Grand Award - Construction
Highway and Transportation

New Tacoma Narrows Bridge

Location:Gig Harbor
General contractor: Tacoma Narrows Constructors, a joint venture of Kiewit Pacific Co. and Bechtel Construction Co.
Owner/developer: Washington State Department of Transportation
Engineers: Parsons, HNTB
Contract amount: $615 million




Photo courtesy of Kiewit Pacific Co.
Tacoma Narrows Constructors built two 500-foot-tall towers for the new Tacoma Narrows Bridge. Set 2,800 feet apart, the towers help compose the longest suspension span built in the U.S. in four decades.

The new Tacoma Narrows Bridge is one of the most ambitious and publicly scrutinized construction projects the state has ever seen. It is famous as the longest suspension span built in the U.S. in four decades, and it stands amid the hallowed ruins of its infamous predecessor, Galloping Gertie, which collapsed in 1940.

The deck stretches 5,400 feet from end to end, and the main span is 2,800 feet from tower to tower. Major work included installing the caissons for the two 500-foot-tall towers, building the towers, spinning the cables and assembling the deck. During the final phases, 46 deck sections weighing an average of 450 tons each were lifted and attached to suspension cables. In some cases the deck sections were lifted into a temporary position and then swung or “trapezed” into their final locations.

The work took place in the Tacoma Narrows’ unique setting. The channel experiences tidal fluctuations of up to 16 feet, and currents reach nearly 13 feet per second. Water passes under the bridge at a rate of 31.7 million gallons per second.

The separation between the new and existing caissons is only 65 feet. This environment required Tacoma Narrows Constructors to use an adjustable anchor system to keep the caissons on target for touchdown on the sea floor. Despite the significant water flows, the project team touched down both caissons within 6 inches of the design location, well within the 3 feet allowed by the designer.

Tacoma Narrows Constructors worked with the state Department of Transportation under a design-build contract, the first major transportation project in the state to use that delivery model. Construction began in 2002 and concluded in July 2007.

The project maintained a visible public profile throughout its duration. Tacoma Narrows Constructors participated in an ongoing neighborhood communication program, held monthly meetings to promote minority business participation, and held regular tours for unions and college students. Media from around the world covered every step of progress.

Judges called the project “amazing” and a “major achievement.”



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