Locating the Fire Alarm Box
Scheme Developed to Make It Easier for Man in Fire House to Locate the Fire Alarm Box From Which the Signal Was Flashed
MANY changes have taken place in the methods of transmitting fire alarms in recent fires. A few years ago residents of small cities (and even today residents of small villages) were aroused by the clanging of church or school bells. Any means possible was used to inform the community that a fire was raging and to call the volunteers to duty.
Then came the telephone, an instrument which today plays a most important part in notifying fire fighting companies that fire has started its destructive work again in the community.
With telephones now more common as home equipment than ever before, the problem of letting the fire department know that there is a fire can be solved comparatively easily. But the telephone is not without its handicaps, according to fire chiefs and other officials, and they are very serious handicaps, indeed.
It is the general opinion among these officials today that the safest and most positive method of sending a fire alarm to headquarters is by way of the fire alarm box. located on the street corner or in public buildings. The principal reason for this belief is that most of the chance for human error is eliminated as the action is entirely automatic after a person pulls the box lever.
When the mechanical parts of a fire alarm box are set in motion the slow revolution of a notched wheel, called the break wheel, opens and closes the electrical circuit of the box. Every time a notch passes the contact point the circuit is opened thus interrupting the steady flow of current through the box and shutting off the current which holds the hammers of the various gongs in the fire stations in place.
The notched wheel is coded with the particular number of the box so that if three and four blows are struck in close succession it is known that the box number is thirty-four. As soon as the number is struck on the gongs the firemen refer to their filing devices for the number “34,” find the location of the box pulled and proceed to the fire.
The efficiency of this system is evident. The chance for human error is almost completely eliminated. There are no excited voices to understand, only a mechanical box to obey.
In an effort to further eliminate mistakes in sending fire alarms by telephone or by the alarm box method, Edward R. Swett, Jr., of Muskegon, Michigan, has devised a new transmitting fire alarm system for use in Muskegon, which can also be installed in any city regardless of size.
In the new system more of the responsibility of the operator or sender of the fire alarm is transferred to the mechanical parts bf the system thus further eliminating the chance for error.
The key to the system and the point about which it revolves is a large map of the city in which the system is to be used, divided into zones, districts and blocks, all of which are numbered. The map is equipped with a lighting system with bulbs for every street. The small electric bulbs are so placed that when switches opposite a list of the street names along the edge of the map are thrown, two lines of lights cross at the intersection of streets reported to be nearest the fire, this locating exactly the zone, district, and block of the fire.
The second most important feature of the system is the card file, copies of which are kept at the central alarm headquarters and at every fire station in the city.
Upon the cards kept in this file is the following information. The number of the card, the location of the alarm, the fire companies which are to respond to that location on the first, second and third alarms, and any other information necessary for the proper dispatching of fire fighting apparatus.
The card number, of course, corresponds to the zone, district and block numbers by which the nearest street intersection is designated. The system provides for four numbers for all boxes instead of a mixed system of one, two and three or more numbers for boxes. The advantage of having the same number of digits or every box having four numbers, is alone a great advantage. Under conditions found where one, two, three and even four numbered boxes are used, it is impossible for anyone to determine when the box first conies in as to what digit box it is. They are, therefore, placed at the disadvantage of not knowing positively when one round of the box has been completed. For an example, suppose that box “5531” was pulled. In their anxiety to respond to the alarm firemen left on the first two or three numbers, namely “55” or “553” and as soon as the apparatus had cleared the engine house the last one or two numbers came in. An error of this kind, of course, sends the apparatus to a different point in the city, and is liable to turn into a very serious error.
The first number gives the zone, the second the district, in the zone, and the third and fourth the block number. Each fire company is responsible for fires within its district or zone.
For instance, a fire alarm box in Zone (5) may be pulled and the alarm will come in to the central headquarters as “5531.” The first digit designates Zone (5); the second marks the box location as in District (5), and the last two digits designate Block No. (31), the exact corner the box is located on.
When this signal has been received by the operator, it is a simple matter to relay the information to the fire stations where each captain can refer to his filing system, know wheer the fire is, if not in his own district, and where his company is to go on the second or third alarm.
When telephone alarms are received by the operator, levers opposite the names of the two streets given, or the street intersection on the map, will be thrown and the two streets will be lighted up by the small bulbs, showing instantly the zone, district, and block number. The operator then, upon getting this information, sets this number up on the transmitter which relays the calls to the various stations automatically. Consequently as far as the firemen in the engine houses are concerned, they get the call in exactly the same way as if the fire alarm box had been pulled on this corner, whether there is actually one located there or not.
One of the many advantages of the new system is the saving in time, by insuring that every company in the city will know the exact location of the fire within a few seconds after the gong starts ringing. Instead of relaying the information as to the location of the fire by mouth, the operator merely turns to the transmitter sending the proper numbers by the mechanical devices instead of depending upon human chances for error, caused by similarity of street names found in so many cities, mispronounciation, etc.
Zoning the city provides for unlimited territorial expansion in the future, as all that there is necessary to do when new territory is annexed is to put in new districts.
The problem of finding suitable numbers for new fire alarm boxes to be installed in the future is also eliminated as each street intersection has a number definitely established, and when a box is to be erected on any given corner, all that it is necessary to do is to get this number from the Fire Alarm Board and order the new box with that number.
This system has been installed in Muskegon, Mich., and Grand Rapids, Mich.