A rendering of the new Route 7 Wittpenn Bridge.
Construction of the new Hackensack River bridge linking Jersey City and Kearny, N.J., via New Jersey Route 7 has taken a big step forward with the recent and long-awaited installation of the lift span deck.
The new structure, which will replace the existing 90-year-old Wittpenn Bridge, was supposed to begin carrying traffic last year, but a harsh winter in 2018 and additional time needed to put in place mechanisms to raise the bridge caused delays, according to the New Jersey Department of Transportation (NJDOT).
The main approaches to the bridge are from NJ Rt. 1 and Rt. 9 in Jersey City and, across the river, from Rt. 7 in Kearny. Work on them are complete, so once the lift span portion of the bridge is finished, the bridge can open to traffic.
According to DOT spokesman Stephen Schapiro, that should happen by spring 2021.
Once traffic is on the new bridge, he added, workers will finish construction of a new exit ramp to Newark Avenue in Jersey City. Improvements to the Fish House Road interchange in Kearny also will be completed.
The deck, considered to be "orthotropic," is made of structural steel plate stiffened in longitudinal and transverse directions, which enhances the plate's bending resistance to more efficiently bear wheel loads and distribute those loads to main girders.
This type of deck structure is much lighter than the concrete slab used in a more conventional girder bridge. It's also more costly to fabricate because of the amount of welding involved.
Although the Rt. 7/Wittpenn bridge project marks the initial use of this type of deck in New Jersey, orthotropic decks can be found elsewhere around the United States, mainly in California, and in other countries. For instance, San Francisco's Golden Gate Bridge, open since 1937, had its original concrete deck replaced with lighter, stronger orthotropic steel deck panels between 1982 and 1986.
For the Rt. 7/Wittpenn project, the contractor — CCA Civil Inc. of Jersey City — shipped the steel in several panel sections from the Pacific Northwest south toward Mexico and Central America, through the Panama Canal and the Caribbean to the United States.
Since their arrival in 2017, they have sat in a barge moored in the Hackensack River at CCA's expense.
It took three days at the end of September for a crane barge, which Schapiro described as one of the largest in the United States, to lift the three sections of the deck and position them, aided in its movements by tugboats.
"Once the three deck sections are connected, railings and sidewalks will be installed, the cables will be attached, and the machinery and electrical work, including the control house, needs to be completed," explained Schapiro.
He added that before opening to traffic, the lift span will undergo testing to make sure it moves properly. Once those trials are completed and the bridge has opened, the existing Wittpenn Bridge will be demolished.
The entire job is now projected for completion by fall 2022 or early spring 2023.
The overall cost of the project, which began in November 2011, has risen by about 5 percent, from the $473.4 million budgeted for the five contracts awarded by NJDOT, combined, to $495.8 million.
Schapiro said the increase was, "mostly related to additional utility work and ground improvements needed for foundation work."