.
HAND CREWS AND CIVILIANS
Working stump jumpers and hand crews together along a fire line is dangerous and unnecessary. Hand crews, fire spotters, and other personnel should operate a safe distance from the area in which trucks are working. Hand crews working in dense brush with smoke conditions may not be visible to the truck crew. They should have portable radios to communicate with the truck officers and incident commander. Truck crews must remain alert not only to fire behavior but to everything occurring around them, including the presence of civilians. I have never seen a brush or forest fire that did not attract bystanders. It is not uncommon to find hikers, hunters, and other outdoor recreationists in the woods at or near the fire. The tactical operations of fire suppression must address safely removing these civilians from the scene. In suburban Long Island areas, children pose the most difficulty in this regard: They often refuse to take directions from firefighters. To maintain fireground safety, it is critical that all civilians and nonessential fire personnel be removed from areas where stump jumpers and other equipment are in use.
THINK “SAFETY FIRST”
Training, experience, and remaining alert to changing conditions are prerequisites for safely suppressing a wildland fire. No brush fire should ever be considered routine, and firefighters never should become so complacent or overconfident that they believe their trucks or crews can handle any situation. It is a mistake to assume that the risks to equipment and crews are the same for all fires.
Keeping in mind the “Safety First” tips (at right) can help make your next wildland firefighting experience safer and more efficient.
Obviously, we must do more to improve firefighter safety. By continuously thinking “Safety First,” many of the problems and accidents associated with the use of stump jumpers in wildland fire suppression could be avoided.
|
|
n FRANK M. PANEK is a biologist with the National Park Service in Washington, D. C., and a member of the Manassas (VA) Volunteer Fire Company. Formerly, he was a captain with the Rocky Point Fire Department in Suffolk County, Long Island, New York, and the Regional Supervisor of Natural Resources for the New York State Department of Environmental Conservation. He has a Ph.D. in zoological science.