Radio installation tips for fire fighting equipment When installing communication systems in fire fighting equipment, early customer involvement in the process, planning and protection of interconnection wiring add up to a successful installation.
Fire fighting equipment presents some of the greatest challenges to installers and technicians. This equipment can range from older pumper trucks, to super-size response trucks used at major airports, to multiple-story ladder trucks found in urban areas. In any case, the installer faces a variety of factors that need to be addressed for any communications installation to be successful. Planning is essential.
Part of the planning covers the type and location of operator interfaces such as control heads, intercoms, displays and keyboards. Once their placements are decided, location of the receive-and-transmit (R/T) units and cable routing can be determined. The problem of chafe can be addressed in planning. Chafe happens when wires rub against others in a harness or at attachment points. Once installed, especially in hidden areas, wiring problems can be difficult to trace, so to combat this problem, the installer can use spiral or cylindrical looming material to protect wires. Additionally, using care when wiring attachment points will help to reduce wear. Choosing rounded crossing points or strapping protective material around sharp edges will help to prevent chafe-related problems. (See Photo 1 below left.)
When installing remote control heads or intercoms on ladder trucks, do not overlook hydraulic control lines or breathing air feed lines as guides for routing wires. Do not use these lines as a carrier by attaching the wiring directly to them. Use care, and avoid creating additional problems for firefighters with wire and cable unwisely placed. In Photo 2 above, the firefighter is pointing to cables that are placed where they cannot be stepped on as the ladder is used. Talk to the user as much as possible to learn what can and cannot be done in routing wire and installing equipment. Avoid splices on outside runs of wire because exposure to the elements is sure to cause problems.
Occasionally, “drip loops” may be useful in both keeping water out of connections and providing strain relief, especially in extremely cold climates. Connector “boots” or nonconductive sealants help to protect wiring and antenna cable connections from the water, foam and harsh conditions found on the job. If you use these coverings, be sure to include them as part of your periodic inspection program. Also, wiring and cables can become extremely brittle in cold weather, and the problem is magnified as the equipment leaves the warm station and heads into the cold. The operations crews can check some of these items as part of their routine maintenance, so get them involved. They can spot a small problem before it becomes a major repair effort.
Protecting communication system electronic units is important. In Photo 3 on page 12, the R/T unit is mounted on the operator cab wall. This neat installation keeps the R/T dry and out of the way, avoids cable runs underfoot, and makes it easy for the maintenance technician to check or service the unit. The speaker is close to the driver, which is important in a high-noise area. Photo 4 below shows how important it is that all equipment operators be able to reach communication system controls while driving. If you are unsure, have the operator sit in the cab while placing the control heads. Do not forget that the operators wear gloves, so space the controls to allow extra room, if at all possible.
Antenna installation may take some thought. In Photo 5 on page 14, you can see the antennas installed on a super- size pumper used at a major airport. This mount setup keeps the antennas out of the way of the roof turret operator, provides a good ground plane and allows adequate clearance from objects that could block the signal while allowing access for maintenance and inspection. Agencies that require wide-area coverage should consider high-gain antennas or mobile amplifiers. Keep in mind that antennas are less expensive than amplifiers, and high-power output levels may cause interference problems. Alternate antennas, such as directional discontinuity ring radiator (DDRR), serpentine, glass-mount or vertical collinear arrays may be more appropriate for your agency. Take some time to look at antenna catalogs as part of the planning process. You may find some new ideas on vehicle mounts and innovative antenna designs. Call advertisers-most manufacturers and dealers are happy to answer questions and provide suggestions on how to fulfill your antenna requirements.
Customer involvement is a key factor in customer satisfaction. In talking with fire equipment operators in Anchorage, AK, I found that some original equipment manufacturer (OEM) communications equipment had to relocated because of accessibility problems. Planning with the customer in mind saves time and money. When installing communication systems in fire fighting equipment, early customer involvement in the process, preplanning and protection of interconnection wiring add up to a successful installation. Involve equipment operators in your periodic inspection and maintenance program to ensure continued, trouble-free communications as well as increased fire fighter safety.
My thanks to the men and women of the Anchorage Fire Department, Station 1, Ladder Truck 1, Shift C, and Public Affairs Officer Cleo. Additional thanks to Anchorage International Airport and Tom Eral, Bobbie Frisby, Rich Hittle and the rest of the professional crew working to make our lives safer.