The heavy rescue truck is rapidly gaining popularity in fire departments across the country. Once considered a specialized apparatus found only in a few large Eastern cities, heavy rescues are now being used by many departments to handle a wide variety of emergency rescue operations.

The rising popularity of heavy rescues reflects the growing number of ems and rescue calls that departments have been experiencing over the last three decades. In some departments, 80-90% of the calls are for emergency medical or rescue incidents.

At the same time, the types of rescue incidents have become more diverse. Departments where the most serious rescue call was for a cat in a tree are now being asked to handle incidents involving vehicle extrication, trench rescue, building collapse, swiftwater rescue, and a host of other emergency situations.

The tools required for these rescues have also become more numerous and complex. Pry bars and come-alongs have been supplemented with hydraulic rescue tools, low-pressure lifting bags, winches and even cranes. As rescue tools and equipment compete for compartment space on pumpers and ladder trucks, many departments are turning to a dedicated heavy rescue unit to solve the problem.

A toolbox on wheels The decision to specify a heavy rescue, as opposed to a smaller medium or light rescue, is usually based on the number and types of hazards in a department's jurisdiction. For example, if a department has few special hazards in its area, and most of its rescue calls are for the occasional vehicle accident on the local highway, it may elect to carry limited rescue equipment on a pumper or light rescue. On the other hand, if it has numerous special hazards, such as recreational water or hiking areas, busy Interstate highways, tall or confined-space structures, or industrial plants operating large machinery, it may need to specify a heavy rescue to carry all the required equipment.

The commonly used dividing line between a heavy rescue and a medium rescue is defined by the body length, although in some cases it's defined by gross vehicle weight rating or the equipment carried. (See sidebar at right.) The typical body for a heavy rescue is about 18 to 20 feet long, although bodies up to 24 feet aren't uncommon.

Because of the growing number of specialized rescue tools and equipment, there's been a move away from the traditional walk-in rescue body to the compartmentalized walk-around body, or "toolbox on wheels," as some people call it. To provide seats for the crew and comply with the nfpa 1901 standards for crew compartments, departments usually opt for a custom or commercial four-door cab. Some manufacturers offer the best of both designs with a combination walk-in/walk-around body that has crew seating built into part of the body and compartments in the remainder. This configuration allows the use of a lower-cost two-door cab while offering the advantages of a stand-up crew space.

To maximize storage space, heavy rescue manufacturers use every conceivable cubic inch. Roof-mounted compartments are often used for bulky or little-used equipment like ground ladders and large lifting bags, with access to the roof provided by a fixed stairway or ladder at the rear of the body. Underbody storage trays are common, as are wheel-well compartments.

Equipment carried within the body is usually stored in roll-out, tilt-down trays to give immediate visibility and access to every part of the tray. Other tools are secured to both sides of vertical slide-out boards for quick retrieval. Long items like backboards and Stokes baskets are stored crossways in the body. Extended front bumper pans may carry hydraulic tools and hose reels to give quick access for vehicle extrications.

Multifunctional vehicles Another trend in heavy rescues has been the move to multifunctional vehicles, especially in departments with limited personnel or financial resources. Rather than specify vehicles that can serve only as rescues, some departments are looking for other ways to use them.

One popular way is to use an area of the vehicle as a command center. Some departments specify a four-door custom cab, often with a raised roof, and have the rear crew compartment modified to serve as a small command area. The rear street-side cab door may be omitted, and a desk with communications equipment installed in that area.

Other departments use a crew compartment built into part of the rescue body as a command center, with a curbside or rear-access door. This configuration gives stand-up room in the command center, allowing it to be used as a changing area for dive teams or as a rehab area for firefighters.

Another popular multifunctional use is as a support unit for firefighting operations. A high-pressure air cascade unit can recharge up to 60 scbas on the scene, and a high-output electrical generator and elevating light tower can provide wide-area lighting. Taking this idea one step further, the addition of ground ladders and a small amount of equipment can turn a heavy rescue into a service ladder truck, which may gain the department additional iso credit.

Finally, an increasing number of heavy rescues being specified with small water pumps and tanks for fire suppression. This is especially true when the rescue responds to a lot of vehicle accidents. Rather than tie up a pumper to stand by while the extrication is in progress, the rescue crew can lay a line from its own unit. A 250- to 500gpm pto pump and a 200- to 300-gallon tank are the most common configuration for heavy rescues. Adding Class A and B foams gives the system the punch required to handle most small fires.

Options are standard Most manufacturers will tell you that there's no such thing as a standard heavy rescue. In addition to a range of cab and body styles, there are an equally wide variety of options.

For example, it's estimated that 80% of the heavy rescues being built today have some sort of elevating light tower, and about 20% have two or more. Each light tower provides 6,000 to 9,000 watts of illumination and can be remotely aimed from the ground. Additional fixed lights provide perimeter illumination, as well as lighting for the compartments and the crew/command areas.

Electric power is usually provided by a 20- to 60-kilowatt ac generator driven off the transmission power take off. This configuration generally takes the least amount of space and is quieter to operate. Some rescues use a hydraulic-driven generator powered by a hydraulic pump on the pto. This configuration allows the hydraulic system to compensate for varying engine speed to maintain full electrical power. Other generators are run off separate diesel engines.

Hydraulic power for rescue tools is often provided by an electric-driven hydraulic pump run off the generator. The tools are connected to the pump through hoses stored on reels in the rescue body. Some departments also carry a portable engine-driven hydraulic pump to let them make rescues beyond the reach of the hose reel.

A high-pressure air cascade unit can be used to provide breathing air for confined-space rescues and to recharge scba at fires. Some units have a complete high-pressure breathing air compressor and fill station. A low-pressure air system can be charged by the vehicle compressor or regulated off the high-pressure cascade and is used to provide air for rescue tools and lifting bags. Again, hose reels add flexibility.

Winches are also a popular option. A 4,000- to 12,000-pound pinnable electric winch with receivers on all four sides of the vehicle is often specified. This allows the truck to act as an anchor for vehicle stabilization, and it also provides a tie-off point for rope rescues. Some departments specify larger 20,000-pound winches on the front or rear of the vehicle in addition to the portable winch. A few heavy rescues are built with A-frame derricks or extendible boom cranes for heavy lifting.

To keep the hundreds of tools and pieces of equipment organized, departments are specifying tool storage brackets and systems. Some systems use slotted tracks with corrosion-resistant brackets. The brackets can be mounted in any position and can be quickly relocated to accommodate tool and equipment changes. The use of dedicated brackets for each tool or piece of equipment also helps personnel identify missing items before leaving an incident scene.

Compartment floors are often lined with open-grid matting to cushion the contents and provide drainage. The matting also reduces rattles from loose equipment, which is important when a crew compartment or command area is incorporated into the body.

Other options include drop-down awnings on one or both sides of the vehicle for shelter, extendible body sides to increase floor space in command areas, roof-top storage compartments or roof observation decks with safety railings and non-slip decking, separate vented compartments for rope storage, and mist generators or fans for firefighter rehab in hot weather.

The choices are almost endless.

Rescue vehicles are classified as "special service fire apparatus" in the 1999 edition of nfpa 1901. Here's a rundown of the standard's applicable sections:

* Table 2-2.2 shows which chapters apply.

* Table 10-1 shows the miscellaneous equipment weight allowance based on the gross vehicle weight rating.

* Section 8-5 lists the required equipment.

* Section A-8-5 in Appendix A lists additional equipment that departments may want to consider when specifying a rescue.

Equally important are the regulations and conditions that state and federal government agencies may place on rescues. For example, Pennsylvania offers low-interest loans for volunteer fire departments to purchase apparatus. For rescues, the amount of the loan depends on the gvwr. Likewise, rescue vehicles funded by fema are required to carry certain equipment.

If a department wants to run a heavy rescue as a service ladder to gain iso credit, it needs to be aware of the iso equipment requirements.

Heavy rescue trucks built for service in Canada have to meet Canadian osha and uls standards, which differ in some requirements from the United States' nfpa, osha and ul standards.

Here are some manufacturers that build heavy rescue vehicles.

American Fire and Rescue 219-642-4954

American LaFrance Corp. 877-827-2075

Central States Fire Apparatus 605-543-5591,

Emergency One Inc. 352-237-1122,

Ferrara Fire Apparatus Inc. 225-267-7100,

4 Guys 814-634-8373,

Hackney Emergency Vehicles 800-763-0700

KME Fire Apparatus 800-235-3928,

Luverne Fire Apparatus Corp. 800-621-0243,

Marion Body Works 715-754-5261

Pierce Manufacturing Inc. 920-832-3000,

Saulsbury Fire Rescue 800-627-5050