by Adriana Casarez
Materials and Manufacturing Directorate

8/8/2007 - WRIGHT-PATTERSON AIR FORCE BASE, Ohio (AFPN) -- Scientists at Tyndall AFB, Fla., have developed ultra high pressure water firefighting technology that has resulted in a smaller, leaner air transportable fire truck.

Starting in fiscal 2008, these new trucks can be deployed in sets of two on a C-130 Hercules, whereas the former fire trucks could only be carried one at a time aboard the aircraft.

The Air Force needs a fire truck that is designed to be reliable, lightweight and compact, said Virgil Carr, the fire research program manager.

"The Air Force currently uses the standard P-19 fire truck which faces great difficulty when deployed because it doesn't easily fit into a C-130 aircraft," Mr. Carr said.

In order to transport it, the roof turret must be removed and then reattached when it's back on the ground, he said.

The scientists are a part of the materials and manufacturing directorate's airbase technology division. The directorate is, in turn, part of the Air Force Research Laboratory, headquartered here. The AFRL's fire research group at Tyndall AFB, began a program in the late 1990s to develop technologies that enhanced the performance of current firefighting technology.

Initial efforts were directed toward developing a single system that would address two-dimensional flowing fuel fires (pool fires) traditionally fought with Aqueous Film-Forming Foam, and three-dimensional fires (flowing fuel fires) fought with Halon 1211, an agent that changes from liquid to gas during application. The foam works by forming a barrier between the fire and fuel surface preventing the flame from spreading. The initial approach showed great potential. However, it resulted in an unacceptably expensive system.

"This research has led to revolutionary concepts in firefighting equipment and firefighter technique and strategy, including ultra high pressure water technology," Mr. Carr said.

"In September 2002, scientists began research on the use of ultra high pressure technology for extinguishing hydrocarbon fuel fires. In 2003, a major breakthrough occurred when (Materials and Manufacturing Directorate) developed an air-deployable all terrain vehicle with a mounted ultra high pressure system."

This apparatus, referred to as the first response expeditionary vehicle, was the initial ultra high pressure system developed by the fire research group. Currently it is the only firefighting asset in the Air Force inventory able to be dropped from an aircraft. It has been commercialized and can be bought from Rosenbauer America. Ultra high pressure technology has proven to be three times more effective than traditional firefighting agent delivery systems and allows for smaller trucks to be built with equivalent capability.

Materials and manufacturing directorate scientists then began work to modify a P-19 that would be as effective as the standard vehicle. The platform was designed to incorporate three different agent application technologies: ultra high pressure water technology; compressed air foam; and dry chemical agent.

The major characteristics of the ultra high pressure P-19 involve a bumper turret capable of supporting both ultra high pressure and combined agent nozzles, along with separate ultra high pressure and combined agent hand lines. The roof turret has been removed because qualitative fire testing, as well as quantitative flow characterization has shown that the 300 gallons per minute ultra high pressure bumper turret has firefighting effectiveness equivalent to that of the standard 500 gallon roof turret. Feedback from operators has shown it to be more ergonomically correct for the firefighter because they can see both the agent stream as well as the target from one vantage point.

The ultra high pressure P-19 at Tyndall AFB was the result of much computational technology and experiments that eventually resulted in downsizing a standard truck, said Mr. Carr. The water carrying capability was reduced from 1000 gallons to 730 gallons without losing any firefighting effectiveness. This 730-gallon water carrying capacity is roughly equivalent to the 750-gallon future fire trucks that will be bought using ultra high pressure agent delivery systems. These new trucks will be at least twice as effective as the current P-19, resulting in the equivalent of three 1000-gallon existing fire trucks on the ground.

"Since the UHP P-19 has been brought to full operational capacity, the test bed has shown significantly increased firefighting effectiveness over the standard P-19 even though it discharges only 60 percent as much firefighting agent," Mr. Carr said.

With these promising results and endorsement of nearly all Air Force major commands, a need was presented to create guidelines for future aircraft rescue and firefighting vehicles. AFRL has collaborated with the Air Force Civil Engineering Support Agency to determine specifications for the next generation aircraft rescue and firefighting vehicle based primarily upon the current capabilities of the ultra high pressure P-19 demonstrator.