First Steel Girder Assembly Installed on Tappan Zee Bridge

The project’s first steel girder assembly, measuring 410 ft long, combines the strength of three separate girders into a single structure. (Photo: New York State Thruway Authority) 

The first massive section of structural steel for the approach span of New York’s new Tappan Zee Bridge was successfully installed last week using the “I Lift NY” super crane. Placed near the Rockland County side of the bridge, the 1,110-ton, 410-ft-long section -- made up of welded girders that will support the road deck -- will be joined by 133 additional girder assemblies in the coming months to connect the concrete piers.

The assembly was prepared at the Port of Coeymans in Albany County, where crew members used approximately 6,600 bolts to connect the individual 12-ft-tall steel girders, according to the New York State Thruway Authority. The assembly was then placed on a barge and floated down the Hudson River to the project site, a 95-mile journey.

The Thruway Authority says the bridge will use more than 100,000 tons of domestically produced steel. High Steel Structures Inc. and Hirschfeld Industries (both AISC/NSBA Members and AISC Certified fabricators), have joined to furnish the approach span steel, while Canam-Bridges (an AISC/NSBA Member and AISC Certified fabricator) is fabricating the main span steel. If laid end to end, the new bridge’s girders would stretch for over 30 miles. In addition to supporting the road deck, the assemblies include infrastructure to carry communications, electrical power, water and compressed air to support bridge operations.

As more steel continues to connect concrete piers over the coming months, the new crossing’s final form will become increasingly recognizable to all. The super crane, capable of lifting nearly 2,000 tons, uses a series of anchor lines to pivot in place and make adjustments while installing the assemblies.

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