Fire Protection Features at PanamaPacific Exposition
Certainly no exposition had a fire protection system comparable with the one installed at this one, and it may safely be said that few communities enjoy an equal security against fire. Located as it is within the city proper and close to the residential district, the Exposition represents a tremendous fire hazard to the city, and the problem of fire protection was carefully studied by the engineers of the Exposition in consultation with the Board of Fire Underwriters. In compliance with the general plan adopted, a high pressure water system was installed throughout the main portion of the grounds and as far west as the Live Stock section. The system was designed to operate as a part of the city’s auxiliary water supply system and to be capable of delivering 15,000 gallons per minute at any hydrant, at a pressure of 200 lbs. per square inch. The distribution system includes 52,000 lineal feet of pipe in sizes from 6-inch to 16-inch lapwelded pipe and Dresser all-steel couplings are used throughout, with extra heavy flanged cast iron fittings and valves. All hydrants arc of the flush type, set in circular concrete manholes with wooden covers. The hydrants have two 3-inch outlets and are spaced approximately 300 feet apart. With the exception of the Fine Arts and Horticulture buildings, the high pressure system is brought into all exhibit buildings. Four 8-inch pipes are run into each building, one from each side, and serve the inside and roof hydrants, the automatic sprinkler system, the cornice sprinklers and the roof monitors. The 8-inch valves controlling the supply to the buildings are kept closed, but the 4-inch by-pass valves are left open. This practice was adopted to limit the damage in case of a break inside the building. These 8-inch control valves are located outside the buildings and in the same manholes are installed 6-inch cross connections to the low pressure supply, with check and gate valves, so that in the event of a failure in the high pressure supply the sprinklers will be fed from the low pressure system. The roof and inside hydrants have 3-inch outlets, and arc so located that any portion of the roof or floor can be reached with 150 feet of hose. The monitors have a capacity of 1,500 gallons per minute and are set so as to play on the buildings opposite them as well as on the roofs on which they arc located. The cornice sprinklers are arranged to produce a water curtain on the sides of the building which face one another and are less than 150 feet apart. Automatic sprinklers are installed in all exhibit buildings, with the exception of the Palaces of Machinery, Horticulture, Fine Arts, the Festival Hall and the administration portion of the California building. The domes in the eight buildings of the main group and the ceiling of the Palace of Machinery are not equipped with sprinklers, as the height is so great that the effectiveness of sprinklers is questionable. In the design and construction of the buildings fire protection was borne in mind. Concealed spaces where a fire might flourish unobserved were carefully avoided, and heat curtains were used extensively to prevent circulation of air and insure the confinement of heat and operation of the automatic sprinkler and fire alarm systems. Reinforced concrete fire walls were built where the architectural requirements resulted in buildings being connected by colonnades or other decorative features. The exterior building walls were carried down to the ground surface and sheathed on the inside to a height of 12 feet above the floor. The roofing used had a top sheet of either crushed brick or asbestos, and wire glass was used in all skylights, preventing fire being caused by anything falling on roofs. Additional protection was afforded by hydrants connected to the domestic water supply system by the installation of 3-gallon chemical fire extinguishers and by suction pipes at the various parts to be used in connection with fire engines. The fire department is operated as a part of the city’s department, which answers all alarm calls on the Exposition grounds. Three fire houses, with equipment, are located on the grounds. A complete fire alarm system was installed and a complete central office located in the Liberal Arts building is operated as an exhibit. All exhibit buildings and many of the detached buildings, especially those having moving picture apparatus, arc equipped with an automatic fire alarm system of the pneumatic tube type. Copper tubing not exceeding 1,000 feet in length is run around the ceiling or parts of buildings where heat from a fire would quickly affect the tubing. The tubing is 0.09-inch outside diameter with a hose approximately 0.045-inch in diameter. One end of each tube is connected to a detector, consisting of a sensitive metallic bellows such as is used in aneroids. In the event of a fire the pressure of the air in the tubing is increased, due to the expansion of the contained air and the bellows expands and closes an electric circuit, which in turn sends a signal to the central fire alarm station and to the annunciators placed at the building entrances to inform the fire department of the location of the fire. The bellows mechanism or detector is located in a steel cabinet which contains five detectors, each connected to about 1,000 feet of tubing. The buildings of the main group have at least five of these cabinets in each building, and some as many as eight, while the buildings of minor importance have a lesser number. The fire protection measures adopted by the Exposition cost in the neighborhood of $900,000, but the fire losses up to August 1 have been insignificant.