www.enr.com/articles/174-reshaping-of-barclays-center-arena-made-possible-by-collaboration-digital-tools

Reshaping of Barclays Center Arena Made Possible By Collaboration, Digital Tools

July 16, 2012
Developer Gambles on Modular High-Rise for Atlantic Yards Sports Village

Opportunity knocked for SHoP Architects on July 2, 2009. On that Thursday, Bruce C. Ratner, the beleaguered developer of the controversial Atlantic Yards sports village planned for Brooklyn, N.Y., made an offer that any architect would be crazy to turn down but almost as crazy to accept.

Ratner wanted SHoP to put a better face on a critically panned redesign for his $825-million Barclays Center arena—the centerpiece of the 22-acre transit-oriented development. And he wanted a sketch from SHoP in only five days.

The offer was loaded with other challenges and sensitivities. Ratner had knocked on SHoP's door precisely because he was under pressure to improve the arena's architecture.

Yet SHoP, formed in 1996, had never done any part of an arena or so expansive a facade. And it would be enhancing the work of a veteran arena firm—Ellerbe Becket Architects & Engineers PC (EB).

As facade-design architect working directly for Forest City Ratner Cos. (FCRC), SHoP would have to jump on a moving train and interface with EB—the architect-of-record—and the rest of the arena's design-build team, formed a year earlier. By July 2009, the 675,000-sq-ft project was well into design development, on course for a fall 2012 opening. That meant SHoP's hands were tied, though loosely, in terms of its enclosure redesign.

"We were told, 'You can't change the Ellerbe Becket program, which worked so well, or the form, which fit so well on the site," says Christopher Sharples, one of the founding principals of SHoP, New York City. "It was a heavy lift," he adds.

SHoP had been watching the troubled project from afar: Two FCRC subsidiaries, Atlantic Yards LLC and Brooklyn Arena LLC, had gained state approval of the public-private Atlantic Yards master plan by Gehry Partners, based on "starchitect" Frank Gehry's iconic architecture.

But in 2008, the Gehry arena was over budget, reportedly priced at $1 billion.The recession was in full swing and FCRC could not get financing.

To cut costs, FCRC decided to switch architects and start from scratch, says Robert P. Sanna, director of construction and design development for the Brooklyn-based developer.

SHoP was aware that its redesign was going to be highly scrutinized. The New York City architectural community and the village's foes had felt double-crossed when Ratner tossed the Gehry design.

Despite all the warning signs, SHoP took the job. "We felt by joining the team, we could have a positive impact on the project and the city of New York," says Jonathan L. Mallie, a SHoP principal.

So instead of relaxing over that July 4 weekend, four SHoP partners huddled to come up with some ideas. On Monday, July 6, SHoP showed Ratner a sketch of an arena contoured by a latticework system of pre-weathered steel panels.

SHoP spent the summer of 2009 studying the skin and its impact on the structure, interfacing with the project's local structural engineer, Thornton Tomasetti (TT). In early September, when FCRC unveiled SHoP's scheme, it wasn't excoriated or widely praised. One critic likened the arena to a giant bottle opener.

The arena has three systems of 12,000 pre-weathered panels, with no two alike. Panels cover 85% of the arena's surface.

A lower band wraps the exterior wall at the suite levels. A "halo" surrounds the arena at the roof. There is also an entrance canopy over the public plaza. The canopy, which cantilevers 85 ft beyond the main entrance, has an opening in it the size of a basketball court. The inner surface of the opening is clad with video boards and latticework. The canopy's soffit is completely clad with the latticework.

Awkward Position



However, SHoP wasn't the only firm in an awkward position. In late 2008, FCRC approached EB with a dubious offer it didn't refuse. "Bruce Ratner said, 'I literally want you to take Conseco Field and place it on our site,'" says Stephen J. Duethman, the project manager in Kansas City, Mo., for EB, which, as a result of a merger, operates under AECOM's name.

That strategy was not possible, he adds. But, in 2009, EB did as little as possible to modify its Indianapolis arena so that it would fit into a tight urban site. Then, FCRC and its arena design-build contractor, Hunt Construction Group, developed a guaranteed maximum price.

"[EB] inhaled the Gehry building, rendering it smaller and more compact," says Sanna. "It saved us a lot of money," he adds, declining to be more specific.

The total cost of the facade redesign is $54 million. "We had to make the investment for public reasons," says Sanna.

After SHoP joined, the team regrouped to get the arena finished for a Jay-Z concert on Sept. 28 and the Brooklyn Nets upcoming season. As it turned out, the job was not yet out of the woods.

Last December, the facade fabricator, ASI Ltd., Indianapolis, defaulted financially. Only a third of the job's 564 pre-weathered megapanels were done, none of the 239 halo panels were made and none of the 216 canopy units detailed.

"On Dec. 23, we got a call that ASI's bank had shut the plant and locked the doors," says Gus Yogmour, senior bond claims counsel for ASI's surety, Ohio Farmers Insurance Co.

The surety was committed to picking up the slack. But the geometric complexity and engineering of the curtain wall made that a daunting task. Yogmour says it was the most complex exterior wall he had ever seen.

FCRC and Hunt had required a full- payment performance bond for the original $32.4-million contract. By Jan. 8, the surety had bought out the bank's position and reopened the plant. "We had tried to re-let the contract, but we could not find anyone who could do it in a timely manner," says Yogmour. "There was too great a learning curve."

Instead, the surety hired 190 of ASI's employees, offering incentives to finish the job. Before restarting work, the surety also hired a rust expert to make sure the panels left on the line during the shutdown were properly treated. The surety also retained Fasano Acchione & Associates LLC to manage the job.

To help make up lost time, the surety leased a second, more sophisticated cutting machine. On May 5, the team completed all the enclosure units. The halo and canopy are set to be done next month.

To date, there is no claim from Hunt. "It's a good story," says Yogmour.

Over the summer of 2009, SHoP exported 20 examples of the rain-screen wall's form iterations to TT, using the project's 3D model. "The ability to execute the complex design quickly is a result of using technology embraced previously by all team members," says Thomas Z. Scarangello, TT's chairman and CEO.

"In a very short time, SHoP was able to figure out the building," adds Scarangello. With building information models (BIMs), "we were looking into each other's heads in a deep way, very quickly."

That's in part because SHoP also is committed to virtual design and construction (VDC) tools. "From the very beginning, we understood the power of technology to manage complexity," says Mallie.

In 2007, aiming to better control its designs, SHoP formed SHoP Construction Services. Mallie also is the managing director of the spin-off, which offers construction management and VDC services.



For the arena facade, SHoP Architects hired SHoP Construction for constructibility reviews, automated quantity takeoffs for exterior materials and model integration with EB's and TT's building systems.

To develop the surface geometry to study initial forms, the architect used software called Rhinoceros, a stand-alone 3D modeling tool developed by Robert McNeel & Associates. When SHoP identified the final form, it switched to CATIA, a multiplatform CAD/CAM software suite developed by Dassault Systemes.

Hunt awarded the $32.4-million exterior-wall contract to ASI in February 2010. Soon thereafter, SHoP Construction became a subcontractor to ASI to detail the pre-weathered steel panels.

SHoP also developed a 3D model that would enable ASI to fabricate the panels using computer-numerically-controlled equipment, without creating its own BIM.

"If we could sequence and control information [digitally], the facade contractor didn't care how many unique panels there were," Mallie says.

Rely On It

TT's use of BIM facilitated the entire job, starting with the structure. For the work, TT gave the steel fabricator its Tekla Structures model and said, "Rely on it," says Scarangello.

"We used TT's unconnected model," says Chet McPhatter, chief operating officer for the Lynchburg, Va.-based fabricator Banker Steel Co. "This is very rare on a project of this type and is a viable option if the engineer is good at detailing."

On the arena in general, thanks to the model-sharing, the approval process was 50% faster than normal, says McPhatter.

Hunt already had bid the foundation and steel packages, when FCRC introduced the new facade scheme. The new steel had to be added.

BIM-sharing allowed Banker to quickly add the facade steel to the mill order and the steel package. "It just took a lot of work," says McPhatter.

On the west side of the building, the halo extends about 20 ft above the roof surface and 20 ft away from the face. To support these, TT cantilevered roof columns beyond the roof. A system of horizontal girts spanning between trussed vertical frames supports the lattice and attaches back to the cantilevered columns.

The canopy is supported by a network of steel trusses. Pairs of cantilevered trusses are laced together to create box trusses north and south of the canopy opening.

To achieve the long cantilever, the backspans of the box trusses—12.5 ft deep at supports and 9 ft, 10 in. deep at the tips—extend 100 ft into the arena, above the west entrance, to engage the arena bowl's primary columns. Another box truss spans 120 ft across the west tip of the structure. At the east side of the opening, three cross-trusses skewed in plan frame out the east face of the opening.

To limit fieldwork, Banker added SHoP Construction's facade connections to its shop drawings and installations.

Automation



After SHoP Architects finalized the flocking pattern, SHoP Construction developed initial panel prototypes in the model. Then, it used CATIA to "unfold" the 12,000 panels of different shapes and sizes, followed by SigmaNEST's CAD/CAM fabrication and cutting software to nest panels based on the installation schedule.

Using CATIA, SHoP Construction then developed a workflow that allowed for the automatic generation of the 12,000 fabrication tickets. Each ticket has an automatically populated chart containing bending information for each panel.

SHoP also developed tickets for the rails that support the panels. Using the model, SHoP coordinated the fabricator's steel-panel support system that connects panels to the base-building enclosure.

Panels have been delivered to the site grouped into megapanels. SHoP also provided a megapanel sequencing model. Color-coded elements are automatically linked to Hunt's project schedule.

In its shop, ASI developed a 60-day pre-weathering patina line, which produces rust. The 3,000-panel-capacity line has racks that resemble a dry cleaner's line.

SHoP had learned that ASI was developing an electronic tracking system for each panel, using plastic tags with bar codes. Jumping off that, SHoP Construction generated a virtual tracking application using a custom iPhone interface to provide real-time updates to the remote building team as panels were fabricated.

On the factory floor, using the iPhone's camera, workers would scan tags as panels went through each weathering stage: water-jetting, surface preparation, bending, dipping and rinsing, and hanging.

"We don't know of any other tracking system that uploads to the model and provides a visual interface," says Mallie.

Mallie considers the app a prototype, for it was used only before ASI shut down. He says there is a "strong possibility" a similar app may be adapted for SHoP's second Ratner project: a 32-story Atlantic Yards residential tower overlooking the arena. That is, if Ratner's modular high-rise scheme, not yet a slam dunk, goes forward.