PORT ANGELES — The final three pontoons for the state Highway 520 floating bridge over Lake Washington near Seattle will make their way through the Strait of Juan de Fuca this week.
Three tugboats — the Western Ranger, Arthur Brusco and Nancy M — are towing the giant floats from Grays Harbor on the Pacific coast, around Cape Flattery and through the Strait of Juan de Fuca to Puget Sound, then through the Hiram M. Chittenden Locks in Ballard and finally into Lake Washington.
There, they’ll join the 74 previously constructed pontoons that together will support the world’s largest floating bridge.
Just when the football-field-size floats will pass points on the Strait is uncertain. They are expected to be in Seattle’s boat channel Thursday.
To track the tugs, go to http://tinyurl.com/PDN-marinetraffic. Placing your cursor on one of the blue arrows that represents a tug on the marine map will reveal its name.
A pontoon photo contest on Twitter is now underway, with five winners set to receive a tour of the new floating bridge as it’s built on Lake Washington.
Jon Marmor, editor of the University of Washington’s Columns magazine, will judge the competition.
Past photos of state Highway 520 pontoons will be accepted, as will new photos. Submissions will be accepted through noon Monday.
“This contest is a fun way to acknowledge the four years of hard work that went into building the 77 bridge pontoons,” said Dave Becher, state Department of Transportation engineering manager with the project.
Contractors built pontoons for the new bridge in Aberdeen and Tacoma.
Of the 33 constructed in Grays Harbor County, 21, including the final three, are the massive longitudinal pontoons — 360 feet long, three stories high and 11,000 tons.
They form the backbone of the new bridge.
Contractor crews on the lake continue to bolt together and anchor pontoons in their final position.
The new bridge, with six lanes, a shoulder for disabled vehicles and a bicycle/pedestrian path, is designed to resist stronger windstorms than the current bridge.
It will be 7,710 feet long, a replacement of an earlier 7,578-foot-long bridge.
The state Legislature established a program limit of $4.65 billion. As of January, the program had spent $2.07 billion, or approximately 45 percent of the program cost limit, according to Transportation.
The first of the new bridge’s pontoons arrived in Seattle on Aug. 11, 2012.
The completed bridge is scheduled to open next spring.