Information from Seattle Department of Transportation

As part of our ongoing efforts to upgrade and repair the Spokane St Bridge (West Seattle Low Bridge), we will be installing a new communications line which connects the bridge control tower to the bridge's moving parts. 

While this work occurs, we will temporarily close a trail spur that branches off the main West Seattle Bridge Trailway. The impact to people who bike, walk, or roll in the area will be minimal. Our project closure site will not affect the main trail over the Spokane St Bridge, or the primary bike route between West Seattle and Downtown used by most people on bikes. Instead, we will be closing a section of the trail that provides an optional loop around the foundation of the Spokane St Bridge used by some bikers.

We are placing a new communications line underneath the Duwamish River. 

The Communications System runs along the bridge currently. We want to change this. 

This communication line is linked to the control system, which opens and closes the low bridge. The original system of buttons, switches, and wires is about 30 years old. To remedy this, we will be rerouting the wires connecting the control tower with the motors that open and close the bridge off of the high bridge to a new conduit under the West Duwamish Waterway. This work will increase the resiliency of the West Seattle Bridge system and help decouple the low bridge from the high bridge. 

When our work is complete, the communication line will run underneath the Duwamish River. 

The system includes computers that control the machinery that lifts and swings the spans and activates the gates that prevent traffic and people from crossing when the low bridge is open. It also includes the communication lines that connect the computers, control tower, and the moving parts to one another. 

By making these updates, we are proactively addressing the risk of potential component failures associated with operating the bridge.