Apparatus, Features, Wildland Urban Interface

Darley Builds MaxWASP Pumper for the Johnson Siding (SD) Volunteer Fire Department

Johnson Siding (SD) Volunteer Fire Department had W.S. Darley & Company build a MaxWASP (Wildland Attack Structure Protection) engine on a Ford F-550 4×4 four-door chassis. (Photos 1 and 2 courtesy of Johnson Siding Volunteer Fire Department.)

By Alan M. Petrillo

The Johnson Siding (SD) Volunteer Fire Department covers 64 square miles of rural residential area, forest, and wildland urban interface (WUI) in the center of South Dakota’s Black Hills National Forest, with a population of 3,000 that doubles most summers with tourists. The department has 20 volunteer firefighters who operate out of two stations and wanted to replace a Type 1 pumper with a smaller, more nimble WUI pumper.

The Darley MaxWASP engine for Johnson Siding has a copolymer body with integral 300-gallon water and 25-gallon foam tanks, a Darley PSMC 1,500-gpm pump, Darley AutoCAFS system, a 120-cfm rotary screw CAFS air compressor, and a FoamPro 2001 foam system.

Steve Smart, Johnson Siding’s chief, says the department was seeking to purchase “something easier to maneuver that one person could handle in starting to get water onto a fire before other apparatus began arriving.” He adds that “our department is sometimes hurting for personnel during the daytime, and we have some volunteers who are intimidated driving a full-size pumper.”

In building the MaxWASP, Darley lifted the vehicle a couple of inches to get clearance for Super Single wheels and tires, put on fender flare kits, and added a custom full-width powder coated aluminum front bumper with a 8,000-pound Warn winch. (Photos 3 through 6 courtesy of W.S. Darley and Company.)

After investigating small pumpers made by different manufacturers, Johnson Siding chose W.S. Darley and Company for its wildland attack structure protection (WASP) engine. Troy Carothers, AutoCAFS manager at Darley, says Johnson Siding asked for a number of modifications to the WASP design and ended up tagging the finished product the MaxWASP. “We lifted the vehicle a couple of inches to get the necessary wheel clearance for Super Single wheels and tires,” Carothers points out. “We had to carve out the front fenders and put on fender flare kits because of the wider front and rear tire stance, added a custom full-width powder-coated aluminum front bumper, and removed the rear dual wheels and replaced them with Hutchinson 20-inch wheels with Beadlocks and Continental MPT 81 335/80 R20 tires rated for 70 miles an hour.”

MaxWASP compartments are protected by rollup doors, with the exception of the air bottle storage compartment in front of the rear wheel.

Carothers notes that vehicle has a copolymer body with integral 300-gallon water and 25-gallon foam tanks, a Darley PSMC 1,500-gallon-per-minute (gpm) pump, a Darley AutoCAFS system, a 120-cubic-feet-per-minute (cfm) rotary screw compressed air foam system (CAFS) air compressor, and a FoamPro 2001 foam system plumbed to three CAFS discharges of two 1¾-inch cross lays of 200 feet each, and one 2½-inch preconnect at the back of the truck of 250 feet with a Task Force Tips Blitzfire nozzle. The MaxWASP also has a three-inch Storz discharge on the curb side opposite the pump panel.

Darley created a custom console for the driver and officer in the Ford F-550.

Smart says that when considering the smaller pumper, the department wanted CAFS on the vehicle. “With CAFS, we carry the equivalent of 1,000 gallons of water in a 300-gallon water tank,” he says. “We also have CAFS on our Type 3 wildland engine that has a 1,000-gpm pump, and a 500-gallon water tank.” Johnson Siding also runs two Ford F-550 Type 6 wildland engines, a pumper-tender with a 750-gpm pump and 2,000-gallon water tank, a rescue truck with an eight-bottle cascade system, a Chevy Suburban for medical calls, a Polaris Ranger, a rehab trailer, and a chief’s vehicle.

Besides space for large diameter hose, the hose bed of the MaxWASP has provision of a 2½-inch preconnect of 250 feet that Johnson Siding uses with a Task Force Tips Blitzfire nozzle.

One of the modifications Johnson Siding made to the body was to make a single, wide compartment out of the front and middle compartments of the three-compartment body, Smart notes. “We also added a SCBA storage compartment for six bottles, and at the top rear of the vehicle on each side, we used the 10-inch square spaces behind the roll-up door mechanisms to add compartments accessible from the back for long handled tools,” he says. “We also added hard covers on the hosebed and removed the revolving bubble lights at the rear and replaced them with small LED strobe lights, which allowed us to slide the three-section 20-foot extension ladder off of the top right side.”

Carothers points out that the MaxWASP has a foam tank refill pump system, a Darley AutoFill valve for the water tank, and an 8,000-pound Warn winch on the front bumper. “Every detail on this MaxWASP was analyzed to maximize ground clearance and storage space,” he says, “yet keep the vehicle lean and mean with the 19,500-pound GVWR of the Ford F-550 four door, 4×4 chassis.”

ALAN M. PETRILLO is a Tucson, Arizona-based journalist, the author of three novels and five nonfiction books, and a member of the Fire Apparatus & Emergency Equipment editorial advisory board. He served 22 years with the Verdoy (NY) Fire Department, including in the position of chief.