Best of 2005 Awards

Third Avenue Bridge

Project of the Year: Bridges

Though not as famed as the Brooklyn Bridge, the Third Avenue Bridge over the Harlem River has long been a vital part of New York's road network, carrying 80,000 vehicles a day from the Bronx to Manhattan. But the deteriorating structure that first opened in 1898 had clearly seen better days.

Those conditions laid the groundwork to totally replace the bridge, a project that reached substantial completion this year. It garnered not only top honors in its category from the Best of 2005 jury but also made the panel's short list for the overall project of the year.

"It was an incredibly complex project," one judge said.

The project called for intimate involvement from numerous government agencies; the need to keep road and river traffic flowing as work proceeded; and the development and execution of an intricate design for a new swing-span bridge that will meet the city's traffic needs for decades to come.

"The contractors had incredible permitting issues on gaining access to the river bottom," one judge said. "The city really constrained them, because it wanted to make sure they did this job right. There are several other bridges they plan to replace upriver."

The design team, led by Hardesty & Hanover of New York, planned a bridge that maintains the historic aesthetic of its four-lane predecessor while enhancing traffic flow and safety. Instead of the old layout of a pair of side-by-side, two-lane spans, the new five-lane alignment more smoothly manages traffic congestion. It also cuts down on lane-changing difficulties that had contributed to a high accident rate on the old span.

The four-year, $128 million project also involved the replacement of approach ramps, mechanical and electrical systems, and the bridge's control house, as well as rehabilitation of the rotating gears to work with the new swing span. Led by New York-based Parsons Brinckerhoff as construction manager and resident engineer and the New York affiliate of Turkey-based KiSKA Construction as general contractor, the project team working for the New York City Department of Transportation included specialists such as engineers, naval architects, structural monitors, safety inspectors, and community outreach officers to assist the motoring public.

Although the original plans called for the bridge to be completely closed for six months, the department instead decided to have the contractors keep two lanes of traffic and one sidewalk open throughout, requiring the installation of a temporary span running parallel to the old structure. The 300-ft.-long temporary steel plate span allowed the team to limit full traffic closure to just two weekends. The project also had to meet a U.S. Coast Guard requirement to have at least one navigational channel open at all times.

The entire bridge, including approaches, is 3,500 ft. long, with 17 steel girder approach spans leading to the 350-ft. long, 6-million-lb., steel through-truss swing span. Forged at a mill in Alabama and shipped to New York on an ocean-tow barge, the project team floated the span into place on the Harlem River in October 2004, with the first two lanes of traffic opening two months later.

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All five lanes opened by February, with intermittent closures throughout the year as work continued. Final touches, including new streetlights, work on an off-ramp, and final mechanical and electrical tasks, are scheduled to wrap up in early winter.

The new bridge will operate more efficiently because it uses a center pivot bearing instead of the rim-bearing design it supplanted - a change that also made the replacement span easier to install. It features a 65-ft.-long, 100-ton steel box girder that transfers the span's entire weight to the center pivot, which is a spherical roller thrust bearing that is 5 ft. tall and nearly 10 ft. in diameter.

The bearing is designed to handle the 6-million-lb. vertical load and a 1-million-lb. horizontal seismic load. The truss connects to the transfer girder via more than 400 high-strength 1-in. bolts.

"It's unbelievable how complicated the construction is of the systems required to move the spans," one judge said. <<

Key Players

Owner/Client: New York City Department of Transportation

Design Team: Hardesty & Hanover; Philip Habib Associates; B. Thayer Associates; Gandhi Engineering

General Contractor: KiSKA Construction

Construction Manager: Parsons Brinckerhoff

Steel Fabricator: G&G Steel

Steel Detailer: Amec Zizka

Asphalt: Cofire Paving

Mechanical: E-Mech Contracting

Plumbing: Empire State Piping

Stone Installation: Graniteworks

Rebar Installation: Island Reinforcing

Utilities: Peduto Construction

Electrical: D.L. Blaine Corp.

Pile Installation: Underpinning & Foundation

Rebar Installation: United States Rebar

Submarine Cable Installation: UWL Co.

Engineering: Haley & Aldrich; Urbantech

Surveying: Loftus

Community Outreach: Zetlin Strategic Communications