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SR 520 Bridge Program News

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I-5 to Medina: Bridge Replacement and HOV Project

Medina to SR 202: Eastside Transit and HOV Project

Pontoon Construction Project groundbreaking
Pontoon Construction Project Groundbreaking

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SR 520 email update - April 14, 2014 

Pontoons on the move to Lake Washington
Crews are towing four longitudinal pontoons from their temporary moorage location in Grays Harbor to Lake Washington, where they will support the new floating bridge. These pontoons are from the third cycle built in Aberdeen.

  • Longitudinal Pontoon P left Grays Harbor on Thursday, April 10, and arrived on Lake Washington on Sunday, April 13.
  • Longitudinal Pontoon O is currently in transit, towed by the tugboat Ocean Ranger. It left Grays Harbor on Sunday, April 13. The tugboat Nancy M will take over near Port Angeles, and Pontoon O is expected to arrive at the Hiram M. Chittenden Locks later this week.
  • Crews are also scheduled to tow longitudinal Pontoon M from Grays Harbor beginning on Wednesday, April 16. The tugboat Ocean Ranger will tow the pontoon.
  • Longitudinal Pontoon N is scheduled to depart Grays Harbor during the next safe weather window, later this month.

Check out our online tracker for a visual map of pontoon locations and status.

Fourth cycle of pontoons in Aberdeen set to float out this week

Crews are nearing another major milestone at the pontoon construction site in Aberdeen. Crews there will work through the night on Tuesday, April 15, with the first pontoon scheduled to leave the casting basin close to midnight to coincide with the high tide necessary for float-out. Next, the pontoons will be towed to the Port of Grays Harbor for inspections, and stored in the harbor until they make the journey to Lake Washington to support the new SR 520 floating bridge.

These pontoons are the fourth of six cycles to be built in Aberdeen. This group of pontoons includes four large longitudinal pontoons, each a football field in length, as well as two smaller supplemental stability pontoons. With these pontoons complete, 52 of the 77 total pontoons needed for the new bridge will be complete.

Following the Aberdeen float-out, we’ll send links to photos and videos so you can see the pontoon action up close.