BY ERIC D. RUGGERI
No word sums up Kennett Square (PA) Fire Company’s newest midi-attack pumper better than versatile. The vehicle is a 2003 Mercedes Benz Unimog U500 4×4 chassis with custom bodywork by General/Rosenbauer completed in 2004 (photo 1). Although officially recognized by the Chester County Fire Chiefs Association as a quick-attack vehicle, Kennett originally designed the vehicle as a large-diameter hose wagon. It carries 3,000 feet of five-inch and 1,000 feet of three-inch supply line (photo 2). It also has two two-inch preconnect hoselines mounted on the front bumper. The multifunctional unit can operate as a hose tender, a quick-attack brush vehicle, or a light rescue.
The Unimog’s advanced technology includes a high-performance hydraulic system with quick-disconnect attachments and an in-cab joystick controller. It can accommodate a wide range of implements including snowplows, street sweepers, dozer blades, and cranes. The chassis, which originated in Europe in 1951, is built in Germany. In January 2003, the Unimog was introduced to the North American commercial market. It is now a member of the Freightliner Truck Group, a Daimler Chrysler company, headquartered in Portland, Oregon.
Rosenbauer America is a consolidation of Central States Fire Apparatus, General Safety Equipment, and RK Aerials-all were brought under the Rosenbauer umbrella in the 1990s. Prior to that, Rosenbauer had built fire apparatus for more than135 years, originating in Linz, Austria. Although another apparatus manufacturer has created a demo unit on the Unimog chassis for the fire service, Kennett Square’s Rosenbauer is the only known completed unit of this type in active use by a U.S. fire department. The vehicle comes with a $320,000 price tag, fully equipped and with roll-up compartment doors. After chassis delivery, the bodywork was finished at Rosenbauer’s Wyoming, Minnesota, plant.
The Unimog U500 chassis features the Mercedes Benz 280-hp electronic MBE900 six-cylinder turbocharged diesel engine and an eight-speed forward/six-speed reverse Mercedes automated manual transmission with Telligent® gearshift system and a two-speed transfer case. It’s highly maneuverable with permanent all-wheel drive and a tight turning radius and 18 inches of ground clearance. It can tackle 80-percent inclines and tread 30 inches of water. “In four-wheel lock, you can sink this truck up to the top of the 385/85/R20 tires, and it will crawl out on its own without any tire slippage,” says Kennett Fire Company President Anthony Talamonti.
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 1, 2) The Kennett Square Unimog midi-attack vehicle was designed as a large-diameter hose wagon. (Photos by author.) |
A four-section 10-foot, five-inch-wide Schmidt snowplow was purchased for the unit. One person can install it using the quick-attach hydraulic coupler in about three minutes. The $10,000 2,650-pound option will be installed on the truck during the unpredictable Pennsylvania snow season that sometimes calls the company into the more rural sections of the district when local roads have not been plowed and conditions hinder the response of the larger apparatus.
“When it snows, our idea is to send the Unimog in first with the snowplow to access the fire location to allow the bigger trucks to get in,” explains Kennett Chief Steven Melton. “If it has to fight fire when it gets there, it can. Or, it can wait for the balance of the apparatus coming,” Melton adds.
With the traction control selectable from 80/20 for normal driving conditions to 50/50 for off-road, the truck will crawl 250 feet in 20 minutes at 2,000 rpm. “This truck brings an entirely new concept to the term laying in,” observes Talamonti. “Now you can cut across country, off-road and lay your five-inch supply line, which results in shorter lays and quicker establishment of your water supply.”
The vehicle is 10 feet high and 21.8 feet long and has a gross vehicle weight rating of 33,000. The driver’s compartment offers a high-visibility, commanding view because of its seat position behind the front axle and a large multilayer, ultrawide windshield.
ULTRA HIGH-PRESSURE PUMP
Kennett Square’s vehicle is equipped with a Rosenbauer UHPS ultra high-pressure 10 gallons-per-minute pump rated at 1,450 psi and powered by a 16-horsepower Vanguard gasoline engine. It carries a conservative but ample 200 gallons of water and 30 gallons of foam. The 200 feet of ultra high-pressure, noncollapsible rubber hose is contained on a “rapid reaction” hose reel and mounted on a Slide Master rollout tray. The UHPS is specifically designed for an initial quick attack with small amounts of water. The ultra high-pressure extinguishing agent combines minimum amounts of water at maximum pressure using a long, thin hose, resulting in water droplet sizes for use with both a full and a spray setting. The small water droplets absorb heat efficiently and create less steam than some conventional systems. One firefighter with 20 gallons of water can extinguish the average working car fire with the UHPS system in less than two minutes.
 (3) A 2,000-pound front counterweight is mounted in place of the seasonal snowplow. |
The thin, light hose can also easily be pulled up staircases and around corners, angles, and edges. It is ideal for structural firefighting and is less fatiguing than using the larger, heavier conventional firefighting lines. The combination of volume and pressure creates a high level of kinetic energy that penetrates the burning object and extinguishes it.
For rescue responses, the unit carries a full complement of Power Hawk P-16 12-volt battery-powered rescue tools with spreader, cutter, and rams; a full set of Milwaukee 18-volt battery-operated hand tools; and an American Airworks two-bottle 6,000-psi air system for running air bags and air work tools. The vehicle is also equipped with a bed-mounted Warn 9,000-pound capacity winch with outlets on both sides of the body. Additional equipment mounted on the truck includes a 24-foot extension ladder, a 6,500-watt Honda gas generator, a 12-volt positive-pressure, battery-powered Ram fan with 25-foot vent tube; 3,500 watts of scene lighting using seven 500-watt pole lights; three SCBAs; two Craftsman 3,500-pound floor jacks; a Res Q Tek cribbing assortment; and an assortment of class A, B, C, and D extinguishers.
 Kennett Square’s 2004 Unimog: (4) Right-side compartmentation-slide-out-and-down rescue equipment trays. (5) Left-side compartmentation-high-pressure pump. |
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The Unimog was financed as part of a $1.6 million grant for three new replacement vehicles for Kennett Township and Kennett Square Borough municipalities, which make up Kennett Fire’s primary first-due territory. Two identical HME/Rosenbauer rescue-pumpers will be delivered later this year, to complete the package. The short wheelbase attack vehicle was designed with the various terrains currently found in the response territory in and around the Kennett Square area, which includes the tight city alleys in town, a section of a U.S. Route 1 bypass, and the long and winding development streets found in the rolling hills of Southern Chester County. “Its 154-inch wheelbase is shorter than most American-made crew cab pickup trucks,” Talamonti says. “And at 70 miles per hour, this truck rides as comfortably as a standard pickup truck, and that’s with the snowplow on,” he adds.
GERMAN TECHNOLOGY COMES TO THE UNITED STATES
Talamonti first learned about the Unimog chassis for the fire service at the 2002 Interschutz fire symposium in Hannover, Germany, while on a business trip. However, Kennett Fire Company’s European ties with the fire service date back to the 1970s, when its members became friends with members of the Hampshire Fire Brigade of Winchester, England. The two groups visited each other’s country and exchanged ideas on firefighting and apparatus. The Hampshire group served on Kennett’s aerial apparatus replacement committee in 1998.
This is not Kennett Fire Company’s first turn at setting trends in the Pennsylvania volunteer fire service. In 1974, it claimed to have invented the first tanker/pumper combination with a midship pump and a six-inch dump valve. The unit carried 2,000 gallons of water and used a 1,000-gpm midship pump, manufactured by Bruco, on a Ford C series tandem axle chassis. The immense vehicle has since been retired. Then in 1998, Kennett was the first fire department in the United States to place in service a Metz 102-foot aerial on a Volvo chassis. It was the first time since the 1960s that Metz had apparatus with the newer aerial technology in the United States. ■
■ ERIC D. RUGGERI has been a member of the West Chester (PA) Fire Department since 1984 and is also a member of the Kennett (PA) Fire Company. A police officer by trade, he is also the emergency management coordinator for East Bradford Township and a graduate of the Delaware State Fire School.
