Mobile air/light units are finding homes with fire departments across the county. These multifunctional vehicles provide breathing air, electrical power and area lighting to help emergency personnel work more efficiently and stay on the scene longer. They also can dramatically improve the safety of rescuers and victims alike in a variety of life-threatening situations.

Air/light units are used at major fires, rescue operations, hazmat incidents and many other emergencies ranging from earthquakes to bio-terrorist attacks. Their ability to supply breathing air lets them support operations in high-rise buildings, tunnels, underground garages, malls, storage tanks, waste pits and other enclosed spaces. Their ability to supply electrical power and lighting makes them useful at incident scenes or to support emergency control centers, base camps, temporary evacuation shelters, medical facilities and other key installations.

Departments with older apparatus that aren't equipped with electrical power or breathing-air systems may find that purchasing an air/light unit is less expensive than retrofitting their older rigs. And because air/light units operate separately from other apparatus, they can be deployed where needed without tying up an engine or truck company. Some departments have joined with their neighbors to purchase a single air/light unit that responds throughout the region, thus further reducing the cost while still gaining all the advantages.

Hackney built this multipurpose air/light/hazmat unit for the Seattle Fire Department. It features Hackney's proprietary Automatic Deploy Staircase, an Onan 40kw generator, and a Scott breathing-air compressor and fill station.

Features improve functions
As with any apparatus, more features mean more functions. The best approach is to carefully select the features you need to perform the functions you face.

Breathing-air systems rely on cascades or compressors to refill SCBA cylinders or supply breathing air to remote locations through hoses. Cascades carry the air in several large high-pressure cylinders plumbed together. They have only a limited supply, however, and are often used by departments with limited applications or budgets. Using breathing-air compressors with cascade storage cylinders allows unlimited operation, and this combination is favored by most departments. SCBA fill stations are designed to rapidly and safely refill one or more cylinders at a time depending on the expected application. Breathing-air hose reels can provide a sustained air supply to personnel working several hundred feet from the apparatus without requiring that they periodically stop to swap air cylinders. The hose reels are connected to the appropriate regulators and controls for safe operation. Some air/light units also carry a supply of spare air cylinders or SCBA for use by additional personnel as they arrive on scene.

Electrical power systems rely on vehicle-mounted generators to provide line voltage power. The generators may be driven by separate engines or by the vehicle engine through power takeoffs or hydraulic drives. Each drive system has its own advantages. Most air/light units are equipped with large generators of at least 20kw output to provide sufficient power for multiple functions. The power is distributed through control panels with appropriate gauges, controls and protection devices. Fixed receptacles and electrical cable reels provide power for lights, tools, ventilation fans and other devices. They also can connect to building electrical systems through pre-installed transfer switches on the structures.

Most air/light units also have a variety of light sources, including fixed or elevating lights to illuminate the immediate area, plus several portable lights for use inside structures or in areas where the apparatus lights can’t reach.

Finally, departments can make their air/light apparatus double as rehabilitation units by adding some equipment. For example, an awning can provide protection from the rain and sun. A drop-down bench can let personnel get off their feet. An electric misting fan can help combat heat-related fatigue, and a built-in coffee maker or refrigerator in an outside compartment can supply hot or cold drinks.

NFPA sets the standard
NFPA 1901, Automotive Fire Apparatus, classifies air/light units as special-services fire apparatus and sets general standards for the overall vehicle design and performance. It also establishes specific requirements for the major components typically installed on air/light units.

Chapter 23 of the 2003 edition of NFPA 1901 covers line voltage electrical systems including generators, line voltage wiring, cable reels and lights. Chapter 25 covers air systems including breathing-air compressors, cascade storage systems, fill stations and hose reels.

Departments that purchase air/light units should be familiar with the NFPA requirements and should include them in their specifications and delivery inspections. As with any NFPA standard, taking exception to the requirements is never a good idea and can place departments in a position of potential liability.