We've all seen the images on TV and in the newspapers: wildland fires threatening populated areas as firefighters desperately try to save homes from the advancing flames. It's happened in California. It's happened in New Mexico. It's happened in Florida, New York and other states.

In many cases, firefighters have been hampered by apparatus that are either too small or too large for the job. Small brush trucks have the mobility to reach the fire, but often can't pump enough water to effectively protect structures. Larger municipal pumpers have the pumping capacity to protect structures, but often can't negotiate narrow roads and steep driveways to reach them.

As built-up areas push deeper into brush-covered wildland, a new type of fire apparatus has emerged. The wildland-urban interface pumper combines the maneuverability and mobile attack capabilities of a wildland pumper with the pump capacity and equipment of an urban pumper. It's a combination that gives firefighters a big punch in a small package.

Dual roles

Wildland-urban interface pumpers evolved from the heavy wildland engines used by a number of state and federal forestry departments in the 1980s. These rigs usually had larger pumps and tanks than other wildland pumpers and carried a crew of three to six personnel. The pumps were driven off transmission ptos or separate engines to give full pump-and-roll capabilities. Although these engines were originally designed to fight vegetation fires, it became increasingly common for them to be used for structural fire protection and suppression as well.

Modern wildland-urban interface pumpers are distinguished by several unique features derived from earlier heavy wildland engines. These features emphasize the dual roles these engines play.

Maneuverability. The first thing you notice about wildland-urban interface pumpers is that they have short wheelbases and sharp front-axle wheel cuts, which give them tight turning circles for maneuverability on narrow roads with sharp turns. They also have high ground clearances and sharp angles of approach and departure to let them climb steep driveways and negotiate uneven terrain. Optional 4×4 drives allow them to travel on unpaved roads or cut across country to reach the fire lines.

Low center of gravity. Because interface pumpers carry more water, hose and equipment than smaller and lighter wildland pumpers, it's important for them to be built with low centers of gravity for stability on side slopes. Lightweight materials and integral tank and body construction help reduce the vehicle weight, while low-mounted pumps and equipment help drop the center of gravity.

Pump capacity. Because of their dual roles, interface pumpers have pumps with enough capacity to handle structure fires as well as wildland fires. This usually requires a minimum of a 500gpm pump with a 4-inch inlet and one or more 2H-inch discharges. Larger pumps with capacities up to 1,000gpm can take advantage of a high-volume monitor or multiple handlines. To accommodate a running wildland attack, pumps are usually driven off a transmission pto or a separate engine. Some interface pumpers have hydraulically driven water pumps powered by hydraulic pumps connected to front-engine ptos.

Tank capacity. Interface pumpers generally have 500- to 750-gallon water tanks with integral 20- to 40-gallon foam tanks. This allows them to make blitz structural attacks or sustained wildland attacks without relying on hydrants.

Hose and equipment capacity. For maximum effectiveness, most interface pumpers carry several hundred feet of 2H-inch or larger supply hose, plus additional 2H-inch attack lines. They also carry a complement of ground ladders, forcible-entry tools and large-flow nozzles for structural fire attack. Pumpers that are also used for rough-terrain rescues often carry a variety of rescue gear.

Personnel. It usually takes at least two firefighters to make an exterior structural attack, and it takes four or more to make an interior attack. That's why interface pumpers are usually specified with four-door crew cabs and seating for four to six personnel. scba seats allow the crew to exit the vehicle and make a rapid interior attack when necessary.

Trend toward bigger rigs

While the first generation of wildland-urban interface pumpers were beefed-up wildland rigs, the next generation may be scaled-down urban rigs, or at least that seems to be the trend.

In Southern California, smaller Type III engines on commercial chassis (see ICS designations sidebar above) are starting to give way to larger Type II engines that incorporate features borrowed from their urban pumper counterparts. For example, the Riverside County Fire Department just received nine Type II pumpers on four-door commercial chassis equipped with 1,000gpm pumps, 500-gallon tanks, hydraulic ladder racks, and larger complements of hose and equipment. To accommodate the bigger components, these Type II engines have wheelbases of about 175 inches, which is still far shorter than the 190- to 230-inch wheelbases found on many urban pumpers.

Other departments have shortened up their custom chassis “flatland” pumpers to better handle firefighting in the interface zone. For example, by eliminating some compartment space, using a more compact engine and pump, and employing an L-shaped water tank, the Los Angeles County Fire Department was able to design a prototype Type I interface pumper equipped with a 1,000gpm pump, 750-gallon tank and compressed-air foam system, all on a four-door custom chassis with a 160-inch wheelbase.

In Nevada, the Ruhenstroth Volunteer Fire Department of the East Fork Fire and Paramedic District combined a short-wheelbase 4×4 chassis with a short four-door custom cab to give them a Type I interface rig equipped with a 1,500gpm pump, 750-gallon water tank, 55-gallon foam tank, and a full complement of hose, ground ladders and equipment.

Special options

Because interface pumpers have special roles, they have some special options that aren't found on other pumpers.

The American LaFrance Unimog 4×4 pumper, expected to be in production by late 2001 or early 2002, has an optional dozer blade to cut fire breaks. The blade can be raised, lowered and angled side-to-side by the operator using a joystick control. With an eight-speed automatic transmission and a two-speed transfer case, the Unimog can hit highway speeds to reach a fire, then gear down for maximum traction when using the dozer blade. Central tire inflation will also be an option to allow operation on soft soils.

KME offers their exclusive Flameshield burn-over cab-protection system on their Renegade Square MFD interface pumpers. The system includes high-temperature window glass and door gasket materials with a system of drop-down reflective window curtains that provide protection for the crew against 2,000°f outside temperatures and direct flame impingement for up to five minutes.

If an interface pumper is also used for off-road rescues, it may be modified to carry rescue gear. The new E-One Puma has a transverse compartment ahead of the pump to carry backboards or Stokes-type rescue baskets. Interface pumpers may also carry basic vehicle extrication gear and medical supplies. Some pumpers have front winches for over-the-side rescue work and vehicle stabilization.

Other options offered by many manufacturers include remote-controlled monitors and metal hosebed covers (to prevent drifting embers from igniting the hose jackets), as well as hinged tailboards and steps that flex when the vehicle encounters severe changes in slope or hits rocks.

Some experts believe the disastrous 2000 fire season may be the start of a period of shifting weather patterns and dry summers throughout many areas in the United States.

Recently, the U.S. Forest Service announced it would fill approximately 3,500 positions to bring its firefighting force up to the 100% level for the upcoming fire season. Other departments are responding by purchasing new interface pumpers, establishing water supply drafting points and encouraging property owners to clear vegetation from around buildings.

Interface pumpers under NFPA and ISO

Wildland-urban interface pumpers fall under nfpa 1901, Automotive Fire Apparatus (1999). Apparatus with pumps of at least 250gpm whose primary purpose is to initiate fire suppression attack on structural, vehicular or vegetation fires are covered under the Initial Attack section. Apparatus with pumps of at least 750gpm whose primary purpose is to combat structural and associated fires are covered under the Pumper section.

Departments must decide the primary role of an interface pumper when specifying components to comply with nfpa 1901. Interface pumpers are not covered under nfpa 1906, which is restricted to smaller wildland pumpers whose primary purpose is to combat vegetation fires only.

The Insurance Services Office will recognize a wildland-urban interface pumper as an engine company if it meets their minimum standards. Interface engines need to have 500gpm or larger pumps and 300-gallon or larger tanks to receive full credit for the pump and tank capacities. Smaller interface engines will generally fall short in the areas of hose and loose equipment, specifically 2H-inch hose, ground ladders, scba and heavy-stream devices. Larger interface engines can meet most, if not all, of the iso requirements. Departments are encouraged to consult their local iso office before specifying any fire apparatus.

ICS designations for interface pumpers

Wildland-urban interface pumpers are often designated as Type I, Type II or Type III under the Incident Command System, which was devised to give incident commanders a better picture of their resources during large-scale, multi-agency wildland fires.

For example, a department responding from out of the area might say it was sending “one Type I and one Type III engine,” which would give the incident commander much more information about what to expect in the way of equipment and personnel than if the department simply said it was sending “two pumpers.” A summary of the minimum ics engine company requirements appears below.

ICS minimum engine company requirements

	Type I engine	Type II engine	Type III engine
Pump	1,000gpm	500gpm	120gpm
Water tank	400 gallons	400 gallons	300 gallons
2H-inch hose	1,200 feet	1,000 feet	None
1H-inch hose	200 feet	500 feet	1,000 feet
1-inch hose	None	300 feet	800 feet
Ladder	20-foot extension	20-foot extension	None
Heavy stream	500gpm	None	None
Personnel	4	3	3

Manufacturers

Here are a few manufacturers of wildland-urban interface pumpers:

American LaFrance
888-alf-trck for your nearest dealer, <www.americanlafrance.com>

Boise Mobile Equipment
800-445-8342, <www.bmefire.com>

Central States Fire Apparatus, a division of Rosenbauer America
605-543-5591, <www.centralfire.com>

W.S. Darley & Co.
800-323-0244, <www.wsdarley.com>

Emergency One
352-237-1122, <www.e-one.com>

Ferrara Fire Apparatus
800-443-9006, <www.ferrarafire.com>

General Safety Equipment, a division of Rosenbauer America
651-462-1000, <www.general-safety.com>

Gregory Fire Apparatus
510-635-7171, <www.firegregory.com>

Hi-Tech Fire Apparatus
209-847-3042

KME Fire Apparatus
800-235-3928, <www.kovatch.com>

Luverne Fire Apparatus
605-582-2300, <www.luvernefireapparatus.com>

Master Body
323-564-6901, <www.masterbody.com>

Pierce Manufacturing
920-832-3231, <www.piercemfg.com>

S&S Fire Apparatus
800-451-7180, <www.ssfire.com>

Smeal Fire Apparatus
402-568-2224, <www.smeal.com>

Westates Fire Apparatus
800-547-7311, <www.westates-body.com>

West-Mark Fire Apparatus
800-692-5844, <www.west-mark.com>