Spanning the Hudson
It’s coming in the form of a monster crane known as the Left Coast Lifter, which is floating through the Panama Canal on a barge this month. When this behemoth–as long as a 30-story building is tall–reaches the Hudson in New York, it will get to work on the construction of a replacement for the aging Tappan Zee Bridge.
The Tappan Zee Bridge was considered an engineering marvel when it opened 58 years ago on Dec. 15, 1955. The cantilever span, which looks like a gigantic replica of something a kid in the 1950s would build with an Erector Set, is more than 16,000 feet long and has a maximum clearance of 138 feet over the river.
The Tappan Zee is the longest bridge in New York State because the state decided to build it on the widest point on the Hudson. Don’t ask us to explain why they did this, or why, a few years ago, they decided to rename it the Governor Malcolm Wilson Tappan Zee Bridge to honor an Empire State chief executive who accidentally became governor for one year when Nelson Rockefeller became Vice President of the U.S. It’s a Noo Yawk thang.
Back in the ’50s, a new bridge was needed 25 miles north of New York City to service the suburban sprawl that eventually turned the counties (in NY and NJ) surrounding the nation’s largest city into a megalopolis of nearly 20 million people.
Urban planners in those days assumed that the best way to alleviate exponentially growing traffic congestion was to widen highways and build more bridges. In recent years, this conventional wisdom has been challenged: some experts have opined that we actually make traffic worse by continuously expanding our roads and bridges. In other words, if you build it, they will come–and sit, bumper-to-bumper.
A few of these eggheads bravely suggested that instead of replacing the Tappan Zee, NY should drastically reconfigure its traffic patterns and lighten the load by expanding mass transit into its nether regions. A reasonable idea if you can start from scratch, but since the interstate highway system already exists there wasn’t any support for an undertaking that would rival the construction of the Egyptian pyramids.
So the New York State Thruway Authority gave the green light to a $3.9-billion replacement for the Tappan Zee, to be built next to the original. The project, consisting of twin roadbeds on pilings supported by elegant European-style cables, was made a top priority by Gov. Andrew Cuomo. Cuomo has mandated that the first half of the span be ready to receive traffic two years from now, with the entire project completed by 2018.
Enter the Left Coast Lifter, which is able to hoist 1,900 tons in a single heave. Tappan Zee Constructors, a consortium of four engineering and construction firms that is building the new bridge, says the plan to use the mega-crane enabled them to bid $800 million less than competitors for the project, according to a report in The New York Times.
Large steel girders for the new bridge deck and its supports will be linked together on land; these spliced modules (each weighing up to 1,100 tons) will be ferried out into the river on barges and raised into place by the Lifter, which is powered by three 806-horsepower engines. Tappan Zee Constructors says the land-based prep work is safer and more efficient than piece-by-piece construction on the water. Once the first of the new twin spans is open for business, the Lifter also will be used to dismantle the original Tappan Zee.
Gov. Cuomo apparently has developed a crush on the 6,750-ton Left Coast Lifter and wants to rename it the “I Lift New York,” the Times reports. We hate to spoil the party, but before NY and California start wrestling over bragging rights for the Lifter, it might be useful to remember the humongous crane actually was put together in Shanghai in 2009.
Regardless of who gets the credit, if everything goes according to plan in 2016 it’ll be time for some traffic on the new yet-to-be-named bridge over the Hudson.