Rockefeller University Team Takes Modular Delivery to New Lengths
Riverside high-flying acts for Manhattan research building move modular delivery into the 21st century
For physician-scientist Richard P. Lifton, 19 nights of intentional sleep disruption last summer had nothing to do with a medical experiment. Lifton woke up at 3 a.m., in New Haven, Conn., to watch a construction webcam set up 70 miles away at Manhattan’s Rockefeller University—a campus that overlooks the FDR Drive along the East River.
Each night, the camera recorded a daring maneuver—the lifting, swinging and setting of a 50-ft-tall, 45-ft x 90-ft module over the drive during a five-hour window, when the six-lane artery was closed to traffic. The 500- to 788-ton modules stretch 960 ft to camouflage the drive, creating two acres of real estate out of thin air.
The high-flying acrobatics would have been bold enough had they been executed from terra firma. For the $300-million Marie-Josée and Henry R. Kravis Research Building, each of the 19 mostly two-story mods—no two alike—was barged in and erected from the tidal river. All lifts had to be done during slack tide, while most of the city slept.
“It was high drama all summer,” says Lifton, who had a vested interest in the operation’s success. Having worked at Yale University since 1993, Lifton was about to become Rockefeller University’s president.
While there were learning curves and some column shims necessary to resolve fit issues, the lifts from June 15 to Aug. 17 “went very well, and we finished on time,” says Barry King, president of NYC Constructors LLC. Last April, during the job’s preassembly phase, the river building’s steel contractor, Banker Steel Co. LLC, acquired NYCC.
The modular approach took a year less than on-site “stick” building, says Curt C. Zegler, construction executive for the job’s at-risk construction manager, Turner Construction Co.
Zegler also figures the owner saved $20 million by avoiding an extra year of project oversight and reduced productivity from restricted work hours over the drive.
The 135,000-sq-ft laboratory is the centerpiece of the $500-million Stavros Niarchos Foundation-David Rockefeller River Campus. Rockefeller University will repair the seawall and a parallel stretch of a public riverwalk.
For the river campus, the school is spending $60 million in capital reserves. It took on $100 million in debt and has raised $315 million of the $340 million needed. It also is setting up a $1-million endowment to maintain the riverwalk and has given $150,000 to Friends of the East River Esplanade.
Park Over the Parkway
Thanks to its green roof, integrated with the grounds of the 14-acre campus, the two-story lab is effectively putting a park over the parkway and linking the campus to the riverwalk. “You have a building that creates this extraordinary open space,” says Rafael Viñoly, principal and lead designer of Rafael Viñoly Architects. RVA is master planner, design architect and architect-of-record.
Set between taller “bookend” buildings constructed over the drive and hugging a 65-ft-tall retaining wall to the west, the lab has only an eastern exposure. “From the campus side, you can’t see it,” except for its two rooftop pavilions, says Jay D. Bargmann, RVA’s senior vice president.
Viñoly wanted a horizontal profile to encourage interdisciplinary collaboration among the school’s 600 researchers. Open-plan labs can be reconfigured without an outside contractor.
The hemmed-in setting over the drive was an obvious one for the building, says Viñoly, who acknowledges the technical and logistical complications of the site. Fortunately, the void had been available since 1973, when state legislators granted air rights to a consortium of contiguous institutions: the nonprofit school, New York Hospital (NYH)—renamed New York-Presbyterian—and the Hospital for Special Surgery.
High Risk, High Reward
Since its founding in 1901, the school, centered on research and graduate education in biomedical sciences, chemistry, bioinformatics and physics, has enabled its faculty to take on high-risk, high-reward projects. All told, 24 of its scientists have won Nobel prizes, and 20 have won the prestigious National Medal of Science. Contributions include the discovery that DNA is the basic material of heredity and the determination that a virus can cause cancer.
By green-lighting the modular approach, the school is staying true to its high-risk, high-reward philosophy. “The client had the courage to approve the plan and trusted us to execute the job, which wasn’t a walk in the park,” says Peter M. Lehrer, chairman and CEO of Lehrer LLC, the owner’s adviser.
The modular delivery by barge has a precedent: In 1994, a team installed seven 830-ton units to form a 485-ft-long platform over the drive for a 12-story air-rights addition to NYH, the lab’s northern bookend (ENR 8/7/95 p. 24). “We were intrigued by New York Hospital,” says George B. Candler, the school’s associate vice president of planning and construction.
For the school, NYH stood as proof of concept and paved the way for a less tortuous sequel—at least concerning approvals. NYH approvals took six years and cost $150 million. The school spent less than two years on them, from August 2012 until May 2014. Together, planning, which began in mid-2011, and approvals cost only $7.5 million, says Candler.
For Zegler, a 1995 ENR article on the NYH job, which he reread 20 years later when he got the lab assignment, was a cautionary tale. “It gave me a clear understanding of what we were up against,” he says.
With the exception of Zegler, key individuals on the lab project, including the structural engineer, steel erector, marine contractor and Lehrer—whose former firm, Lehrer McGovern Bovis Inc., was NYH’s construction manager—are veterans of the NYH maneuvers. That gave the school some comfort, says Lehrer.
NYH veteran Aine M. Brazil—vice chairman of structural engineer Thornton Tomasetti (TT), which engineered NYH and the lab—agrees but adds, “The sequel is an order of magnitude more complex because we took everything done before to the next level.”
Brazil was not initially on TT’s lab team. In early 2014, RVA’s Bargmann, the school’s Candler, Turner and TT engineer Akbar Tamboli, who recalled the NYH job, started discussing the modular strategy. That summer, Tamboli, who was nearing retirement, brought in Brazil.
At that time, there was consensus that the project should be designed and documented to permit off-site construction or a more traditional “stick-built” approach. “It was important to keep our options open to ensure a competitive bidding situation,” says Brazil.
During preconstruction meetings with 10 steel contractors, there was “a lot of resistance against modular delivery from the river,” says Zegler.
In mid-2015, Banker with NYCC—one of two qualified bidders—proposed the most aggressive plan: minimize the number of lifts by maximizing module size and include all three decks. “Banker and NYCC had a courageous attitude,” says Brazil.
Banker won the $56-million steel contract in June 2015. “We do risky jobs, but the lab was riskier because we were on the water” and flying mods over one of the busiest highways in New York City, says Chet McPhatter, Banker’s chief operating officer.
Banker’s contract included $46 million for fabrication and a Keasbey, N.J., wharf operation, to receive and pre-erect the steel, and $10 million to extract the modules, load them onto barges, ship them and erect them over the drive.
Banker mitigated its risk with the right team members. “We have been working in New York City with NYCC since 2005,” says McPhatter.
NYCC’s King also had cut his teeth on NYH, working for steel erector Larry W. Davis, NYH’s mastermind. Further, Davis consulted to NYCC on the lab.
Even Banker’s heavy-lift marine contractor, Donjon Marine Co. Inc., was an NYH veteran. Donjon used the same 1,000-ton derrick barge, the Chesapeake 1000, nicknamed “Chessy.” And Banker used the same New Jersey wharf used for NYH’s preassembly.
Though the general concept was the same for NYH and the lab building, the specifics were very different. For starters, NYH was a single story; the lab was two stories. And though there were still main modules alternating with infill modules, every lab mod was different.
The lab benefited from the use of 3D laser scanning to create profiles of the Manhattan-schist retaining wall, existing buildings and other conditions. It also had the advantage of building information modeling. TT created the structural BIM and shared it with Banker for further development. Even the 90 tons of temporary erection trusses were in the model.
In the 1990s, all calculations of load conditions for each module were done by hand. For the lab, “we could run the model several times with different load conditions,” applying different weights, determining the center of gravity and more, says King.
For example, NYCC did studies of lifting the modules with the pavilion steel already erected. The weights were too high on those modules. Instead, the pavilion steel was loaded onto many modules, spreading out the weight, and stick-built after the lifts.
For NYH, two main modules were erected, followed by an infill module between them. For the lab, with one exception at the north end, modules went in sequentially—south to north—because the derrick barge, with its 238-ft-long boom, was farther from the seawall. That created height clearance issues for the infill modules, says John Witte, executive vice president of Donjon.
The lab’s three-level steel frame, with composite concrete-and-metal-deck floors, consists of 88-ft-long to 92-ft-long plate girders at each level, spanning east to west, with beams spanning north to south. Y-shaped columns, 96 ft apart, support the building on the east side. Columns 48 ft apart support the building on the west side. The building sits 18 ft above the drive.
Floor to floor, the 5-ft-deep girders are linked by diagonals, which allow all three levels to satisfy vibration criteria for the labs, according to TT. Floor diaphragms transfer wind and seismic loads as much as 200 ft to mechanical rooms on the west side of the building. The decks have no expansion joints. Instead, the north end of the platform is seated on slide bearings.
Structural design for the final building and temporary stability issues “overlapped considerably” as a result of the erection method, says Brazil. This required close collaboration between TT and Banker-NYCC.
The school hired TT’s construction engineering arm to design and document two complete modules in its 3D model. Each main module includes the upper V-portion of the frame’s Y-column, vertical columns, interior posts, braces, beams and girders with seated connections, which receive the infill beams. A typical infill module has two temporary erection trusses per floor for stability because it lacks girders.
Crews preassembled the modules in their final condition at the yard in New Jersey. In addition to steel, each mod included metal decks, some concrete, stairs, sprayed-on fire resistance and sprinklers. At the wharf, workers also loaded the mods with material, such as rebar and pavilion steel, to be installed on site. They also commissioned the lifting frame.
To prepare for the preassembly, crews set a steel grillage on the wharf’s timber mats. The grillage served as a foundation for the prefab structure.
There was a work-around because the wharf could only handle 600 ft of structure. Consequently, last April, after the first 10 modules were done, NYCC disconnected the first five, and Chessy lifted each onto a transport barge outfitted with special saddles. Then, Donjon tugged the module barges north to Port Elizabeth, N.J., where they stayed for two months. From April to July, workers preassembled the remaining five modules.
Meanwhile, site preparations were underway in Manhattan. From January 2016 through last July, after the foundations were finished, crews used a hydraulic crane to install the column stubs. For this work, there were partial lane closures on the drive.
The actual lifts—always between 11 p.m. and 5 a.m., when there was a slack tide—consisted of three basic moves: lift, swing and land.
On June 13, staging began for the lift of the first main module, scheduled for June 15. First, during a daytime slack tide, tugboats moved Chessy into position alongside the seawall and secured it to sea anchors to the north and south. Then, crews installed Chessy’s steel mooring arm to the lab’s structure.
On June 14, also during slack tide, workers hung the mod’s lifting frame from Chessy’s hook, using four synthetic rigging slings on each side of the module. Steel slings would have weighed too much.
NYSS managed the lifting frame and the sling length using a remotely controlled hydraulic leveling system, installed on the lifting frame. For NYH, the hydraulic leveling system was manually operated.
The high-tech leveling system was first used at the preassembly yard. “It allowed us to store the hydraulic cylinder positions so we could reuse them,” says NYCC’s King. “We wanted to maintain the same geometry to avoid racking and overstressing the slabs.”
That night between 6 p.m. and 9 p.m., the module barge was moved into position along the seawall, north of the derrick barge. Then, crews connected the lifting frame to the module. Next, the Chessy operator lifted the module and tugboats removed the transport barge. Chessy, with its load, was ready to swing.
During each lift, the derrick barge would rotate 90°. That, in turn, would rotate the module into its landing position onto awaiting column stubs or seated connectors.
Bolting had to be done quickly, before the road could reopen. The moment a module was in position, ironworkers would begin bolting the connections and column support points on all three levels at once, says King.
Once bolting was done, workers disconnected the lifting frame. Chessy would rotate back. The next day, it was moved north 50 ft to the next position.
Tugs moved the empty barge to New Jersey, while the next module barge moved from New Jersey to Manhattan. The basic choreography was repeated 19 times.
Only the third module took two nights to install, due to the need to shim its western column stubs. “Once we learned we had to super-elevate the modules, we did adjustments prior to setting all the rest,” says King.
For Turner’s Zegler, an incident one Saturday morning gave him some unexpected perspective on the nerve-racking operation. After wrapping up a lift ahead of schedule, Zegler and his team walked to 63rd Street and York Avenue, along the west side of campus, to check for cars exiting FDR Drive, which would have meant it reopened to traffic.
There, Zegler noticed a pregnant woman, apparently in labor, standing on the curb. He quickly offered to help her husband, who was searching in vain for a cab.
His team took to the street. Turner’s superintendent, Claude Wuytack, convinced a cab driver to ditch his fare and take the couple to the hospital, says Zegler. “They thanked us, and we said, ‘If it’s a boy, name him Turner.’
“We felt we did so much more in that three minutes than in the previous eight hours,” adds Zegler.
Rockefeller University’s Lifton didn’t catch the Good Samaritans on the webcam. But he has seen a great deal of positive action since Sept. 1, when he arrived on campus. That’s because the president’s house, at the north end of campus, gives him a ringside view of the progress of the job, which is 51% finished and on schedule for substantial completion in October 2018.
For the cause, Lifton has even given up his driveway, the only route into the site. He often watches the hydraulic crane off-loading trucks, just 50 ft from his living-room window. “It’s spectacular,” he says.
The lab building, which is updating the school’s aging research infrastructure, figured into Lifton’s decision to take the reins at Rockefeller University. “The project is an inspiration for the entire campus,” he says.