The Tappan Zee Hudson River Crossing is being designed and built by Tappan Zee Constructors, LLC (TZC), a consortium of some of the world's best-known and most highly-regarded design, engineering and construction firms, including Fluor, American Bridge, Granite, and Traylor Bros., along with key design firms HDR, Buckland & Taylor, URS, and GZA. TZC is working closely on the project with a team of employees from the New York State Thruway Authority and the State Department of Transportation.
The 3.1 mile twin span cable-stayed bridge with angled main span towers is the single largest bridge construction project in New York’s history. The bridge will revitalize the existing Governor Malcolm Wilson Tappan Zee Bridge that connects Rockland County to Westchester County over the Hudson River.
Almost 6,000 steel-reinforced precast-concrete panels, each about 12 ft. long and up to 45 ft. wide, are being placed on the steel-girder system, supported by 68 football-field-sized pile caps, precast by Cape Charles, Virginia-based Bayshore Concrete Products. Crews placed the last of the 300-ton pile caps in the summer of 2015, reinforcing each cap with galvanized steel and sealing with up to 750 cu. yd. of concrete.
A milestone in the construction of the 61-year-old Tappan Zee Bridge replacement was achieved in February 2016 with the erection four 645-ton crossbeams. Using the famed Left Coast Lifter, which is one of the largest floating cranes in the world, the placement of the four crossbeams marks the midway point for the five-year project. The new work is located just north of the existing bridge. That bridge now carries 140,000 vehicles daily. When completed, the 96-foot-wide new northern structure will carry eight temporary lanes of traffic by the end of 2017. The north and south structures will each carry four lanes of traffic. Plus, the northern bridge will include a bicycling and pedestrian lane.
Work began on main span steel in June 2016, installing four large pre-assembled sections of steel, weighing nearly 340,000 pounds each, atop the main span crossbeams. In July 2016, TZC completed installation the first stay cables. Each side of the bridge's towers will require 12 pairs of stay cables to support the main span roadway, utilizing 700 miles of metal strands in total.
The Tappan Zee Hudson River Crossing is needed because the number of vehicles crossing the bridge every day far exceeds the number it was designed to handle, traffic jams and delays are a regular occurrence, accident rates are high, and maintenance costs on the old bridge were expected to be $3 to 4 billion over the next 20 years.
After more than a decade of delay, the new bridge to replace the Tappan Zee is becoming a reality. The first span of the new twin-span bridge is scheduled to open in 2016, and the new bridge should be complete in 2018. The new bridge will be designed and constructed to last 100 years without major structural maintenance.
The new bridge will be a visually striking, recognizable landmark, and one of the widest cable-stayed structures of its kind in the world. The Tappan Zee Hudson River Crossing will mean less congestion for motorists, with eight traffic lanes, four breakdown/emergency lanes, and state-of-the-art traffic monitoring systems, as well as a dedicated commuter bus lane from the day it opens. Designed and constructed to be mass-transit-ready, the new crossing will be able to accommodate bus rapid transit, light rail or commuter rail. The bridge will also include a bike and pedestrian path.
The total cost of the new project far less than initially expected. The design-build contract for the bridge will help keep the project on-budget and on-time, because financial risk associated with most cost overruns or schedule delays lies with the contractor, rather than toll payers or taxpayers.
TZC is a strategically formed consortium of design-builders created to deliver the best project team to successfully build the Tappan Zee Hudson River Crossing on time and within budget while achieving the highest environmental standards.
The TZC team partnership is based on aligning cultures within each firm that will steer the strategic planning throughout the project. These key cultures shared by the team start with a no-nonsense outlook on safety. TZC team members all share excellent safety records and invest great resources and planning to ensure that each employee is trained and prepared to work in a safe environment.
TZC has set aside 10 percent of the total project budget as the Disadvantaged Business Enterprise (DBE) goal, which equates to about $314 million in subcontract opportunities. DBEs are encouraged to attend TZC’s monthly orientation meetings, where they can meet with DBE program and procurement team members.
TZC is proud to have been selected to design and build the Tappan Zee Hudson River Crossing. The team understands the importance of this project to the New York area and is committed to supplement the New York State Thru Authority’s Public Information Plan with a proactive approach to public involvement and community outreach. The first span of the new twin-span bridge is scheduled to open in 2016, and the new bridge should be complete in 2018.
To date, the team has placed 143,432 cubic yards of concrete. Main span concrete placement is 80 percent complete, while main span pylons concrete placement is 25 percent complete. Approaches concrete has reached 70 percent completion. The team has erected 46,000 tons of pre-cast concrete and 36,000 tons of structural steel this year.
During the 2016 construction season, the team will primarily focus on structural steel erection, pre-cast deck plank installation and Stage 3 work occurring at the Westchester and Rockland side abutments, tying the bridge from Westchester Shore to Rockland Shore.
Sources: www.newnybridge.com and tappanzeeconstructors.com
Photos Courtesy New York State Thruway Authority.