East Link Light Rail I-90 Track Bridge System Animation

As part of the East Link project to extend light rail from Seattle to Redmond, Washington, Sound Transit, the public transportation agency for the Puget Sound region, selected the team of Parsons Brinckerhoff and Balfour Beatty to design, develop, fabricate, and test a track system capable of taking light rail over Lake Washington via the Homer M. Hadley Memorial Bridge -- the fifth-largest floating bridge in the world.

Operating light rail on a floating bridge is no mean feat -- there is currently no precedent. The floating span of the Hadley bridge is in constant motion due to changes in water level, wind speed, and temperature, and the degree of these changes varies with the season and with the vehicle load.

To accommodate the wide range and magnitude of movements to which the Hadley is subjected, the Parsons Brinckerhoff/Balfour Beatty team has conceived, developed, analyzed, evaluated, and tested the Curved Element Supported Rail (CESuRa) track bridge system. This 3D animation, prepared by Parsons Brinckerhoff's visualization team, presents the CESuRa concept, demonstrates its performance in simulated conditions, and illustrates how the track bridge system is incorporated into the larger East Link project.

To learn more about this project and the CESuRa track bridge system, read the feature story here: http://bit.ly/2q6Oho4