The Fire Alarm Telegraph Circuit
Part 2: Growth of auxiliary systems and development of municipal facilities for multipurpose use
Fire detection and alarm wed through sprinkler systems
A natural outgrowth of the municipal fire alarm system was its adaptation for the protection of public buildings and industrial property. Initially, municipal circuits were carried into such properties and there connected to standard street boxes, thus reducing the time required for turning in an alarm. But there were justifiable objections to running municipal fire alarm wires into these properties; notable was the relatively poor quality of wire and installation materials and techniques then available. Officials understandably feared that the quality of municipal fire alarm service would be impaired and yet they were anxious to meet the needs of influential taxpayercitizens.
The records are not clear, but they credit a Mr. Rogers of Providence with the development in 1881 of the first “auxiliary” fire alarm system which permitted an interior non-code hox (basically a simple switch) to actuate a street box without the disadvantages previously mentioned. Improvements quickly followed and the first extensive auxiliary system was installed in San Francisco. In 1894 the Manhattan Auxiliary Fire Alarm Company was formed, and after a long controversy, connections were made to street boxes in the New York municipal system.
Interior stations in the auxiliary system were arranged to trip—from local battery power—“master” boxes on the municipal circuit, sending in to fire headquarters the master box code number. The weak link was maintenance of the interior system and specifically of the local battery. Periodic failures led to the development of the “shunt-type” master box, which permitted the municipal circuit to be carried into the protected property with the arrangement that an accidental break or an actual alarm would actuate the master box.
For many years thereafter, controversy continued as to the relative merits of the two auxiliary systems. Many chiefs preferred to rely on their own municipal maintenance crews to insure local system integrity rather than on the inexperienced and untrained local property personnel. The present-day high reliability of batteries and other power supplies and of cables, wires and installation procedures has reduced the controversy to academic proportions.
Defection and alarm wed
Earlier—in 1874—Henry S. Pannelee of New Haven invented the sprinkler head in an attempt to make fire contribute to its own extinguishment. Four years later the first practical sprinkler valves began to appear, along with many refinements to provide a fully automatic sprinkler system. During this period varied types of thermal electrical detectors were developed, chiefly open circuit and unsupervised; later, improved types were developed. The “fixed-temperature” type operated when the heat reached a predetermined temperature level; the “compensating” or “rate-of-rise” type responded to a certain rate of increase in temperature.
Central stations, proprietary systems watch over industry
These principles are still popular today, but the products then offered suffered greatly in comparison with those of the high-quality design and construction sold now. Today one may select from a wide range of reliable products in these categories, as well as from those employing modern techniques to detect the presence of smoke or the products of combustion.
As might be expected, these automatic detectors soon found their way into the auxiliary fire alarm circuits to help reduce the time from the start of fire to the alarm. Also, as sprinkler system reliability increased, means were found for connecting the alarm valve to the municipal fire alarm circuit to make fire tell on itself. These important developments helped tremendously in closing the gap between the start of fire and the arrival of the fire department. However, there was fear that the cure might be worse than the illness, as experience disclosed many false alarms and system failures. Chiefly these were due to lack of maintenance or poor maintenance.
There was need for insuring highquality performance from the interior systems, both electrical and sprinkler: batteries to be maintained; devices to be checked; tests to be made; valves to be supervised; and myriad other possible causes of failure to be guarded against. This led to the formation of companies offering the combined package of equipment and service and those contracting for service only. Each municipal system in a sizable population area afforded commercial opportunities for enterprising persons. And in the early part of the current century many such local companies were in existence as well as a number of larger central station companies.
The latter companies had found practical means for combining fire alarm with the plant supervisory and watch services which were becoming increasingly popular and thus had a two-stringed bow. To a property owner who essentially needed a watch or plant supervisory service, and who could acquire fire alarm protection also for a small additional cost, the concession in diluted quality of the latter service seemed minor. By 1930 the many local auxiliary fire alarm companies offering fire alarm services ex clusively were either swallowed up or absorbed by the fast-growing central station companies.
While smaller factories and build ings were installing city-connected auxiliary systems, the larger industrial concerns, with extensive property were being protected by self-sufficient systems of the so-called “proprietary” type. These were similar to those installed by the municipalities except for the more liberal use of automatic detection devices and frequently with combined supervisory and watch facilities. Many such systems were (and still are) user-owned and maintained; others are rented on a maintainedservice, annual-payment basis.
Interior alarm systems for private use can be (and the early ones were) extremely simple—no more complicated than the common door bell system. An actuating device (the pull station), an audible alarm (bell or horn), and a power supply are essential components. However, a wide range of variables are offered in the present-day “local” system.
The system can be “non-code,” sounding only a general alarm, or “coded,” sounding a distinctive alarm for each station or area. Also there are “pre-signal” systems, providing for an advance alarm at a staff location and requiring a secondary manual action for sounding the general alarm. Except where these local systems are required by law for protection of life or are intended to secure insurance premium reductions, the type and arrangement selected for a particular property depends on the preference of the building owner or, as often, of the seller. By and large the systems sold today as such adhere closely to the standards set forth by the National Fire Protection Association Committee on Signaling Systems and Detection Devices, thus assuring the buyer of acceptable quality standards. UL-listed components are likewise desirable.
As noted above, the auxiliary system served admirably the need of the small factory or property wishing to get an alarm through quickly to the municipal fire department which had a street box alarm system. It did not meet the need of those in a municipality without such a system or where the plants were remotely located from the municipal circuits. To fill this gap, the so-called “remote station system” was evolved about 10 years ago and has become increasingly popular, not only for user-owned systems but also for those maintained by central station companies.
The remote station system employs separate wires (usually leased from the telephone companies) to transmit distinctive alarm and trouble signals to a municipal fire station. There is an attempt today to standardize on such equipment, particularly for the control panel at the fire station, thus simplifying supervisory responsibilities.
Certainly, industrial fire alarm is today a bigger and a faster growing industry than is the municipal fire alarm industry which sired it. This is in good measure due to the encouragement and financial support rendered by the insurance companies, which have been quick to recognize its worth in protecting insured values and to provide for this factor through attractive insurance rate reductions— some voluntarily bestowed, others forced under pressure of competition.
Broad programs needed
Municipal fire departments have contributed significantly to the high degree of industrial fire alarm protection existing today. Not only have municipal officials encouraged and advised, more importantly they have generously lent their facilities and services. Not always has this been accomplished without opposition, for there were—and perhaps still are— those who draw a narrow line between public and private, as if the private fire could be expected to remain such!
Certainly fire is no respecter of persons or artificial boundaries, and it logically should be so treated. Even as municipalities have generally taken over the distribution of water as a public service, perhaps the day is not far distant when they will view fire protection as of similar public interest and for the common good require, provide and administer it in all its phases. Not to adopt broad programs of this kind in areas of such national importance is to invite Federal intrusion to fill the gap.
“What do you want to accomplish?” is the only question
The municipal fire alarm system is much more than an alerting system; it is an organizer of the fire department in an emergency. Preplanned functions of the department are placed in systematic operation immediately on the first alarm, each company and individual fireman springing into action automatically. Modern equipment and technological knowledge is capable of expanding automation even further in today’s fire alarm system. The fire alann engineer has only to ask: What do you want to accomplish?
Circuits are versatile
The municipal fire alarm system, with its extensive wired circuits fanning out to all sections of the area and its extreme flexibility, affords an excellent opportunity for preparing a program for emergency area service. Many years ago it would have been unthinkable—perhaps dangerous—to use these circuits for other than the original purpose. Today, however, electronic improvements have taken broad and reliable form to permit many uses for these circuits and at little cost.
For many years fire alarm circuits between independent municipal systems have been interconnected to permit coded messages to be exchanged. A message from one municipality in the Boston area, for example, may be sent simultaneously to as many as seven neighboring communities. Each of these communities may similarly retransmit to others, and so on until the message has been spread throughout the wide area. Although such service today is primarily by code, no engineering problems are encountered in providing voice communication throughout the same interconnected wired network.
Currently fire alarm manufacturers are furnishing equipment for connection to fire alarm wires for police communication and for control of other municipal functions. Encoders and decoders connected in such fire alarm circuits provide means for controlling and supervising power station equipment, water works devices and other vital services. Traffic light control is well within the realm of possibility.
The municipal fire alarm system— never used to full capacity—may soon prove to be even a bigger and sounder investment than has previously appeared in helping to provide rapid area communication in emergencies. The ability of the system to transmit quickly and reliably codes for a predetermined message satisfies the need for reducing in-service time. Employment of radio utilizes important air time often needed for other transmissions; also whether radio can be used at all will depend on need for secrecy and other factors relating to the emergency. Voice on wire may well be a desirable or necessary substitute.
From early times, as noted above, automation has been an important feature of the fire alarm system. Looking ahead, one can visualize the use of modern computer techniques to further improve fire department planning and response. Information stored in the computer “memory” can readily be recovered and transmitted automatically to all responding and alerted stations, furnishing to them complete pre-fire plan instruction.
The first successful demonstration of the electric telegraph in its Washington-to-Baltimore debut was signaled with the words: “What hath God wrought?” Were Samuel Morse alive today, he might view with pride the fire alarm system which he helped to develop and ask that same question in its original form: “What wonder has God wrought?”