Type: Floating Bridge with Retractable Draw Span
Location: Jefferson County, WA
Owner: Washington State Department of Transportation
Stafford Bandlow Engineering personnel were responsible for the inspection of the cathodic protection corrosion control for this six-hundred-foot structure.
The Hood Canal Bridge is a floating concrete structure that carries two lanes of traffic over the Hood Canal in Washington State.
The bridge structures are comprised of a series of pontoons and one of the pontoons in each structure is movable. The movable pontoons are withdrawn to create a maximum six-hundred-foot opening in the channel. With the exception of the two movable pontoons, the pontoons are anchored in place by steel rope anchoring assemblies.
The submerged portion of the steel anchor cables and anchors are protected against corrosion damage by impressed current cathodic protection systems, whereas portions of the cables in the associated bridge wet cells are protected by a galvanic cathodic protection system utilizing zinc anodes. An in-depth inspection of all cathodic protection system components of the impressed current and the galvanic cathodic protection systems was conducted as part of the project scope. Investigation of hydrogen evolution from the impressed current cathodic protection system was also conducted. When necessary, the outputs of impressed current cathodic protection system were adjusted. The task was concluded with a comprehensive report that described the status of the systems and deficiencies identified during the inspection. It also provided recommendations for effective and enhanced cathodic protection technologies that, if implemented, would improve corrosion mitigation.