Towers on new Tappan Zee Bridge set to rise

• Crews will begin building the towers will begin later this summer.
• The new bridge will feature eight towers, each standing 419 feet.
• Construction of the concrete bases that the towers will stand on is nearly done.

Construction of the towers that will give the new Tappan Zee Bridge its distinctive look could start next month.

Each of the eight towers on the cable-stayed crossing will be as tall as a 42-story building.

Work is now wrapping up on the two giant concrete islands on which the 419-foot-tall towers will stand — four on each concrete foundation.

The bases, officially known as the main span pile caps, will help support the weight of the twin crossing, one of the widest in the world.

Crews have been pumping approximately 10,000 cubic yards of concrete in each of the giant tubs that make up the bases since last month, Tappan Zee project officials said this week in response to a query from The Journal News.

The two foundations are the largest on the project and each one covers 64 steel tubes that reach hundreds of feet deep into the Hudson River. They are colossal in their own right, considering:

• Each one is 360 feet long — or longer than a football field — and 60 feet wide.

• They are 14 feet tall, composed of concrete interlaced with reinforced steel bars, or rebar.

• The pile caps are 1,100 feet apart, leaving plenty of room for marine traffic to travel the river's deep-water channel under the main span.

David Capobianco, who oversees design and construction of the $3.9 billion project for the state Thruway Authority, recently said it takes eight days worth of pouring concrete to fill up the pile caps. Eight pours were spaced two weeks apart in order to allow the concrete to cure and so additional rebar could be installed.

"Each of these pours takes the better part of a 24-hour day," Capobianco said.

Three floating plants have been supplying concrete for the piles caps, whose construction began last fall.

In the meantime, construction is continuing across the 3-mile length of the river. Five girder sections have been put in place near the Rockland shore while other bridge piers are being built. The first road deck panels that will go on top of the girders are expected to be installed in the fall.

The first crossing is scheduled to open to traffic in December 2016.

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