State DOT Says Jobs Float in, SR 520 Pontoons Float Out

Pierce County Executive Pat McCarthy emphasized the importance of the SR 520 bridge replacement to both the Puget Sound region economy and its quality of life. 

“Our region’s economy depends on a thriving two-way trade – and that trade can only happen on a strong, effective transportation system across the state,” said McCarthy, who also serves as vice president of the Puget Sound Regional Council executive board. “Transportation projects like the SR 520 Bridge Replacement and HOV Program are never just about one county or city – they support us all. That’s why we must continue to invest in a system that moves people and goods across our state.” 

Port of Tacoma Commissioner Connie Bacon said, “It has been gratifying to see pieces of this key regional transportation project take shape here in the port industrial area. We applaud transportation investments that keep people and goods moving and contribute jobs to our trade-rich state.” 

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The pontoons built in Tacoma, known as supplemental pontoons, will provide stability and flotation when attached to longer longitudinal pontoons built in Aberdeen. The supplemental pontoons each weigh 2,500 to 2,820 tons and measure 100 feet long, 50 to 60 feet wide and about 28 feet tall. 

Two of the pontoons from the latest cycle will be towed to Lake Washington this week and four will remain in Tacoma until additional longitudinal pontoons arrive on the lake. During the course of bridge construction, 44 Tacoma pontoons will be joined with 33 pontoons built in Aberdeen for a total of 77 pontoons needed to construct the world’s longest floating bridge. 

“Tacoma is proud of the industry that has kept our economic engine humming through difficult times,” said Tacoma Mayor Marilyn Strickland. “Tacomans love bridges, and we’ve helped build the second Tacoma Narrows Bridge, the Hood Canal Bridge and now SR 520. We’re proud to be part of the team that is building a floating bridge that will serve the Puget Sound region for generations to come and is the longest in the world, to boot!” 

Float Out Path
Information about Tacoma pontoon float-out activities Jan. 28-31 can be tracked online Photos of today’s event and float-out activities will continue to be updated on the WSDOT Flickr site:


The SR 520 Floating Bridge and Landings Project replaces the vulnerable floating bridge and approaches. Contractor Kiewit/General/Manson, A Joint Venture, has a $586.6 million contract to build the floating bridge, anchors and 44 supplemental pontoons. Construction is under way on Lake Washington. The floating bridge contract requires the new, six-lane SR 520 floating bridge to open to traffic by July 2015, but includes incentives for an earlier opening in December 2014. 
Information is available at