A tension grid is a type of non-standard catwalk

Catwalk (theater)

A catwalk is an elevated service platform from which many of the technical functions of a theater, such as lighting and sound, may be manipulated.- Function :...

 though it does not meet the structural standards of a traditional catwalk. It is composed of a tightly stretched grid of steel

Steel

Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

 cables that create a taut floor that is strong enough for technicians to walk on.

Benefits

Lighting instruments can be hung on a pipe grid just above the tension grid; there is no need for holes, as the light

Stage lighting instrument

Stage lighting instruments are used in stage lighting to illuminate theatrical productions, concerts, and other performances taking place in live performance venues. They are also used to light television studios and sound stages.Many stagecraft terms vary between the United States and the United...

can shine through the grid, virtually unobstructed, to the stage. Cables and electrical wires can pass through, and special fixtures may be used to allow beams and other solid material to pass through.

This style of catwalk is popular in new and remodeled theatres due to the flexibility it provides. Use of a tension grid does not require working off of edges as a traditional catwalk does, as lights are over the walking surface, not next to it. As a result, many consider tension grids safer in terms of risk of falling.

Costs

Tension grids require regular inspection. Lights shining through the tension grid light up a section of the grid itself, which some audience members find distracting. The cables of the grid absorb and redirect some of the light from a fixture, leading to a negligible loss in total light output. Working on a tension grid takes time to get used to because of the bouncing nature from walking across the surface. This motion coupled with the illusion of no floor at times makes it disconcerting to some.