Spokane St Swing Bridge (low bridge): Epoxy and carbon-fiber strengthening work complete

The Spokane St Swing Bridge (low bridge) swings open for maritime traffic to pass through.

With repairs on the West Seattle Bridge (high bridge) complete, we shifted our focus to the Spokane St Swing Bridge (low bridge), which served as a vital connection to West Seattle for emergency services, transit, those seeking life-saving medical treatment, and freight during the 2 ½-year high bridge closure.

This week, the low bridge project reached an exciting milestone as we finished epoxy crack injections and carbon-fiber wrapping on the interior and exterior of both spans. These methods, which we used on the high bridge, reinforce the structure’s concrete, which will prepare it to serve the community for decades to come.

We began the low bridge strengthening work by injecting small cracks with an epoxy compound to prevent them from growing in the future. This method was used on the high bridge during its rehabilitation.

We began working on the low bridge in summer 2022 when inspections teams began mapping cracks on the exterior concrete. Shortly after, we started constructing work platforms underneath the low bridge as high bridge repair work wrapped up.

Once we hoisted all four platforms up to the underside of the low bridge, we began filling cracks and applying carbon-fiber to the concrete. We repeated this process inside of the bridge’s spans. In early October, we lowered and dismantled the work platforms.

We assembled 4 work platforms and hoisted them up to the underside of the low bridge. These platforms enabled easier access for crews working on the bridge’s exterior.

We reinforced the interior walls of the bridge’s spans by applying sheets of carbon-fiber wrapping.

With strengthening work complete, we will continue to take steps to preserve the service life of the low bridge through other maintenance and capital projects.

Next, we’ll upgrade the bridge’s controls and communications lines, which allow it to open and close for marine traffic. We will also replace one of the hydraulic lift cylinders inside the bridge’s east pier. The lift cylinder acts as a pivot point on which the bridge can turn as it swings open and closed for marine vessels.

We’ll use this email list to keep the community updated on future low bridge project milestones. For more information, please visit the Spokane St Swing Bridge project webpage.

Phone line in community languages