Cedar River Bridge

The BNSF Cedar River Bridge project replaces the existing 1914 steel truss bridge superstructure with a new steel girder bridge. The existing steel truss bridge was too narrow for Boeing to deliver their new 737 fuselages to an assembly plant in Renton, Washington. In addition to replacing the superstructure, work included repairing the substructure, installing new abutment pile, new precast abutments and approach spans, regrading the site, new track, sub-ballast, and ballast.

The Cedar River is a salmon-bearing stream with spawning beds immediately below the bridge. The project team carefully adhered to prohibitions preventing them from touching these protected waters. Environmental compliance required careful attention to erosion control, suspending environmental protection fabric below the bridge to ensure no construction debris could fall into the river, and performing safe lead paint abatement on the 1914 truss.

Access to the site was limited by the river, environmental restrictions, overhead high-voltage power lines, I-405 to the east, and Houser Way to the west. To replace the existing bridge under these conditions, Atkinson constructed a large, wheeled platform using a project-built king-post truss system to roll the existing structure away and to roll the new steel girders into place. The rolling operations required detailed engineering and planning and considerable site-utilization planning to perform this operation within the limited site.

A noteworthy aspect of this project was the City of Renton's initiative to mount a CCTV camera on the old City Hall roof. This camera provided live, streaming video to the public throughout the entire construction project. Many residents actively monitored the progress and even witnessed the historic bridge being moved off the river on the rolling platform. Ultimately, the operation was completed successfully, adhering to the project timeline and in full compliance with environmental permits.