PRLog (Press Release) – Oct 05, 2010 – The new Miami Marlins stadium took a giant leap forward on a rainy evening of Friday, September 24, when a huge segment of the retractable roof was put in motion for the first time.  Engineers and technicians from Uni-Systems, the designers and installers of the roof mechanization system, were 200 feet in the air, late in the evening, to power up, manipulate, and launch the recently completed roof panel. 

The structural roof elements, fabricated by Canam Steel and hoisted into place by LPR Construction, were built on the transporters designed, fabricated, and installed by Uni-Systems, beginning in July. The transporters are large motorized units that precisely control the roof movement using high technology and space-aged components. The September 24 roof move was made possible by hydraulically decoupling the steel roof from the temporary construction towers (known as shoring towers or falsework) below. 

With that work complete, Uni-Systems personnel engaged the roof motors, moving the roof section from the west end of the stadium to the east end, vacating the shoring towers, leaving them available for work to begin on the next roof section. 

Typically, construction of a stadium with long-span structural members requires the setup and dismantling of multiple shoring towers covering the length and width of the facility. With the Marlins new facility, Uni-Systems has employed a narrow band of shoring towers spanning the width of the stadium at the west end. 

The roof mechanization equipment allows the roof section to be moved off the falsework. This capability enables the falsework to be used for additional long-span structural construction saving a significant amount of schedule time as well as reducing waste from the inefficiency of discarded falsework. The system employed at the new Miami Ballpark is the most efficient shoring system employed to date, minimizing unnecessary falsework and maximizing 21st-century green technology. 

Additionally, the progressive roof construction method allows the construction team to do most of the heavy steel erecting at one location on the construction site providing a significantly safer environment for virtually hundreds of other construction workers to complete their work on the balance of the stadium and the bowl without the danger of personnel working above. 

“This is a great success,” said Bart Riberich, president of Uni-Systems. “These accomplishments require extraordinary amounts of effort and oftentimes personal sacrifice on the part of our engineers and technical crews.” 

According to Alan Wilcox, senior mechanical engineer at Uni-Systems and manager for the Miami Ballpark project, the lower east panel, which weighs 1,200 tons (the approximate weight of four empty Boeing 747 airliners) and spans 530 feet (162 meters), was moved using four of the ten motors on each side of the roof. It operated at its minimum design speed of approximately seven feet per minute and it traveled 430 feet (131 meters) down the track. 

The massive roof, when completed, will comprise three moveable panels that will cover an area over 288,000 square feet (27,000 square meters). The 8,300-ton roof is designed to travel at 40 feet per minute (12 meters per minute), which is significantly faster than any other retractable roof in Major League Baseball. 

Additionally, Miami presents some of the highest wind conditions experienced in the United States and it must be able to withstand hurricane force winds. Uni-Systems engineers were required to not only provide a bulletproof retention system for the finished stadium, but also provide a construction and erection system and a temporary propulsion system that would be capable of resisting a full-blown hurricane at any point in the three-year construction schedule. This was a challenge not seen before on any retractable roof stadium in the world. 

“It may not seem like an impressive step for a roof to move when it’s designed to do just that,” said Pete Fervoy, business development manager at Uni-Systems, “but the first move of the roof is a test of all the work we’ve put into the project over the past 27 months. It’s incredibly rewarding to see all of our hard work – and the work of our project partners – become reality as that roof makes its first move, testing all of its integrated mechanical and electrical systems.” 

The Marlins worked for 10 years to secure a deal for the construction of a new ballpark. In 2008, a new financing plan was finally approved, calling for the construction of a new stadium on the former site of the Miami Orange Bowl. 

The stadium’s plans call for a retractable roof that will fully enclose the building and allow climate control, as well as numerous features like a home run celebration feature, aquariums, and the largest plaza ever placed around a stadium in the United States. Construction on the facility began in 2009, and work on the facility and the large retractable roof is proceeding ahead of schedule. 

The move was conducted as part of an overall construction plan with Populous, the architect; Hunt/Moss, a joint venture, the general contractor; Walter P Moore, the structural engineer for the roof; and Bliss & Nyitray, the structural engineer for the stadium bowl for the new facility. This is the sixth retractable roof designed, built, and commissioned by the Uni-Systems/Walter P Moore team.