The second cycle of new 520 Bridge pontoons that floated out of Aberdeen last month is now on the move, with the first tugboat delivery to Lake Washington expected this afternoon between 3-6pm. The surreal sight of a 360-foot-long concrete box floating through the Ballard Locks and Montlake Cut could make tonight’s rush hour commute more interesting than usual. The other new pontoons are, for the time being, heading to various moorage sites around the state, as crews are still working to fix the cracks in the first cycle pontoons delivered to Medina last summer.
Drivers, boaters and residents around Lake Washington should be on the lookout for State Route 520 bridge pontoons moving through the lake this month.
Contractor crews will float one pontoon through the Hiram M. Chittenden Locks in Ballard between 3 and 6 p.m. this afternoon, Wednesday, May 15. A pontoon already on the lake will be moved from its current staging location to another location on the lake, making way for a pontoon from Aberdeen to use that staging area when it arrives on the lake later this month.
Two of the six pontoons recently constructed in Aberdeen have been towed to a moorage site in Tacoma and a third is on its way later this week. The final two pontoons from the second cycle of pontoons built in Aberdeen will remain moored in Grays Harbor until they are needed for bridge construction.
On Lake Washington, crews will prepare four pontoons from the first cycle built in Aberdeen for additional modifications recommended by an expert review panel in February. The Washington State Department of Transportation is coordinating with floating bridge contractor Kiewit/General/Manson, A Joint Venture, to finalize the details and timeline of the work.