Journal of the Society of Motion Picture Engineers (1930-1949)

apart from this, . however, it has been shown that they lead to improved program presentation and better general safety conditions for both the public and the theater personnel. This is important; twenty years of good engineering design and proven operational practices have created public confidence in theater safety. This could be destroyed by a single instance where loss of life was rightfully or wrongfully attributed to a relaxation in the presently accepted standards. Furthermore, it should be kept constantly in mind that there is no moral defense for anyone who may be responsible for deliberate laxity in the construction and operation of theater projection rooms if a fire does occur and the sordid picture of a disastrous panic is the tragic result. TELEVISION INSTALLATIONS Projection Rooms The equipment necessary in television station projection rooms creates possible hazards of the same type inherent in the projection rooms of motion picture theaters. With the present use of 35mm film and projectors equipped with the Synchro-Lite, instead of the conventional carbon-arc lamps, hazards affecting the safety of the operating personnel are definitely and continuously present. For example, this gas-discharge gap lamp employs potentials up to 5000 v across its terminals. The standard motion picture projection equipment, as observed in television station projection rooms, consists of two 16mm projectors and two 35mm projectors, each equipped with the Synchro-Lite as the light source. As long as 35mm film continues to be used for programming purposes, the hazard inherent in the possible use of nitrate base film will require the acceptance of safety regulations as heretofore found necessary in the projection rooms of motion picture theaters. The panic that may be created by the sudden and violent combustion due to the ignition of perhaps a thousand or more feet of nitrate film, or the uncomfortable situation incident to one of the operating personnel lying prone from the effects of an electric shock, are possible situations requiring very special consideration from those individuals charged with the responsibility for formulating safety rules and regulations for television station projection rooms. The safety requirements for projection rooms in television stations should include as a minimum: (a) standard fireproof construction of the projection room; (b) the proper floor dimensions to provide good operating conditions; (c) approved storage facilities for the film; (d) an approved rewinding device for 35mm film; (e) the installation of approved, self-closing, automatically controlled fire shutters for the port holes; (f) the proper projection-room ventilation, including both gravity and forceddraft methods; and (g) the provision of adequate means for instant exit for the operating personnel through openings equipped with fireproof self-closing doors opening outward. As in the case of theater projection rooms, nearly all of these requirements are fully justified on a simple common-sense basis without any consideration of the special hazards introduced by the possible use of cellulose nitrate film. A typical television projection room incorporating the design features which have been mentioned would be self-contained, having the moving picture machines project the light through a wall directly into the camera chain located in the adjoining room. Figure 1 shows in detail some of the safety features incorporated in a typical well-designed television studio projection room. Studios With the increasing use of a great variety of household appliances in the production of television programs, haz 214 September 1952 Journal of the SMPTE Vol. 59