FIRE ALARM SYSTEM, MINNEAPOLIS. MINN
THE first fire alarm system at Minneapolis, Minn., was installed in 1875. It had then only 37 boxes, each costing $250, and its extreme limit was Franklin avenue on the west. The system has gradually been improved, till now it is one of the best in the United States. The improvement is mainly due to the persevering efforts of Chief Stetson, who also during seven years has left nothing undone to have the fire department wires placed under ground, with those of the electric light companiesand telephone companies to follow within the specified limits. Since Chief Stetson’s return to the department in 1895,many important additions and improvements have been made to the service. A new switchboard and two new repeaters have been purchased and placed in the central office at headquarters, whereby the operations of service have been greatly facilitated.
The present lire alarm signal service (Gamewell) has cost in all about$80 000, and is maintained at a yearlyaverage cost of between $7,000 and $8,000. Each keyless box, of which there are 35, cost $165, and the common boxes, 280 in all, $125. These are provided with 300 miles of underground, and 200 miles of overhead wire, the distance between boxes north and south being 10 miles.
The headquarters of the fire alarm telegraph is in a small office at fire headquarters at Third avenue N and Second street. It consists of a central or battery station, the wire circuits of which connect the central office with the street signal boxes. To supply the electro-motive force 900 battery cells are required. These are located in the basement at fire headquarters.
The system is commonly known to electricians as “ The Automatic Central Office. ” Its chief features are the big switchboard and the two repeaters, the latter of which cost $3,000 each. The city is divided into 15 circuits, and the repeaters are so arranged that a signal on any one circuit is instantly repeated on all the others. It enables the connection of signal boxes, bell strikers, gong strikers and indicators indiscriminately and directly with each other.
One conspicuous feature in the new service is the large switchboard, with its double row’ of shining bells across the top; and these bells make up a perfect chime.
This switchboard is a very fine piece of electrical mechanism, as, indeed, are also the signal boxes themselves.
The fire alarm department which is under the charge and supervision of Zach. T. Morrison, chief electrician, who, with an assistant and linemen at headquarters, has likewise control of the police signal wires, all of which are underground and are of standard, paper fibre solid-core twisted-pair cable.
The system is also connected with the public telephone exchange, and Chief Morrison has three telephone operators at headquarters with him.
The probabilities are that, in order to save time in the fire service of the city, the present system will be changed into the central-office system, when all alarms will be received at the central office and, sent to the engine house by the operator.
During the first year 1 12-circuit Gamewell automatic repeater and 1 22-circuit marblcized slate switchboard have been added to the fire alarm department, and live new circuits have been built, ‘file system at present includes the following: Fifty miles of poles; 200 miles of aerial wire; 200 miles of underground wire; 1 12-circuit,and 1 10 circuit automatic repeater with 1 4-circuit automatic repeater in reserve; 275 fire alarm stations; 34 electro-mechanical gongs; 1 22-circuit marblcized switchboard; 8(19 cells of “gravity” battery; 37 cells of I .a Clanche battery. The batteries connected with the system have been moved from the second floor to the basement of the headquarters building for the sake of obtaining more suitable room.
During the past year there were sent over these wires,out of 770 alarms for fires, 551; 59 by telephone, 23 by American District telegraph. 19, personal service; 148, still; 1, first alarm special call; 16 second alarms; 7 third alarms; 2 second and third alarms combined; and 19 special calls. The department has traveled, in answer to calls, 6,062 miles—total distance traveled both ways, 12,124 miles, or an average of 192*3-9 miles to each apparatus. Engine companies stretched 273,950 feet of hose—about 89 4-5 of a miles (engine company No. 1 stretched the greatest number of feet. 43,150). Hook and ladder companies have raised 19,256 feet of ladders, and hook and ladders carrying small chemicals have discharged 328 charges of small chemicals; chemical engines have discharged 443 tanks, making a grand total of chemicals used of about 26.658 gallons. The total amount of hours’ service at fires has been 5,201.25, an average of 82 12 hours to each company.
It is needless to say one word in praise of the Minneapolis fire department. The high reputation it has earned under Chief Stetson and his officers is too well established to require further commendation.