News and Events

Construction of the new Tappan Zee Bridge reaches halfway point

8.2.2015

buildingsWork on the massive $4-billion project has reached the 50 percent mark two years after it started, Tom McGuinness, construction compliance engineer for the New York State Thruway Authority, said Wednesday during a media boat tour of the 3-mile site.

“You have a tremendous number of people dedicated to the project right now and every day there’s just a lot of activity taking place,” he said.

Much of the first year’s work took place below wter but that has changed dramatically as drivers from the bridge can easily see the action.

By the end of this year, McGuinness said the goal is to have all construction taking place above the Hudson River.

The first of the bridge’s two crossings is still on schedule to open to traffic in December 2016, followed by the second span less than a year later.

Here’s what’s happening now on the water and what’s in store for the rest of 2015.

Tappan Zee Constructors has begun building the cable-stayed bridge’s eight angled towers, each one as high as a 42-story building.

“The bridge is going vertical,” McGuinness said.

When completed, the towers will stand more than 100 feet — or 10 stories — taller than the top of the existing Tappan Zee Bridge.

By December, the towers will be visible to drivers as they cross the bridge — one more piece of eye candy to rubberneck.

Four towers are being built on each of the two football field-sized foundations on either side of the river’s 1,140-foot-wide main channel.

Crews are using self-climbing boxes to put together the steel reinforced frame and pour concrete into them, building the the tower section by section. After leaving the concrete to cure for up to 14 days, the boxes move up 12 to 18 feet to the next section.

Each tower will require 26 lifts, or 208 in total, project officials said.
Work is being done on all eight towers simultaneously using special narrow cranes that are securely mounted into the base of the foundation so they can reach high elevations.The tower cranes are the only ones on the project that are not positioned on barges.

“As these towers grow taller, we’ll outgrow the reach of the cranes that we have on site. That’s when these(tower) cranes will take over,” said McGuinness of the equipment that’s typically used in cities to build high rise buildings.

Construction of the towers, each of which will stand at a five degree angle, is expected to wrap up next summer.