Yenra : Sports : Retractable Roof Stadium : Retractable Roof at Reliant Park Stadium

Houston's Reliant Park has the National Football League's first retractable roof stadium - made possible by GE Fanuc Automation.

The fully automated, two million-pound retractable roof - which was designed, manufactured and installed by Uni-Systems - features an automation system from GE Fanuc Automation, a unit of GE Infrastructure. The new roof will open and close an estimated 120 times each year for the next 30 years - taking fans outdoors when the weather is great, and indoors when it's not so great.

According to Lennart Nielsen, Senior Electrical Engineer at Uni-Systems, precision and reliability is essential. "When an announcer tells a stadium full of people that it's time for the roof to roll, it had better roll on time, every time, not only for the show, but for safety," Nielsen says.

With the help of GE, Reliant Park's bi-parting retractable roof consists of two large panels that open at the 50-yard line, then ride along steel rails at 35 feet per minute under ideal wind conditions, reaching each end zone about seven minutes later.

The heart of the roof transport control system is a GE Fanuc Series 90-70 Programmable Logic Controller (PLC), which sets the travel speed based on data collected from wind sensors. The Series 90 also controls the 20 GE AF-300 G11 Adjustable Frequency Drives that move the wheels on the carriers. Data is transmitted over fiber optics running up to each roof section, where the signals are converted to microwave.

At a control center, GE Fanuc CIMPLICITY HMI Plant Edition software collects data from sensors on the roof and in the system and gives the operator a graphical, easy-to-use view of the system on a standard PC. CIMPLICITY's screens show an overhead diagram of the stadium with the retractable roof sections sliding back and forth.

With the click of a mouse, the operators can call up multiple views of the system and its components. They can work the entire system just as if they were touching buttons on the actual drive, as well as see, diagnose and deal with problems. For additional monitoring, live cameras feed images from four roof locations into the central control room. "GE's Fanuc control system provides tremendous diagnostics capabilities," Nielsen says. "If there's a problem, we will find it right away."