Previous construction updates:
- Drydock in the water: SR 520 coffer cell arrives on Lake Washington, Nov. 22, 2013
- SR 520 pontoons on the move in October, Oct. 11, 2013
- Third cycle of SR 520 pontoons complete in Aberdeen, Oct. 5, 2013
- SR 520 Pontoon W key cracks repaired, Sept. 11, 2013
- Repairs complete, SR 520 pontoon headed home, Aug. 23, 2013
- Eight is great – new SR 520 pontoons to float out this weekend in Tacoma, July 26, 2013
- Costs for SR 520 pontoon repairs announced, July 30, 2013
- SR 520 pontoons readying for a busy summer, June 06, 2013
- SR 520 pontoon progress and May movements, May 15, 2013
- Second cycle of SR 520 pontoons leave the Aberdeen Casting basin, Apr. 29, 2013
- WSDOT announces SR 520 pontoon design changes and repairs, results of internal review, Feb. 26, 2013
- Experts confirm rebar provides pontoon structural capacity, Dec. 21, 2012
- Continued progress on SR 520 east approach bridge piers, Dec. 14, 2012
- Quality assurance program working as planned on pontoon project, Nov. 21, 2012
- Major work continues on new SR 520 floating bridge, Nov. 14, 2012
- SR 520 bridge pontoon videos, interviews and correspondence posted online, Nov. 9, 2012
- WSDOT makes changes to improve oversight of pontoon construction, Oct. 25, 2012
- More SR 520 bridge pontoons under construction in Aberdeen, Sept. 27, 2012
- First new SR 520 bridge pontoon en route to Ballard locks, Aug. 8, 2012
- Pontoons floated out of Aberdeen casting basin on July 30, 2012.
- First pontoon repairs were found to be successful on June 26, 2012, but additional work is needed.
- Damage was discovered to new pontoons in May, 2012: 4-6 weeks of repair work is expected.
- Installation of the gate for the pontoon casting basin was completed Nov. 4, 2011.
- Construction of the first interior walls for the SR 520 pontoons started Sept. 23, 2011.
- Excavated dirt from casting basin helps city of Hoquiam project. July 15, 2011.
- First casting basin pour completed in Aberdeen on July 8, 2011.
- Excavation work on the pontoon casting basin started May 2, 2011.
- Pile driving for the pontoon casting basin started the week of Feb. 28-March 4, 2011.
Apr. 29, 2013 - Second cycle of pontoons float out in Aberdeen
Crews reached another milestone on April 29 as they floated out the second cycle of six pontoons built in Aberdeen. Check out our float-out photos on Flickr and watch our YouTube video.
Feb. 26, 2013 - Pontoon Expert Review Panel Update
Read the Expert Review Panel report, Phase 2 (pdf 1.08 mb).
Aug. 28, 2012 - Pontoon Peer Review Panel Update
In May 2012, cracked concrete and spalling were discovered in one of the Aberdeen pontoons. In response, WSDOT convened a panel of experts to investigate the first cycle of Aberdeen pontoons. The panel has completed its work and WSDOT has reviewed its recommendations.
Aug. 27, 2012 - Pontoon Inspection Update
As pontoons arrive on Lake Washington, we continue to inspect them prior to assembly of the new floating bridge so they will support the new SR 520 floating bridge for 75 years or longer. This video inside a pontoon on Lake Washington for the new SR 520 floating bridge shows an internal leak that has since been repaired. The video may be used by some to say the pontoons are leaking. We want you to have the full story.
This leak is not water from Lake Washington. Instead, it involves water that we added to the inside of the pontoons as temporary ballast to lower them to the height of the new bridge. In this one location shown in the video, there was a small hole between separate, water tight compartments inside the pontoon. The hole was repaired as part of the inspection process.
Inspectors also noted condensation on the walls of the pontoons where repairs were made in Aberdeen. We are continuing to work with the contractor to make the necessary and minor repairs on the pontoons to meet our high safety standards. WSDOT is continuing its due diligence to ensure that the pontoons meet the specifications of the contract. WSDOT is committed to building a new SR 520 floating bridge that is safe for drivers.