Cramming: Modern problems of the mobile equipment installer.
Modern wireless phone providers are lucky. To them, “equipment installation” consists of delivering the new handset in a logo-laden, color-printed cardboard box. Many of you may remember when a “compact” mobile telephone consisted of a F.A.C.T.S. head and a TLD-1100 trunk unit with a connecting cable the diameter of a hot dog.
While users among the general public have fared well with miniaturized handsets and one-piece, two-way radios, public safety agencies have been burdened with an expanding inventory of electronic equipment aboard the typical fire apparatus or law enforcement sedan. The problem is well known by (and near to the heart of) every installer: How can we cram about a dozen different types of devices and systems into a neat-looking and ergonomically efficient package that will fit into the “air-bag friendly” space of a police-type sedan?
Although the auto manufacturer’s drawing of the driver’s compartment indicates a generous space for equipment layout, it really works out that the installer has some room on the floor (if allowed the luxury of bucket seats) and only a little room in front of the dash. (The allowed dash space is about the size of a shoe box after you step on it.) Here again, in the area of system integration and mobile equipment installation, public safety follows the technology curve that is led by consumer electronics. With the exception of the slowly emerging A.L.E.R.T. prototype cruisers (see www.iacptechnology.org), there hasn’t been any significant push or agreement on industry standards for the installation of public safety mobile equipment. Fortunately, the size of the individual pieces of newer equipment is shrinking and is often less demanding on automotive electrical systems, which are becoming more robust. Fire apparatus manufacturers can provide a variety of console and compartment spaces. Currently, two automakers produce full- sized (more or less) cars to accommodate the myriad lights, brackets and antennas for law officers (and, eventually, cab drivers when the cruisers end up at a municipal auction).
Several major distributors of consumer-based mobile installation supplies have emerged, offering a wide variety of materials readily suitable for public safety equipment installations. Even with better, smaller equipment and readily available installation supplies, the main problem that still remains is the installer’s time required to prepare the vehicle and equipment and then to complete the actual “cramming” process.
Our small department has wrestled with this problem for years and reached two conclusions. Neither axiom is particularly brilliant, but they are valid nonetheless: 1. Prewire as much as possible. 2. Spend as little time “in” the car as practical.
Our shop has one great luxury: We outfit all our of cars the same way. Large public safety agencies, as well as small commercial shop installers, often share the common problem of being tasked to install a different complement or layout of equipment in each vehicle. Making each car a custom installation requires even more shop time. Often, budget-limited customers don’t understand (and don’t want to pay for) the time it typically takes to change over a vehicle.
In an effort to pre-assemble and prewire equipment, we’ve begun routing almost all wiring to a common control box mounted in the car trunk. We chose the trunk over the engine compartment because of the adverse effect on fuses and circuit breakers from the elevated under-hood temperatures. Photo 1 on page 16 shows the trunk equipment box of a typical police cruiser. This is our “version 3.0” of an idea started back in 1975. Then, prewiring consisted of simply mounting a few circuit breakers, the radio A+ fuse and a contactor onto a piece of plywood that was screwed to the left front inner fender. With the new assembly, connection to all the car wiring is via two plastic AMP plugs on the back of the box. Circuitry on the left wall of the box is for light flashing and lamp cutout. The compartment on the right of the box houses an isolated second battery to provide power to the emergency equipment and radios separate from, but charged by, the vehicle system. The mobile data Bell South Wireless radio modem is mounted on the box lid and the remote-head Maxtrac two-way radio is mounted on the box floor. Photo 2 at the left shows the equipment console of a Lenexa Fire Department Unit 922. Through the specification and purchase process, Division Chief David Kuntz has evolved this console device so that all vehicles bought in the recent years have a readily accessible place to mount the control units or radio units.
Even after the pre-wiring is completed, extensive installer time is required “in” the driver’s compartment to physically mount and then electrically connect all the various equipment (more on that next month).
Oh. One more thing. While you’re planning the installation-don’t forget the cup holder. This is not to show officers how thoughtful the radio shop is. It’s to keep them from using your radio equipment as a coaster.