A $1.6bn project to raise the height of the Bayonne Bridge between New Jersey and Staten Island, thereby allowing larger container ships to reach terminals at Port Newark and Elizabeth, is to open on 30 June, six months earlier than scheduled. Â
The "navigation clearance" scheme was a highly unusual challenge for the civil and structural engineers of Skanska Koch and Kiewit Infrastructure. The aim of the work was to raise the deck of the bridge from 47m to 66m above the Arthur Kill tidal straits.
It accomplished this by building a second deck above the first, and then demolishing the original, a construction method that allowed the crossing to continue working during construction.
New Jersey Governor Chris Christie announced the early opening at a press conference this week. He said: "This is truly an engineering marvel. Engineers have compared it to performing open heart surgery while the patient runs a marathon.
Although the bridge may finish six months early, that does not take into account the fact that it is also about two-and-a-half years late.
The first completion date was given in 2010 as the end of 2015. This was intended to match the opening of the expanded Panama Canal, which has increased the size of container ship plying between the Atlantic and Pacific.
That deadline was missed owing to a combination of engineering issues, in particular the fabrication of precast piers, and winter blizzards. Â
The new height will allow ships carrying up to 18,000 containers to access Newark Bay. At present the bridge restricts entry to ships carrying up to 9,500 containers – tiny vessels in today’s sea freight market.
The four New Jersey terminals add up to the third biggest port in the US, so the Bayonne bridge is a complementary piece infrastructure to the canal.
The delays led to an increase in costs from $1.3bn to $1.6bn – a figure that does not take into account a $2.1bn programme of dredging to increase the depth of the channel below the bridge, nor a $2bn programme of improvement works on the terminals themselves. Altogether, the cost of improving post facilities in Newark wil come to about $6.7bn.
The Bayonne bridge is the fifth longest steel arch bridge in the world, and the longest when it was opened in 1931.
Image: The bridge with both decks in place (Arnold Reinhold)