Fire Alarm Telegraphy

Fire Alarm Telegraphy

The article “Non-Interference and Succession Boxes in Fire Alarm Telegraphy,” appearing in the June Number of The FIRE ENGINEER, was read by me with mixed feelings of pleasure and disappointment. Pleasure in that an attempt has been made to lay before those who are interested, reliable information with regard to a matter about which little is generally known or written. Disappointment in that the description of the functions of some of the apparatus mentioned, while technically all that could be desired, yet was meagre and involved and not sufficiently clear as to give the uninitiated a proper understanding of the subject.

I hesitate to supplement anything written about fire alarm boxes by one so eminently qualified to write as Mr. Faller, and I appreciate that the article was merely one of general description and not of detailed information, but in the interest of a spread of useful information I am taking the liberty of elaborating somewhat on what Mr. Faller has said about the Wiederhold box.

This type of box operates normally on closed circuit, but will function and preserve its non-interfering features whether the line is open or closed. When the box is operated the first function of the mechanism is to ground the circuit, which ground connection is broken when the first notch on the code wheel passes under the circuit breaking device. As the circuit breaking device passes out of the notch and rides on the periphery of the code wheel, the ground connection is again restored to the line. This operation is repeated for each make and break of the circuit in accordance with the predetermined number of the box, and it follows from this, that while this type of box is in motion, the circuit is alternately grounded and opened by the mechanism.

Referring to the attached diagram, it is apparent at once that when box 2 is set in motion and a ground connection is established at G2, two circuits having a ground return, G2-G, have been made, one containing battery B, relay A, and Box No. 2, and the other containing battery Bl, Relay Al, and Boxes 4 and 3. When the circuit breaking device passes into the first notch of the code wheel, it is obvious that both these circuits are opened simultaneously, causing the Relays A and Al to function. Similarly if box No. 4 is operated and no other box on the line is functioning, two circuits will be alternately made and broken, one containing battery Bl, Relay Al, and box 4, and the other containing battery B, Relay A and Roxes 2 and 3. It is evident then that when only one box on the line is operating, the effect upon the line relays is exactly the same as would be produced by a plain interfering box. If, however, boxes 2 and 4 are operating simultaneously, it is obvious that box No. 2 will actuate relay A only as it is manifestly impossible for any electrical disturbance set up in box. No. 2 to pass through the line to relay Al since the line at box 4 is either grounded or open; and similarly no disturbance in the circuit set up in box No. 4 will actuate relay A for the reason that the line is either grounded or open at box No. 2. Hence there can be no inter ference of signals when two boxes are operated on the same circuit at the same time. But it follows naturally that all boxes connected on the line in that portion of the circuit away from the relays and between the two boxes in motion are inoperative. Referring to the diagram, it should be plain that while boxes No. 2 and No. 4 arc operating, box No. 3 is shunted out or insulated from the circuit by the alternate grounding and opening of the circuit at boxes No. 2 and No. 4.

SCHIEMATIC CIRCUIT OF WIEDERHOLD FIRE ALARM BOX

Flight per cent of all fires last year were due to electricity. Cheap insulation, amateur wiring, short circuits and arcs caused more fires than the old kerosene lamp.

FIRE ALARM TELEGRAPHY.

0

FIRE ALARM TELEGRAPHY.

Mr. Joseph W. Stover, president of the Gamewell Fire Alarm Telegraph Company, of New York, recently delivered a lecture at Columbus,Ohio,on the subject of “Telegraphic systems for the facilitation of fire and police service.” Much of the information it contained has already appeared from time to time in the pages of FIRE AND WATER; but at Columbus, Mr. Stover, who is essentially an up-to-date and progressive man, gave some additional facts founded on more modern experience. Coming from such a source and an authority so unimpeachable as Mr. Stover, his words carry more weight than those of an ordinary speaker.

Mr. Stover pointed out that there are now nearly 800 places in the United States equipped with fire alarm telegraph service; and so wonderful has been the advancement in the system from its early beginnings at Boston in 1866 that

to-day a fire alarm system, as found in our large cities, is one of the most complete triumphs of modern skill and genius in the application of electrical science to the uses of mankind * * * The perfected fire alarm service of to-day is an evolution, not the work of any one or two men; but the outcome of the combined inventive genius.and mechanical skill of many.

Mr. Stover then passed on to the storage-battery system and its advantages in the way of economy and saving of room.

The history of fire telegraphy (he went on) has not only shown rapid progress towards greater certainty of operationand a multiplication of the functions of the apparatus to meet the demands of nineteenth century civilization, but every effort that science and ingenuity could muster has been brought to bear on the vital question how to save minutes, and even seconds, in giving alarms of fire. In spite, however, of all the progress in this direction, it was, until quite recently, necessary for the person discovering a fire to run to the street box to give an alarm. The alarm once given, not a second is lost in getting the engines to work; but the time lost in getting to the street box, which may be two or three blocks away, or in getting from the upper story in the building to the street, is of such incalculable value that a system has been devised whereby this valuable time is saved. This system is known as the auxiliary fire alarm; and its use in the dozen or more important cities of the country in which it has already been placed has conclusively demonstrated its importance and value. The history of the auxiliary system is a continous record of fires “nipped in the bud,” of lives saved, and of a greatly reduced rate of property lost. This system practically multiplies the number of street signal stations indefinitely. It,in effect, brings these street boxes within dwellings, factories, hotels, schools,and other institutions. Any desired number of small auxiliary boxes, about the size of a man’s hand, can be scattered throughout a building in convenient locations; and these are electrically connected with the nearest street fire-alarm box. In case of fire it is only necessary to break a glass in the front of an auxiliary box, pull down a ring, and the street box to which it is connected is immediately set in operation, and the alarm promply transmitted. In case of fire in a school! where the lives of children are the first care, the teacher can pull the auxiliary box at her desk, and, secure in the knowledge that help is coming, lead her pupils out without panic. From this brief explanation you can easily understand the great value of such a system in factories, hotels, theatres, and even in private dwellings. Chief Bonner, of the New York fire department, says that he “counts seconds” in getting to fires When it is a question of minutes saved, the gaeat value of such a system as the auxiliary cannot be overestimated.

In concluding what I have to say on the subject of fire alarms, permit me to add that,to secure satisfactory results the systems used must be prompt and certain in action and durable in construction. The street stations should be easily accessible and so simple that anyone discovering a fire will know how to use them; in fact, so perfect that mistakes in starting an alarm will be impossible. The alarm apparatus must be powerful enough to waken men,if asleep,and reach them anywhere within city limits. In the construction of firealarm telegraphs, long experience and superior mechanical skill are of the utmost importance. Everything should be of the best material and workmanship. Much of the apparatus must be placed out of doors, exposed to wind and rain and the constantly recurring changes of our variaole climate; hence, the finer parts must be substantially made and carefully protected. Poitions of it may stand unused even for months, but. when needed, it must respond quickly and correctly. A single failure might result in a loss far beyond the cost of the best system; and it is poor economy which regards cheapness as of more importance than reliability. The lines should be built with the best quality of galvanized iron or hard-drawn copper wire,every joint soldered,thoroughly insulated, and secured to poles not less than twenty feet above the ground. Where the circuits leave the central office and enter bell towers, engine houses, or street signal boxes, iron wire should be well soldered to thoroughly insulated copper wire leading to the apparatus. During recent years, in large cities, it has become necessary to protect the wires of fire and police telegraphs by placing them in cables in underground conduits. It is of the utmost importance that this work should be perfectly done, in order that the fullest benefits may be realized from the expense required in making this important change.

JOSEPH W. STOVER, PRESIDENT GAMEWELL FIRE ALARM TELEGRAPH COMPANY, NEW YORK.

After speaking of the benefits resulting to the community from the extension of the telegraph alarm system to the police department also, Mr. Stover insisted upon the importance of the municipal authorities seeing to the installation of such systems, which should be the best—the cheapest system being seldom the best, while the “ best most always proves the cheapest.”

Statistics (Mr. Stover added) show that for the past ten years the losses by fire have averaged over $100,000,000 per annum. This amount dissipated in flame and smoke! Individually owners may be partially reimbursed by insurance; but none the less the loss is actual. It is so much wiped out—just the same as if it had been thrown into the sea. In New York city, just as the present administration of the fire department was claiming a great reduction of losses for 1896 and 1897. as compared with previous years, the board of underwriters of that city, reports that for May,June, and July of this year, the losses have been $615,293, while forth# same three months of 1896 the losses were but $339,325. The fact is that comparisons in this line seldom establish anything,and excessive losses in a given time cannot always be attributed to the inefficiency of the fire department, anymore than an exceedingly limited amount of loss in a given period can be always attributed to superior management or efficiency of that department. But one thing a city official can always count on—that unexpected and excessive losses by fire in a municipality will surely be the subject of investigation by insurance interests; and it is, therefore, for their own credit, as well as for the interests of those who have placed them in office, that everything pertaining to the .ire department shall be at the highest point of efficiency.