Wisconsin Administrative Code › Department of Safety and Professional Services › SPS 301-399 - Safety, Buildings, and Environment › SPS 375-379 - Buildings Constructed Prior to 1914 › Chapter SPS 377 - Theaters and assembly halls › Section SPS 377.11 - Proscenium curtain

Current through June 24, 2024
(1) In every theater or assembly hall having
				  a stage which is more than 6 feet higher or wider than the proscenium opening,
				  the proscenium opening shall be provided with a rigid metal curtain or a
				  curtain of asbestos conforming to the following specifications, or of
				  equivalent approved construction.
(a) Asbestos
				  curtains shall be substantially woven of asbestos fiber not less than 95% pure
				  and shall weigh not less than 21/2 pounds per square yard. There shall be
				  incorporated into the yarn before weaving, either monel metal, nickel, brass or
				  other metal or alloy, having no less strength than these metals at temperatures
				  up to 1700º Fahrenheit and no less resistance to corrosion at ordinary
				  temperatures.
(b) All seams shall
				  be vertical, shall be lapped not less than one inch and sewed in 2 rows with
				  not less than 1/16 inch pure asbestos twine. At the top and bottom of the
				  curtain a 21/ 2 inch (or larger) steel pipe shall be placed and shall be
				  securely fastened in and covered by the curtain. The curtain shall overlap the
				  proscenium wall not less than 12 inches at each side and at the top, and shall
				  be guided at each side by metallic loops or rings sliding on a 3/8 inch steel
				  cable or No.
6 U. S. Standard gauge wire.
(c) In addition to any decoration, the
				  curtain shall be painted on both sides with a mineral paint, having a silicate
				  of soda binder, which will completely fill the cloth. Filler paint shall have
				  not less than 4 parts of casein in each 10 parts of silicate of soda. The paint
				  shall be well brushed into the cloth so that no light or smoke can come
				  through.
(d) For curtains of any
				  type, the connections between curtain and wall shall be made as nearly
				  smoke-proof as possible. Smoke grooves or pockets shall be of structural steel
				  shapes and plates not less than 1/4 inch thick. These grooves or pockets shall
				  be not less than 14 inches deep and 6 inches wide and shall be set back from
				  the face of the arch at least 6 inches. They shall extend from the stage floor
				  to a point 3 feet above the top of the raised curtain, and shall be securely
				  bolted to the proscenium wall.
(e)
				  Provisions shall be made to prevent the curtain from leaving or binding on the
				  guides under any conditions. Appropriate limit chains shall be provided to stop
				  the downward travel of the top of the curtain at a line not less than 12 inches
				  above the top of the proscenium opening. No part of a curtain, nor any of the
				  curtain guides, or equipment, shall be supported by, or fastened to, any
				  combustible material.
(f) The
				  hoisting apparatus for the curtain shall be designed with a factor of safety of
				  8 or more.
(g) Besides the regular
				  operating mechanism there shall be an emergency device which will allow the
				  curtain to drop by gravity. The device shall be so arranged that it can be
				  easily operated by hand from each side of the stage and from the fly galleries,
				  and also that its operation will be controlled by 135º fusible links, or
				  other approved heat release devices, placed on each side of the stage, and when
				  thus operated it shall descend at its normal rate of speed.
(h) The curtain and its operating mechanism
				  shall be so designed and constructed at all points, whether specifically
				  mentioned or not, as to form an efficient and reliable barrier against fire and
				  smoke, according to the best practice.
(i) Detailed plans and specifications for all
				  curtains and their operating mechanism shall be submitted to the department for
				  approval before installation.