Fly System - Fly System Infrastructure

Fly system infrastructure consists of the relatively permanent load-bearing and load-transferring structures of a stage house. The infrastructure, generally fabricated of structural steel members, is sized by a structural engineer during the design of a new theatre, or theatre renovation. Rigging system infrastructure ultimately limits a fly system's capacity.

Building codes generally require that fly system beam design meets the L/360 rule: beams shall not deflect by more than the length of a span divided by 360. For example, a 30-foot head block beam should not deflect more than 1 inch under the system design's maximum loading condition. Beam design using the L/360 rule typically results in beams with a yield-strength significantly higher than the maximum loading condition, effectively providing a factor of safety.

Linesets are manually operated from a locking rail such as this one.

Loading bridge. Weights are seen on floor.

Grid-less fly tower with catwalks. Battens (yellow), under-hung blocks and lift lines are visible.

Channel-type grid with upright blocks and lift lines visible.

Channel-type grid, viewed from below with drapes, battens, and electrics visible.

Upright loft blocks on a channel-type grid.

Famous quotes containing the words fly and/or system:

“After us they’ll fly in hot air balloons, coat styles will change, perhaps they’ll discover a sixth sense and cultivate it, but life will remain the same, a hard life full of secrets, but happy. And a thousand years from now man will still be sighing, “Oh! Life is so hard!” and will still, like now, be afraid of death and not want to die.”
—Anton Pavlovich Chekhov (1860–1904)

“The moral immune system of this country has been weakened and attacked, and the AIDS virus is the perfect metaphor for it. The malignant neglect of the last twelve years has led to breakdown of our country’s immune system, environmentally, culturally, politically, spiritually and physically.”
—Barbra Streisand (b. 1942)