First pontoons float to Lake Washington for 520 bridge replacement project
Aug 12, 2012, 10:18 AM | Updated: 5:21 pm
![]() Bright lights and powerful tugs help to get the job done. (Photo: WSDOT.gov) |
The first of six new large pontoons has arrived in Lake Washington and is waiting to be installed on the 520 bridge.
At 360 feet long, 29 feet tall, and 75 feet wide, the pontoon weighs 11,000 tons and is the largest ever built in Washington state. The pontoon was built in Aberdeen and towed 260 nautical miles from Grays Harbor to Shilshole Bay by the tugboat “Peter M.” and transferred to tugboat “Nancy M.” for the half-hour trip through the Ballard locks.
“It just fit width-wise. There was about a foot or so to spare on each side, and then room for a tug in front and a tug behind,” said Joy Carpine-Cazzantini, of the Washington Department of Transportation.
The first major part of the new 520 floating bridge is now anchored off of Medina, in Lake Washington, until it is ready for installation as a part of the 520 bridge replacement project.
The second pontoon is scheduled to make the same trip, towed by the “Ocean Ranger” tug, through the locks late on Monday August 13.
These pontoons are just part of the first round manufactured for the new bridge. A total of 77 new pontoons must be made and floated into Lake Washington before the 520 is replaced.
To track the progress of the tugboats, check out the Marine Traffic Tug Tracker.
Jillian Raftery contributed to this report.

