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History of the San Francisco Fire Department Fire Operations During the 1906 Earthquake by Patrick H. Shaughnessy 1906 Death of Chief Sullivan 1907 AWSS Proposal By Rolla V.Watt 1911 AWSS Civil Service Questions
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Water Supply System
Bureau of Engineering and Water Supply San Francisco Fire Department Every San Franciscan is familiar with the great San Francisco Earthquake of April 18, 1906, and the conflagration which followed, leaving a major portion of the City in ashes. Few people, however, know that most of the damage resulted not from the 'Quake, but from the ensuing fires the worst fire in the history of the United States. More than 300 water main breaks and over 23,000 broken water services turned the water distribution system into a sieve, and reduced water pressure to the downtown area. Four days later, by the time the fire was finally extinguished on April 21, all of the City's downtown area was destroyed. Twenty- The 1906 Earthquake crippled the City's water supplies, and left firefighters literally drafting from sewers in an effort to halt the conflagration, and the people of San Francisco blamed the destruction of the City on the failed water system. Insurance rates soared, and, in some areas, coverage was unobtainable. In 1908, Marsden Manson, the City Engineer, conducted a study of 250 cities throughout the world to develop plans for a guaranteed water supply system for the sole purpose of fire protection. Exhaustive tests of pipe materials, valves and hydrants were conducted, and many eminent engineers of the period were consulted. All arguments were for a separate fire combat water system and against a private system outside the jurisdiction of the Fire Department.
The solution was the design and construction of the Auxiliary Water Supply System
(AWSS) for fire protection a separate and distinct water supply system for fire
protection use only with the Fire Department solely responsible for its
maintenance, operation and development. Adequate volume and pressure
were the primary foundations of the many ideas which eventually evolved into the San
Francisco AWSS. More water main pressure meant less dependency on the horse-
The AWSS remains the only high- Strongly influenced by the insurance companies of the period, the AWSS is dedicated to the principle that the City will never again be destroyed by fire, at least not for lack of water for fire fighting purposes. It is capable of covering a city block (100,000 square feet) with water to a depth of 25 feet in one day.
Over the years, as the needs of the City have grown, the distribution system has been
improved and increased, from an original 72 miles of mains with 889 hydrants, to a 1997
total of 150 miles of 8- The AWSS system utilizes San Francisco's hilly terrain and waterfront perimeter to the best advantage with an excellent combination of features. The structure and design of each component illustrates how the design engineers aimed to defeat the devastating results of earthquake and fire. These include:
When the entire fresh water system fails or is depleted, there are two emergency saltwater
pumping stations built on the Bay's shores, each with a pumping capacity of 10,000 gpm,
which can supplement the water supply with saltwater at a pressure of 300 psi. The
stations, built on solid rock, are self-
When and if the emergency back up pump stations fail, two fireboats (originally the
Dennis T. Sullivan and the David Scannell), the Phoenix and the
Guardian can make hose connections directly into the AWSS via five special
manifolds along the Bay's perimeter. The Phoenix has a pumping capacity of over 9,600
gpm, equal to that of one of the stationary pumping facilities. The Guardian has the
largest pumping capacity of any fireboat in the world (24,000 gpm) and is the only fireboat
that is outfitted with a 5-
A network of cast iron and special ductile iron distributing pipes in three levels, or zones, with a total length of 150 miles of mains, fitted with 1550 special hydrants, gate valves, and fireboat connections.
In a last-
Thirty-six water suction connections surround the City's waterfront to allow fire engines to draft saltwater from the Bay of San Francisco. The mains in the lower zone at the city's base elevations are under a static pressure of 160 psi. If, during the process of a fire in the lower zone, the incident commander needs an increase in pressure above that normally supplied to the lower zone, a radioed command will put Ashbury Tank on the line; gate valves between the two zones will be opened by a tank attendant at Jones Street Tank, and the pressure in the mains at the city's base will increase to 214 pounds per square inch (psi). Should it be necessary to increase the pressure further, another order will place the Twin Peaks Reservoir on the line and increase the static pressure to 328 psi. If for any reason the quantity of water delivered in either zone is not sufficient, the supply can be increased by placing either one or both of the saltwater pumping stations in service.
The original pipe distribution system is constructed of special extra-
A special double-
During the 1906 earthquake, areas of filled or man-
Specially designed dry barrel hydrants were used. The hydrants are equipped with three
3.5-
The need for extensions and relocation of the distribution system has prompted the City to
update the original system with new materials and construction techniques. Because the
original cast materials were found to be extremely expensive to manufacture and install at
present-
Ductile iron pipe with push-
To provide a restraint against pipe joint movement resulting from the static pressure force,
special ductile iron collars were designed. These can be slipped onto the pipe and held
together with tie bolts. One collar is held by the pipe bell and is designated as the "bell
collar"; the other is held by steel stops welded to the spigot end of the pipe and is
designated as a "stop collar." The steel stops are only one inch in radial height, so they
effectively carry no bending load. The stop length varies from two inches for eight-
Special ductile iron pipe fittings were designed to be used in conjunction with the modified
commercial pipe. To reduce pattern costs, the fittings utilize industry-
In an emergency situation, every second of time can mean lives. No one understands that
better the Fire Department. The AWSS, in conjunction with a new Supervisory Control
and Data Acquisition (SCADA) system, can now better ensure that the necessary
component for fire combat water is available immediately in any situation.
The AWSS allows for dynamic routing and rerouting of water throughout the three primary
zones of the system via valve sites. The challenge in emergency situations is to determine
where the water is needed to operate the valve. This can prove cumbersome and labor-
The SCADA system operates on the existing 800 mHz trunked radio system in use city-
The two Central Control Processors (CCPs) are based on a VAX 4000 platform running a
software package with a graphic user interface. This is a very user- Another unique feature of the SCADA computer system is the provision of control capabilities from either one of the two fireboats that patrol San Francisco Bay. This challenge is met by providing radio link and laptop computers to the fireboats running the same software program. These devices are also carried in the vehicles of the three Fire Department division chiefs. This provides a full range of operational capabilities from many decentralized points an invaluable asset in the event of a disaster.
Though in operation since 1912, the AWSS still has many integral sub-
Incorporated into the design of the AWSS is the ability to expand along with the ever-
San Francisco Fire Department Business number (415) 558-
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