The Salmon Bay Rail Bridge Project
Since the early 1900s, the BNSF Salmon Bay Rail Bridge has enabled freight and passenger trains to cross the Lake Washington Ship Canal in Seattle. Commercial and recreational vessels pass under the bridge as they navigate between Lake Union and Puget Sound. From food and lumber to Amtrak travelers and Sounder commuters—the bridge is not only a critical link for BNSF’s distribution network, but also for businesses and families across the Pacific Northwest.
Over the years, BNSF has invested millions to extend the operational life of the century-old Salmon Bay Rail Bridge. Upgrades and maintenance have kept the bridge structurally safe and sound. However, frequent openings to accommodate marine traffic have taken a toll on the counterweight system. Diagnostics indicate that this system—which allows the bridge to open and close—is starting to fail.
Based on expert analysis and review, BNSF has developed a heavy maintenance strategy to replace both the trunnion bearings that allow the counterweight to rotate and the steel and concrete that account for most of the counterweight. This approach will keep the majority of the Salmon Bay Rail Bridge—which is in good condition—intact, and safely address maintenance needs with the lowest environmental and community impact.
- Great Northern Railroad authorized construction of the jackknife-style bridge in 1912.
- The bridge spans Salmon Bay and connects the Magnolia/Interbay and Ballard neighborhoods in Seattle, Washington.
- For over 100 years, the bridge has been an essential component of commercial and recreational traffic in the Pacific Northwest with approximately 30 to 40 trains—including Amtrak and Sounder passenger trains—crossing the bridge each day.
Since bridge completion, frequent maintenance and upgrades have ensured its safe and efficient use.
Major updates include:
- 1948 – Counterweight rebuilt
- 1980 – Main operating strut replaced
- 1995 – Main drive machinery and motors replaced
- 2010 – Counterweight trunnion bearings replaced
- 2013 – Most recent replacement of movable joints
- Timber tie deck replaced multiple times over the years
- Common steel maintenance such as replacing stringers and repairing corroded members has occurred throughout the life of the bridge
- Operator house has been continuously updated and maintained
- The bridge is critical for freight mobility. Manufacturers, distributors and retailers depend on daily shipments that cross the bridge to supply their operations, including shipments to and from the ports of Seattle and Tacoma.
- The bridge facilitates marine and recreational boat traffic between Salmon Bay and Puget Sound with more than 40,000 commercial and recreational vessels transiting the canal via the Ballard Locks each year.
- Commuters and travelers benefit from passenger rail service over the bridge on Amtrak and Sounder trains. Keeping the bridge operational will ensure continued service without significant interruptions.
- Freight mobility enabled by the bridge helps reduce stress, wear and tear and congestion on Washington’s roadways. The federal Government Accountability Office (GAO) has estimated the per-ton-mile social costs—including collisions and pollution—of trucking are six times greater than for rail.
Starting on Nov. 16, BNSF crews will be on-site to make repairs on the steel tower supports on the south side of our Salmon Bay bridge. There will be some temporary supports as part of the work. The work is expected to last about four weeks and crews will be working generally between 9 a.m. to 2 p.m. There will be some lane closures, but BNSF will work to minimize impacts as much as possible.