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Why did an architect need a solid nesting program?

And how the metal fabrication benefited

Why did an architect need a solid nesting program? - TheFabricator.com

Figure 1: The preweathered panels of A588 steel that hang on the exterior of the Barclays Center are designed to help the huge arena blend into its Brooklyn, N.Y., surroundings. Photos courtesy of SHoP Construction.

Cut and bend 12,000 unique, preweathered, 0.1875-in.-thick panels of A588 steel in a tight time frame—the job sounds daunting for any metal fabricator. Luckily, the sister company of an architectural firm was there to make the job easier.

Those panels were for the façade of the Barclays Center, a sports and entertainment complex that opened its doors to the public in September 2012 (see Figure 1). The newest arena on the New York map happens to be in the shadow of a shopping mall site that was once proposed to have a domed stadium for the Brooklyn Dodgers—before they left for Los Angeles in 1957. The Barclays Center’s construction was a major league occurrence.

The redevelopment of the Atlantic Yards area in Brooklyn actually dated back to 2004 when the idea of an arena was first introduced. But like for any large project, pushback abounded. Protests, lawsuits, financial issues, and the economic downturn all contributed to development delays.

That changed, however, in early March 2010 when the final legal decision was handed down, approving the state’s use of eminent domain and allowing construction to begin. By that time, the developer, Forest City Ratner Companies, hired Ellerbe Becket, an architectural firm that had worked on facilities such as Boston’s TD Garden and Cleveland’s Quicken Loans Arena, and quickly brought on SHoP Architects, located on the other side of the Brooklyn Bridge in Manhattan, as creative collaborator.

With the green light clearly in focus for all, it was time to go. Brooklyn was not only getting a new arena, but a regular tenant for it as well. In September 2009, Russian billionaire Mikhail Prokhorov bought controlling interest in the New Jersey Nets of the National Basketball Association in a $200 million deal, and he planned to move the basketball club across the Hudson River to Brooklyn. The goal was to have the team in its new home for the 2012 season, and as most people know, billionaires don’t like to be kept waiting.

In actuality, a construction time frame of a little less than 24 months—from groundbreaking to public unveiling—was a suitable challenge for a firm like SHoP. Not only was it recognized for its design work, but the company had taken steps over the years to set itself apart from other architectural firms. In 2007 the firm’s management team set up a sister company, SHoP Construction Services (SC), to act as a construction administrator—the facilitator of information and coordinator of activities for all the parties involved in a construction project, including the architect, general contractor, real estate developers, and other stakeholders. The move was unique in the sense that most architectural firms are content to focus solely on design; SHoP wanted to be involved in all aspects of building creation, not just the front-end work. The company also has been committed to the use of computer-aided technologies to assist in design, construction, and even fabricating activities.

That desire to streamline information-sharing and use state-of-the-art tools to do that helped the Barclays Center open in time. It just so happened that a nesting software program played an important role.

Same Approach, Larger Scale

The architectural design for the 18,000-seat, multipurpose building called for a glass curtain wall to be covered by a latticework made of A588 weathered steel. The designers chose the material so that it would eventually have a natural rust coloring that would be reminiscent of Brooklyn’s brownstone neighborhoods and the industrial qualities of the Brooklyn Navy Yard. It was not the first time that the firm had worked with weathered panels, but for previous projects the panels were used more as accent pieces, not as the skin for a 675,000-sq.-ft. building that would be a neighbor to thousands of highly skeptical hipsters who now call Brooklyn home.

This job also was a large challenge for SC’s technology-focused approach to information management and communication.

“We are a technology-driven firm, and we’re always trying our best to introduce automation into the design and construction process as much as possible. If you’re clicking too many times, it’s worth stepping back and doing a bit of R&D to automate the process,” said John Cerone, SC’s director of virtual design and construction, and an architect who has had a longtime interest in 3-D modeling. “But this is, without a doubt, our biggest case study in scripting automation and sending it direct to fabrication.”

Why did an architect need a solid nesting program? - TheFabricator.com

Figure 2: The weathered surface of the steel panels is self-healing in the sense that if it gets scratched, it eventually reweathers, enveloping the scratch as if it were never there.

SC routinely uses Dassault’s CATIA® software to model its projects in 3-D. Cerone said that it’s much more than generic building information modeling—or BIM, as the architecture, engineering, and construction industry calls it. BIM suggests a collection of geometry and associated data. Cerone said he sees a CATIA 3-D model as more dynamic, with each element of the building design intricately connected to the next. If a window needs to move, the model dynamically adjusts to accommodate the change; fabrication details associated with the move of the window change as well. It provides one model that constantly evolves, rather than having separate models for visual representation and shop drawings.

That modeling power was necessary because the Barclays Center design called for unique individual panels, not families of same-sized panels, which may have been a much easier fabricating task. An inability to find a means to coordinate and produce the 12,000 panels to meet the tight deadlines would have been a staggering blow to the building’s key design feature.

“We recognized early on that a very powerful CAD/CAM nesting program would be needed in order to get the full range necessary for the project,” Cerone said.

Like so many searches in today’s world, SC started with the Internet. There it found SigmaNEST® from SigmaTEK.

SC worked with some trial demos of the nesting software, and the team members realized that it would work for the project. Very soon they recognized that the software could scale up for the fabricating job, which would entail about 600 tons of steel, and maximize yield for each sheet to keep the job on budget.

SC also found a way to save time in the fabricating process by creating NC pass codes for the fabricator’s waterjets.

“That’s an unusual step to take that was incredibly efficient. [The fabricator] didn’t have to convert it. We provided the code,” Cerone said. “The benefit is reduction of fabrication time. The provision of code does not require additional processing effort.”

Ryan Lustig, SigmaTEK’s northeast regional sales manager, recognized SC as a new type of nesting software user.

“SHoP Construction is a customer that uses SigmaNEST in an ‘out-of-the-box’ way.  They are unique because they do not currently perform their own cutting. Instead, they outsource to manufacturing partners,” Lustig said.

Not an Ordinary Fabrication Job

Any time gained during fabricating operations was a bonus because the panels had to be preweathered for four months before being assembled

into a unitized system, shipped, and installed. If alterations to the panels had been made after the weathering process, rust trails would have appeared in areas of modification, leaving stains on the plaza below.

SC worked with ASI Ltd. in Whitestown, Ind., to fabricate the panels. Going directly from design model to cutting for a job involving thousands of sheets of expensive metal was nerve-wracking in the early stages, according to Cerone, but initial file swaps and fabricating tests revealed that precise fabrications could be created. Soon afterward, the SC team released the first of four production files for batches of 3,000 panels.

ASI Ltd., which fabricated the panels in the summer of 2010, set up a 2,500-ft. linear conveyor system to accommodate the preweathering of the waterjet-cut and formed panels. (ASI Ltd. closed in late 2011.) The parts were hung from hooks and repeatedly sprayed with a combination of rainwater and other natural ingredients and then dried. After four months, the weathering effect on the panels had reached a point where rust trails were no longer a worry (see Figure 2).

During this entire process, SC was able to track material consumption and costs through Sigma-NEST. As the work was being accomplished, the fabricating staff at ASI Ltd. scanned bar codes on job packets, and the information fed into the nesting software. SC then could call up the information in detailed reports, allowing it to maintain tight and accurate control over inventory.

The End Result

On Oct. 15, 2012, the Nets tipped off against the Washington Wizards in a preseason game. The wizards of weathered panels had met the needed deadlines.

“There were no fit issues. Everything worked. We’re proud of that,” Cerone said.

The design is also a success, having won awards and capturing the reluctant respect of many Brooklynites who never wanted to see the arena built. Perhaps it has done even better in capturing the spirit of manufacturing that once was much more prevalent in the very neighborhood that is now home to gastropubs and coffee shops.

Justin Davidson described the building in such a way in the Oct. 1, 2012, edition of New York magazine: “From certain angles and at close-enough quarters the building could be the footing of an ancient iron bridge, an abandoned parking structure, or the shell of a great robotic reptile. There’s something radically revivalist about taking the concept of industrial chic to such an extreme. We’re still not done converting the backlog of ancient factories and disused power plants into condos and museums, and already we’re creating para-ruins, buildings that seem recycled even when they’re new.”

Meanwhile, Cerone said he plans to recycle some efforts from this project. The ability of a small team to turn a design model into thousands of sheet metal parts, while juggling budget, material procurement, and other administrative tasks on a supersized project, is a huge achievement in his mind.

“It takes a lot to set up the system, so there are front-end complexities and challenges,” he said. “But once you set it up, it’s very stable and requires very little effort.”

That’s an architect talking, but metal fabricators can definitely appreciate the concept of creating more with less.

About the Author
The Fabricator

Dan Davis

Editor-in-Chief

2135 Point Blvd.

Elgin, IL 60123

815-227-8281

Dan Davis is editor-in-chief of The Fabricator, the industry's most widely circulated metal fabricating magazine, and its sister publications, The Tube & Pipe Journal and The Welder. He has been with the publications since April 2002.