What do you get when you combine an Apache helicopter, an elephant, and a Formula One race car? If you’re with the engineering team at JRI Inc. in Newark, Calif., you get a Jaguar firefighting vehicle, the first redesign of an airport crash truck in nearly two decades. Starting from the ground up, the team assembled a vehicle with the ability to get to the accident scene quickly whether that’s in a hangar, at the end of a runway, or even off airport grounds, and day or night in any kind of weather. It also has the latest in fire-fighting equipment and can handle 747- sized fires.
Making it Mobile
In the rescue business, speed is life. With a supercharged and turbocharged 600-hp diesel V8 and sixspeed automatic transmission, the Jaguar can roar from 0 to 50 mph in under 20 sec, fast enough to get to almost anywhere on an airport and begin fighting a fire in under a minute. The 21-ton vehicle can reach speeds up to 115 mph, making it far and away the fastest crash truck in the world. But it takes more than just speed to get to a crash.
Studies show that rescue vehicles traveling to accidents spend less than 5% of the enroute time in high-speed straight-line motion. They spend most the time decelerating, turning, and accelerating. And for a big rig like the Jaguar, especially one filled with 1,500 gallons of sloshing water, all those hard stops and sharp turns threaten to topple it or quickly destroy the suspension and chassis.
So JRI engineers borrowed some technology from Formula One racing and jet aircraft to make the Jaguar as agile as its namesake.
Like race cars, the Jaguar uses a monocoque space-frame, a technique that strengthens the frame by a factor of 10 compared to chassis on traditional crash trucks. Lightweight stainless-steel chassis components are welded together into a solid frame that doesn’t twist, flex, or bend. And stainless steel resists the corrosive effects of firefighting agents such as foam and dry powders. The lighter, highstrength chassis reduces maintenance and fatigue-induced damage, while improving handling, speed and braking.
The chassis cradles the 1,500-gallon water tank lower than in other crash vehicles, bringing the center of gravity down from 8 ft to about 4.5 ft. This makes it the most stable vehicle in its class. The tank is also tilted to create a low point at the left front corner for efficient pumping.
For optimum handling, Jaguar rides on a computer-controlled hydropneumatic suspension similar to those found in jet planes. Rather than steel springs, the vehicle is equipped with air shocks and hydraulics that stiffen for cornering or off-road travel. Sensors detect driver and suspension inputs to adjust the suspension in 1/30th of a second. Onboard antilean and antidive stabilizers continually strive to keep the Jaguar level. The driver can change the height of the Jaguar by 20 in., raising it for better off-road clearance or lowering it for high-speed stability. A computer prevents drivers from raising or lowering it to an unsafe position for prevailing conditions.
The headlights also adapt to the terrain. When the computer determines the vehicle has gone off road, it tilts the lights down so the driver can better see the terrain in front of him. Once the Jaguar gets back on smooth road, the headlights flip back up for maximum visibility.
Full-floating axles feature automatic slip control, electronic traction control, and air brakes with redundant air tanks and dryers. The brakes are supplemented with both active and passive antilock controls. Passive ABS, like that found on most new cars, pulse the brakes when sensors detect an impending lockup or slippage. Active ABS, on the other hand, takes suspension and driver inputs to adjust the chassis for maximum stability. The Jaguar carries a total of nine computers controlling various systems. All of this makes the vehicle easier to handle and gives it a smoother ride.
The driver is also helped by an angular wraparound windshield that looks much like the ones found on Apache helicopters. It’s made of bonded, laminated glass and integrated into a protective crash cage. For fire fighting, an overhead window gives unobstructed views when parked close to tall airliners. For added visibility at night or in smoke or fog, the vehicle carries a forward-looking infrared camera mounted above the cockpit. Its images are shown on a head-up display projected on the windshield along with performance information.
To see behind the vehicle, three cameras and television monitors replace left, right, and rearview mirrors. Mirrors, which require two people to adjust and need adjusting for each driver on three daily shifts, often break off since they stick out the farthest on an already wide vehicle. The camera system requires much less maintenance and can see better than a human eye, especially when backing into a darkened fire station on a sunny day. The cameras are also equipped with microphones, so the driver can hear what’s going on outside — and adjust the volume — while sitting in his acoustically insulated and air conditioned cockpit. A four-motor wet-arm wiper system keeps the windshield clean in bad weather, just the type of weather that often precipitates airplane crashes. A global-positioning system lets drivers know where they are to within 3 ft, an important consideration for coordinating rescue efforts for crashes on and off airport property.
With the advent of larger aircraft, greater demands are placed on fire-fighting agentdelivery systems, and the Jaguar’s is top-ofthe- line. A Powerflow turret connected to an Instatak system, both from Colet S.V.O. (Special Vehicle Operations) in Los Altos, Calif., let operators pump water or foam over 300 ft at 300 to 1,800 gallons/min. A computer in the Instatak can be preprogrammed to mix the 1,500 gallons of water and 96 gallons of foam the Jaguar carries. Or mixing can be operator selected. The Jag carries 50% more water and foam than other crash vehicles.
The turret and nozzle swivel horizontally 360° and can tilt between 28 and 85° vertically. When necessary, the operator can extend the turret and hose, letting him place the nozzle in through an airplane door. Then he can turn the nozzle and aim it directly at a fire in the fuselage. The turret can also put out a stream of fog, a technique used to keep fire fighters cool while they battle a blaze.
Because the turret and water-handling system were designing as integral components in the Jaguar, they don’t compromise the vehicle’s stability or mobility. It also means the Jaguar doesn’t need support jacks when it goes into fire-fighting mode.
“And just like most of the Jaguar’s other engineered systems, we built redundancy into the fire-fighting systems as well,” says Ralph Colet, the vehicle developer. “Overall, the Jaguar has been engineered to surpass response-time requirements for reaching a crash or fire site almost anywhere on airport property, and to extinguish a fire in less than a minute,” says Ralph Colet, the vehicle’s developer.
Rescue crews at Hartsfield International Airport in Atlanta have had the chance to test Colet’s statements as they assessed the Jaguar over a long-term period. So far they’ve been completely satisfied. In one accident, for example, a DC-9 had a fire break out between the interior and exterior walls just prior to take off. With its wing tanks fully loaded with fuel, a fatal explosion could have happened in seconds. In less than a minute, a Jaguar was on the scene to extinguish the fire and cool the plane, saving 55 passengers and five crew members. The airport has since ordered 10 more, including an extended version capable of carrying 4,000 gallons of water.