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1945 Theatre Catalog, 4th Edition, Page 256 (232)

1945 Theatre Catalog, 4th Edition
1945 Theatre Catalog
1945 Theatre Catalog, 4th Edition, Page 256
Page 256

1945 Theatre Catalog, 4th Edition, Page 256

Fire Protection Equipment for the Theatre

What Fire-Fighting Equipment is Needed


And How it is Used is Clearly Explained,

Fire extinguishers are provided for general protection against incipient fires and for safeguarding specific hazards which are known as likely points of origin for fire. Before suitable extinguishers can be selected for these purposes, it is necessary to know something of the nature of tire, the means by which it may be extinguished, the extinguishers which provide these means, and what kinds of fire may occur in the theatre and where.

In order to have a fire, there must be sufiicient Heat and sufficient oxygen, in addition to a material that will burn. To put out a fire, therefore, either the heat or the oxygen must be removed from the burning material. To reduce the heat, extinguishers which provide water or chemicals in water solutions are used, since water is a highly effective cooling medium; to remove the oxygen, an extinguishing agent which will separate the burning material from its air supply is necessary. With some kinds of fire, either method may be used, but this is not true of all fires and the


Preside"! of the Chemical Fire Extinguisher Association

method employed will be determined by the nature of the materials involved.


Fires in ordinary combustiblesepaper, cloth, wood, and similar materialseare defined as Class A fires. They can be put out by either the cooling or the smothering' method, but cooling is the more effective.

Fires in flammable liquidsegasoline, oil, kerosene, paint, grease and the like eare designated as Class B fires. They are best extinguished by smothering.

Fires in live electrical equipment are known as Class C fires. Since the application of water to such fires may damage the equipment and endanger the fire fighter, it is essential to use extinguishing agents that are non-conductors of electricity.

Extinguishers which may be used on

THE SODA ACID EXTINGUISHER acts through the pressure created when sulphuric acid acts on sodium bicarbonate dissolved in water. When the extinguisher is inverted, these two chemicals react, and the carbon dioxide formed forces out the water. The 21/2-gallon extinguisher is rated as one unit of protection. It should be serviced immediately after use, or at least once a year, to make certain that it is always ready for action.


Class A fires only are the pump tank, the soda acid, and the gas cartridge types.

Those which may be used on both Class A and Class B fires are the foam and the loaded stream types.

Those which may be used on Class B and Class C fires are the vaporizing liquid and the carbon dioxide types. These may also be used successfully on small Class A fires where there are no drafts or air currents, if the fires are not too deeply entrenched.


Every approved fire extinguisher bears an Underwriters, Laboratories, label that indicates the class or classes of fire for which that extinguisher should be used and the number of extinguishers of that capacity which are considered necessary to comprise one unit of protection. The symbols, tiA-l, B-lji for instance, on the Underwritersi inspection label mean that the extinguisher so labeled is approved for use on Class A and Class B fires and that it constitutes one unit of protection for either class of fire. The relative amount of fire protection afforded by the different types and sizes of portable extinguishers has thus been standardized according to units, and the number of units required in any particular location depends on the severity of the incipient fire that may be anticipated. While most of the approved types of extinguishers are made in more than one size, only the most common sizes will be discussed here.

Pump Tank

The pump tank contains plain water which is discharged by means of a builtin hand pump. Anti-freeze chemicals approved for the purpose may be added to the water. One 5-gallon or two 2%,gallon extinguishers are rated as one unit of protection.

Soda Acid

The principal extinguishant in the soda acid type is water. Pressure is generated when bicarbonate of soda (dissolved in the water) and sulphuric acid (in a bottle suspended in the neck of the extinguisher) are mixed. The mixing takes place when the extinguisher is inverted. One ZlAg-gallon extinguisher is rated as one unit of protection.


The foam extinguisher, which is shaped exactly like the soda acid, contains a solution of bicarbonate of soda and a foam stabilizing material dissolved in water and, in an inner cylinder, a solution of aluminum sulphate in water. When the extinguisher is inverted, the mixture of the two solutions generates pressure for the discharge and at the same time creates foam which blankets the burning material and smothers fire.

1945 Theatre Catalog, 4th Edition, Page 256