Slot grid ceiling. Fly system - Wikipedia
Also, three-dimensional sets e. If the loft blocks are mounted to roof beams loft block beamsthe system is called an under-hung counterweight rigging system. We cobbled together jigs on a workbench to make assembly faster—1x stops that held the pieces in lucky slots jak grac while we assembled the hollow backing.
Loft blocks may be equipped with idler pulleys or sag bars to limit the sag of horizontally running lift lines on under-hung systems. It is standard practice for overhead rigging lines and hardware to be slot grid ceiling with at least an 8-times safety factor to help ensure the protection of cast and crew.
Hoist winch motors are either fixed speed or variable speed. The combined weight of the arbor and its counterweights initially matches that of the batten so that when the batten is not being raised or lowered, it will tend to remain motionless at any arbitrary elevation above the stage. The function of a typical line set is to fly raise and lower a slender beam typically a steel pipe known as a batten or a bar in the UK by hoisting it with lift lines typically synthetic rope or steel cable.
Line set functions include: As more weight is added to the batten in the form of curtains, scenerylighting equipmentand rigging hardwarethe system is rebalanced by adding more counterweights to the arbor.
Variable speed motors are used at line sets requiring dynamic motion that may be viewed by the audience e. Standard pipe battens are typically designed to support 15 to 30 pounds 6.
Some large theatres, such as the Metropolitan Opera House Lincoln Centerhave more than independent, parallel counterweight line sets, while smaller venues may only have a few line sets for the most frequently adjusted loads, such as electrics.
Over time polyester rope became more popular than manila in hemp systems and for use as the operating lines in counterweight systems. An "unbalanced working line set" should never be allowed to exist over the stage.
Line set functions[ edit ] Line sets are typically general purpose in function, meaning they can perform any number of functions which vary depending upon the requirements of a particular theatre production. As I tell my customers: Those substitutions permit the flying of greater loads with a high degree of control, but with a loss of flexibility inherent to most hemp systems.
Flexibility is lost because most components of a hemp system may be repositioned, while counterweight system components are relatively fixed. Steel bands are a relatively new type of line used in steel band hoists.