Some adequate provision should be made to deluge the stage with water in case of an outbreak of fire in that section. Should fire occur in the dressing or other rooms, chemical extinguishing tanks are the best known aid in confined areas. The excessive cost of installing an elaborate so-called "patent" sprinkler system compels the serious consideration of a home-made substitute. The regular sprinkler systems on the market works automatically by excessive heat melting an alloy composition sealing the sprinkler heads, thereby releasing the water constantly held in the pipes. This sealing substance melts at a temperature of about 110 degrees Fahrenheit, and when the water is once released nothing but an exhaustion of the supply can arrest it.
This automatic device has the doubtful advantage of working whether any one is present or not, although it is difficult to conceive of a theatre ever being without a watchman on guard. Should it go off by reason of heat generated under tin or glass roofs, or for other causes than heat from fire, irreparable damage might be done before the flood could be arrested.
A home-made contrivance, consisting of two three-inch iron standpipes located on each side of the stage and embedded in the walls that will feed three parallel perforated one-inch pipes, suspended horizontally above the flies, would be cheaper and more reliable. These pipes should be kept empty except in times of fire, when water could be turned on from the stage, or from outside the building by means of double valves penetrating the exterior walls.
For safety from interference, these valves could be installed in glass-fronted box inclosures, to be broken by a blow when necessary. If brass or bronze pipes are used for the overhead sprinkler pipes, five rows of small holes may be drilled in each, about three or four inches apart, without fear of corrosion. The undermost row should be drilled perpendicularly through the pipe and the uppermost row at an angle of 45 degrees, the two intermediate rows being midway between the two first described rows, and drilled at corresponding angles. Such a distribution would afford a wide and ample range of water spray from each pipe. If the pipes used are of iron they are subject to corrosion, and brass nozzles or some equally effective sprinkler head must be employed to prevent the holes from clogging with rust. Similar sprinklers should also be provided for the large workshops and storage rooms.
In the absence of a sufficient local water pressure for such a system a standard automatic air-pressure water tank could be employed in pref-ence to erecting an unsightly gravity tank on the roof. These air pressure tanks are much cheaper to install than gravity tanks, and the air pressure that forces the water upward is easily replenished by a few weekly plunges of a hand pump or they may be automatically regulated by a small motor.
The placing of hose on reels or racks for use in stage fires is without reason; first, because in the event of a sudden and serious fire the person to seek safety without waiting might be the very one relied upon to use the hose; secondly, because pure rubber hose, the quality usually recommended, is quickly ruined by dry-rot after it has been hanging unusued for a short time. But if hose must be bought, it is best to purchase cotton hose, as this kind is the cheapest and most durable. In many theatre fires the hose has been discovered reposing undisturbed on its rack after the fire has been extinguished and the damage done.
The city of Boston advocates the use of a patented fan-tail nozzle which, when attached to either a high or low pressure standpipe, spreads a huge fanlike spray that serves as a water curtain.
With a fire-resisting roof, solid fireproof party walls, metal exterior doors and metal framed outside windows glazed with wired glass, combined with a close observance of the foregoing precautions, any well planned and properly constructed theatre will be immune from fire calamities.
Plan of Orchestra Well.
Model Orchestra Well at Wagner Opera House, Bayreuth.