Local Information

Done; Pontoon construction for new SR 520 wraps up

Monday, March 9, 2015 - 14:13

Ian Sterling, WSDOT communications, 206-819-7230

Elected officials and workers celebrate completion at Aberdeen casting basin

ABERDEEN – Pontoon construction for the new State Route 520 floating bridge is now complete. The final three football-field-size structures will float out into Grays Harbor early Tuesday morning. All 77 pontoons for the Washington State Department of Transportation’s newest floating bridge will soon be on Lake Washington.

Deputy Secretary of Transportation Cam Gilmour, Quinault Indian Nation President Fawn Sharp, Aberdeen Mayor Bill Simpson and SR 520 Program Administrator Julie Meredith were among the speakers at an event to mark the milestone.

“As part of the world’s longest floating bridge, the pontoons built here in Grays Harbor County will support a highway corridor vital to our state’s economy,” said Gilmour during the celebration today at the pontoon casting basin in Aberdeen. “These pontoons will help provide a safer and more reliable connection between communities on both sides of Lake Washington.”

WSDOT contractors built pontoons for the new SR 520 floating bridge in both Aberdeen and Tacoma. Of the 33 constructed in Grays Harbor County, 21, including the final three, were the massive longitudinal pontoons – 360 feet long, three stories high, and 11,000 tons.

The casting facility in Aberdeen also turned out two cross pontoons that bookend the floating portion of the new bridge, and 10 supplemental stability pontoons, which are about the size of a basketball court. Pontoon construction in Aberdeen began in winter 2011. Crews also built 44 supplemental stability pontoons in Tacoma.

“On behalf of the SR 520 program, we want to thank Grays Harbor County, the people of Aberdeen and the hundreds of workers who came together to build these pontoons,” said Meredith.

The final three Aberdeen-built pontoons will now be inspected and then towed to Lake Washington to join the 74 other completed pontoons.

Contractor crews on the lake continue to bolt together and anchor the pontoons to form the world’s longest floating bridge. The new bridge, with six lanes and a bicycle/pedestrian path, is designed to resist stronger wind storms than the current bridge. The new bridge is scheduled to open in spring 2016.

For information on road closures associated with SR 520 construction, please visit the SR 520 Orange Page and follow us on Twitter.

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