{{Unreferenced, date=June 2009 A catwalk is an elevated service platform from which many of the technical functions of a

theater Theatre or theater is a collaborative form of performing art that uses live performers, usually actors or actresses, to present the experience of a real or imagined event before a live audience in a specific place, often a stage. The perfor ...

, such as lighting and sound, may be manipulated.

Function

Catwalks are used to suspend lighting instruments and microphones directed at the stage. The catwalks provide easy access for theater personnel to perform common tasks. For example, lights may need to be accessed for maintenance, position adjustment, or addition and removal of

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and gobos.

Placement

Typically, catwalks are located in positions hidden from audience view or directly above an audience, and are considered "behind-the-scenes". For example, many

proscenium A proscenium ( grc-gre, προσκήνιον, ) is the metaphorical vertical plane of space in a theatre, usually surrounded on the top and sides by a physical proscenium arch (whether or not truly "arched") and on the bottom by the stage floor ...

theaters have a series of two or more catwalks running parallel to the

proscenium arch A proscenium ( grc-gre, προσκήνιον, ) is the metaphorical vertical plane of space in a theatre, usually surrounded on the top and sides by a physical proscenium arch (whether or not truly "arched") and on the bottom by the stage floor ...

above a false ceiling. Stairs or a ladder up to the catwalks is usually located somewhere backstage. In modern theatres, many architects design catwalks into the "look" of the theatre. In

black box In science, computing, and engineering, a black box is a system which can be viewed in terms of its inputs and outputs (or transfer characteristics), without any knowledge of its internal workings. Its implementation is "opaque" (black). The te ...

theatres, catwalks and pipe grids may be the only architectural feature. A catwalk may also be placed upstage of the

as part of the

fly system A fly system, or theatrical rigging system, is a system of rope lines, blocks (pulleys), counterweights and related devices within a theater (structure), theater that enables a stage crew to fly (hoist) quickly, quietly and safely components suc ...

. These may be fixed, or they may be able to be raised and lowered.

Construction

Structural

Most catwalks have several battens (pipes) that lighting fixtures may be attached to. Lights are usually attached by a C-Clamp or a hook clamp around the pipes. In addition to this primary attachment, fixtures generally have an additional safety cable attaching them to the catwalk, so that if the clamp or bolt gives way, the safety cable will catch the light. This is used because the lights are generally very expensive and heavy, but mainly to protect the audience members and performers from the possibility of fixtures falling down from the catwalks. Catwalks often include a platform for a spotlight operator to work from.

Electrical

A typical catwalk has a built in

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to carry power for the lighting fixtures from the

dimmer A dimmer is a device connected to a light fixture and used to lower the brightness of the lighting, light. By changing the voltage waveform applied to the lamp, it is possible to lower the luminous intensity, intensity of the light output. Alt ...

s. They often hold other electrical wiring, for example standard sockets for tools,

coaxial cable Coaxial cable, or coax (pronounced ) is a type of electrical cable consisting of an inner conductor surrounded by a concentric conducting shield, with the two separated by a dielectric ( insulating material); many coaxial cables also have a p ...

for projection and video monitors, built-in safety lighting to protect technicians, audio cables, and special cables for headset communications with other technicians.

Safety

Since a catwalk is usually placed high above the floor, spaces where lighting instruments can go are usually chained or otherwise blocked off when a light is not present to prevent people and/or objects from falling through. The instruments themselves are attached by a safety chain to prevent them from falling. Technicians normally attach objects (such as

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es) to themselves before going onto the catwalk, so that such objects cannot fall and possibly injure someone or damage something. This also prevents objects from falling into a place where they cannot be retrieved, such as between the catwalk floor and the ceiling, or into an

HVAC Heating, ventilation, and air conditioning (HVAC) is the use of various technologies to control the temperature, humidity, and purity of the air in an enclosed space. Its goal is to provide thermal comfort and acceptable indoor air quality. ...