New Reliant Park Stadium Scores Big with GE-Controlled Retractable Roof |

New Reliant Park Stadium Scores Big with GE-Controlled Retractable Roof

New Reliant Park Stadium Scores Big with GE-Controlled Retractable Roof
Uni-Systems Designs and Installs World's First Retractable Roof for the NFL, Increasing Player and Fan Comfort during Every Game

HOUSTON ¾ December 18, 2002 ¾ When the National Football League’s newest team, the Houston Texans, kicked off at Reliant Park earlier this fall, they began playing in the world’s first retractable-roof NFL stadium. The fully automated, two million-pound retractable roof – which was designed, manufactured and installed by Minneapolis, Minn.-based integrator Uni-Systems – features an automation system from GE Fanuc Automation, an affiliate of GE Industrial Systems. With safety and reliability as key design priorities, the new roof will operate an estimated 120 times each year for the next 30 years – keeping fans and players comfortable through every game.

Fielding a Winning System
According to Lennart Nielsen, senior electrical engineer at Uni-Systems, precision control in sports venues 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 show purposes but for safety reasons,” 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. Ten tri-chord trusses with a carrier at each end support the roof panels. Each carrier has two wheels that ride on a 960-foot rail supported by two massive super-trusses running parallel to the field.

The heart of the roof transport control system is a GE Fanuc Series 90™-70 Programmable Logic Controller (PLC), which determines travel speed based on data collected from wind sensors and controls the 20 GE AF-300 G11™ Adjustable Frequency Drives that move the wheels on the carriers. Data is transmitted via 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 and provides the stadium operator with a graphical, user-friendly representation of the roof transport system on a standard PC. Screens in CIMPLICITY show an overhead diagram of the stadium with the retractable roof sections sliding back and forth. Each section has eight control panels to control each individual drive and motor.

The operator can double click on any panel, and it expands to fill the screen. The panel door then swings open to graphically show all of the components. Inside each panel is a GE drive and several Genius® intelligent I/O blocks. The operator can click on the drive and step through all of the parameters, just like physically touching the buttons on the front of the drive. The operator can also click on the Genius blocks and see individual system faults. For additional monitoring capability, live cameras feed images from four roof locations into the central control room.

Additionally, built-in redundancy ensures precision and reliability. Each of the GE Fanuc Genius I/O blocks located on the roof panels incorporates three high-speed counter modules that feed precise positioning data to the PLC. Two of the three encoders must agree on the position to within a tight tolerance before the PLC commands the motors and drives to move.

Over the Goal Line
GE Fanuc’s Genius, working together with CIMPLICITY HMI Plant Edition software, offers a greater range of capabilities and better reliability than any other high-speed control system Nielsen has seen. The speed with which information is communicated ensures that each side of the roof rolls on cue, while the ability to pinpoint and diagnose any problems from the control center keeps the roof rolling as planned.

“GE Fanuc’s control system provides tremendous diagnostics capabilities,” Nielsen says. “If there’s a problem, we will find it right away.”

Additionally, Nielsen appreciates the fact that GE Fanuc offers a range of automation products that integrate well with other system components—and he has been equally as impressed with the people behind the automation. “Power/mation, my local distributor in Minnesota, supports GE extremely well,” Nielsen says. “When you work on a project as large as a football stadium roof, supplier support is extremely important. We know we can rely on GE Fanuc’s products and Power/mation.”

About Uni-Systems: Putting Large Structures in Motion
Founded in 1967 as a small mechanical engineering firm, Uni-Systems has evolved into a $20-million company that specializes in the design and delivery of systems that move large structures. The large structures in question range from aircraft hangar doors and maintenance docks to NASA’s rocket assembly vertical lift doors to, most recently, retractable stadium roofs. A roof that Uni-Systems installed at the Houston Astros’ stadium has been performing “extremely well for three seasons,” according to Nielsen, and the company is developing several others, including the one at the Houston Texans’ Reliant Park. “Our expertise and experience in moving large objects gives our customers a sense of security, no matter what the industry,” Nielsen said.

The dependability of GE Fanuc’s automation products and the support provided by their local distributor helps give Uni-Systems, their structures, and, in turn, their customers, the security, safety, and reliability they require.

About GE Fanuc Automation
GE Fanuc Automation North America, Inc., is a leading global supplier of automation solutions and is a joint venture between GE and FANUC, Ltd. of Japan. GE Fanuc products and services include the iFIX® HMI/SCADA platform, ROI-enhancing Plant Intelligence systems, CIMPLICITY® collaborative production management software, nano to high-end PLCs, a wide range of CNCs, motion control, operator interfaces, industrial computers, lasers, and a wide range of integration and customer support services. Headquartered in Charlottesville, Va., GE Fanuc is part of GE Industrial Systems. For more information, visit

About GE Industrial Systems
Since the founding of the General Electric Company by Thomas Edison in 1882, GE Industrial Systems has been known for technical innovation. GE Industrial Systems has over 7,600 U.S. and foreign patents on products that help provide peace of mind for people, the properties they own and their workplaces. In 2001 alone, GE Industrial Systems filed more than 200 U.S. and 340 foreign patent applications.

GE Industrial Systems spans the globe as an industry leader in integrated industrial, electrical and security equipment, systems and services. The business brings to customers the latest technologies that are used to distribute, protect and control energy and equipment, and to provide premise management. GE provides innovative product and service solutions for commercial, industrial, residential and utility customers. For more information visit the website at:

About GE
The General Electric Company (NYSE: GE) is a diversified technology and services company dedicated to creating products that make life better. From aircraft engines and power generation to financial services, medical imaging television programming and plastics, GE operates in more than 100 countries and employs more than 300,000 people worldwide. For more information, visit the company's Web site at

For more information, visit or contact: GE Fanuc Information Center, P.O. Box 8106, Charlottesville, VA 22906, Phone: (800) 648-2001, Fax: 434-978-5205, e-mail: [email protected].
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