Information from Seattle Department of Transportation
 

 From Friday, April 20 (starting at 6am) through Sunday, April 28, the Spokane St Swing Bridge (low bridge) will temporarily be closed to people driving, walking and biking. This closure is necessary because the Seattle Department of Transportation (SDOT) crews have to move the control tower wires from the West Seattle Bridge (the high bridge) to a new underground conduit below the West Duwamish Waterway and replace the control system. These wires are connected to the hydraulic system that opens and closes the bridge. The West Seattle Bridge (high bridge) will remain open during the low bridge closure.

Travelers will need to detour to other routes. During the closure of the low bridge, here are options for reaching your destinations:

• Riding the bus: Buses provide a reliable option for travel across the Duwamish Waterway via the West Seattle Bridge (high bridge). They accommodate people walking, biking, and rolling, offering the fastest route without driving. Use King County Metro’s trip planner for route and schedule details.
• Riding the Water Taxi: The West Seattle Water Taxi offers direct service to downtown Seattle and operates seven days a week. Large vessels can accommodate up to 26 bikes.
• Driving/Carpooling on the West Seattle Bridge (high bridge): The West Seattle Bridge (high bridge) remains open for drivers with no vehicle access restrictions. Note that pedestrians and cyclists cannot use this bridge.
• Walking, biking, and rolling: For people who bike, walk or roll, there are several other routes to get around the closure. Check out the SDOT Bike Mapto find available bike facilities. For people who walk or roll, we recommend utilizing public transit to reach your destination.

We are offering assistance to people impacted by the closure to use transit with a rewards code available through the TransitGo app. For detailed instructions on how to access this reward, please refer to the provided link. 
 
For more detailed information about the closure and how to get around, visit our SDOT blog.

Why this work is needed

This closure is another phase of the Spokane St Swing Bridge Rehabilitation Program,which involves upgrading the control system responsible for operating the low bridge. The current system is over 30 years old. This upgrade will improve the overall resiliency of the West Seattle bridge system.

This work involves replacing logic controllers, which manage the lifting and swinging machinery of the spans and activate gates to block traffic and pedestrians when the bridge is open. It also includes upgrading communication lines between computers, the control tower, and moving components, as well as replacing wiring, mechanical switches, and push buttons.

Upcoming Maintenace

The next step in the maintenance process is to overhaul the two cylinders in the west piers and to switch out the repaired lift cylinder with the old one at the east pier. Crews replaced the west pier’s cylinder in 2018 with a spare cylinder. The rehabilitated cylinder from the west pier will be installed on the east pier. After the swap, the removed cylinder will be inspected, refurbished, and stored as a spare cylinder. 

Over the next two years, SDOT will complete additional maintenance and upgrade work on the low bridge which will require short-term closures of the bridge for people walking, biking, and driving, including the replacement of the lift cylinder. SDOT will share more details about the timing of these closures as planning efforts continue.