Wildland fire apparatus: How to spec out for safety, endurance

By Doug Feldman
Rosenbauer West Coast sales/distribution

The modern day wildland engine must be engineered much differently than a city pumper for safety and durability reasons. While the differences are difficult to spot on the outside, it’s far more obvious when you take a look at the underside of the apparatus.

Sub-frame body mount

The most important vehicle component for a true wildland apparatus is the body sub-frame, which must allow the body to flex when firefighting on rough and uneven forestry terrain.

If the body mount does not allow for this flex, the body structure itself will adsorb the energy and will lead to premature failure of body components.

One testing procedure commonly used to check the sub-frame is the opposing axle lift test. This involves raising opposing tires at least 12" off the ground and opening each compartment door.

They should open without any binding of them. While in this position, look for driveline interferences, start the pump and check all PTO shafts.

Look for fan shroud obstructions make sure the pump house structure is not impeding on any plumbing components.

If your body is not mounted with a wildland-type sub-frame, it will not last long in the forestry environment.

Ember protection

Keeping windblown embers from entering into the engine and cab is paramount for the protection of firefighters and their ability to pump water.

Several stainless steel screens are required: Two air intake and fresh air intake screens will help prevent live embers from entering the engine and cab.

Wrapping air and fuels lines below the frame rail will protect these lines from ember melt-through and prevent a rupture of critical fuel and air lines caused from embers resting on these lines.

Tilt-table testing

The wildland apparatus must have center of gravity engineered into the body build up when considering components, loose equipment and crew placement.

The industry standard method for checking this is the tilt-table testing method. The minimum criteria should be 30° when fully loaded with equipment and crew.

Basic wildland features
Some basic specification items on a typical wildland engine include: International MAXFORCE 9, 4 door cab, all wheel drive, 330 HP, 950 lb torque engine, Allison 3000 EVS Transmission with two speed transfer case, 35,000 GVWR, 2-stage 500 GPM main pump and 150 GPM auxiliary pump, 500 gallon poly tank with separate 20 gallon foam tank, and Class A foam.

The Rosenbauer Group is the world’s second-largest manufacturer of firefighting vehicles. It has a wide range of municipal firefighting vehicles and aerials built to both European and US-Standards (NFPA) as well as an extensive series of aircraft rescue and firefighting vehicles, industrial firefighting vehicles, advanced firefighting components and fire and safety equipment. For more details, go to Rosenbauer.com.