Artec's plan called for multiple motorised acoustic canopies and acoustic curtains that can be adjusted to change the room's response. Acoustic canopies are usually made of wood, but the Palladium required an unusual material for such an application: large panels of clear glass. The glass keeps the canopy from masking the Palladium's intricately decorated domed ceiling. The glass panels vary in size and thickness, measuring an inch at their thickest points.
To accommodate the canopies, the J. R. Clancy team designed and built massive hoists with capacities of 23,000lbs. Each of the four hoists has a motor brake, supplemented with a 30-inch diameter disk with dual airbrakes. "The hoists are traveling drum hoists, with lift lines that come directly off the drums to enter a complex web of blocks," said Bridget Cox, Clancy project manager. "The blocks divert the lift lines to the correct ceiling tubes through the dome. To ensure the safety of the audience, we used a ten-to-one design factor - so the lift lines can support ten times the weight required by the system. For additional safety, we added air caliper brakes or dual overspeed brakes on each hoist, and electronic load cells for each of the 81 lifting cells."
Sound technicians can raise and lower the canopies using Clancy's SceneControl 500 automated control system, which provides top-of-the-line motion control and 3D visualization of the performance space. SceneControl's industrial-grade controller, developed by Clancy, is based on the same processor used for elevators-making it one of the most reliable systems in the industry.
Clancy engineers designed the hoists so they could be disassembled, loaded into the attic in pieces, and reassembled. This made it possible to install the hoists in a narrow, closed space above the hall's domed ceiling. Clancy's design team worked closely with Artec to develop an ingenious lifting system that allowed the hoists to fit into the space without compromising the architecture.
In addition, Clancy provided eight hoists in the ceiling to lift the concert lighting trusses. Three more hoists raise and lower the speaker clusters, which are stored in the basement in ready-to-use position. Hoists with capacities from 1,500 to 3,600lbs support the speaker clusters, each with motor and load brakes for additional safety. Clancy even fabricated the hall's acoustical curtains in a custom colour to match the room's finishes.
Beyond the acoustics, Clancy provided and installed a 61-by-9ft Gala Spiralift forestage lift with 21ft of travel, which moves a forestage section into place to extend the platform when a full orchestra performs. Gala & Clancy collaborated on the design and construction of a house mix lift with 17.5 feet of travel, for use in moving the sound-mixing console into place in the audience chamber when front-of-house mixing is required.
(Jim Evans)
