In The Limelight
Fire Curtains

First Things First
If your theatre has a fire curtain, when was the last time that you checked its operation?

Limelight recommends that you test the emergency operation of your fire curtain at least every 90 days. We also recommend that at least on a biannual basis you have your fire curtain inspected by a qualified person. This inspection should include a visual inspection of the curtain, rigging and all release devices, as well as a test of each emergency release device.

If you can't remember when the last time your fire curtain was inspected or tested, we recommend that you make arrangements, right now, to rectify a potentially dangerous situation. [See Fire Curtain Hall of Shame below right]

Purpose & Essential Requirements
Fire curtains are intended, in the case of an emergency, to restrict the passage of heat, flame, gases and smoke from the stage area into the audience area while the audience is being evacuated.

• They must be able to be deployed either automatically or manually.
• They must withstand tremendous heat.
• They must be impervious to smoke and gases.
• They must be capable of withstanding significant physical abuse.
  

Typical Installation
The "typical" installation includes:

• Fire Curtain - A curtain made from a "fireproof" fabric, larger than the proscenium opening
• The fire curtain is rigged to hang very close to the back side of the proscenium
• It is stored above the proscenium
• Curtain Guides - The vertical edges of the curtain are guided by cables which are set inside of metal (smoke pocket) channels either side of the proscenium
• A fire line runs from the floor on one side of the proscenium, over the top of the stored curtain, and down the other side of the proscenium to the floor
• The fire line is rigged so that the curtain is released should the line go slack either automatically (by the melting of fusible links) or manually
• A conspicuously placed sign offers instructions for manually releasing the curtain

Fire curtains are made from a specialized fabric capable of withstanding both high temperatures and physical stress. Historically, fire curtains were made with an asbestos fabric, but this has been replaced today by high-tech materials without the hazards associated with the use of asbestos. The most widely used fabric is Zetex. Zetex is woven from a texturized silica-based yarn.

The most common installations are the straight lift curtain, which requires that the area above the proscenium be greater than the height of the proscenium; and the braille lift curtain, which requires as little as one half the height of the proscenium above the proscenium.

The straight lift system uses a counterweight set to balance the curtain. The line set is purposely kept out of balance, or designed to be automatically made out of balance, so that when released, gravity will bring the curtain in. Rather than a rope lock, the hand line is held by the fire line.

In the braille lift system, the top of the curtain is dead-hung and then the bottom is lifted, either by the use of a manual or power winch, causing the curtain to fold accordian-style.

The fire line is connected to the winch so as to release the clutch should the line go slack, thus releasing the bottom of the curtain. The fire line, used in both straight lift and braille lift applications, is a rope line that runs from the floor on one side of the proscenium opening over the top of the fire curtain and down to the floor on the far side. The fire line is attached to the curtain rigging system in such a manner that should it go slack it will release the hand rope lock and/or add weight to the load of the curtain; or release the winch clutch.

Inline, along the length of the fire line are fusible links - specially designed links which melt at 160 degrees releasing the rope. In addition, the rope may be released manually at either end by use of pull rings.

Curtain guides are used along the vertical edges of the curtain to guide it along tensioned wire rope in order to prevent the curtain from bowing under the uneven atmospheric pressure on the two sides of the curtain (hot side and cold side).

The tensioned curtain guide cables are enclosed inside of vertical steel channels attached to the upstage side of the proscenium wall. These smoke pockets serve to prevent smoke and gases from escaping around the ends of the curtain.

There are other systems, as well as numerous variations on the basic systems briefly describe here. For a more information about fire curtains and how we can help, please contact us. We also recommend a detailed illustration - "How Manual & Fire Curtain Rigging Works" from J.R. Clancy. Call or email us to request a copy. Please note that E.S.T.A. (Entertainment & Services Technology Association, www.esta.org) is currently developing a set of technical standards for Fire Safety Curtain Systems.

For more information, call call 1-800-243-4950