When you think of 4x4 emergency vehicles, what comes to mind? Brush trucks? Sure. ARFF and rapid intervention units? Yes. What else? If you’re drawing a blank, maybe this article can give you a new perspective on some of the operating conditions and types of vehicles for which you might want to specify 4x4 drive.

Think of some of the worst conditions you might encounter -- rain, snow, rocky trails, sandy beaches -- and ask yourself if you could respond without the advantages of 4x4 drive.

Sometimes when it rains, it pours. Low-lying streets flood and dirt roads turn into rivers of mud. Could you get through under those conditions without high ground clearance and extra traction?

If it snows in your area, do the snowplows run at 1 a.m. in the middle of a storm? Do all the hilltop homeowners clear their driveways? Again, high ground clearance and extra traction often make the difference between getting there or not.

If you live near an outdoor recreation area, how many hikers, bikers and climbers get into trouble just off the edge of a paved road? More than likely you will have to travel several miles on unpaved roads and across open terrain to reach them.

In these situations and many more, 4x4 drive can be a real lifesaver.

Many Applications

Applications for 4x4 emergency vehicles go far beyond the typical brush truck. Here are a few examples where fire departments are using the capabilities of all-wheel drive.

Ambulances. This is a common application in areas where snow, mud and rough terrain would hamper other vehicles. Several manufacturers offer 4x4 chassis suitable for ambulance service. The GSA KKK-A-1822E standard covers both 4x2 and 4x4 ambulances.



Wheeled Coach built an ambulance on a Chevrolet 4x4 chassis for Leadore, Idaho. All-wheel drive is often used in rural areas where snow and dirt roads might hinder other vehicles. (Mark Boatwright photo).

Pumpers. In addition to small grass rigs and brush trucks, 4x4 drive is often specified on larger pumpers, pumper/tankers and brush tenders operating in wildland or urban interface areas. NFPA 1901 covers structure pumpers and pumper/tankers. NFPA 1906 covers wildland pumpers.


The El Dorado County FPD in the Sierra Nevada foothills of California runs this Ferrara pumper on an HME custom chassis. It has a 1,250gpm pump and a 500-gallon tank to handle both structure and interface fires. High ground clearance and 4x4 drive let it travel under tough road and weather conditions. (Garry Kadzielawski photo.)

Rescues. This is a very popular application in many parts of the country where off-road travel is required. Most 4x4 rescues have walk-around bodies built on light-duty or medium-duty commercial truck chassis. A few are built on heavy-duty custom chassis. NFPA 1901 covers rescues as a special services fire apparatus. It also covers related vehicle equipment such as winches and generators.



The San Bernardino County Fire Department station at Lake Arrowhead, Calif., handles numerous vehicle accidents and rescues with this KME custom 4x4 rescue squad. (Chuck Madderom photo.)

Hazmats. Many rural departments are seeing an increase in illegal drug manufacturing activities and hazardous chemical dumping in remote areas. Some departments are using light-duty 4x4 hazmat trucks to make the initial evaluation of these incidents and contain any immediate hazards. Samples of the suspected materials are then brought back to a larger haz-mat unit for testing and a determination of the required action. NFPA 1901 covers hazmat trucks.

Aerials. Yes, some departments run 4x4 and 6x6 aerials. This is especially true in crowded ski resort areas where overnight storms can block the roads with several feet of snow. Departments should be aware that most aerials already have a somewhat higher center of gravity than other apparatus, and the addition of all-wheel drive will raise it even further. Vehicle stability should always be a consideration. NFPA 1901 covers aerials.

Command and communication centers. If your department faces the possibility of large-scale incidents in difficult terrain, you may have to take your command center near the action. One department recently purchased a 40-foot command center on a custom 4x4 chassis to protect a large nuclear laboratory plus the nearby town and surrounding forested area. NFPA 1901 covers command vehicles as special services fire apparatus.

Consider the Alternatives

Before you spec all-wheel drive on your next vehicle, consider the alternatives. Do you really need this feature, or is it just nice to have? If it's nice to have, can you justify its cost? And if all-wheel drive can take you where other vehicles can’t go, ask yourself if you really want to send people there. Could the situation be handled in a safer and more effective way?

One alternative to all-wheel drive is a tire-pressure control system used on some military vehicles. This feature allows the driver to partially deflate all the tires when travelling across soft surfaces at low speeds. Decreasing the tire pressure increases the footprint of the tires to give more support and increased traction. When the vehicle reaches a hard road surface and the driver increases the speed, the system automatically reinflates the tires to their normal pressure. This system is best suited for operation on sand and other soft, dry soils and is less effective on slippery surfaces. Several manufacturers offer this system, and many customers find it to be a less-expensive alternative to all-wheel drive.


4x4 Chassis Manufacturers

Here are a few manufacturers that build 4x4 chassis and/or 4x4 emergency vehicles:

American LaFrance
www.americanlafrance.com

Boise Mobile Equipment
www.bmefire.com

Chevrolet
www.chevrolet.com

E-ONE
www.e-one.com

Ford
www.ford.com

Ferrara
www.ferrarafire.com

GMC
www.gmc.com

HME
www.hmetruck.com

International
www.internationaldelivers.com

KME
www.kovatch.com

Odyssey Automotive
www.odysseyauto.com

Peterbilt
www.peterbilt.com

Pierce
www.piercemfg.com

Seagrave
www.seagrave.com

Spartan
www.spartanchassis.com

Sterling
www.sterlingtrucks.com

Westates
www.westates-body.com

Wheeled Coach
www.wheeledcoach.com