In the late 1800s, a pair of calamitous urban fires made it tragically clear that something had to be done to protect people and property from the perils of raging flames. These events led to the eventual development of automatic fire detection and reporting.

Early methods of transmitting fire warnings utilized metallic wires. However, wires have the drawbacks of potentially being severed, shorted or faulted to earth ground.

Fortunately, techniques have evolved through the years, to the point where it is now possible to wirelessly transmit fire information via long-range radio networks. Dealers such as Protection Systems of Phoenix are discovering how long-range radio can help them best protect and serve their customers.

Devastating Fires Jolt Chicago, Boston in Late 1800s

In the fall of 1871, Chicago experienced one of the most devastating fires of all time. In less than three hours, nearly the entire city was consumed by fire. Before 24 hours had elapsed, the Great Chicago Fire had killed 300 people, destroyed 17,000 structures and left 100,000 people homeless. By the time it was reduced to smoldering remnants, the community had realized $400 million in property damage.

The second notable municipal-wide fire that contributed heavily to advancements in the fire industry as we know it today was that of the Great Boston Fire, which took place the following year, in 1872. Like O’Learys’ barn, it was not until the fire was well underway that firefighters received the signal.

The Boston blaze resulted in the destruction of 776 structures, 13 deaths and the loss of upwards of $76 million in public and private funds.

Historic Blazes Trigger Fire Detection Advances

Certainly, there were two primary lessons learned from these two catastrophic fires. The first was the need for automatic fire detection, and the second was in the area of automatic fire reporting.

Concerning automatic fire detection, it became obvious to experts that something had to be done to guard society against a repeat performance. Thus, within a year, the fire industry had produced automatic sprinklers and, soon afterward, automatic heat thermostats.

Concerning the second lesson, and the focus of this article, the fire industry responded by developing the means of automatically alerting firefighters when a fire has been detected, thus eliminating the need for a person to sound the alarm.

Traditional Wire Susceptible to Several Shortcomings

The earliest method used for transporting fire signals to a central point involved the use of metallic wires. Signals were sent from the protected premises to a central location over metallic cable, much as they are today.

Of course, there is no denying that, under normal conditions, metallic wire works quite well at transporting alarm signals from one location to another. However, veteran dealers will agree that this method presents potential problems.

A good example of this can be, upon occasion, witnessed at today’s typical central station. For example, over the course of time, problems can develop with the telephone lines that central stations lease from telephone companies. When this occurs, service is often lost for a period of time, until the problem is discovered and the telephone company (telco) is notified.

One recent example of this was witnessed in my office building in the northeast. A communication failure on a keypad led our technician to investigate, beginning at the RJ-31X jack. Because the line appeared to be clear and in working order, he called the central station, which then confessed that it was experiencing a problem with a telephone line. At the time, a technician was on the job working to correct it.

Radio’s Redundancy, Flexibility Get Critical Signals Through

Throughout the years, many dealers have come to believe that radio-based reporting, whether used for backup or as a primary means, offers greater redundancy where it involves the transmission of critical signals to a central station.

Two signal paths and a digital alarm communications transmitter (DACT) have become the de facto standard. However, as radio reporting technology and the physical network have improved, so has the industry’s devotion to a radio-based solution.

In many cases, radio-based central station reporting involves the use of one hard-line telephone circuit and one radio channel. Under Section 5-5.4.1, Other Transmission Technologies, NFPA 72, 1999 Edition, fire technicians are required to utilize two signal paths to the central station – either two hard-line telco circuits or one radio and one hard-line circuit. “If a portion of this communication path cannot be monitored for integrity, a redundant communications path shall be provided” (Section 5-5.4.4.3, NFPA 72, 1999 Edition).

When used in this manner, failure of signal path must be reported to the central station, also termed a supervising station in NFPA 72, within 5 minutes of said failure.

If both signal paths have been disrupted for any reason, known or unknown, this condition must be announced locally to those at the protected premises. Such a catastrophic failure must also be reported to the supervising station within 24 hours. If the failure occurs at the supervising station, this condition must be rectified within 30 minutes.

There are, of course, a host of other criteria to which dealers must adhere when addressing the fire reporting system that they install. For more information, begin with Section 5-5.3.3.2.

Phoenix-Based Dealer Relies on Long-Range Radio Network

“We use radio alone to send signals to our central station, as opposed to using a telephone line with radio as a backup,” says Irv Berger, president of Protection Systems. When the manufacturer of the conventional radio system Protection Systems was using suddenly phased out portions of its product offering, Berger turned to AES of Peabody, Mass., to meet his company’s long-range radio needs.

“It’s a cornerstone of our fire alarm offering,” adds Berger’s son, Protection Systems Operations Manager Jeremy Berger. “We save the time and the recurring expense of dedicated telephone lines for our customers.” ?

In general, fire technicians like the Bergers have, or will, turn to long-range radio to solve a variety of fire reporting problems. Many of the problems encountered by dealers involve the growing obsolescence of metallic telco technology.

The highest order of long-range radio, and the one used by Protection Systems, is referred to as Type 4. A Type-4 system, as defined and specified by NFPA (Section 5-5.3.4.4, NFPA 72, 1999), must be situated so it is in constant and ready contact with at least two radio-frequency (RF) receiving sites.

The system must also contain two transmitters that have the ability to supervise all RF transmitters located on a given site from all other RF transmitters on that site. Failure of any RF unit must be reported to the supervising station.

20-Story High Rise Calls for Multiple Transceivers

“In a 20-story office complex, we recently installed an AES transceiver to cover the building, but we experienced trouble hitting another subscriber unit,” explains Irv Berger. “That was when we decided to install not one, but two additional units on the roof. Not only did this provide the retransmission of fire signals that we needed for the one [radio transceiver] in the bowels of the building, but it also enabled us to meet Type-4 requirements under UL and NFPA.”

The additional two units on this tall building also enable Berger’s company to offer Type-4 service elsewhere in the vicinity. “Every one of our units comply with Type-4 requirements,” continues Berger. “UL [and NFPA] require redundancy, and because of our UL Certificate, we don’t have a choice. Besides, it’s easy to achieve.”

According to NFPA

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