Weekly Update: West Seattle High-Rise Bridge Stabilization

West Seattle Bridge at sunset. Photo Credit: Madison Linkenmeyer

Every Monday, we’re posting a blog to keep you informed about our progress to stabilize the bridge, our efforts to address traffic and mobility, and other items related to the West Seattle High-Rise Bridge closure.


In this week’s update:


High-Rise Bridge Stabilization

Kraemer North America, our contractor for the stabilization work, is working every week, Monday through Saturday from 6 AM to 4:30 PM, to stabilize the bridge. This past Sunday, October 11, they worked during these same hours, from 6 AM to 4:30 PM.

Stabilizing the High-Rise Bridge is necessary to preserve public safety and the integrity of the bridge so all options remain on the table for a repair or replace decision. Stabilization puts us on the right path if repair is determined to be the best option. If we move forward with replacement, stabilization ensures no further damage is done and that the public is kept safe during design and construction of the replacement.

The table below provides details on recent and upcoming West Seattle Bridge-related work:

Recent and Upcoming WorkDetails
We expect stabilization work will be complete by the end of the year. This work includes:
Carbon fiber wrapping weakened areas of the bridge; adding post-tensioning inside the girders; injecting epoxy into cracks that are wider than 0.3mm. The epoxy injections don’t stabilize the bridge; they help prevent further deterioration by protecting the post-tensioning steel inside from corrosion.   Monitoring and inspection activities will continue even after stabilization work is complete.  

This coming week, the contractor is planning to:  
Continue installing the post-tensioning system. The Pier 18 release may happen as soon as the week of October 19.

During daily work, you may see:  
Some crews working on top and under the bridge; scaffolding and crews working on platforms suspended under the bridge; large equipment and vehicles delivering, moving, and storing materials.

There is also work taking place inside the bridge that you will not be able to see:
Monitoring cracks, and installing the additional post-tensioning strands.

Over the next few weeks, the contractor will:  
Continue stabilization work listed above and will also work to “release” the restrained bearing at Pier 18. We could be doing the Pier 18 “release” as soon as the week of October 19. Leading up to the Pier 18 “release”, the contractor will be installing a post-tensioning system inside the girder.

Other stabilization work will include:
Applying additional layers of carbon fiber wrap to the girders after the Pier 18 release and post-tensioning are complete. Once all stabilization work has been finished, we will lower the work platforms onto barges. This will likely be in late November.

Decisions in the coming weeks:
We will make the final determination as to whether we will move forward with repairing the current bridge or replacing it with a new structure. With our replacement consultant HNTB on board, we are ready to pivot to designing the demolition and replacement structure, should it be determined that it’s in the public’s best interest to replace rather than repair. 

Since we closed the bridge in March, we have:
Installed an intelligent monitoring system to better understand what type of stabilization and repairs would be needed and to monitor the bridge during this work; designed and started to install stabilization measures; built and hoisted custom work platforms; completed the first phase of carbon fiber wrapping; started the cost-benefit analysis (CBA) that will help inform the decision to repair or replace the bridge.   

Traffic Alerts:

We do not anticipate any additional traffic impacts from the bridge stabilization work over the next few weeks. 

While we do not anticipate significant impacts to traffic below the bridge, you may see some traffic control signs and devices. These signs and devices are meant to keep the workers and traveling public safe.

While the majority of the traveling public will see little to no traffic impacts during Pier 18 work, there may be lane reductions on Klickitat Ave SW and SW Klickitat Way on the west and south sides of Harbor Island.

Please obey all traffic control signs and devices and do not attempt to move them.

Paving at the intersection of West Marginal Way SW and Highland Park Way SW

SDOT crews will complete some additional paving this week (the week of Oct. 12) near the intersection of Highland Park Way SW and West Marginal Way SW. The paving is being done in advance of some bus stop changes near the intersection. The work will require a right lane closure on Highland Park Way SW outside of peak hours.

Upcoming Community Outreach

Our outreach team is continuing to connect with the community to gather input and hear about day-to-day experiences in West Seattle and the Duwamish Valley. Below is a list of our upcoming events:

  • Tuesday, Oct. 13: Maritime Community Town Hall
  • Tuesday, Oct. 13: South Park Neighborhood Association meeting
  • Thursday, Oct. 15: Sound Generations meeting
  • Friday, Oct. 16: Georgetown Community Home Zone walk
  • Monday, Oct. 19: Georgetown Community Council meeting

Visit our West Seattle High-Rise Bridge website to stay up-to-date on the bridge, see frequently asked questions, view inspection reports, and find links to our West Seattle Bridge blogs.