Buildings are generally designed to be permanent, immutable structures. But this is not always the case...
The new roof over the Arthur Ashe Stadium at the Billie Jean King National Tennis Center in Queens, New York, appears almost straightforward: the slightly domed 236,600-square-foot canopy contains two 500-ton rectangular panels that separate to frame a 250-foot-square slice of the sky. Designed by the Detroit-based architecture firm ROSSETTI, the new roof is the United States Tennis Association’s response to rain delays that in recent years had regularly plagued the U.S. Open Tennis Championships held in the late summer at the Flushing Meadows complex.
But devising and constructing the $150 million shelter for the almost 24,000-seat venue was not so simple. The primary complicating factor: the original 1997 stadium, which was also designed by Rossetti, had not been conceived to support a roof. So the new element would need to be wholly independent of the original’s precast-concrete seating bowl and steel structure. What’s more, the team was hampered by the marshy site, which had been used as an ash dump. Ahmad Rahimian, the U.S. director of building structures for WSP, the project’s structural engineer, sums up the challenges as “poor soil, long spans, and a tight budget.”
ROSSETTI principal Jon Disbrow refers to the solution as “an umbrella,” but one that straddles the existing stadium. It is supported on eight steel columns—each with two branchlike braces—placed just outside the corners of the existing building’s octagonal footprint. The columns, which sit on top of piles as deep as 200 feet, hold up four nearly 500-foot-long trusses, two spanning in each direction. These in turn support a network of steel joists and bracing, over which a membrane of Polytetrafluoroethylene (PTFE)—a lightweight material resistant to heat and UV degradation—is stretched.
The new roof was built without disrupting the U.S. Open schedule. It was constructed, starting in late 2013, in three discrete phases, each conducted in the 11½-month period between tournaments: first the foundation work, then the primary steel structure, and finally, this summer, the retractable-roof components and PTFE skin.
Now that the new roof is in place, it looks as though it was always intended to be there, adding a bit of interest to the stadium’s slightly stubby profile. But one aspect of the newly covered stadium that not everyone is pleased with is its acoustics. Some players at this summer’s Open reportedly complained that the roof amplifies the noise made by the spectators, making it hard to concentrate. As part of Rossetti’s design, perforated metal panels backed with mineral wool were installed at the roof’s perimeter to dampen reverberation, according to Disbrow. He says that additional measures could be implemented, but so far the USTA hasn’t asked the firm to do so.
Although acoustics may still need to be addressed, the new canopy does work admirably in a variety of modes and conditions, as any adaptable building should. Even in the open position, the majority of the venue’s seats are in shade, shielded by the fixed roof’s PTFE skin, which blocks 90 percent of visible light. So even though the new lid was conceived primarily as an umbrella, it also serves as a parasol, allowing fans to enjoy tennis at Arthur Ashe, rain or shine.
Blog adapted from an article written by Joann Gonchar for Architectural Record
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