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Celebrating the Centennial - 1876

How the Fire Alarm Telegraph is Worked - 1877

Fire Alarm Operations during the Great Earthquake and Fire - 1906

Construction of The Central Fire Alarm Station - 1912

House of Alarm Bells - CFAS - 1937

Fire Alarm Operations during the 1989 Earthquake

Fire Alarm Operations during the Oakland Firestorm



by John Joseph O'Brien
April 2, 1951


...The people living in our great city take many things for granted. Almost every day of their lives, they see some phase of our city government in operation. Many of us, I am sure, have often seen the fire apparatus rushing to the scene of a conflagration; many too, perhaps, have often taken this same action for granted. The story of how the fire engines are dispatched to a fire will, I believe, prove interesting to the reader who will endeavor to bear with us while we present this treatise.

Photograph of the San Francisco Fire Alarm Office in the Exempt Firemans building on Portsmouth Square Many years ago when San Francisco was still in its youth, on October 5, 1863 to be exact, David Scannell, then Chief of the S.F.F.D., took the occasion to thank the Board of Supervisors for its prompt action in drawing to completion the plans for the Fire Alarm and Police Telegraph. [1] Up until that time the fire alarms were run from the old bell tower at 9 Brenham Place, which was located at Portsmouth Square.

In May 1864, James Street entered into a contract with Messers. Kennard and Co., of Boston, to furnish the City of San Francisco with a complete fire and police telegraph system for the sum of $24,000. [2]
The system was put into operation on April 24, 1865, and Charles A Stearns was its first superintendent. The complete system consisted of only thirty seven miles of wire. A typical set of directions for the proper use of the fire alarm boxes of the day is given below:
Upon the discovery of a fire near your signal box, turn the crank slowly and steadily about 25 or 30 times, then wait a few moments, and, if you hear no ticking in the box, or alarm on the bells, turn as before. If you still near no alarm, go to the next box and given the alarm from that. Never open the box or touch the crank, except in case of fire. Never signal for a fire seen at a distance. Be sure your box is locked before leaving it. [3]
In 1866, Mr. Greenwood, Superintendent of the Fire Alarm and Police Telegraph said:
A careful study during the past year reveals the fact that, out of the one hundred and nine actual fires that have occurred, fully two-thirds of the alarms have been struck before any appearance of the fire could be seen from the top of the City Hall. [4]
In the year 1899, the department made its first inspections of electrical installations in San Francisco being constructed or in the course of repair.

Upon the inauguration of the new Charter, January 8, 1900, the Fire Alarm and Police Telegraph was superseded by a new department created as the Department of Electricity. [5] During this year the department received a total of 864 alarms of which 473 were first, 16 second, 5 third, and 370 still alarms. The number of police messages handled was 114,526. [6] Also during this first year of operation under the Department of Electricity, the alarm system had in operation the following equipment:

175 tappers, 128 gongs, two automatic whistles, two tower bells, 557 miles of wire, 1,262 poles, 2,372 cells of battery, 303 fire boxes, 200 police call boxes, 43 engine house equipments, and equipment in the five central police stations.
All during this period the alarm office continued in operation at the address on Brenham Place. Then came the catastrophe of April 18, 1906. The Department of Electricity had, prior to this time, been erecting a new fire alarm office in the famous City Hall of that time. The office was in the course of being built. W.R. Hewitt was the Chief of the Department also during this time, having served from 1900 to 1908. Like most everything else in the central area, the then operating alarm office on Brenham Place was heavily damaged by the earthquake and fire. the new switchboards, then in the course of being constructed for the new office in the City Hall, were also destroyed. The fire losses suffered by the Department of Electricity together with the earthquake damage amounted to $177,400.

The damage is itemized in the lines to follow:

1. Central office of the Department, City Hall, including all records - $40,000. 2. Damage to underground system - $40,000. 3. Overhead construction - $35,000. 4. Engine house equipment - $18,500. 5. Fire boxes - $16,500. 6. Police boxes - $15,000 7. Central Fire Alarm Office (Brenham Pl.) - $7,500. 8. Police station equipment - $4,800. [8]

The alarm office to be located at the City Hall was never actually occupied. In this paper we shall indicate that it was the second home of the fire alarm, however, because if the disaster did not take place in 1906, then the City Hall would have been the permanent home of the central fire alarm office. Since this location was meant to be permanent, we can say at least that the proposed location at the City Hall was to be the second home of the fire alarm system and said location deserves recognition by being listed as the second of the five locations occupied by the fire alarm system from its inception to the present day. We shall speak of the other locations occupied by the central fire alarm office shortly.;

Following the fire and earthquake, the Central Fire Alarm Station was moved to a house located at 2032 Steiner Street. This place was a two story frame building. It was a fire hazard and was found to be totally unsatisfactory.

Next, the Central Fire Alarm Station was moved from the Steiner Street address and was set up on the second floor of a Class "C" brick building located at 55 Fulton Street. This location was likewise found to be inadequate. Permanent offices were always the goal sought by the Department of Electricity officials.

San Francisco Central Fire Alarm Station During the Fiscal Year of 1914 - 1915, the Department of Electricity manufactured and completely installed the electrical equipment at the new Central Fire Alarm Station in Jefferson square. The station is properly located at Turk and Octavia streets. The building was dedicated on February 28, 1915. Since all of the electrical equipment for the new station was manufactured in the Department's own shop and can truly be said to be homemade, it certainly represents the results of a task that is a credit to home industry.

The cut over of all working lines from the old station at 55 Fulton Street to the new station in Jefferson Square was accomplished with remarkable ease and efficiency by the underground department under the direction of Mr. Ralph W. Wiley, Engineer of Underground Construction. The entire transfer of all working lines from the old station to the new was accomplished in three minutes. At no time was a single line, engine house or fire alarm box out of service or inoperative.[10]

Chester Balliette, chief fire dispatcher, at the console at 1003 Turk St. In order to give a picture of the worth and significance of the present alarm office, I shall quote from an article by Mr. Chester L. Bailliette, Chief Operator of the system in 1931, and appearing in the Municipal Record for July of that year.

"There is one building in San Francisco upon which disaster must never fall, and to that end has been protected by every precaution that engineering could devise; it is a steel frame, reinforced concrete building meeting highest requirements of the National Board of Underwriters and is completely isolated from other buildings by being placed in the center of four blocks of public park, a block away from the nearest buildings in any direction.

"This building, The Central Fire Alarm Station, houses the complicated electrical equipment which comprises the fire alarm telegraph system of San Francisco, and which must function perfectly at all times in order that alarms of fire may be promptly received and transmitted to the Fire Department. It is the nerve center of the Fire Department, and, if out of commission, would leave them helpless like a man paralyzed." [11] Apparatus in the station is of local manufacture consisting of a cable terminal in the basement, and operating boards, central desk, power and lighting circuit control boards and telephone switchboard on the first floor. Circuits enter headquarters underground in six-40 conductor, two-50 conductor, one-60 conductor, and one-80 conductor lead sheathed cables and terminate at the distributing rack in the basement.

Each box circuit has a milliammeter (an instrument for measuring electric currents in 1/1000 of an ampere), pilot lamp, illuminated box list, power transferring and ground testing switches, rheostat, sounder, silencing switch, and on each side of the circuit, a signal key and relay. On a shelf in front of each panel are one or two inking registers. During receipt of an alarm, visible indications are given at the box circuit panel by the illuminated box list, pilot light and milliammeter, audible indication by a sounder and the signal is recorded by one pen of an inking register. [12]

Each alarm circuit has a milliammeter, illuminated station list, power transferring switches, ground testing switch, rheostat, supervising relay and register relay. Weak supervisory current, supplied by dynamotors, is interrupted by multiple contact relays and 240 volt Direct Current is thrown directly on the lines for sending out signals. During the transmission of alarms all sounders are silent, and a pilot lamp is lighted at the telephone board. Outgoing signals are recorded by a two pen register at the control desk. [13] In service are 70 box, 11 primary (or alarm), 11 secondary (or joker), and 2 traffic warning circuits. The traffic warning circuits are put in operation if the fire apparatus is required to cross Market Street; they are operated from two to five minutes when necessary. Approximately 60 percent of box circuits and 72 percent of alarm circuits are in underground cables. Fire boxes on each of the box circuits are connected in series, that is, they are connected like a string of old fashioned Christmas lights. Although we remember these old lights as troublemakers, since when one went out the whole string was extinguished, fire alarm boxes, on the other hand, are connected in such a manner for a very good reason. It is true that when the line is broken by some interfering object a whole circuit goes dead. This is because no supervisory current is flowing in the circuit. When everything is all right - no breaks in the line, etc., - a steady D.C. current flows in each of the circuits. This steady flow might seem a wasteful operation, but, as we shall see, it is better to have current flowing when all is in order and then not have a current flow when some irregularity has occurred. This is the principle used in all other alarm systems, warning devices, etc. This same principle of using the lack or absence of something to indicate the presence of some danger is also used in the air-brake systems in railroad trains. In the train, air is actually used to stop the vehicle, but the absence of air in the break setting line is used to open the valves under the cars and allow the air, which is compressed in tanks under the cars, to escape to the brake cylinders and thus apply pressure to the brake shoes.

Now in the case of the fire alarm circuits, this principle is again used to advantage. Here, however, electricity rather than air is the force with which we are dealing. If the circuit is interrupted for any reason, then the supervisory current flowing through that circuit is halted. In addition to indicating that danger has occurred to the circuit, the periodic interruptions caused in these series circuits by the equipment in each fire alarm box also indicate that a fire alarm has been pulled.

The Central Fire Alarm Station is supplied with varied sources of power. One Direct and two Alternating current circuits supply power to the building. Provisions are also made, in the event of failure of any or all outside sources of power, for the starting of a 7.5 kilowatt 120 volt D.C. generator. This building is capable of furnishing enough power for emergency lighting and for charging the batteries, etc. Such a machine, although it is tested once a week, would be used only if all outside power were cut off. [14]

What happens when an alarm comes in? Well, it is manifested by a blinking pilot light, telegraph sounder, illuminated box list, and inking register. This occurs at the central station. We must now give the answer to the question which asks us about the operation of the alarm box on the street.

Believe it or not, these boxes act like electrical switches. They are, however, mechanical in operation. When the boxes are tested every thirty days, they are wound like clocks. Such a winding makes them ready to transmit twenty-two separate alarms at four rounds per alarm. Surely, no one box is used to send twenty two alarms each month, but if an excessive number of alarms were pulled from one box, all that would be necessary would be to rewind the box. The mechanical feature of the boxes is not, therefore, considered to be a defect of any sort; they are perfectly reliable.

When the handle on a certain box is pulled (let us say it is box 7743), what actually happens is that the pulling of the handle releases an electric brake on the inking register attached to that circuit and which is located at headquarters. Next, the coded digit wheel in the box starts to revolve. This coded wheel has notches cut in it and forms one constant of the circuit. A stationary finger forms the other contact. As the wheel revolves, the notches cut in it pass under the stationary finger and the circuit is interrupted for a fraction of a second while this is taking place. This interruption in the circuit causes the pen on the inking register at the central station to rise and make a mark on the already moving tape. [15] The inking register which responses to a certain box is obviously the one connected to the circuit to which that box is connected. The tape reading for an alarm pulled at box 7743 would look like this:

(------- ------- ---- --- ). Since each box sends out four rounds of the alarm, the completed tape for an alarm would look like this:

(------- ------- ---- ----   ------- ------- ---- --- Continuing
------- ------- ---- ---    ------- ------- ---- ---)

...following the second round of an alarm being received at the Central Fire Alarm Station, the relay operator checks the number and the key operator, using a telegraph key, transmits two rounds of the alarm over each class of alarm circuit. He starts the Police radio transmitter and announces the box number twice. If the fire apparatus has to cross Market Street, the traffic warning bells are sounded for a period of from two to five minutes.

The control desk for the fire radio is also located at the Central Fire Alarm Station, but due to the high frequencies used in this two way ratio, its transmitter is located on the side of Twin Peaks. Fire companies receive the reports of fires by means of the fire alarm bells in the fire houses. Sometimes, however, the various chiefs are away from the fire houses and they are notified of a fire by means of this high frequency radio. Since both the chief's autos and the central station are all on the same broadcast frequency, a two way conversation can take place between the cars and headquarters, between headquarters and cars, or among the various cars that are in service. [16]

When each shift of operators comes on duty at the Central Fire Alarm Station they wind all register springs and test all circuits for crosses and grounds. Ground tests are made for each box circuit at the end of each box test. Among the other duties of the operating personnel are the checking of the operation of the Police radio transmitter, the maintenance of the automatic time for the traffic signals (old bird cage type-the new signals have their master control at the end of each street they serve). The crew also records all box tests and directs the work of clearing box circuit troubles. Test signals are sent out over the system three times daily. The day I visited the office, March 20, 1951, a power shovel had just finished tearing out six lines buried underground out near the Bayshore Freeway. The "hospital circuit" at headquarters was put into use in order to bypass the break and restore to operation an otherwise inoperative circuit. Many "joker" or report signals are sent out on the secondary alarm wires to transmit business, et. Pay day is announced to the Fire Department by the 7-7 signal. This is a type of signal that is carried over the joker circuit.

Assignment officers from the Fire Department are on duty in the assignment office. Two lieutenants or a lieutenant and a captain are on duty at one time and, following a third alarm, a battalion chief. It is their duty to announce and direct the movements of fire apparatus for special types of services and also to bring in engines from outlying districts to cover for those who might be in service at the time.

The Department of Electricity, in addition to operating the fire alarm system and maintaining same, also performs the following services for our community:

1. The electrical inspection of old and new buildings and the supervision of overhead construction.

2. The collection of fees for electrical inspections.

3. The operation, maintenance and extension of the fire alarm and police signal systems of the city.

4. The manufacture of such equipment as is necessary to properly maintain and extend the fire alarm and police signal systems.

5. Traffic signal maintenance and repair.

6. Parking meter maintenance and repair.

Ralph W. Wiley, previously referred to as the Engineer of Underground Construction was the Department's former chief. Mr. Wiley invented the old "bird cage" type of traffic signal which is gradually being replaced now by street signals of a newer and improved design. In order to regulate the operation of his "creations," Mr. Wiley also invented the automatic electric timer which is located at the Central Fire Alarm Station. This device still regulates the signals which are still in use. Mr. Wiley died in 1949 and was succeeded by Gordon C. Osborne, who now directs the numerous and varied duties of the Department of Electricity.


[1] San Francisco Municipal Record, Louis C. Levy, Editor, San Francisco: July 1931. Vol. V No. 5 p.13

[2] Ibid.

[3] Ibid.

[4] San Francisco Municipal Reports 1865 - 1866, For the Fiscal Year Ending June 30, 1866. San Francisco: Towne and Bacon Co., p. 218

[5] San Francisco Municipal Reports 1899 - 1900, For the Fiscal Year Ending June 30, 1900. San Francisco: The Hinton Publishing Co., p. 569.

[6] Ibid.

[7] Ibid.

[8] San Francisco Municipal Reports 1907 - 1908, For the Fiscal Year Ending June 30, 1908. San Francisco: The Neal Publishing Co., p. 713

[9] Municipal Record, July 1931. p. 16.

[10] San Francisco Municipal Reports 1914 - 1915, For the Fiscal Year ending June 30, 1915. San Francisco: The Neal Publishing co., p.530.

[11] Municipal Record, July 1931, p. 20.

[12] City and County Record, George H. Allen, Editor and Publisher, San Francisco: January - February 1949. Vol. XVI Nos. 1&2. p. 23.

[13] Ibid.

[14] Ibid, p. 24.

[15] This information was gathered at the author's visit to the Central Fire Alarm Station.

[16] Ibid.

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