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Spokane St Swing Bridge remains closed while SDOT repairs machinery damaged after ice storm power outage

Closure for people biking, walking, and driving and freight traffic will last minimum of 2 weeks.

Update (December 31, 2022)

Our team of bridge engineers and technical experts have been in the bridge every day since the recent incident and will continue to work on repairs over the weekend. We are actively repairing what we can now, as we also continue to work to understand the full scope and cause of the damage and to estimate the timeline to complete repairs.

At 3 a.m. this morning, electricians completed repairs to a flooded underground power conduit, replacing 500 feet of damaged power lines. We are continuing to assemble the equipment necessary to overhaul the damaged hydraulic cylinder that lifts the moveable bridge.  

Here are some of the other repairs that we have been working on over the past week:

  • Reprogramming electrical components and analyzing the machine programming.
  • Conducting comprehensive inspections on all hydraulic bridge components.
  • Building and assembling the equipment necessary to move the 15,000-pound cylinder.
  • Working with our contractors and suppliers to order necessary parts and equipment.
  • Examining and repairing flooded power conduits and damaged high-voltage power cables.

Click here for resources to get around during the Spokane St Swing Bridge closure. In addition to engineers and technical experts working to repair the bridge, we also have a team addressing the impact the closure has on people who bike, walk and roll. We are continuing to work on possible measures to make the bike detour route as intuitive and comfortable as possible.

Click here to learn about the ongoing comprehensive program to maintain and preserve the bridge which began before the intensified issues arose during last week’s storm. In the past few months, we completed work to strengthen the bridge structure and replace several hydraulic pump arrays. We had already begun preparations to rehabilitate the currently damaged hydraulic cylinder and replace the computer control system.

The Spokane St Swing Bridge (Low Bridge) will remain closed for at least two weeks while our crews continue working to repair mechanical issues that intensified after a power outage during the ice storm on Friday, December 23.

Our engineers and crews are working as quickly as possible to develop a repair plan and schedule, and we will update the public as soon as more information is available. The bridge is currently open for maritime traffic and is closed to all vehicle, bicycle, and pedestrian travel.

Detour routes:

  • People traveling by car may use the West Seattle High-Rise Bridge.
  • Freight and people operating trucks headed to Terminal 5 in West Seattle may use the West Seattle High-Rise Bridge or West Marginal Way SW.
  • People riding King County Metro buses are not affected because transit does not use the Low Bridge during normal operations. We are coordinating with Metro to plan for potential snow storms, as the Low Bridge is a part of the transit snow network.
  • King County has expanded its Water Taxi service this winter with sailings seven days a week. The Water Taxi serves people walking, rolling, and biking unless sailings are canceled as a result of high winds and waves. The Water Taxi is not scheduled to sail on Sunday, January 1, or Monday, January 2.
  • People biking may also use the 1st Ave S Bridge.

Federal law gives the U.S. Coast Guard authority over maritime travel on the Duwamish Waterway and requires us to keep the waterway accessible for ships. The east channel’s bridge remains open, connecting Harbor Island and Terminal 18 to Sodo and the Spokane St Viaduct.

The Spokane St Swing Bridge (low bridge) shown as closed in an orange line. The West Seattle High-Rise Bridge (high bridge) is shown as open in green. Public access to Harbor Island is shown in dashed blue. East Marginal Way and West Marginal Way streets are also labeled.
Map of the closed Spokane St Swing Bridge (low bridge). The West Seattle High-Rise Bridge (high bridge) remains open. Graphic: SDOT.
Photo of the Spokane St Swing Bridge open to marine traffic and closed to vehicle, bicycle, and pedestrian travelers. The Low Bridge and West Seattle High-Rise Bridge are in the upper part of the photo, with the Duwamish Waterway in the bottom part of the photo.
Photo of the Spokane St Swing Bridge open to marine traffic and closed to vehicle, bicycle, and pedestrian travelers. Photo: SDOT

The problem initially appeared to be associated with a computer issue that occurred while the bridge was powering back up after a power outage. Once the computer issue was resolved, engineers found previously identified minor issues with the hydraulic system that moves the bridge had intensified.

We complete regular inspections of the Low Bridge and had existing plans to repair these aging components in 2023. However, after the power outage, it was discovered that previously manageable small-scale issues had escalated into more severe problems. Until these components are fixed, the bridge cannot be reliably moved without risking more severe long-term damage.

Our engineers are working as quickly as possible to analyze repair options. While there is not yet an estimate for how long bridge repair will take, we expect the closure to last for at least two weeks.

We are working to minimize effects on the traveling public to the extent possible and communicating with its regional partners, including King County Metro, the freight community, and the Port of Seattle.

Based on the evaluation results, additional Low Bridge closures for repairs may be needed in 2023, along with closures associated with planned capital improvements to the bridge next year.

We have been proactively working to maintain the Low Bridge as part of ongoing bridge preservation efforts. In addition to the immediate work to resolve this hydraulic system issue, we have several planned and recently completed improvements to the Low Bridge, including:

  • Structural rehabilitation, including carbon-fiber wrapping and epoxy crack fillings, which is complete
  • Bridge communications and control system upgrades (planned for 2023)
  • Bridge lift cylinder rehabilitation on east side of the waterway (planned for 2023)

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