Specifying the Small Stuff

First, outline any special design features required on the apparatus. Examples include a short wheelbase; tight turning radius; and specific height, width, weight, or length to meet local operating conditions. Before you can specify compartment widths or cab extensions, evaluate the length of the apparatus. Most new apparatus are considerably larger, resulting in many red faces among fire chiefs who have specified units that cannot fit in older firehouses!

When calculating the allowable overall height of the apparatus, consider the grade of the fire station driveway. As the front axle of the unit departs down a steep ramp, a “see-saw” effect takes place behind the rear axle, raising the back of the unit several inches above its flat ground height measurement. This is especially true when there is an excessive overhang behind the rear axle and the apparatus is tall at the rear, such as in the case of a rescue truck. You can get help before you make a mistake! Almost any manufacturer’s engineering staff can calculate the rise if you provide accurate measurements of the door entrance height, inside height, ramp angle, and ramp length. NFPA 1901 now requires a marker in the cab to advise the driver of apparatus height, length, and weight.

Also consider the angle of approach and angle of departure. This is measured as a straight line from the bottom of the tire to the lowest hanging projection in front of the front axle and to the rear of the rear axle. NFPA 1901 calls for a minimum 8 angle both front and rear. You might need to specify a greater angle if you will encounter steep hills or even a steep apron outside the fire station.

Since we are carrying more hose, more water, and more people, apparatus also weigh more now than in the past. Fire stations with a basement or crawl space under the apparatus floor might require a professional engineer to evaluate the load-carrying capability of the floor. There has been more than one instance of apparatus going through the floor!

Quite often, I see fire departments using a manufacturer’s specification to develop their own but staying with the axles in the sample spec. This could lead to serious problems if another manufacturer’s building methods increase the weight of the vehicle. If it turns out to be overloaded, remember: YOU specified the axles.

When it comes to axle and suspension capacity, I believe these two items might be better left up to the bidders. I usually specify “axle capacity and suspension commensurate with the estimated in-service weight of the apparatus.” Stopping and steering are best accomplished when the axle loading is close to capacity. This is one case where more is not always better. Be sure to remember that the manufacturer will calculate the axles on the NFPA miscellaneous equipment load unless you specifically call for a higher equipment load.

The miscellaneous equipment allowance in the standard is as follows:

• Pumper: 2,000 pounds.

• Rescue pumper with more than 250 cubic feet of compartment space: 2,500 pounds.

• Initial Attack: 900 to 2,000 pounds.

• Mobile Water Supply: 1,000 pounds.

• Aerial: 2,500 pounds.

• Quint: 2,500 pounds.

• Special Service: 10-15,000 Gross Vehicle Weight Rating (GVWR): 2,000 pounds. 15-20,000 GVWR: 2,500 pounds.
20-30,000 GVWR: 3,000 pounds.
30-40,000 GVWR: 4,000 pounds.
40-50,000 GVWR: 6,000 pounds.
50-60,000 GVWR: 8,000 pounds.

60,000 and up: 10,000 pounds.

If you need help calculating the weight of the equipment you intend to carry, you can look in Annex C of NFPA 1901 and do it manually or go to the Fire Apparatus Manufacturers Association Web site (www.FAMA.org). Click on the “Equipment Weight and Cube Calculator,” and download the spreadsheet. Insert the quantity of each item of equipment, and it will automatically calculate the total. Remember, hose and ground ladders are NOT considered loose equipment. Do not include them in the calculations. They are figured separately.

Another important weight factor is the maximum number of persons to ride on the apparatus. The manufacturer must provide seats and seat belts in a fully enclosed area for the total number of personnel specified. Each seating position is calculated at 200 pounds. This number will directly affect the size and configuration of the cab as well as the axle capacities and GVWR.

The maximum turning radius of the apparatus is another important consideration, especially in garden apartment or condo complexes where the access roads are narrow and include parked vehicles. As the apparatus gets longer, it will require more space to make a turn. Turning radius measurements are taken at different places and will vary widely. The “Society of Automotive Engineers (SAE) turning radius” is measured at the center of the outside tire and doesn’t really tell us much about the space needed to make a turn. When a manufacturer quotes a “curb-to-curb” radius, this is measured to the outside edge of the front tire, considering that any front or rear overhang will pass over a curb. The “wall-to-wall” turning radius is measured at the outermost point of the apparatus, including the front bumper and rear overhang, when making a turn. This measurement gives the best indication of the real area required to complete a turn.

You must specify the apparatus road performance if it is to exceed the minimum specified in the standard. The following are the basic requirements in the standard:

• From standing start, attain 35 mph in 25 seconds on level road;

• Attain a minimum top speed of 50 mph on level road;

• Maintain a minimum of 20 mph on any grade up to and including six percent; and

• At 20 mph, stop in 35 feet.

Most departments’ specifications indicate a number exceeding the 50 mph top speed, especially if responding on expressways or highways. I would caution against making the top end too excessive, as inexperienced drivers moving at a high rate of speed with heavy apparatus is a formula for disaster. Another benefit of limiting top speed is that departments can obtain better “low-end” performance because of the rear axle ratios.

Operating on grades is another consideration when specifying your apparatus. The standard says that you should indicate the maximum grade the apparatus will climb if higher than six percent. A six-percent grade is not very aggressive. If your department routinely operates on steep hills, obtain and include information from the town engineer. Parking on a grade greater than 20 percent might require a front wheel brake lock to keep the apparatus from rolling.

When considering the performance of your specified apparatus, request a computer-generated engine/transmission SCAAN (System for Computer Application Analysis) from the manufacturer. Using all of the calculations of engine, transmission, axles, tires, weight, and so on, the computer can accurately predict the performance on flat ground as well as on grades.

NFPA 1901 lists the size of the fuel tank as a performance standard. The quantity of fuel must be sufficient to allow the pump to operate at capacity for 21⁄2 hours or at 60 percent of the rated horsepower for 21⁄2 hours. If you need to exceed these minimums, you can specify a larger tank. Some purchasers find it desirable to have a fuel fill on each side of the apparatus to expedite filling. Just remember that the fuel fill generally takes up some space at the rear wheel well where SCBA cylinder storage is generally located.

ENGINE AND DRIVELINE

When specifying an engine for your apparatus, there are a couple of important considerations. The first is the size of the engine. Heavier apparatus like aerials and platforms will require a higher horsepower engine. Also, pumpers with larger rated fire pumps (1,750-2,000 gpm) will most likely require a big engine. Often, a truck committee will go for the biggest engine available. This has several adverse effects on the overall apparatus. First, larger engines cost more than mid-size engines, and they are heavier. This might require a heavier front axle and larger front tires, which will reduce your turning radius. The same is true of the transmission and driveline. The added engine horsepower and torque require heavy-duty driveline components. Finally, when you specify a large engine, it sometimes limits the choice of cabs and chassis in which it will fit, which could drive up the overall price. By all means, get an engine that will do the job for you, but avoid trying to assemble a “rocket sled on rails!”

Another consideration is the convenience of getting warranty work done. Investigate the location of repair facilities that can provide the service you need. In metropolitan areas, all of the manufacturers might have dealers, but in some areas of the country, it might be easier to obtain service on one brand than on others.

When specifying an engine, indicate any special cooling system requirements and the type of coolant required. Silicone or “blue-stripe” hoses add longevity over standard rubber hoses. Be sure to include constant torque hose clamps as well. A cooling system filter that contains chemicals to maintain the pH level of the coolant is a good feature to keep the cooling system free of contaminants. Be sure to note any local extremes, such as excessively high or low temperatures, in which the apparatus will operate. The minimum and maximum ambient air temperature in the standard are 32°F and 110°F, which will certainly not fit all purchasers’ needs.

(1) Consider a vertical exhaust stack on units where personnel work around the apparatus at ground level. (Photo by Ron Jeffers.)

You can specify the type of fuel and air filters required if you have special requirements. In most cases, the filters the engine manufacturer specifies will sufficiently protect the engine’s vital fuel system. A fuel/water separator is a worthwhile investment, as it provides the opportunity to drain condensation from the fuel system and sounds an alarm in the cab if water contamination is detected in the fuel. Your department mechanic will appreciate isolation valves before and after the fuel filters to prevent the loss of prime when changing the fuel filters during maintenance.

The requirements for ember separators in the engine air intake have increased in the most recent edition of NFPA 1901. The standard now states that the ember separator must prohibit embers 0.039 inches from passing through. This was primarily because commercial pumpers used in wildland firefighting were catching fire from sucking embers into the air cleaner while pumping. If you have specified a commercial chassis, be sure to check this feature, as some manufacturers are reluctant to make any changes to the air intake system because of warranty issues.

The engine exhaust system must direct the exhaust away from any operating position. Generally, this has led to the exhaust being directed to the right side on mid-mount pumpers. If you are specifying a rear pump panel on the right side (curbside), be sure to have the exhaust directed to the opposite side of the apparatus. Consider a vertical exhaust stack for special service vehicles such as hazardous materials units, rescue trucks, and air supply units, where personnel work around the truck at ground level. There is probably nothing worse than having your haz-mat team be overcome by exhaust fumes while getting dressed to enter a hostile environment! When checking your apparatus, also be sure that the exhaust is shielded near equipment or compartments to prevent excessive heating. If a station exhaust system is installed, specify the correct termination for the apparatus exhaust.

The driveshaft transmits the torque from the transmission to the rear axle. The rating of the joints used in the driveline will depend on the torque and weight of the vehicle on which they are being used. It is a good habit to require in your specifications that the drive-shaft be dynamically balanced before installation. Most manufacturers routinely do this because it reduces vibration from an out-of-balance condition. Some fire departments require that the driveshaft have a containment cage, a couple of steel straps that will prevent the shaft from damaging wiring, and air lines and plumbing under the apparatus if a universal joint fails. I once had a loose driveshaft snap the bottom drain off a hydraulic tank on an aerial that resulted not only in an out-of-service apparatus but also in a rather large haz-mat spill!

As I said earlier, I generally let the bidder propose the axles necessary to carry the fully loaded apparatus. In some cases, the bidder must decide if a single rear axle will suffice or if tandem axles are required. This can be an extremely important decision on heavier apparatus such as aerials, quints, mobile water supply units, and large rescue trucks. Although the tandem axle will obviously cost more (because of the additional equipment) and will generally cause the apparatus’ overall length to increase, consider the benefit of additional braking on the second axle for both stopping and parking. The maintenance costs of the additional tires may be offset by the maintenance savings on suspension and brake parts on the tandem axle vs. a heavy single-axle vehicle.

BRAKES, AUXILIARY BRAKING DEVICES, AND SUSPENSION

Generally, two basic types of brakes are used on fire apparatus: disc brakes and S-cam drum brakes.

Disc brakes have a two-sided disc vertically mounted that spins with the wheel. A caliper holding the brake pads surrounds a portion of the disc. When the brakes are applied, the caliper squeezes the brake pads against the disc, slowing down its rotation.

S-cam drum brakes have standard brake shoes that are anchored and pivot at one end, with a roller attached to the other end. When the brakes are applied, the S-cam turns and the roller moves up an incline, expanding the brake shoe linings against the inner surface of the brake drum.

Both types of brake systems stop the vehicle by creating friction between the brake linings and the rotating disc or drum. This friction creates heat that causes problems for the brake system. When the brake linings heat up, they tend to become glazed, which increases stopping distance. This problem is more pronounced in drum brakes for two reasons:

1. The heat is contained within the enclosed drum as opposed to the open spinning disc, which is out in the free air and well ventilated.

2. When the brake drum is highly heated, it expands slightly, which reduces the pressure against it by the brake shoes.

Overall, disc brakes tend to run cooler and stop better, but they have had some reported maintenance problems such as shorter life. Drum brakes tend to heat up and fade during long operations, but a larger friction surface area of shoe contact reportedly makes them better as parking brakes on the rear axle. Some departments specify disc brakes on the front axle and drum brakes on the rear. In either case, ask your salesman about premium linings, which are most suitable for fire service use.

The braking systems on heavy fire apparatus are typical air brake systems much like those found on commercial, over-the-road trucks. One difference is that fire apparatus require a quick buildup section in the air reservoir to allow the apparatus with a discharged air system to move within 60 seconds.

The system components start with an air compressor mounted to the engine to provide the compressed air for the brake system. The ambient air drawn into the compressor and compressed becomes very hot. When this air begins to cool in the reservoir, moisture is released. Moisture in an air brake system can cause serious malfunctions, as small orifices and air lines can become blocked or malfunction, causing air leaks from moisture that turns to ice. Fire apparatus are required to have an air dryer, which has a desiccant filter to remove moisture from the air. Also required are an automatic moisture ejector and a pressure protection valve that deactivates air-operated accessories such as air horns when the air system drops below 80 psi.

You can specify an isolated air reservoir for the air horns to help maintain a sufficient quantity of air for their activation. You should drain the air tanks periodically as part of an operator preventive maintenance plan. To expedite this process, manufacturers can install pull-cord bleeders or automatic bleeders in place of the standard petcocks.

The apparatus can be equipped with an auto-ejection air intake to keep the brake system topped off from the fire station compressor or a small on-board air compressor powered from an electrical shore line.

The air brake system on a fire apparatus cannot be used to provide compressed air for emergency operations such as air lifting bags or air chisels. The compressor cannot supply the quantity of air required for these tasks. One thing you can do is provide an air chuck, hose, and tire inflation tool to add air to the tires or inflate pressurized water extinguishers from the air brake system.

AUXILIARY BRAKING SYSTEMS

In addition to the foundation brakes, apparatus will require an auxiliary braking system if the GVWR is more than 36,000 pounds. The auxiliary braking systems help stop the vehicle faster and extend the life of the foundation brakes.

All auxiliary braking devices can interface with the anti-lock braking system (ABS) required on all fire apparatus. If the ABS detects a wheel lockup, it will disengage the auxiliary braking system to help avoid a skid.

The four types of auxiliary braking devices in use on fire apparatus are the electrical driveline retarder, the hydraulic transmission retarder, the engine compression brake, and the engine exhaust brake. Let’s go over each type and discuss their pros and cons.

The electrical driveline retarder has rings of coils that make up a powerful electro magnet. A rotor (or rotors) is attached to the driveshaft in close proximity to the coils. When activated, the retarder engages in four progressive levels of strength, creating a magnetic field that slows the rotors. This type of retarder is the fastest to apply and release as it operates at the speed of electricity. This can be extremely important if the ABS system detects a wheel lockup and disengages the unit. It is extremely effective as an auxiliary braking device. Control is generally achieved by pressure on the brake foot valve, but some have been wired to start applying when the accelerator is released. On the down side, it is probably the most expensive of the systems, it adds weight to the driveline, and it can momentarily draw up to 200 amps on full application. However, a properly sized battery bank can compensate for the amp draw.

A hydraulic transmission retarder has a rotor-stator chamber attached to the rear of the automatic transmission. The rotor, with fins attached, turns with the output shaft of the transmission. When the device is activated, the chamber fills with transmission fluid, slowing the turning of the rotor. The transmission retarder is also a very effective auxiliary braking device because it is attached directly to the driveline after the transmission. It can be programmed to apply either entirely by brake pressure or a percentage of application when the accelerator is released.

One of the drawbacks of the hydraulic transmission retarder is that it generates heat in transmission fluid that requires an additional cooler. The heat is then transferred from the cooler into the engine’s cooling system. This could create a problem in hotter climates. Another concern is that the hydraulic transmission retarder is not quite as fast releasing as the electric retarder. This might lead to a problem if the driver encounters a wheel lockup and there is a delay in the release time.

Changing the application spring when the retarder is installed can program the maximum retardation power of the unit. It is less expensive than the electrical retarder but more expensive than the other two.

The third type of auxiliary braking device is the engine compression brake. The engine brake turns the engine from an energy-producing power plant to an energy-absorbing air compressor. In a diesel engine, the piston typically moves up, compressing and heating the air in the combustion chamber. When it reaches the top, fuel is injected into the hot air mixture, which ignites and drives the piston down on the power stroke. When the engine brake is activated, the piston compresses the air in the cylinder, but instead of fuel spraying in to create power, the exhaust valves open and the air is exhausted. All of the energy needed to compress the air is absorbed, slowing down the engine. The engine brake generally has dash control switches that turn the system on and off, as well as a switch for low, medium, and high settings. Releasing the accelerator activates the engine brake.

The exhaust brake is the simplest and least expensive of the auxiliary braking devices. It is installed between the exhaust manifold and the exhaust pipe and restricts the exhaust exiting the engine when activated, causing the vehicle to slow down. Some engines are not compatible with an engine compression brake, so an exhaust brake might be a good alternative.

The retardation effort of the engine brake and the exhaust brake is somewhat less extreme than the two driveline units. Both slow the engine before the torque converter and automatic transmission, whereas the other two have a direct effect on the turning of the driveshaft.

Although all of the auxiliary braking devices interface with the ABS system to help avoid skidding, it is extremely important that the apparatus drivers read and observe all operator instructions about the discontinuance of their use in slippery conditions.

ABS SYSTEMS AND Automatic Traction control

An ABS system is required on all apparatus. Wheel sensors detect wheel lockup and apply and release the brakes on the affected wheel up to five times per second. The most important difference in an ABS- equipped vehicle is driver training. Drivers must be taught to firmly apply the brakes and let the computer do the work. This is directly opposite from the way most of us learned to stop a skidding truck, which is to pump the brakes. The ABS system can interface with all of the auxiliary braking devices to disable them in case of wheel lockup.

When specifying an ABS system, consider automatic traction control (ATC), which can be incorporated as part of the system. The ATC system detects wheel spin during acceleration and applies braking to the slipping wheel to regain traction. The ATC system generally comes with an override switch so the driver can allow the wheel spin if the apparatus is stuck in snow or mud.

SUSPENSION

Apparatus suspension also presents several choices for the purchaser. In the past, the typical heavy truck suspension used on fire apparatus consisted of leaf spring assemblies on the front and rear axles. Although there is absolutely nothing wrong with this type of suspension, some purchasers desire an improved ride and improved handling. The improvements were generally not sought out of comfort but to reduce damage to the apparatus body and equipment from severe road shock.

Purchasers often specify air-ride rear suspension. Large, rubber, inflated air bags provide a softer ride than leaf springs. Some report that an apparatus using air-ride suspension feels like it is leaning on turns (much like a tour bus), but it definitely provides a softer ride. This can be critical for a tillered apparatus where the tillerman is sitting directly over the rear steer axle and there is little head room in the tiller cab.

Independent front suspension is now becoming very popular in the fire service. Instead of having a single axle beam running across the front, independent axles are attached using “A” frames, much like a car. Some models use torsion bars to provide the spring action; others have coil springs. Having driven both types over rough terrain, the independent suspension gives a better ride in the apparatus cab. Independent tests by one manufacturer showed a consistently shorter stopping distance with this system, which may have been associated with larger disc brakes used in the application. Airport crash trucks have used independent suspension for a long time, primarily for the stability it provides when going off-road.

While we are talking about brakes and types of suspension, another option you may want to consider is an automatic lubrication system. This system has a reservoir containing chassis grease, a pump, and plastic lines that carry grease to remote areas of the apparatus. Small plastic lines replace the grease fittings in the chassis components that require periodic lubrication such as leaf spring pivot pins, brake parts, and steering joints. The pump is programmed to inject a predetermined amount of grease into these lubrication points at certain intervals. Lack of proper preventive maintenance is probably the leading cause of component failure, and keeping them lubricated can result in a large cost savings during the life of the vehicle. This is particularly true of leaf spring shackle pins. If the pins “freeze up” because of a lack of lubrication or because of corrosion caused by road salt, they fail to pivot, which causes the leaf spring to absorb all of the road shock, resulting in cracked and broken springs. One major city with very bad streets tried a number of preventive maintenance measures to avoid broken leaf springs. Installing an auto-lube system has all but cured the problem.

TIRES AND WHEELS

The last axle components are the tires and wheels. Once again, it might be better left up to the bidder to propose the proper tire size and load range. The purchaser can specify a brand or simply indicate the type of tread desired. In areas of snow and ice, most specify mud and snow tread on the rear tires and highway tread on the front. Balance the tires to improve performance, especially at highway speeds.

The manufacturer will need to know if you desire the standard steel painted wheels or polished aluminum. Some have felt that aluminum wheels simply enhance the apparatus’ appearance. Although it generally does, an additional benefit is that aluminum can absorb heat, which helps draw it away from the brake system. In either case, “dress up” kits consisting of stainless steel lug-nut covers and hub covers are available to enhance the appearance.

(2) The rear portion of the cab of this rescue unit is used as an equipment compartment. The personnel ride in the rescue body. (Photo by Ron Jeffers.)

In areas of the country where ice and snow are routine, skid chains are used in addition to mud and snow tires. Installing full-wheel chains can be quite a task, especially if the person installing them is not familiar with the process. Although full chains provide good grip in ice and snow, they can do a lot of damage to the wheel wells and compartments if they are driven for any period of time on dry roads. When one of the cross bars breaks, it just whips the apparatus unmercifully. If you are responding when this happens and can’t discontinue the response to remove the chain immediately, the damage can be severe. One answer to this problem is using automatic skid chains.

(3) A raised roof crew cab makes it much easier to get in and out of the cab. (Photo by Ron Jeffers.)

Several manufacturers make automatic skid chains. All work in a similar manner. The automatic skid chain units are mounted to the rear axle, usually using the “U” bolts that hold the springs to the rear axle. The units comprise an air chamber (similar to a brake chamber), a connection linkage, and a pivoting swing arm with a small rubber-coated wheel with various lengths of skid-chain attached. In the “off” position, the spring inside the air chamber holds the chain wheel up and out of the way. When the driver activates a dash-mounted switch, an air solenoid inflates the chambers, causing the chain wheels to swing down and contact the inside of the spinning tire. As the chain wheel spins, it “slings” the short lengths of chain under the tire, creating a rotating skid chain.

The great thing about automatic skid chains is that they are readily available any time the driver needs them. When the main streets are plowed dry (which could cause regular chains to break) and you turn into a shady side street, you might encounter ice that requires the use of chains. Or, you might begin to respond and realize that the temperature and moisture on the road have presented a “black ice” coating that is very dangerous. Flip the switch, and you’ll have the traction of skid chains.

Follow the manufacturer’s instructions. Many limit the top speed while using automatic chains to 25 to 35 mph. You may wish to have the apparatus manufacturer place a small instructional plate near the switch reminding the driver of this limitation.

APPARATUS CAB FEATURES

When specifying apparatus cab features, first determine how many firefighters are going to be seated during a response. The manufacturer must provide seating with seat belts for each riding position. The number of riders will not always dictate the size of the cab. Some rather small cabs pack in 10 seating positions, in which case you hope the “big guys” make the next rig out!

In apparatus purchasing, everything is a trade-off. If you specify a large roomy cab, it adds to the wheelbase and the apparatus’ overall length, which reduces maneuverability. In career departments, where staffing is historically low, a smaller cab is generally the norm. A problem I often see in the volunteer sector is planning for a response on “meeting night” when everyone is there, even though the normal response might be five firefighters at most.

If size and price are not problems, you can get the longest cab available and put only six seats in it. It is much more comfortable donning SCBA and getting ready to fight a fire when you are not packed shoulder-to-shoulder. This type of setup also allows for the installation of a compartment in the cab to hold EMS equipment or sensitive instruments like thermal imaging cameras or carbon monoxide or gas detectors. If you are installing rechargeable equipment in a cab compartment, specify the 12-volt wiring that is necessary or, preferably, a 110-volt power strip attached to the shore line.

Cab sizes and seating configurations will vary from manufacturer to manufacturer. This is where your research comes in. You cannot determine how comfortable or functional a cab is by looking at brochures. Get out there with your friends and actually sit in the cab. You can do your research at trade shows; or, ask the salespeople where they have delivered an apparatus of similar design, and contact that department. I’m sure that it will share its opinion with you.

If overall height is not an issue, a raised roof in the crew cab is a great addition. Even in a smaller cab, the raised section makes it much easier to stand up in and get in and out of the cab. The raised section can be equipped with windows, which add light and increased visibility to the crew cab. Just remember, if windows are on the front of the raised section, cab light bars cannot flash into the windows.

(4) When specifying an extended cab, you can use the lower portion on each side as compartments. The upper portion of the compartment is transverse for equipment such as hooks. (Photo by Ron Jeffers.)

Comparison measurements can be made from the center line of the front axle to the back of the cab. If you don’t have any size restrictions, an extended cab is obviously more comfortable and generally affords the opportunity to add cab compartments at the rear. Some of these can have a transverse section at the top, which is extremely useful for storing long items, like a pike pole, that a firefighter can retrieve when exiting the cab. Generally, the lower portion can be made deep enough for SCBA cylinder storage racks, or it might be a good location for a handlight and irons for a search team.

EQUIPMENT MOUNTED IN THE CAB

NFPA 1901 indicates that any tools or equipment located in the riding compartment must be secured in brackets or in a latched compartment capable of withstanding a 9-g deceleration force front to back and 3-g deceleration force side to side. The basic, nonscientific mathematics of g forces is the weight of the object times the g forces. So, a 12-pound sledgehammer would require brackets that can hold 108 pounds front to back and 36 pounds side to side. Standard tulip clips don’t qualify! There are commercially available brackets for almost all shapes and sizes of tools that do qualify, or the tools can be mounted in a compliant compartment. The safest way is to keep the tools out of the riding compartment and mount them externally or in an outside compartment.

(5) Do not carry loose equipment in the riding compartment. These irons are mounted to the bumper extension, which makes them readily available. (Photo by Ron Jeffers.)

While we’re talking about mounting equipment, SCBA in the cab has also presented a problem. For many years, the standard required collision restraint straps that meet 9-g deceleration requirements. The problem with the old spring clips with straps was that firefighters refused to attach the collision-restraint strap, leaving the 4,500-psi cylinder held by just the spring clips. In a collision, they were dislodged. The NFPA Apparatus Committee offered two ideas to solve the problem. The first was to do away with the spring clips and install a clamping device that would have to be activated when the SCBA was placed in the seat. Although very effective, some felt this would add significantly to the price of the rig. The committee decided on a performance-type requirement, which is that the SCBA cannot be placed in the bracket without attaching the compliant collision restraint. This has led to the 45 , “V” shaped brackets and strap. You can order the clamping type if you want, but the “V” clip is less expensive and complies with the standard.

(6) Hooks are mounted to the rear of the cab, where they are accessible without having to open a compartment. (Photo by Ron Jeffers.)

Some progressive departments have removed the SCBA from the cab completely. They have found that the additional 30 seconds it takes to dismount and don the SCBA allows the officer time to give his report and formulate an attack plan with the crew. It is obviously safer during the response and while getting into and out of the cab as well.

Another area of confusion is the interpretation of the number of SCBA needed. The standard states, “one SCBA for each assigned seating position but not less than …” and the minimum number is inserted for each type of apparatus. This does not mean that every seating position needs an SCBA or that the SCBA must be placed in a seat. This just means that the fire department determines which of its members dons SCBA; it has nothing to do with mounting them in the cab.

If SCBA are mounted in the seats, manufacturers can supply “parade panels.” These are flat panels usually held in place with self-fastening strips to cover the SCBA when it is not in use. If the SCBA is going to be donned during a response, obviously the panel will have to be removed before the firefighter sits in the seat. This is more of a visual accessory than a functional one.

SEATS

There are several varieties of material to cover the seats. Vinyl was used exclusively for many years. The problem was, if it was punctured or ripped, it resulted in permanent damage. Out comes the roll of duct tape! Many of the newer fabric-covered seats can be punctured, and the fabric just closes up around the hole. Also, the fabrics used in seats today are extremely strong and rip-resistant. This is the time for research into the fabrics available as well as the color that will complement the interior (without showing the dirt!).

(7) Self-contained breathing apparatus (SCBA) in the cab must be in compliant brackets that cannot hold the cylinder unless the proper restraint is attached. (Photo by author.)

You will notice that all apparatus manufactured in compliance with the 2003 edition of NFPA 1901 have red seat belts. This was done so the officer can visually observe their use. With black belts, you could not distinguish the seat belt from the SCBA straps, handlight straps, or portable radio straps. Another action the committee took was to require a rigid stalk for the attachment end. This places the coupling section of the belt within easy reach of the rider, eliminating the need to dig down next to the seat to find the end. Most manufacturers offer an optional system that indicates if a seat is occupied and the belt is not connected, much like that in the family automobile.

CAB INTERIOR LIGHTING

(8) An SCBA mounted in the driver’s seat is unusual but available. (Photo by Ron Jeffers.)

Cab lighting is another area with many options. Most specifications contain dual red/clear cab interior lights. The red lights are available and can be switched on to preserve your “night vision” when donning an SCBA or buckling your coat. This is especially important when you are going to step out of the cab into darkness. The problem is that most manufacturers routinely wire the white lights to the door open switch. So as you respond with your red interior lights on, everything is fine. But when you arrive at the scene and open the door, the white lights come on, which just killed your night vision! Specify that the red lights be three-way switched, meaning they can be manually activated and come on with the door open. Have the white lights manually switched only. This way, when you exit the cab, the only white lights you will see will be the lower step light and the underbody lights illuminating the ground so you don’t step into a rut, hole, or ditch. You can increase the number of these combination red/clear lights so that there is one over each seating position. That way, you’ll have plenty of light in the cab and each responding member will have one within easy reach. Another good interior light to specify is a gooseneck map light the officer can use for viewing maps or preplans while responding. This can be equipped with a red filter for night vision as well.

SPOTLIGHTS

Cab spotlights, which used to be routine, now must be specified. The mounted lights are convenient for aiming at a target when you are on-scene, but they are a little more difficult to operate for spotting house numbers. Many departments have gone to large, handheld 12-volt lights that offer a point-and-shoot type configuration. Be sure the light has a compliant bracket. It cannot hang from a hook.

(9) Conspicuous red seat belts are now required by the standard. (Photo by author.)

In cabs with side-protection air bags, some mounted lights are not permitted, as they interfere with the air bag’s activation. If you still want a fixed light that is controllable from the cab, some models contained in a clear dome on the cab’s roof are available; they can be controlled electrically from inside the cab, much like remote-controlled mirrors.

RADIO EQUIPMENT

Although I generally recommend that radios be installed locally, consider where you are going to mount your radio equipment because the builder can do some preparation work to expedite and enhance the installation. Some departments specify a radio compartment under or behind the officer’s seat. Most radios have a separate transmitter and a remote control head. It is generally a good idea to have the manufacturer install the wiring for the radio, especially on modern apparatus that have complex wiring systems. The wiring will generally include a full-time fused power line (to hold the radio’s memory) and a switched power line to turn the radio on when the apparatus is started. Request a direct battery ground line as well, to avoid a poorly grounded radio, which could lead to interference. I also recommend that the manufacturer install the antenna(s) on the roof and route the cable(s) to the radio compartment. This will help avoid a radio installer’s pulling down the headliner and drilling into the cab roof, which could lead to leaks if improperly done.

When ordering radio equipment for the apparatus, you must tell the supplier the distance from the radio compartment to the pump panel extension head, if one will be used. On tilt-cab units, this will involve routing the cable to the front of the cab pivot and then back to the pump panel control, which is considerably longer than the standard one that just goes to the back of the cab and out.

BUMPER EXTENSION

Manufacturers can mount the front bumper directly to the front of the apparatus frame or on a bumper extension. A bumper extension is a good mounting location for tools, reels, a winch, hose bins, air horns, sirens, and so on. Generally, the front bumper extension is covered with aluminum treadplate. I always specify that this treadplate be an NFPA-compliant, slip-resistant type. Although this area is not “officially” a step because it is generally too high from the ground and does not have the required handrails and illumination, you know that firefighters will climb on to clean the windows! To most of the fire service, the wiper arms are perfectly adequate “handrails”! Help avoid an accident, and make it nonslip.

The front bumper extension is some prime “real estate” for mounting various options and accessories. Hydraulic rescue tool reels, wire reels, hose boxes, forcible entry tools, and trays are only some of the items you can mount there.

(10) The bumper on this unit flips down to expose the front trash line. (Photo by author.)

When you spec hose boxes, consider employing a grid in the bottom to allow air circulation; drain holes; and, if you desire, a cover. If the hose tray is to be preconnected to a swivel above the bumper, indicate that the cover must be notched to allow the hose to enter the tray with the cover closed. Some hose box specifications call for a hinged bottom or front to allow the hose load to drop on the ground when deploying the line.

Speaking of hose swivels, one problem encountered with these devices is that when the hoseline is charged from the pump panel, the swivel can pivot and hit the cab face. Mechanical blocking devices are available to prevent this. Another help might be to install a gate valve at the bumper location. This way, a firefighter has to charge the line from the position of deployment to make sure all the hose is out of the box and away from the apparatus.

(11) This front bumper extension swivel is blocked from striking the cab by the upright rods installed. (Photo by author.)

A similar situation can occur with the installation of a front suction swivel on a tilt-cab apparatus. Most of the time, the swivel must be in the forward-facing position so the surface of the cab won’t come in contact with it when tilted. Although the manufacturer will generally put a label next to the cab tilt switch, if you really want to prevent an accident, have the swivel electrically interlocked with the cab tilt pump. A sensor installed on the swivel prevents the cab tilt pump from operating unless the swivel is in the correct position. Better to be safe than sorry!

(12) The gated wye installed on this front bumper discharge forces a firefighter to verify that the hose is out of the tray before charging the line. Additionally, it provides a second discharge outlet. (Photo by Ron Jeffers.)

Since the front of the apparatus is usually a difficult place to find enough space for compliant reflective striping, consider a chevron-type marking on the bumper. It is not only more attractive than a plain stripe, it is also more visible. Heavy-duty, painted, steel bumpers are used in some locations.

(13) A position sensor installed at the rear of this front suction swivel prohibits the cab-raise pump from operating unless the front suction is facing forward, preventing damage to the front of the cab. (Photo by author.)

Depending on the location of the apparatus being used and the type of equipment protruding from it, rubber dock bumpers might be a good addition to protect this equipment. In addition, lighted sight rods that mark the ends of the bumper assist the driver in judging turns in tight quarters.

Finally, remember that the front bumper extension was NOT intended to be a platform to lift the apparatus for towing. Many inexperienced tow truck operators have done thousands of dollars worth of damage to the front of the apparatus trying to pick it up from the front bumper. In many cases, you can specify that the front bumper extension be reinforced for towing, but it will certainly add to the cost of the apparatus. The best policy is to research and obtain the contact information of a heavy-duty towing company in your area that has an under-slung wrecker that can pick the apparatus up by the front axle without contacting the bumper area.

CAB TRIM

Sometimes fire departments want to make all of their apparatus look alike. If you want stainless-steel trim bands across the front and down the sides, they must be specified. Another area that is more for durability than appearance is the rear cab wall or roof overlay with treadplate. The rear wall overlay will help prevent damage from road debris hitting the back of the cab while maintaining a pleasant appearance. The roof overlay will provide an element of protection from fire debris and on rear-mount aerials, where a firefighter might step on the roof. Once again, use slip-resistant treadplate on the horizontal roof surface.

(14) This heavy-duty steel bumper has reflective tape in a “chevron” pattern. (Photo by author.)

Cab steps and the cab floor must be constructed of, or overlaid with, compliant material. Rubber floor matting has become very popular, as it helps insulate from noise and heat as well as provides a compliant surface. It should be neatly dressed with metallic molding to hold it down and prevent a tripping hazard.

The two basic choices of mirrors are the longer, narrow “West Coast” style that is generally held at the top and bottom by pivoting brackets and the more square “bus mirror.” Both can have a convex mirror added to improve visibility next to the apparatus, and both have advantages and disadvantages.

The West Coast types are generally cheaper and more easily replaced if broken. The mounting arms can pivot to allow some movement if they come in contact with a fixed object. Drivers who are used to this type of mirror feel that you can see farther behind the apparatus because the mirror is longer.

The bus mirrors are often mounted to the front cowling of the cab, but some can be mounted to the cab doors. The advantage of having the mirrors out front is that the driver doesn’t have to move his head from side to side to view the mirrors, thus keeping his vision primarily forward toward the roadway ahead. One disadvantage of having the right mirror mounted to the cab face is that it is possible that it will be in line with the portion of the windshield where the wiper deposits snow, ice, and rain. Remember, the bus mirrors are mounted with very substantial single arms that are more expensive to install and to replace.

Both types of mirrors can be equipped with heated glass and remote- control adjustments. Remote control can be very important when various firefighters jump into the driver’s seat to respond. Adjust the mirrors before the apparatus moves. It is extremely dangerous to be looking to the rear to adjust a mirror while the apparatus is moving forward.

Another mirror you might consider for safety is a convex mirror mounted over the right front corner of the windshield. This will give the driver a view of what is directly in front of the apparatus, which might be difficult to see from the driver’s seat.

(15) A convex mirror mounted on the front corner of the cab gives the driver a view directly in front of the apparatus. (Photo by author.)

Windows are another area of cab trim that offer many choices. All window glass should be tinted to some degree to aid in cooling. In extremely hot climates, some specify dark privacy tint to help keep the sun out. Roll-down windows in cab doors are fairly standard, but the method of rolling them down varies. Crank windows are generally the standard. I don’t know what it is in the fire service, but these cranks are often stripped or broken! Electrically operated roll-down windows are very reliable and also give the officer or driver the option of closing windows that were left open.

A couple of other window features include sliding cab-side windows for ventilation and small rear “opera” windows in the back of the cab. They allow the crew to get a view of the approaching traffic before opening the cab doors. If a wide body is installed, such as on a rescue truck, consider a small convex mirror mounted near the front of the crew cab doors to give the same indication.

CLIMATE CONTROL

Climate control, including heating, air- conditioning, and ventilation, is an important feature on all apparatus. With the advent of the fully enclosed cab and full bunker gear, firefighters can become uncomfortably warm in the apparatus cab.

The first thing you should consider is proper ventilation. Roll-down windows in the cab and crew cab doors are rather standard, but sliding side windows in the cab are optional. Some locations have power roof vent fans installed to remove the heat that gathers at the ceiling. In any case, the more ventilation that can be provided in the cab, the better!

Despite what you might have heard, air- conditioning is not required in the standard, but it is certainly an excellent feature where the climate is warm, even if only in the summer. The best justification for this option is that it can help rehabilitate a crew that has been fighting a fire in personal protective gear. In areas of the country where climates are hot, it is essential, especially when you are riding next to a 400-hp engine that is generating a lot of heat in the cab.

When specifying air-conditioning, consider specifying optional insulation in all of the void spaces in the cab walls and ceilings. This will help keep the cab cool. Also, although the color of the apparatus is strictly up to the purchaser, a white roof will help reflect some of the radiant heat away from the top of the cab. Conversely, a black roof might help with heat absorption in cooler climates.

Don’t forget the crew cab when specifying cab heaters. Auxiliary heaters, generally installed under the crew cab seat risers, will help maintain a level of comfort when responding to or returning from a call. Some departments specify shutoff valves for the additional heaters to isolate them in the summer. Don’t forget to open the valves as winter approaches!

CAB CONTROLS

Another area of important information you should include in your specifications is the mounting location of various switches and instruments that will be used during a response. Obviously, the driver will have all of the gauges, controls, and switches required to operate the vehicle on the road. Additional controls should be left up to the officer or firefighter sitting in the officer’s seat.

16) Pump shift controls mounted in a dark location (like under the dash) should be illuminated. (Photo by author.)

One of the most interesting times of the preconstruction conference is deciding the location and operation of the various audible warning devices. Although the driver should have access to these controls, it should be the officer’s responsibility to operate sirens and air horns.

You can specify a selector switch that allows the driver to switch between the vehicle’s “city” horn and the air horns from the steering wheel. Since the driver should keep both hands on the wheel at all times, it is a dangerous practice to install lanyards mounted to the ceiling to sound the air horns for the driver.

Foot switches are often specified for the siren(s). One problem is that some cabs are very tight, which can result in inadvertently stepping on the siren button. To avoid this, you can request that the siren floor switches be activated only when the master warning light switch is “on.” This accomplishes two things. First, you won’t scare the heck out of some old lady sitting at a red light, and second, if you forget to activate the warning lights on a run, you’ll know just as soon as you try to crank up the siren!

Some of the other controls better left up to the officer are things like floodlights, the control for traffic directional arrows, radio equipment, and any other switch not directly related to operating the vehicle. Some departments install a second “master warning light switch” on the officer’s side so the officer can activate the lights if the driver forgets.

An officer’s side speedometer can be a good addition to help keep the driver under control. Many manufacturers offer an “information center” on the officer’s side that displays an array of information including speed, outside temperature, time, stopwatch, and direction.

One thing I have observed quite often on apparatus is that the pump shift control is located basically under the dashboard. You should be absolutely sure of two things if this is the case: that the pump shift indicator lights are easily visible from the driver’s position and that the pump shifting instructions are illuminated for night operation. These are important safety features that should receive your attention.

Another important safety feature I have been “preaching” about for many years is the location of the parking brake control. Most manufacturers locate it near the driver’s right knee. The problem with this location is that in a modern tilt-cab apparatus, the engine is under the “dog house” between the officer and the driver. If the driver is disabled for any reason, the officer cannot reach the parking brake control to stop the apparatus while seated and belted. Ironically, while writing this article, I was sadly informed of the line-of-duty death of a 38-year-old Memphis (TN) firefighter who was at the wheel of an apparatus and collapsed while driving. The e-mail description of what happened stated: “Another fire fighter heroically jumped over the center console, grabbed the wheel, and brought the apparatus to a stop.” In a high-speed situation, the officer performing this heroic act could have sustained serious or fatal injuries.

To avoid this problem, specify that the parking brake control must be easily reached by the driver or officer while seated and belted. A secondary means of activating the parking brake from the officer’s side will be an acceptable alternative. By doing this, you can keep your people seated and belted and provide an extra measure of safety.

Speaking of safety, the 2003 edition of NFPA 1901 requires red seat belts so the officer can observe if his members are belted. Most manufacturers can install a seat belt alarm to warn of occupied seats not in compliance.

The standard requires a “Do Not Move Apparatus” light to warn the driver that he is not in a secure position to move the apparatus when the parking brake is released. This is generally wired to the cab doors, compartment doors, light tower, folding steps, and aerial jacks. I have seen many installations where purchasers specified a rotating or strobe light in the center of the windshield. This temporarily blinds the driver if the light activates during a response. If you desire this type of light, put a shield on the side that faces the personnel in the cab. It will still be very effective without causing a problem. Also, an audible alarm is not required in the standard. If you desire the full warning, you must specify it.

CAB OPTIONS

We have all experienced the inside of a cab littered with map books, preplans, building information, and various other documents we feel are necessary. Consider organizing all of this equipment in a safe, orderly fashion.

Manufacturers can supply a variety of map book holders from slotted trays to actual compartments with hinged doors. Since you generally don’t know the inside cab configuration before the bid, you might wish to make this a performance item in the specifications. Consider a statement such as: “a slotted map tray to hold three three-inch binders shall be supplied and mounted in the cab. The tray shall have a compliant restraining device to hold the binders in place. The exact design and location shall be determined at the preconstruction conference.” This way, you will have the necessary equipment without having to reinvent the wheel.

Many new apparatus do not have a glove compartment. A nice addition is that of a writing desk mounted to the dashboard across from the officer. Specify that it have a hinged lid to hold writing paper or forms, a lip edge to prevent writing instruments from sliding off, and a clip to hold papers. This is quite handy for the officer, who can clip the response ticket right in front of him and have a surface to jot down any additional information.

Some departments have taken this a step further and installed a laptop computer docking station in this location for the officer to send and receive data from dispatch. Just remember, anything mounted in the cab must be secured in accordance with the standard.

Another cab option is a 12-volt power plug, formerly known as the “cigar lighter plug.” This can be quite handy for any 12-volt accessory such as a cell phone charger, a plug-in spotlight, or a power supply for a computer temporarily located in the cab for an incident.

Raised mounting plates on the engine cover will facilitate mounting items such as rechargeable lights and radios without drilling into the engine cover itself. In many apparatus, sensitive electronics are located in the space under the engine cover, and drilling could be disastrous.

Shore line power (120-v) is another good addition to the inside of the cab. A power strip for rechargeable accessories could be located on the engine cover and wired to the auto-eject power line. This will keep items such as portable radios and thermal imaging cameras ready to go while in the station. On units with a generator, a transfer switch can be installed to transfer these outlets from shore line to generator power when you arrive on-scene. This is an expensive option and generally is not needed. If you think you might be at the scene of an incident for a long time and might need to recharge your accessory batteries during this period, you could just plug a short extension cord powered by your generator into the shore line inlet to accomplish the same thing.

Backing up the apparatus can be one of the most hazardous times for the driver, especially if he is alone in the cab. A few safety features might assist in this endeavor. A backup camera mounted to the rear of the apparatus with a small video display in the cab shows what is directly behind the vehicle. This could include objects, other vehicles, and people. The video cameras come in black and white as well as color; some also have sound. On some apparatus, a second camera added to the right side helps the driver see what is next to the apparatus. One tip for rear-mounted cameras is to include a heavy-duty treadplate enclosure around the camera. Most are rather fragile and, when mounted to the rear of the apparatus without protection, are prone to damage from hose couplings or a person’s stepping in the area of the mount, especially when an aerial turntable is at the rear of the vehicle.

Another safety feature is called a backstop device. This unit will actually apply the apparatus brakes if the sensor comes in contact with an object or person. It activates in two ways. The standard method has a rubber sensing bumper mounted to the rear edge of the apparatus. Contact with the bumper activates the brakes. The second method uses electronic sensors to activate the brakes when an object comes within their set range. This could be an important addition for a mid-mount aerial device that hangs off the back of the apparatus. In either case, the driver must reset the system from the cab before continuing to back up after the brakes activate.

LOW-VOLTAGE ELECTRICAL SYSTEMS

The heart of the 12-volt system on an apparatus includes the batteries that provide the power to start the engine and keep it running. Two basic 12-volt batteries are currently used: the 8-D (bus battery) and sets of smaller Group-31 batteries. The models refer to the physical size of the batteries, not their ratings. Although there are many facets of battery selection, I’ll briefly go over the requirements and ratings.

(17) The rubber bumper located at the rear step of this apparatus has a sensor for the backstop device. If it contacts an object while in reverse, it locks the vehicle brakes. (Photo by Ron Jeffers.)

The typical configuration in a fire apparatus is two 8-D batteries or four or more Group-31s. There are two measurements (other than physical size) to consider when specifying vehicle batteries. They are cold cranking amps (CCA), which is the output available at 0 F to crank the engine and reserve capacity (RC), which is the number of minutes the battery can supply 25 amps until the voltage drops one volt (without the alternator operating). Also, keep in mind that 25 amps is multiplied by the number of batteries, not their size.

A typical 8-D battery has 1,400 CCA and 450 minutes of RC. Group-31 batteries can have a rating of 650 to 900 CCA and approximately 210 minutes of RC.

Two 8-D batteries will provide approximately 2,800 CCA to start the apparatus and 450 minutes of RC at 50 amps of draw.

Six Group-31 batteries, referred to as a “6-pack,” can provide up to 6,000 CCA for starting and 210 minutes of RC at 150 amps. As you can see, the six Group-31 batteries give superior performance for starting and three times the output in reserve capacity amperage.

Three Group-31 batteries will fit in approximately the same battery box space as one 8-D.

When specifying batteries, consider maintenance-free batteries with screw stud terminals. Mount them in ventilated battery boxes that are free from road splash. The standard indicates that if the batteries are not accessible with the cab down, jumper studs must be provided. Some departments have jumper plugs installed so it is easier to jump-start the apparatus if the batteries fail.

The apparatus batteries are required to have a way of maintaining their charge when the apparatus is in the station. A simple polarized plug an external battery charger can plug into and an on-board battery charger that receives power through a shore line plug are two ways to achieve this. These onboard chargers usually have a visual display to indicate the level of charge in the batteries. When specifying a charger, be sure to get one that has an output capacity large enough for your battery pack. If you specify the 6-pack, a 30- or 40-amp charger is best.

Many departments specify that the shore line have a plug that automatically ejects the cord when the apparatus starts. If this is the case for you, get the model that has a relay that disconnects the load before it ejects the plug. This will help prevent burned electrical prongs on the inlet caused by the arc produced while disconnecting the plug under load.

Also, bear in mind that shore-line plugs come in various capacities. If you are powering only a battery charger, a 15-amp plug might be sufficient. If you have rechargeable lights, radios, or an on-board air compressor attached to the shore line, you should use a 20-amp model. If you use the shore line for heavy draw appliances such as a block heater or air-conditioning, specify a 30-amp auto-eject.

NFPA 1901 doesn’t specifically dictate the size of the alternator that must be used, but on today’s modern apparatus, you should research the largest alternators that will fit on the engine that powers your apparatus. The standard requires an alternator and wiring large enough to handle the “minimum continuous electrical load” at idle and 200 F under the hood.

The minimum continuous electrical load is defined as the following:

• Engine and transmission electronics;

• Marker, clearance, and headlights;

• Step lights and 50 percent of the compartment lights;

• Minimum warning lights (blocking right of way);

• Apparatus radio at 90 percent receive and 10 percent transmit;

• Pump and aerial operations; and

• Other loads defined by the purchaser as essential.

Also be aware of the alternator’s performance curve. An alternator with a high rating might need to turn at a very high rpm to attain that output. Low rpm performance could be much more important than maximum output because the apparatus idles so much. The manufacturer can easily provide the alternator’s performance curve for your evaluation.

Another requirement states that a load management system must be provided if the total connected load (all electrical appliances) exceeds the alternator’s output at idle. That will probably include most apparatus. A load manager shuts down or “sheds” preselected circuits when the electrical system goes into a state of discharge. Circuits that might be considered nonessential-such as air-conditioning, heater fans, some compartment lighting, and warning lights that are not part of the basic warning light package-can be shut down in stages to maintain the system balance. As the alternator starts to charge again, the circuits are reintroduced in reverse order. Items on the minimum continuous electrical load list cannot be load managed.

When specifying your apparatus, request an electrical load estimate while responding and operating on-scene. This will provide you with a good planning tool for outlining your electrical system.

Reducing the amperage load on the 12-volt system will help keep your apparatus “healthy” and running well. One thing that can help is the use of light-emitting diode (LED) lights on the apparatus. In addition to warning lights, you can specify all of your DOT-required lighting, such as marker and clearance lights, stop lights, turn signals, and running lights, as LEDs. When specifying turn signals, use amber arrow- type LEDs. They are the most identifiable to the driving public, especially with all the other flashing lights on the apparatus. Manufacturers can mount additional turn signals on the lower rear cab corners to warn drivers who “sneak up” next to you and high on the rear compartment face where they can easily be seen over cars ahead.

VISUAL WARNING DEVICES

A radical change took place in the 1996 version of the 1901 standard in relation to warning lights. It determined that the minimum requirement of the previous standard was not sufficient to provide visual warning to the drivers of vehicles with more noise- insulated vehicles.

To better define the necessary warning lights, divide the apparatus into zones (A, B, C, and D), starting at the front (A) and moving clockwise around the vehicle. In addition, divide the apparatus into upper and lower warning light sectors.

The output of the warning lights in each zone and each sector has two different requirements, requesting right-of-way (responding) and blocking right-of-way (on scene). The position of the parking brake controls these two modes.

Light output in each zone and sector is measured in a fan-shaped pattern at 19 points at a distance of 100 feet from each side of the apparatus. The manufacturers have to certify the warning light system as meeting requirements for intensity and number of flashes, and so on. They can accomplish this in one of three ways:

1. Test each vehicle manufactured with special equipment.

2. Perform mathematical calculations on each vehicle using data from the manufacturers of the various lights.

3. Install a group of lights in the locations determined by the lighting manufacturer and pass the lighting manufacturer’s certification on to the purchaser.

This is what has led to “packages” being specified for the upper and lower sector of the apparatus. A lighting manufacturer will provide a list of its products for the upper section of each zone and the lower sector that will be certified to meet the standard. You may use one manufacturer in the upper zone and a different in the lower, but you can’t certify the system with different manufacturers’ lights in the same upper or lower zone. Once you meet the minimum requirements of the standard with one manufacturer’s product, you can then mix and match any additional lights that you want.

Another goal of the standard was to basically define the “outline” of the apparatus with warning lights. Required are upper warning lights at the front and rear of the apparatus. If you use rotating lights, they will cover the upper sides as well. If you use directional lights, such as strobes or LEDs, you also have to provide for side-facing lights, such as on the top rear corner of a rescue body.

The lower zone requires a minimum of two lights in the front, two in the rear, and two on each side. If the distance between the front and rear side lights exceeds 25 feet, an intermediate light must be installed. The side lights are required to be mounted forward of the centerline of the front axle and rear of the centerline of the rear axle.

For the first time, the standard spells out various colors in each zone. It has a disclaimer that the state statutes shall supersede the standard if they are different. The following are the basic colors and zones:

• Red or blue in any zone at any time;

• Amber in any zone while on-scene, but limited to the front while responding; and

• Clear to the front and sides while responding, prohibited to the rear. All clear warning lights must shut down while parked on-scene.

Contrary to what some manufacturers might tell you, the NFPA does not require an amber light to the rear. The reason some units have amber is that their red lights do not have sufficient output to satisfy the zone requirements while on-scene. If your state requires red lights only, or if you want red only, the addition of another light or a different model will usually solve the problem.

The basic warning light package cannot be load managed, but any additional lights you add can-for example, you may want to use one manufacturer’s LED lights to meet the standard but you want to add some rotating light bars over the crew cab doors. This is perfectly alright, and you can load manage the extra lights to shut down if the apparatus goes into discharge.

(18) Traffic-directing lights are very popular. Be sure that they are recessed or protected from damage. (Photo by Ron Jeffers.)

A package can also include a rear traffic-directing arrow stick if it activates with the upper warning lights. These lights are effective for warning vehicles approaching from the rear to merge into a different lane. When mounting these types of lights, be sure to indicate that they should be flush-mounted or protected with a treadplate shield, especially on a pumper. If it is just mounted to the back, a hose coupling will quickly break it.

Another light that can enhance the safety of your vehicle is a third brake light in the upper center of the rear of the vehicle. A third brake light has been added to most cars and is effective in gaining drivers’ attention. Keep in mind that the auxiliary braking device can be wired to activate the brake lights.

The standard calls for a master warning light switch that provides power to the other warning light switches. When all the warning lights are left on and the master switch is activated, all of the warning lights come on at once, which causes the alternator’s heart to skip a beat. You can specify a warning light sequencer that will turn the lights on and off at half-second intervals. Not connecting all of the load at once reduces the shock to the alternator.

The type of lights used varies widely. Most of the rotating varieties have halogen bulbs. These lights generally have higher amp draw than the strobe or the LED types. In addition, bulb life is somewhat limited, resulting in maintenance problems. Halogen rotators do, however, provide excellent lighting in all directions, and you have the added benefit of the light flashes bouncing off buildings, street signs, and so on.

You can also specify oscillating-type lights as halogen or LED. These lights mount flat, and the reflector sweeps a pattern that flashes “around the corner.”

Strobe lights have been in use for many years. They generally use less power than the halogen type but require a high-voltage power pack to fire the strobe. Strobe bulbs usually diminish in output over time and must be replaced.

LED warning lights have swept the fire service! They have gone through numerous “generations” over a short time and now have optics to enhance their performance.

Some of the advantages to using LED warning lights follow.

• They have a very low power draw.

• They have an estimated 100,000 hour longevity, increasing reliability, and reduced maintenance costs.

• They are available in all popular configurations.

• They don’t use colored filters that reduce output.

Some of the disadvantages follow.

• LEDs cost more than halogen or strobe warning lights. Red and amber have come down in price. Blue is more expensive, and green is extremely expensive.

• Clear (white) is not as effective as halogen for backup lights, etc.

• The most effective view is “straight on.” Effectiveness is reduced as you move off to the side. The lighting manufacturers are using various optics to increase the width of the beam.

AUDIBLE WARNING DEVICES

The first audible warning device we consider is a siren. The siren specified must comply with the output requirements of the SAE standard. A siren is an effective warning device because it crosses the entire spectrum of human hearing. If a person is tone-deaf to one particular part of the sound spectrum, a siren will rise and fall above and below that point.

Sirens can be electronic or electro-mechanical. Electronic sirens use an electronic circuit and amplifier to produce a siren sound through a speaker. The electro-mechanical type uses a heavy-duty 12-volt motor that spins a rotor inside a slotted cage, producing the familiar rise and fall of a mechanical siren.

(19) Twelve-volt scene lighting can be mounted on the sides of the cab or body to illuminate the area around the apparatus. (Photo by Ron Jeffers.)

Mechanical sirens are very effective but have large power requirements. Cranked up to the max, a mechanical siren could require 100 amps or more. In the current age of electronically controlled engines, transmissions, and anti-lock brakes, the voltage drop could affect the other electronics in the vehicle, especially if a heavy battery pack and alternator are not provided.

Electronic sirens generally cost less to install and are easier on the apparatus electrical system. They also provide a microphone for public address announcements and a radio position to amplify the apparatus radio.

(20) Another type of 12-volt scene light is mounted over the cab roof as a “brow” light. (Photo by Ron Jeffers.)

Siren manufacturers have developed electronic versions of their electro-mechanical sirens. The units produce sound much like the big mechanical types, can ramp up and down, and have an electronic brake sound. Additionally, they provide PA capabilities and air horn sounds, and they draw only about 40 amps. They are a good alternative to the cost and maintenance issues associated with a mechanical siren. This type of “big sound” siren is also easier to install on an ambulance or a chief’s vehicle.

Air horns are extremely effective for warning traffic of your presence. Not only are they loud, but they also have a directional characteristic about them. In general, you can more easily determine the direction from which air horns approach than a siren, which is more omnidirectional.

Air horns are required to have a pressure protection valve that causes them to stop operating when the air pressure reaches 80 psi. This is an important safety feature because, as explained earlier, braking power is reduced when the air pressure drops. Some purchasers specify an additional isolated air tank for the horns to provide additional sounding time.

All audible warning devices must be mounted low and to the front of the apparatus to help keep the noise out of the cab.

WORK LIGHTING

The standard requires ground lighting around the apparatus under cab doors, where steps to climb onto or descend from the apparatus exist, and to the area immediately behind the vehicle. The purchaser can specify any number of additional work lights.

Many varieties of 12-volt lights are available for area and scene lighting around the apparatus. Some of the larger lights have internal optics so they can be mounted flat and shine their light pattern at an angle toward the ground. This type of scene light mounts nicely on the side of the cab or on the high body sides and rear of a rescue truck. They can be switched from both the cab dashboard and wired to come on when the cab doors are open, to further illuminate the area around the apparatus when stepping out. Rear lights can be used as backup lights and a switch provided at the rear to switch them on as work lights is also an option.

(21) Boat dock lights mounted in the wheel wells illuminate the sides of the apparatus when backing up. (Photo by author.)

Some of the newer 12-volt scene lights make use of high-intensity discharge (HID) bulbs that produce considerably more light than a standard halogen bulb. They have been fitted to mount to the contour of the cab roof, providing scene lighting without the use of a generator. Scene lights over the windshield, known as “brow lights,” are very popular as well for lighting the area in front of the vehicle.

On longer apparatus, such as aerials, boat dock lights on the side of the apparatus can help illuminate the sides of the apparatus while backing up. These recessed lights are angle mounted to shine to the side and rear while in reverse, without interfering with the driver’s vision.

All steps, walkways, and work surfaces on the apparatus need to be illuminated. Obviously, this includes the pump panel. Some manufacturers wire the pump panel lights so that one on each side comes on when the pump is engaged. This provides at least some light until the operator turns on the pump panel light.

BODY AND COMPARTMENTS

When it comes to body construction materials, the purchaser has several choices. The body materials currently produced are galvaneal steel, aluminum, stainless steel, and poly-plastic, similar to the water tank material. Some manufacturers build with one type exclusively; others offer several choices. Each type has advantages and disadvantages.

(22) Apparatus, such as this rescue pumper, have large compartments that exceed the minimum cubic foot requirements in the standard. (Photo by Ron Jeffers.)

Galvaneal steel is sheet steel coated with a galvanizing finish to resist rust. If not finished properly, sections that are welded or ground are prone to rust. The material is relatively easy to work with and, when properly finished, can provide lasting service.

Aluminum is not without its problems when it comes to finishing. If not properly insulated from other dissimilar metals, corrosion can occur, causing what some people call “white rust.” Aluminum is strong and easily repaired.

Stainless steel is a very strong, durable, rust-resistant material. It will, however, generally add to the cost and weight of the apparatus.

(23) A heavy-duty roll-out tray at the rear of this walk-around rescue truck allows for maximum equipment storage and accessibility.(Photo by Ron Jeffers.)

Plastic bodies are relatively new to the fire service. The poly-plastic used is extremely durable, and the water tank can actually be formed as part of the body structure. At this time, it is not as widely used as other materials, but in this age of plastics, I believe it will gain in popularity.

(24) A pull-out, drop-down tray places the equipment stored on it right at your fingertips. (Photo by Ron Jeffers.)

Your research should dictate which is desired and acceptable. Body (and cab) rust proofing might be necessary depending on the construction material and the area of the country in which the unit will be used. Rust proofing might be a good practice where road salt is used excessively or in the salt air near the coasts.

COMPARTMENTS

The amount of cubic feet of compartment space required by the standard is quite small when compared with the units produced today. A pumper, quint, aerial, or industrial foam unit each requires 40 cubic feet of enclosed compartment space. Initial attack units require 22 cubic feet, and mobile water supply units require 20 cubic feet. The largest requirement for compartment space is on special service units, rescue trucks, hazardous-materials units, and so on, at 120 cubic feet. Of course, you can exceed these minimum requirements in your specifications if you need to carry a large amount of equipment.

(25) Vertical slide-out tool boards provide a great deal of equipment mounting surface. (Photo by author.)

Some manufacturers routinely reinforce the bottoms of the compartments, but if you intend to place heavy equipment on the floor, indicate in your specifications that the floors need to be adequately reinforced for the intended purpose.

COMPARTMENT OPTIONS

The standard states only that the compartments need to be weather-resistant, vented, and lighted and must include drainage provisions. There are many options and features for efficiently dividing and using the open spaces inside the compartments.

Adjustable shelves are a good starting point. Tell the manufacturer which compartments are going to receive adjustable shelves so the mountings can be installed. Some specifications state that all compartments will have the mounting installed and also specify the number of shelves to be provided. Purchasers then work out the location and placement of the shelves at the preconstruction conference.

Adjustable roll-out trays help make good use of compartment space, because they provide access to the equipment on the tray without having to leave a lot of room between shelves for reaching in and pulling out the items. Adjustable trays usually come in the standard-duty (250-pound capacity) pull-out tray and the heavier-duty, 500-pound floor-mounted roll-out tray. This type is more suitable for heavy equipment like hydraulic rescue tools, generators, and portable pumps. Long 500-pound trays can traverse the full width of a rescue body and pull out on either side. Another use of this type of tray is through the center of a “walk-around” rescue, where the tray pulls out from the back of the apparatus. It makes good use of a lot of “dead storage space” in the center of the body.

Making good use of the top of high compartments sometimes presents a challenge. Equipment on a standard shelf can be very difficult to reach. One way of dealing with this is to use a pull-out, drop-down tray. When the latch is released, the tray pulls out about halfway, then it pivots down to allow access to the equipment stored on it. One word of caution though: Avoid putting heavy items on this type of a tray. When heavily loaded and pulled out, it can drop rather quickly. Also, mount tools placed on the tray so they don’t become dislodged when you access the tray.

(26) Swing-out equipment racks help to organize deep compartments by allowing storage on both sides. (Photo by author.)

Another method of using space at the top of compartments is to install vertical tool boards. These boards are generally made of perforated aluminum and can hold a great deal of equipment, especially long-handled items like shovels, that would usually just stand in the compartment. The vertical tool boards are mounted on slides at the top and bottom and provide ready access for the tools mounted there.

Purchasers can also use swing-out equipment racks to make good use of deep high-side compartments. Some departments have installed SCBA units on the outside of the rack and spare cylinders on the back side. Each is accessible when the tool board is open.

(27) Nylon cargo nets can contain bulky items like cribbing from shifting and hitting the compartment door. (Photo by author.)

If you have shallow high-side compartments over the wheel wells, you might wish to mount tools to the back of the compartment. There are a few ways to make that process easier without drilling into the hosebed or water tank! First, you can specify that the rear wall be lined with 3⁄4-inch marine-grade, varnished plywood. Then you can use standard wood screws to mount equipment. Aluminum pegboard spaced away from the rear wall is another option. The tools mount to the pegboard. The unit is put in place and secured with the mounting screws. Mounting brackets for various tools are available commercially. In one system, slotted panels are attached to the walls, and the companion brackets easily attach to the slots. If the configuration of the equipment in the compartment changes, it is easy to disconnect and relocate the brackets.

Special needs can also be addressed. Purchasers can specify flat air bag storage slots or breathing air cylinder storage racks. They can be located wherever there is room. Plastic boxes to hold chains or other loose equipment are very handy. The manufacturer can have them custom made with handle cutouts for easy transportation. If you need to contain bulky equipment such as wood cribbing, consider speccing nylon cargo netting. It will keep the cribbing from sliding against the doors and also make it readily available.

The front painted edge of a compartment is one area that takes abuse. Lifting heavy equipment in and out can easily scratch and chip the paint. A simple stainless-steel edge guard along the forward lower lip can eliminate this problem and keep your paint looking good.

To keep air circulating around equipment in compartments, specify compartment floor and shelf grid material. Manufacturers used wooden or aluminum grids in the past. Presently, most of the compartment liners are flexible plastic mat or tiles. They are quite durable and can be easily removed to clean dirt from underneath.

In places where the climatic conditions cause problems for the tools stored in compartments, special ventilation systems circulate air into the compartments at certain intervals. Airport crash trucks with a winterization feature have special heating units that heat the air in the compartments to keep all of the equipment ready for use in sub-zero conditions.

Usually, manufacturers can leave the inside of the compartments as plain unfinished sheet metal or can paint them. Some avoid painting because it is another maintenance issue when the paint gets scratched. Another option is a thick, spray-on plastic coating similar to the type used in the beds of pickup trucks. The material insulates the compartment and will not become damaged from equipment hitting it.

The next decision you will need to make is the style of compartment doors. The two basic types of compartment doors in use are the hinged box-pan, both vertical and horizontal, and roll-up or shutter doors.

If you are specifying hinged compartment doors, you might want to have reflective material on the inside of the compartment door as well as the outside to provide some visibility when it is open. If your compartment is next to the pump panel, consider a “reverse hinged” door setup so the engineer doesn’t have to step around the open door to get fittings.

Horizontally hinged high side doors are sometimes difficult to reach to close, especially for those who are vertically challenged. Aerial trucks set up on outriggers raise the compartment doors even higher. Consider attaching a nylon pull-down strap to the inside of the door to assist in reaching it when attempting to close it.

If the department has a preference, the purchaser should specify the type of door holders and latches. Available methods include the pivoting arm “Cleveland” door stays, springs, and pneumatic cylinders known as “gas shocks.” Gas shocks are used almost exclusively on horizontally hinged doors. Just bear in mind that they wear out over time and might have to be replaced.

On vertically hinged double-door compartments, consider extending the release lever on the second door to make it easier to find with gloves on.

Roll-up doors have been used in Europe for many years and finally enjoy wide acceptance in the United States. One of the benefits is the clear, wide opening when the door is rolled up. This eliminates the problem of trying to remove heavy equipment in locations where hinged doors cannot fully open because of an object or another vehicle located in close proximity to the side of the apparatus. The doors are very convenient for use on compartments inside the cab of a rescue body where space is limited. In addition, many hinged doors have been forcibly removed from the apparatus during response when they come in contact with the overhead door jamb or fire station wall. There are two minor disadvantages to using roll-up doors. If equipment shifts in the compartment during a response and comes in contact with the inside of the door or the roll-up mechanism, it can jam the door. Avoid this by mounting all equipment in brackets.

(28) It is easier to find the release lever on the second compartment door if it is extended like this one. (Photo by author.)

The other problem is the amount of space required at the top of the compartment to allow the door to roll up. Generally, this is “dead space” anyway but on low compartments it could impact the size of the equipment you place in the compartment.

Roll-up doors can be painted or be left in their natural state. If you paint the doors, consider a protective shield around the roller to protect the door when rolled open. The paint is vulnerable to scratching while removing equipment.

You can specify locks for both types of compartment doors. On some larger vehicles with numerous doors, electrically operated locks can lock and unlock all of the doors at once.

The standard requires compartment lighting, but you most likely will get the minimum number of lights to meet the requirements. You can specify additional compartment lighting if necessary. In compartments with adjustable shelves, many departments specify lights under the shelves. Be sure to include excess wire so the shelves can be adjusted in the future. Recessing compartment lights in doors can illuminate the ground around compartments as well. Strip lights mounted in the front corners of the compartments are also becoming popular. Small bulbs in clear plastic tubes do a good job of lighting up the area. One thing you need to pay attention to is the 12-volt current used to light all of these compartments. One way to cut down on the amperage draw is to use LED lighting in the compartments. Although they may not be quite as bright as the standard lights, they are certainly efficient.

STEPS AND STEPPING MATERIAL

The NFPA Apparatus Safety Task Group did a great deal of research to provide measurable requirements for slip-resistant stepping surfaces. The requirements differ for interior and exterior stepping surfaces. Rubber traction mats on cab and crew cab floors provide a slip-resistant surface while also providing noise and heat insulation.

For external surfaces, some manufacturers install metallic nonslip inserts into the steps, treadplate that is punched up from the bottom, or compliant “embossed” treadplate.

To enhance safety, I always put the following sentence in my specifications: “All horizontal surfaces constructed of or covered with treadplate, whether considered a step or not, shall be NFPA-compliant slip-resistant treadplate.” You may wish to cover the cab roof with treadplate to protect the finish, but you know that one day, some firefighter will walk on it, so we might as well try to prevent an accident.

The standard states that at the time of delivery the contractor is to supply you with certification that all materials designed as stepping surfaces meet the NFPA standard. Ask for it.

(29) It is safer and considerably easier to reach the top of an apparatus on a slanted ladder than from folding steps. This commercially available folding ladder is comfortable to climb. (Photo by author.)

Steps or ladders are required so that firefighters have access to all working and storage areas of the apparatus. Slip-resistant handrails are also required at each position where steps or ladders for climbing are located. A good test for meeting this requirement is to climb on the installed steps and “feel” for a handrail to hold on. If it’s not there, request that it be installed.

(30) This rescue truck with rooftop compartments has a stairway installed for safety. Each step is also a compartment to make use of the dead space. (Photo by Ron Jeffers.)

The current folding steps are a great improvement over previous tiny little steps, but ladders provide a safer method for climbing if space permits. Some commercially available ladders fold out at the bottom to provide a comfortable climbing angle instead of the typical vertical ladder. On some “walk-around” rescue trucks, the purchasers have eliminated the rear compartment and put an actual stairway with handrails to reach the hatch compartments at the top of the apparatus.

EQUIPMENT RACKS AND STORAGE

When you lay out the equipment to be mounted, first consider how firefighters are going to reach the equipment.

(31) A single-arm ladder rack takes up some compartment space, but the compartments are accessible from the ends when the rack is lowered. (Photo by Ron Jeffers.)

Mechanical equipment racks, hydraulic and electric, can be used to mount an array of equipment. Ground ladders, suction hose, pike poles, folding ladders, and folding tanks are just a few of the heavy items you can store on the rack.

The two mounting methods for the racks are a single actuation arm in the center and a pivot arm at each end. Although the single arm takes up some compartment space on the side of the apparatus, it provides access from both ends to reach the compartments when the rack is lowered. This system is especially convenient if you use roll-up compartment doors, because there is nothing in your way when retrieving equipment.

(32) This ladder gantry stores the ladder high on the body but makes it easily accessible when needed. This is particularly suitable for a rescue truck body where a standard ladder rack cannot be installed. (Photo by author.)

Another type of ladder rack allows the ladder to be stored flat above the body; when activated, the ladder moves to the back and angles down at the rear. This is a good feature on a rescue truck where a conventional pivoting ladder rack cannot be used. It is also extremely difficult to remove ladders straight out the back of the body.

Just remember that overhead equipment racks tend to add significantly to the overall height of the apparatus. Be certain that enough clearance is available in the fire station!

(33) Overhead equipment racks raise the overall travel height of the apparatus considerably. (Photo by author.)

Two other methods for mounting ladders and suction hose are “through-the-tank” mounts and behind the compartments. The through-the-tank method requires that a rectangular hole be manufactured through the center of the water tank and a door be installed on the rear of the apparatus. The ladders slide out the back of the apparatus, much like the ladder bank on an aerial truck. In the second method, the manufacturer installs a compartment behind the compartments on one side with a door at the rear. The ladders are stored on the beam in this compartment, and they also slide out the back. With this method, you lose some of the upper depth of the compartments, but the ladders are more accessible than in some of the other mounting methods.

HOSE STORAGE AREAS

The minimum requirements for hose storage vary by type of apparatus. On pumpers and quints, the hose storage area need be only 30 cubic feet with two areas, each with a minimum of 3.5 cubic feet, for preconnects. If you intend to carry a wide variety of hose or a larger than required quantity, you’ll need a larger hosebed.

(34) On some apparatus, the ground ladders can be stored in a tunnel installed through the water tank. (Photo by Ron Jeffers.)

Clearly state the hose length, size, and location for the hosebed and preconnects in your specifications. The manufacturer will need this information to provide enough space, and it might affect the axle and suspension required to carry the load.

The way you intend to divide the hosebed will impact the number of adjustable hosebed dividers required. The standard indicates that the hose load can also be mounted on reels if desired.

(35) Another area for ladder storage is in a slot installed behind the high compartments on one side. (Photo by Ron Jeffers.)

Again, when specifying an apparatus, everything involves a trade-off. When you specify a large water tank, the hosebed rises. Think about deploying and repacking hose. Do you need that much water, or is hose deployment more important? With smaller water tanks or the use of an upright tank, the hosebed can be quite low.

The standard does not require a hosebed cover, but one helps protect the hose from the elements and, in some cases, flying embers. Manufacturers generally offer two types of covers: a hinged diamond plate hard cover and a vinyl soft cover. If you specify the treadplate cover, be sure to indicate that it is to be reinforced and compliant slip-resistant treadplate.

(36) When considering hose storage areas, don’t forget about standpipe bundles. The area under the ground ladders is suitable for this type of equipment. (Photo by Ron Jeffers.)

The unit number or a name can be stitched in reflective letters on a soft cover. Discuss the method of holding the cover in place with the manufacturer.

Another reason for using a hosebed cover is to keep hose in place when responding at highway speeds. The lighter supply line large-diameter hose can catch the wind at the front of the hosebed and start to rise. Once it gets going, you can strip an entire hosebed in short order. If you don’t want to use a conventional full hosebed cover, have the manufacturer install a hinged treadplate cover that covers just the front 24 inches of the hosebed. Firefighters can lift it up and latch it for hose packing, then lower it to keep the forward part of the hose from catching the wind.

PAINT COLOR AND REFLECTIVE STRIPING

The NFPA standard states that all exposed ferrous metal surfaces of the apparatus should be painted. It does not recommend a specific color. The apparatus should be as conspicuous as possible for safety reasons. If a two-tone paint job is required, state it in the specifications.

The requirement for reflective striping is a minimum four-inch-wide reflective stripe that covers 50 percent of each side and the rear of the apparatus and 25 percent of the front perimeter. Meeting the front requirement can be tough, especially on commercial apparatus! The four-inch width doesn’t have to be continuous; it can be split into a combination of stripes. Keep in mind that a two-inch-wide reflective stripe that covers 100 percent of the rear of the apparatus is not the same as a four-inch-wide stripe that covers 50 percent of the width.

(37) A smaller water tank can result in a low hosebed that is safe and comfortable when deploying and repacking hose. (Photo by Ron Jeffers.)

Reflective graphics or letters can replace any of the required striping as long as the total linear measurement meets the standard. Units that typically operate on the highways could benefit from covering the whole rear of the apparatus with alternating color chevron striping. This is certainly more conspicuous than a minimum four-inch stripe.

Reflective material is now required inside the cab and crew cab doors. Ninety-six square inches of reflective material must be on the inside of the doors. Some departments have installed reflective “STOP” signs, but some feel they might confuse traffic that would typically pass.

(38) Bold reflective striping on the rear of this apparatus might well prevent an accident, especially on a highway. (Photo by Ron Jeffers.)

Consider using large reflective numbers on the roof of the cab. This is especially good for identifying apparatus from the air in a wildland fire situation or from the upper stories of a city building.

In departments where apparatus move from station to station or that use a reserve fleet, install frames on each side of the apparatus to accommodate identifying number plates of the company using the apparatus.

FIRE PUMP

If your specifications include a fire pump, you have several considerations to address. You must decide on the rated capacity of the pump in gpm, the number of stages, pump type, and pump location.

If you specify a higher-rated pump like 1,750 or 2,000 gpm, you will need a higher horsepower engine to drive it. When you increase the size of the engine, the transmission usually has to be a heavy-duty model, and the chassis often needs to be a more high-end model. All of this tends to drive up the price of the apparatus. Remember, a fire pump’s rated capacity is from draft. If you routinely operate from a positive-pressure source such as a hydrant system, you will easily surpass the pump’s rated capacity. In this case, a lower-capacity pump will still get the job done at less expense. As an example, the largest fire department in the country, the Fire Department of New York typically uses pumps rated at 1,000 gpm.

The primary centrifugal fire pump in use today is the single-stage model. Pump manufacturers report that approximately 60 to 70 percent of the pumps sold are single stage. In the past, apparatus equipped with gasoline engines lacked the horsepower and torque to meet required pressures, so purchasers specified two-stage pumps. Currently, the justification for single-stage pumps is that they are less expensive, have fewer moving parts, are lighter, and require less training to operate.

Consider the following when determining the number of stages for your pump: If normal pumping involves higher pressures at less than half pump capacity, a two-stage pump is probably more suitable. The engine will operate at a lower rpm, which reduces stress on the engine. Typically, this is one or two attack lines operating at 200 psi or more. Another reason for specifying a two-stage pump is if you have high-rise buildings where you might need to pump at higher pressures to reach the upper stories. Some apparatus are equipped with a third stage for high-pressure operations.

If the apparatus is going to be used at an altitude of more than 2,000 feet, or have a lift of more than 10 feet or draft through more than 20 feet of suction hose, the manufacturer must make provisions to ensure that the pump can be certified at rated capacity under these special conditions.

The pump can be mounted midship with a split-shaft transmission, rear-mounted, or front-mounted. With modern electronic controls, the pump panel can be mounted in just about any location, even inside the cab.

PUMP DRIVES

Depending on apparatus configuration and pump size, pumps can be driven by the following:

• pump drive transmission (split shaft),

• power take-off (PTO),

• front of the crankshaft, or

• separate pump drive engine.

Since PTO-driven pumps have become popular, all components (including the PTO) must be able to withstand the maximum torque that might be applied. PTOs have been breaking up and damaging transmissions.

PUMP BODY MATERIAL AND PLUMBING

You can also choose the materials used to construct the pump. The typical pump is cast iron with bronze impellers. Aluminum composite pumps have been successfully used in Europe for many years and are lighter than the cast type. New stainless- steel pump housings are available and show great promise for longevity.

(39) Several types of pump housing materials are in use today, including stainless steel as shown here. (Photo by author.)

The type of plumbing used in the pump has also changed over the years. The old black iron pipe routinely leaked when it rusted around the threads. Later, pump manufacturers substituted galvanized pipe, which cut down on the rusting a bit. Now, most pump plumbing is welded stainless steel and high-pressure hose. Many manufacturers offer 10-year warranties on the stainless-steel plumbing.

PRIMERS

A centrifugal pump requires a positive displacement primer to secure a water source from draft. Several options are available. The standard primer that uses priming fluid is one. A newer replacement uses only water to lubricate the primer, which is a lot more environmentally friendly. There is also an air primer available that uses air from the vehicle to create a priming action.

DISCHARGE AND INTAKE VALVES

First consider the number of discharges you need, the type of connections, and the flow requirements. The standard requires a minimum of two 21⁄2-inch discharge outlets. A combination of all discharges must equal or exceed the pump’s rated capacity. Before LDH discharges, you could quite confidently determine the pump size by counting the number of 21⁄2-inch discharges and multiplying it by 250 gpm. Now, most pumpers have numerous discharges, mostly out of convenience.

(40) Electronically controlled valves and controls have made it possible to locate the pump panel in almost any location. This top-mount pump has a full roll-up door to enclose the controls. (Photo by Ron Jeffers.)

Discharge flow rate calculations follow:

• 21⁄2-inch = 250 gpm

• 3-inch = 375 gpm

• 31⁄2-inch = 500 gpm

• 4-inch = 625 gpm

• 41⁄2-inch = 750 gpm

• 5-inch = 1,000 gpm

• 6-inch = 1,440 gpm

• Waterway = 1,000 gpm

The discharge size is determined by the first hose connection to the pump. For example, if you have a 31⁄2-inch valve and pipe from the pump, terminating in a five-inch storz (LDH) connection, the discharge is rated at 1,000 gpm.

(41) Preconnects can be located anywhere on the apparatus. This unit has three at the rear hosebed. (Photo by Ron Jeffers.)

For safety reasons, no discharge larger than 21⁄2 inches can be located on the pump operator’s panel. Another safety requirement is that any valve three inches or larger in diameter must be operated by a mechanism that will not allow the valve to go from fully open to fully closed in less than three seconds. There are several ways to comply with this requirement: quarter-turn “slow close” valves, power actuated valves that use an electric motor controlled by a switch, and crank type valves. Electrically operated valves have allowed manufacturers to locate the pump panel in almost any location the purchaser wants. The need to run straight push-pull linkages to valves is gone.

All discharges 21⁄2 inches or larger must be fitted with male National Standard Threads (NST). Any local adapter can then be added. In locations where a different thread is used, most add an elbow adapter that has NST on the female side and the local thread on the discharge end.

If you use mostly 13⁄4-inch hose for attack lines, a worthwhile investment is to put a 21⁄2-inch 11⁄2-inch reducer cap on all your discharges. When the firefighter pulls enough hose off the apparatus, he can connect directly to the discharge without hunting for a reducer. The same is true of LDH storz connections. You can use a five-inch storz 21⁄2-inch NST reducer cap, which will provide an additional 21⁄2-inch discharge if the incident doesn’t warrant using the LDH connection.

(42) Preconnects, like the two shown here, can be installed on reels like the two shown in this photo. (Photo by Ron Jeffers.)

You must determine the quantity, size, type of connection, location, and flow requirements for discharges to be used as preconnects. Contrary to popular belief, preconnects do not need to be crosslays. Two preconnects are required on pumpers, but you can locate them anywhere-front bumper, rear step, rear hosebed, or even on reels in compartments.

In many areas of the country, a bumper-mounted trash line has replaced the booster reel. However, many departments still use booster reels for brush and rubbish fires. Booster reels are also used for some high- pressure fog applications. If you specify a booster reel, indicate the location and the size and length of hose that will be supplied or carried on the reel. Although most reels have electric rewind systems, a manual crank is a good backup. If the reel is located in the rear compartment, consider having rollers installed at the back of the apparatus to protect the finish.

If you require a deck gun, indicate the type, mounting location, piping size, and valve arrangement. If you are using a manually operated deck gun, specify a sufficient area for the operator as well as a safe means of reaching the location. A safer alternative is to specify a remote- controlled deck gun to allow operating it from the pump panel or a remote-control tether. Also consider a deck gun with a riser if height is a problem in your station.

One main and one auxiliary gated suction are required. Specify other suction inlets at the front or rear of the apparatus or other auxiliary inlets by location, size, whether they are to be gated or not, and the method of operation.

The standard requires 31⁄2-inch and larger valved intakes to have an automatic-pressure relief valve and air bleeder installed before the valve. Electrically operated butterfly inlet valves, with the required built-in pressure relief, are available to take the place of the standard steamer intakes on the pump. This makes operating easier and eliminates the large external valves previously used.

Keep in mind that front and rear suction intakes most likely will not be able to meet the pump’s rated capacity from draft.

The standard specifies the tank-to-pump flow rate as a performance item. Water tanks with a capacity of 500 gallons and more must be able to flow a minimum of 500 gpm from the tank to the pump and less than 500 gallons at 250 gpm.

The minimum requirements for a tank fill line are a one-inch line from the pump discharge for tanks less than 1,000 gallons and a two-inch line for larger tanks. Filling a 750-gallon tank with a one-inch line is a very slow process. You would probably be better staying with a two-inch line to expedite filling. Don’t go too large on the fill line, as it could damage the water tank.

PUMP PANEL AND INSTRUMENTATION

The surface of the pump panels can be constructed from many types of materials. Brushed stainless steel, vinyl-coated, and powder-coated are just a few. The choice is based more on personal preference or longevity.

(43) Color coding of discharge controls, gauges, drain valves, and discharges simplifies operations. This apparatus purchaser color coordinated the preconnected hoselines with the corresponding controls. (Photo by author.)

Many departments have found it helpful to color code the valve handles, gauges, drains, and discharges. You can find a standard list of color coding in NFPA 1901, Annex A. You can also spell out exactly what legend you want on the panel tags. For instance, I think it is easier to identify the discharges as “Right Side Discharge,” “Rear Discharge,” and “LDH Discharge” instead of “Discharge #1,” “Discharge #2,” and so on. Discuss the methods of color coding with your dealer. Sometimes larger or more conspicuous color coding is available if you so desire.

You must determine how to control the discharge pressure. The two choices are an electronic pressure governor and a standard relief valve.

A pressure governor adjusts the engine rpm to maintain a steady pump pressure or stable rpm setting. This is like “cruise control” for the pump. If increased engine rpm is needed to maintain the pressure, the governor signals the engine to increase output. When lines are shut down, the engine rpm is reduced. Electronic governors interface with electronic engines and transmissions to provide precise control.

(44) Combination pressure/flowmeters provide the operator with information about the discharge. (Photo by author.)

Pressure governors have two modes of operation. One is based on the pressure setting; the other is strictly rpm. When the governor is in the rpm mode, there is NO pressure control. Since it is dangerous to operate handlines under these conditions, specify that the governor must default, or start out, in the “pressure” mode when the pump is engaged. This is one less thing the pump operator will need to consider when operating at the scene of a fire.

The pressure relief valve operates on the principle of mechanically circulating excess pump discharge back to the intake side of the pump. An electronically controlled throttle is used to increase engine rpm.

Both devices must meet a performance standard that requires the discharge pressure rise be limited to 30 psi in a discharge range of 70 to 300 psi pump pressure.

I have seen some new pumpers that have a redundant pressure control system. If the electronic pressure governor fails, the operator opens a small compartment door on the pump panel, flips an override switch to disconnect the pressure governor, and operates a relief valve and throttle.

All discharges 11⁄2 inches or larger must have a pressure gauge or a flowmeter. Flowmeters allow the pump operator to provide a specified gpm delivery without friction loss and nozzle pressure calculations. Dual-reading pressure/flow gauges are also available. Gauges or flowmeters must be within six inches of valve-operating controls to help cut down on confusion.

The master pump intake and pump discharge gauges must be one inch larger than the individual line gauges and grouped within eight inches of each other. Other instruments necessary for pump operation such as throttle control, pressure control, oil pressure, engine temperature, tachometer, and primer must all be grouped together and as far away as practical from the discharges.

Specify any special gauges or controls you desire at the pump panel. A fuel gauge would be handy for long operations. A pump overheat indicator could avoid a serious problem. Also, if the department uses air horns as an evacuation signal, an air horn button on the pump panel could be valuable.

Specify the type of tank level indicators for water and foam tanks. Consider additional indicators in the cab on pump-and-roll units where they are operated by the driver and possibly at a remote tank fill on a mobile water supply apparatus. A common option is to install large tank indicating lights on the side of the cab so they can be seen from a distance. If you do this, have them wired through a relay so they come on only when the unit is in pump. They might be confusing to drivers on the road if they are illuminated at all times.

When specifying a pumper, indicate that a pump panel layout drawing must be supplied for approval. A poorly arranged pump panel can cause problems for the operators for many years.

WATER TANK

If a water tank is required, indicate capacity, tank construction material, and if an internal coating or removable lid is required. The minimum capacity in the standard is

• pumper: 300 gallons;

• initial attack: 200 gallons;

• mobile water supply: 1,000 gallons;

• aerial apparatus: not required-any size if supplied;

• quint: 300 gallons; and

• mobile foam: 500 gallons foam concentrate (water tank not required).

Leaking steel water tanks that require periodic repair were the norm a number of years ago. All types of internal coatings helped stop the rust and corrosion, but eventually they would leak. Most modern tanks on pumpers are made of nonmetallic plastic or fiberglass material that has just about cured the leaking situation.

If the apparatus is being used as a mobile water supply unit, it is required to have a tank dump valve rated at 1,000 gpm. There are standard gravity dumps and jet-assisted dumps that discharge the water at a higher rate of flow. Mobile water supply units are also required to have a direct tank fill rated at 1,000 gpm.

(45) A mobile water supply unit is required to have a dump valve and a direct tank fill. Notice the tank level gauges next to the fill inlet. (Photo by Ron Jeffers.)

Quite often, a fire department requires that a foam “cell” be installed in the water tank. In that case, state clearly in your specifications that the quantity of the foam tank shall NOT reduce the capacity of the water tank. In other words, if you want a 500-gallon water tank and a 50-gallon foam cell, you will not accept a 450 water/50 foam tank. The tank can be built to any specification you have. In addition, the manufacturer must now certify the quantity of the tanks at delivery.

Water tanks, depending on their capacity, can be designed in many shapes that could enhance your finished apparatus. Some tanks are “L” shaped, where the forward portion of the tank, ahead of the hosebed, is elevated. The rest of the tank is under the hosebed floor. This allows for a lower hosebed floor. A common shape is known as a “T” shaped tank. The lower portion of the tank is narrower, allowing deeper low side compartments.

FOAM SYSTEMS

If you require a foam system, first determine the type of foam to be used (Class A, Class B, or both) and which discharges need to have foam capabilities. Once you determine that, you can research the type of system.

Some of the systems available are

• in line eductor on selected discharges;

• around-the-pump proportioning system-once activated, foam is produced from all discharges;

• balance pressure system, which uses a foam bladder or concentrate pump; and

• direct injection method, which uses a concentrate pump controlled by a microprocessor to inject the foam into the water pump’s discharge.

There are some other foam options besides specifying a built-in system. A self-educting master stream nozzle that educts concentrate right at the tip of the nozzle at 350 to 500 gpm is one option. A valve and quick-connect from the foam tank to the area of the deck gun is another option. When foam is needed, the nozzle pickup tube is attached to the quick-connect, the valve is opened, and a foam master stream gun is operational.

(46) A foam quick-connect and valve mounted on the pump panel can supply concentrate for an external eductor attached to one of the discharges. (Photo by author.)

Departments that rarely use foam but have an eductor already might opt to have a foam quick-connect and valve installed on the pump panel. If foam is needed, the eductor is attached to a nearby discharge, the pickup tube is attached to the quick connect, and the valve is opened.

Foam tank refill systems that have an outside pickup connection and an electric pump are available to fill the foam tank from the ground instead of lifting the heavy pails to the top.

Another important tip is to locate the foam tank drain valve under the apparatus or behind an access door. If it is along the row of discharge drains at the bottom of the pump panel, you most likely will be cleaning up a foam spill after a fire when the operator opens all the valves to drain the hoselines!

Compressed air foam systems (CAFS) are a spin-off of the direct injection system. The system uses a foam agent pump and air compressor in conjunction with the fire pump to produce a light fluffy foam that enhances the water’s ability to extinguish fire as well as provides excellent exposure protection. Foam concentrate is injected into the discharge and mixed with compressed air generated by a compressor attached to the fire pump. Foam consistency can be adjusted by the amount of water and air introduced into the line.

The best advice I can provide when specifying a foam system is that you contact an expert from one or more of the various manufacturers of the foam-producing equipment. Most regular apparatus sales people don’t have this type of expertise unless they have been specifying foam systems for their customers for a long time.

AERIAL DEVICES

Three types of aerial device categories are in the standard: aerial ladder (straight stick), elevating platform (aerial ladder platform or tower-ladder type), and water tower. To properly select the right type for your community, conduct a survey of the buildings and how the aerial device will be used.

The rated height of an aerial is from top rung to ground in the most vertical position. For a platform, it is from the top of the platform handrail. The rated load capacities of aerials and platforms are significantly different. An aerial ladder must be able to operate in all positions with a minimum 250-pound load at the tip without water flowing and at 45 and above while discharging water. This is a minimum rating. Heavy-duty ladders feature a greater 500-pound capacity. Consider these if operating at a low angle with long extension is typical in your community.

Elevating platforms have a higher minimum capacity rating than aerial ladders. A platform must be able to operate in all positions with a minimum 750-pound load without the waterway charged and 500 pounds when flowing water. Sometimes a platform is a better choice in suburban settings where the buildings are set back from the street and long extension is normal.

Water towers can be supplied as straight telescoping or articulating. If a ladder is attached to the boom, it must meet all of the requirements of an aerial including width, rung spacing, and 12-inch-high handrails, and it must have the same minimum 250-pound tip load.

A variety of options are available to add to each type of aerial device to enhance operations. For instance, a prepiped waterway added to an aerial provides fast, convenient, aerial master stream application. A minimum 1,000-gpm flow is required on the waterway. Since the monitor might create an obstruction at the tip of the ladder during a rescue operation, the manufacturer can provide a pinable waterway. By moving a locking pin, the waterway nozzle can be secured at the tip of the third section, which will help keep it out of the way at the tip. If you require a straight ladder pipe, it can be pinned at the tip. Electric monitor controls can be installed at numerous locations. A quint I recently inspected had controls for the monitor at the tip, the turntable, the pump panel, and on a tethered remote monitor control.

Also, specify the brand and model of the monitor and nozzle. Automatic nozzles, smooth bore pipes, and piercing nozzles are just some of the choices.

If you do not specify a prepiped waterway, the manufacturer must provide a portable ladder pipe. Newer models have optional electric controls so operators can direct the stream from the ground without putting a firefighter in danger at the tip of the ladder. Additionally, some purchasers specify a “bed pipe” attached to the underside of the bed section of the ladder.

The waterway at the tip of the aerial could also have a valved hose connection, which can be used as an external standpipe for overhaul or if a hoseline is needed on a roof. I would caution against tying up the aerial as a standpipe during active firefights, as the ladder might have to be moved quickly for a rescue or if conditions deteriorate. Having a hose attached will prevent you from making the moves.

Other additional equipment includes an ax and a pike pole mounted at the tip and a roof ladder. Some mount the roof ladder inside the fly section but it often makes the ladder uncomfortably narrow. A better choice is to mount it next to the bed section. As firefighters are climbing up, they can retrieve the ladder and take it to the tip with them if it is needed to reach a peaked roof. The side of the bed section can also be used for an equipment box to hold a stokes basket.

Breathing air can be piped to the tip of the aerial if needed. The storage cylinders that supply the air are mounted at the turntable or next to the ladder. You can specify an additional outlet for the turntable operator as well. Don’t forget to specify a storage box at the turntable to hold all of the mask-mounted regulators and facepieces. Breathing air is not required on an aerial or platform; but if you specify it, clearly specify all the particulars of the type and what is expected.

Electrical lighting (120-volt) and an outlet can also be mounted at the tip of the aerial. These options provide floodlighting from above to illuminate nighttime operations.

Numerous options in addition to the monitors, hose connection, and lighting mentioned above for aerials exist for platform apparatus. A ventilated hose box at the platform will come in handy for stretching an overhaul line. A short (10-foot) section of 13⁄4-inch hose and nozzle is also an excellent overhaul tool while working on building cornices.

Most platform manufacturers have various attachments for supporting a stokes basket, mounting a roof ladder to the side or front of the platform, and lifting equipment (arms). Platforms can have lifting eyes attached to the bottom to serve as an elevated rope anchor point. I have even seen an infrared and video camera mounted to the front of the platform that transmits images to the command post from above.

120-/240-VOLT ELECTRICAL SYSTEMS

If you require a 120-/240-volt system, first consider the generating source. Some common types of line voltage sources are

• gasoline-powered portable generators;

• diesel-powered generators;

• PTO or fan belt-powered generators; and

• hydraulically powered generators that have hydraulic pumps driven from vehicle engines to power the generators.

(47) This elevating platform has two monitors attached. One is electrically controlled; the other has a manual control. Each has a 21⁄2-inch hose discharge. (Photo by author.)

Gasoline- and diesel-powered generators take up space and have their own engine that will require periodic maintenance and repair. In addition, since they have a separate power unit, they could fail to start. A benefit of the lighter weight gasoline generators is that they are portable and can be removed from the apparatus and left at the scene.

PTO generators are generally mounted under the apparatus and are powered by a driveshaft attached to a power take-off at the transmission. This type of generator is particularly suitable for a rescue truck, where the apparatus engine is not needed for anything while parked on-scene. Most PTO generators are rpm-sensitive-that is, the engine must be set to a certain rpm to keep the generator operating at a continuous output. This feature makes it unsuitable for a pumper application, where the engine rpm constantly varies. One thing to remember about a PTO generator mounted under the apparatus is not to go through deep water and then activate the generator. A splash guard will have been installed, but it is not waterproof.

(48) Cord reels are generally mounted high in a compartment, where they are quickly accessible for deployment. (Photo by Ron Jeffers.)

Hydraulic generators use a hydraulic pump driven by a PTO attached to the transmission. The hydraulic fluid is then pumped to the generator under high pressure, and it turns a hydraulic motor that spins the generator. When specifying this type of generator, indicate that it must operate from idle up to the full governed rpm of the engine. Most hydraulic generators can be activated while driving, which makes it handy for illuminating the scene on arrival.

The mounting of any generating source is also important. Gasoline and diesel generators should be mounted so that excessive noise, fumes, and heat don’t enter the passenger compartment.

The capacity of the generating source is based on the intended use. If you have an apparatus that has a few scene lights and a couple of cord reels, a lower output generator will suffice. If you intend to operate a light tower, an air compressor, or any heavy equipment, a higher-output unit is appropriate.

After determining an electrical source, specify the receptacle information, including quantity, amps/volts, style, and location.

Cord reels are quite popular for extending the electrical lines from the apparatus to the scene. When specifying reels, provide information for each reel, including mounting location, amperage, voltage, length of cord, receptacle style or junction box, and type of rewind system. A popular location is high in the tops of compartments against the ceiling. This generally makes good use of dead space.

Be aware that serious voltage drops are encountered in long runs of reel-mounted cord. Heavy-duty, high-draw appliances, such as rescue tools and electric jackhammers, might require a heavier cord on a long run.

Provide 120-/240-volt lighting information next. Specify the quantity, location, wattage, bulb description, and type of mounting. This could vary from fixed lights recessed in the side of a rescue body to light heads mounted on manually raised poles and tripod lights that can be set up at the scene. Low-voltage switching and relays can easily control lights and other remote circuits. If the generator is activated, switches in the cab or on the pump panel can activate lights.

Power-operated light masts have become very popular not only on rescue trucks but also mounted on the cab roofs of pumpers. Numerous models of self-contained light towers provide brilliant illumination at the scene. The standard contains many requirements for light towers, including the ability to operate in a 50-mph wind, having a means for lowering if power is lost, having the tower visible to the operator to avoid electrocution, and so on. Researching the types of towers and light heads is very important.

Finally, the whole line voltage electrical system must be tested at 100 percent capacity for two hours by the manufacturer and certified.

AIR SYSTEMS

If the apparatus is to feature an air system, identify its function first. Some uses include refilling SCBA cylinders, supplying remote breathing air, supplying high-pressure breathing air hose, and supplying utility air. These functions can be accomplished in a number of ways.

A cascade system has a number of semi-permanently mounted storage cylinders that supply an operator’s panel. Operators fill SCBA cylinders using the pressure differential between the source and the cylinder being filled. If you decide on a cascade system, identify the number, size, and pressure of SCBA cylinders to be used in the installation.

Another way to fill breathing air cylinders is to use a compressor. If you decide a compressor is better for your needs, supply the output rating in cubic feet per minute. Be sure that the apparatus has sufficient electrical power for a breathing air compressor. Some electrical motors can require more than three times their operating amperage to start.

If SCBA cylinders are going to be filled at the apparatus, the apparatus must have a fully enclosed SCBA refill station. Some firefighters complain that they have fill lines attached and the cylinder can be filled on their back. There have been cylinder failures during filling that might have been deadly if they were on a firefighter’s back. Specify the location, number of refill lines, and type of fragmentation box desired.

If the unit has air hose requirements, specify the following: discharge flow required in cubic feet per minute (cfm), discharge pressure, if it is for breathing or utility air, length of hose in feet, and if a reel is required and where it is to be mounted.

Air hose must be color-coded by the hose or tags:

• blue: utility air up to 300 psi;

• white: breathing air up to 300 psi;

• yellow: breathing air from 301 to 3,000 psi;

• red: breathing air greater than 3,000 psi.

The standard now prohibits using utility air from the vehicles air brake system for emergency use such as air bags and cutting tools. It still allows nonemergency use such as filling tires and extinguishers, and so on. If it is necessary to provide emergency utility air to an air reel, specify a 444-cubic-foot, 4,500-psi cylinder with a regulator and valve or what is commonly known as an “air cart” attached by a pigtail connection. You will get superior performance over the air brake system.

WINCHES

Some rescue units specify that a winch be installed. If you require a winch, list the single-line pulling capacity and length of the rope. The minimum length is 75 feet. You must also determine the mounting location. If you mount it at the front bumper extension, include a cover to keep the cable clean and four-way rollers around the cable opening.

Winches can be powered electrically or hydraulically. Hydraulic winches are generally more for heavy duty. Be aware that they are expensive and that a hydraulic fluid tank must be located on the apparatus. Electric winches can be controlled by a 25-foot plug-in cord control or a wireless type. All personnel should stay away from the winch cable when pulling to prevent injuries in case the cable snaps.

The standard now sets some requirements for portable winches used with receivers mounted around the apparatus. The receiver must be rated at a 1.5:1 safety factor over the breaking strength of the wire rope being used on the portable winch.

DO YOUR RESEARCH

I hope that the suggestions and tips provided in this article help stimulate your research when purchasing a piece of apparatus. This is an important project! Read the advertisements, contact vendors for information, and attend local shows. The Internet has opened up a world of information for the apparatus purchaser. Use it to your best advantage. And finally, good luck with your apparatus purchasing project. ■