At a 1,100-seat theater
at Rock Valley College in Rockford, Ill., the curtain isnt
the only thing that goes up.
A just-finished $8.5-million
renovation of the open-air Bengt Sjostrom Home of Starlight
Theatre has put on a kinetic canopy that steals
the show for 12.5 minutes. Over the audiences gaze,
the stainless steel covers $1-million center unfolds
to reveal the sky.
Theater canopy lets the stars
or sun shine in.
After exploring a hydraulic
operating system for the skylight, the architect,
Studio Gang/ODonnell, Chicago, with structural consultant
Dewhurst McFarlane and Partners Inc., New York City, opted
for lighter electrical components. The challenge was to design
an assembly, appealing to the eye, that would
lift a 14.5-ton panel quietly and quickly, says Frank Worms,
senior project manager for Uni-Systems, Minneapolis, the engineer-supplier-installer
of the kinetic section.
The theaters multipitched
canopy has a lower, fixed section, 100 ft square in plan,
around a higher, 90-ton movable assembly over the seating
area. The assembly, a hexagon in plan with 40-ft sides, has
six, triangular panels that cantilever from steel trusses
that bear on freestanding columns. Each panel opens to a 68°
pitch and has a 5-hp motor that drives a 50-ton-capacity screw
jack. Panels have a 20-ton dead-load capacity. Control software
only activates after the operator clears digital security,
including biometric thumbprint identification. A backup hydraulic
circuit allows manual operation.