As a cargo ship passed under the Bayonne Bridge on a recent day, Peter Zipf only needed to look down to see why port officials have set out to raise the structure by 2015, when supersized container vessels should be arriving at East Coast terminals.
"As you're standing on the bridge and you look under it, you know, you could almost touch the ship," Zipf said. "It's so tight at times already, so if you can envision the top of the new ships versus the existing level of roadway, there's a clear interference there."
Zipf, the chief engineer for the Port Authority of New York and New Jersey, is overseeing a project that the agency calls "an engineering marvel." The plan calls for raising the bridge deck to 215 feet above the Kill Van Kull — 65 feet above the current clearance — without shutting down traffic between Bayonne and Staten Island, N.Y.
"From an engineering perspective, we had a real challenge on our hands," Zipf said, as the Port Authority is racing against a well-known deadline: By 2015, operators of the Panama Canal expect to have completed a major expansion of the waterway, which will allow larger ships to reach the region's shipping terminals. But most of New Jersey's port facilities are inside the Bayonne Bridge, inaccessible to those post-Panamax ships.
So, months before the agency announced the project in late 2010, engineers began to assess alternatives, Zipf said. They included putting the bridge on jacks, building a new span and installing technology that allowed a section of the deck to elevate when needed.
Zipf noted that the arch of the 80-year-old bridge makes it "a very robust structure," while giving the agency the ability to consider those options. But the Port Authority settled on raising the bridge deck, which Zipf said met the time demands while reducing the impact on local property, the waterway and noise levels.
To devise its plan, the agency recruited high-profile engineering and consulting firms like HDR Inc., Parsons Brinckerhoff and Greenman-Pedersen Inc., along with five building contractors.
"Because time was so critical … we really wanted to put a very aggressive, yet progressive, engineering solution in place," he said. "And raising the roadway gave us the opportunity for that because it minimized the environmental issues."
In July, the Port Authority shaved six months from its project timeline, allowing it to be complete before 2016. The announcement came soon after the Panama Canal Authority said its project could be delayed by six months, to April 2015, providing good news for the agency and local terminal operators.
When construction starts next year, crews will remove and demolish one half of the four-lane bridge, allowing them to build the opposite side of the new deck overhead, Zipf said.
The crews will then repeat the process for the other half, while also building new approach roadways. In the process, the Port Authority will "modernize the bridge, in terms of traffic standards" by widening its lanes and pedestrian walkway, and adding a median and shoulders.
Zipf said the complex plan has featured the work of nearly 70 engineers at the peak of its design phase, which was taking place late last month. Like other bridge projects, the work spans a host of engineering disciplines — from structural and geotechnical, to civil and environmental.
Joe Fiordaliso, president of the American Council of Engineering Companies of New Jersey, said the many engineers in the state view the project as "an audacious undertaking, but one, frankly, that they've undertaken in recognition of how important it is to lift the structure so that those ships can pass through."
"If it didn't represent such a drastic need, they might not be pursuing such a drastic solution," Fiordaliso said. "So I think there's a corollary there between the need and the approach that they've taken.
The Bayonne Bridge initiative, for which the Port Authority has authorized $1 billion, is also one of many key engineering projects currently before the agency. The bistate authority in February unveiled a $500 million rehabilitation project for the George Washington Bridge, and is planning a $1 billion effort to replace the span's steel suspender ropes.
And while bridge and deck replacements are not unusual, Zipf said the Bayonne Bridge project is unique for an engineer in that the agency is elevating the deck while maintaining traffic flow, preserving its historic design and reducing the environmental impact.
"The elements of it have been done before," he said. "The difference here … is that we're putting in all of the pieces together — kind of like a Swiss watch, if you will."
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