The growing number of wildland fires in the United States has caused many departments to take a hard look at the best ways to fight those fires. As a result, some departments have decided to upgrade their brush pumpers to vehicles with larger chassis, pumps, tanks and crews. Here is a look at some of the advantages of these beefed-up brush trucks.

Brush trucks can be classified according to the ICS-type system. (See “ICS Definitions,” page 102.) The most common, and often most versatile, brush trucks are Type-3 wildland pumpers. These bigger units have many of the firefighting capabilities of larger structure pumpers, but retain the maneuverability of smaller wildland engines. They are built on medium-duty commercial chassis with fully compartmented bodies. Four-door cabs provide protected seating for up to five personnel.

One advantage of this configuration is that the engine has sufficient power to drive larger pumps. The required pump capacity depends on the fuel load and expected operating conditions, but flows of 250 gpm are sometimes needed to attack fires in heavy fuels through multiple handlines. Structure fire suppression may require 500 gpm or even higher flowrates. For mobile attack, pumps can be driven directly off transmission power take-offs or through front engine power take-off hydraulic drives to give pump-and-roll capabilities. Alternatively, some brush engines use a second engine-driven pump to provide more uniform water delivery at varying vehicle speeds.

Another big advantage to bigger brush pumpers is that the stronger chassis allows the installation of larger water tanks for sustained operations. Tank capacities up to 750 gallons match higher pump flows and let these pumpers remain on-scene longer compared with smaller units. This is especially critical when brush pumpers are assigned to structure protection. A rough rule of thumb is that an engine in an active structure defense role will consume 400 to 800 gallons of water per hour. Larger tanks help prolong the time between refills when other water supplies are not readily available.

Despite their size, most larger brush pumpers also have surprisingly good ground clearance and visibility. In fact, minimum National Fire Protection Association standards for under-vehicle clearance are actually several inches higher than smaller brush pumpers. The relatively higher position of the cab gives the driver and crew good forward visibility to help spot hazards and sudden terrain changes. It also helps elevate vehicle warning lights for better safety on public roads.

Bigger bodies mean more compartment space, and that is another advantage for departments that want to use their brush pumpers to handle motor-vehicle accidents and off-road rescue incidents in addition to wildland fires. Most big brush trucks have sufficient storage space to carry a variety of rescue and medical gear, including bulky backboards and over-the-side rope rescue equipment. The main hosebed is usually covered with fold-open metal covers to protect the hose against drifting embers and provide a measure of fall protection for personnel while they reload the hose.

For some departments, the biggest advantage to larger brush pumpers is the ability to carry more personnel without sacrificing compartment space or water tank capacity. For safety and efficiency, mobile attacks are best conducted with three personnel — one driving; one walking ahead and to the side with the nozzle to direct the driver and attack the fire edge; and one following behind with a hand tool to deal with hot spots and watch the rear flanks for changes in fire behavior. For structure fire protection, four personnel are the minimum, and five are even better. This is especially true during large-scale, wind-driven wildland fires where the situation requires frequent deployment and retrieval of hoselines over extended periods as pumpers move to protect structures in different areas.

One final note. No matter what type and size of apparatus departments choose to operate, firefighters should always remember that wildland fires are dangerous — whether they are simple grass fires or raging forest fires. Positioning and tactics are as important as apparatus specifications when it comes to attacking wildland fires effectively and safely. Always attack the fire from a cleared area or from inside the burned zone, and always watch the fire and have an escape route if the situation changes.

ICS Definitions

The Incident Command System sets standards for managing emergency situations. An important part of the system is common definitions for different types of apparatus to give incident commanders a clear understanding of the resources available to them.

For pumpers used to fight wildland fires, ICS follows the type classifications established by the National Wildfire Coordinating Group. These classifications set minimum requirements for the pump, tank, hose, equipment and number of crew members. The classifications range from Type 1, which is a large structure pumper, down to Type 7, which is a small patrol pumper.

For example, the brush trucks described in “Beefed Up” are considered to be Type-3 wildland pumpers, although most exceed those specifications in one or more areas. They have pumps rated 150 gpm or more at 250 psi and tanks of 500 gallons or larger. The higher pump pressure requirement reflects the need to deliver water through long hose lays and up steep hillsides, which is often the situation when vegetation or terrain prevent closer attack. To accomplish this, Type-3 pumpers carry at least 500 feet of 1½-inch hose and 500 feet of 1-inch hose, but little or no supply hose. There are no requirements for ground ladders or monitors. The minimum crew is two, although three to five is common.

When specifying wildland apparatus, the ICS classifications should be viewed as refinements to the basic requirements specified in NFPA 1906, Wildland Fire Apparatus.