TV production spaces, part II
Dec 1, 2008 12:00 PM, By Antonio Argibay, AIA
When designing lighting, power and electrical systems, consider these issues.
At the heart of all TV production spaces are the electrical systems. Whether selecting systems for illumination, cameras or microphones, it is essential to understand the options available in order to select the most effective systems for your project. This article will address three primary components: lighting, low-voltage wiring and utility power.
Production lighting rigging systems
The ceiling of a TV studio is a confusing mixture of wires and lights, with no apparent order. With experience, you begin to understand the benefits, limits and applicability of the different methods of supporting the production lighting or rigging. There are four types of lighting systems: dead hung, counterweight, catwalk and motorized. (See Figure 1.)
Dead hung
Figure 1. The four different types of rigging systems
Click to enlarge
Dead hung systems are the most commonly used today and the least expensive to install. They consist of a 1 1/2in pipe grid, spaced at regular intervals between 4ft to 5ft. One set of pipes is supported from the structure above it by 1/2in rods, at intervals matching the grid. The other set of parallel pipes is installed on the underside and perpendicular to the supporting pipes creating the grid. The lighting strips, or battens, for the dimming circuits are clamped to the piping or to the rod supports. The clear benefits of dead hung systems include:
They are inexpensive.
They require little skill to plan and install.
They are flexible and don't require maintenance.
However, they have limitations:
Their flexibility is limited to low grids (14ft range) and to productions that require few lighting changes.
For grids higher than 14ft, ladders are impractical. Genie lifts or other lift devices are generally required. These are difficult to maneuver around a set and may require bridging, moving sets or compromising a lighting plan to provide access.
These systems can be extremely time-consuming, thus inefficient for a production in which the need to access lighting instruments is frequent.
Counterweight
Counterweight systems involve the installation of a parallel piping system, with pipes spaced approximately 4ft from each other and broken into segments of 15ft to 20ft along its distance, which is the width of the studio. One wall, for the whole studio length, is devoted to the counterweights; ropes and the catwalk above are used for loading the weights. These systems have been in use for many years and were derived from theatrical technology. The benefits include:
Lights can be lowered to the studio floor to load the lighting instruments.
Lighting can be lowered for adjustments with manageable access of a ladder or genie lift.
As a system for accessing the lighting support, it is relatively inexpensive.
However, there are limitations:
It requires maintenance and inspection, including periodic reroping.
Cross-piping (linking two parallel light supports with a short, independent pipe) is problematic.
With tall sets, it is not easy to lower the lighting support to easy reach.
Catwalks
Figure 2. An example of a catwalk system
Click to enlarge
Catwalk systems consist of parallel walkways, typically 18in across, with in-between openings that allow the lighting instruments to be lowered and controlled from above. (See Figure 2.) The lighting connector strip, above each row of catwalks, runs the whole catwalk length. Lighting instruments are mounted on telescopic poles, and the poles are clamped to steel supports along the railing or spanning the openings.
They are accessed by stairs, typically located outside the studio. Catwalks are used only in studios with high ceilings (35ft or more), as the bottom of the catwalks is usually installed at approximately 24ft, requiring another 10ft to 12ft above to maneuver the poles.
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