Unique Retractable Roof

The University of Phoenix Stadium can be seen from miles away. This architectural masterpiece stands 206 feet above grade. One of the most unique aspects of this stadium is the state-of-the art roof, designed by engineers Walter P. Moore and Associates, Inc. This design is the first retractable roof that retracts along an arc, compared to other retractable roofs that operate on a single, flat plane. When open, the design provides the right balance of sun on the field and shade in the seats.

The roof uses more than 100,000 square feet of Teflon coated translucent fabric (provided by Birdair), which allows light to pass through. The translucent fabric reduces the need for interior lighting, saving electricity on the stadium’s daily operations and non-sports activities.The roof components were assembled on the ground, and then lifted as a single unit into place at the top of the stadium. The entire construction team worked closely together throughout the 3-day roof lift, which took place in February 2005.

The roof has two large 180-feet long by 240-feet wide panels that retract to uncover the entire playing field. The roof runs at two different speeds, operating at a maximum speed of 25 feet per minute (1/4 m.p.h.). From the open to half-open positions, the roof operates at a speed of 16 feet per minute. From the half-open to closed positions the roof operates at a speed of 25 feet per minute. These speeds take the curve of the roof track into consideration. The time to fully open or close the roof is approximately 12 minutes.

The retractable roof can be operated with up to 4 of 16 motors in each quadrant off line, and can be stopped with up to 7 of 16 brakes in each quadrant off-line. Every time roof movement is initiated, each one of a total of 64 brakes is automatically tested by the control system. In the unlikely event of catastrophic motor or brake failure, roof movement will not take place. This built-in testing and redundancy ensures that the roof will operate safely and reliably.