Seattle’s Sound Transit is one step closer to the first-in-the-world achievement of operating light rail on a floating bridge as construction crews install the innovative track bridges that will enable light rail vehicles to transition onto the floating bridge, and the specialized track attachments that minimize weight and isolate stray current from the electric system that powers the trains.
The process of installing rail on the floating bridge has been underway for a year, but the planning and preparation has been several years in the making. Last summer crews completed post-tensioning of the bridge pontoons, a process that reinforced the concrete with high-strength tensioned strands. Post-tensioning enables the bridge to withstand stronger winds and higher waves, as well as strengthen it to carry light rail tracks and vehicles. With post-tensioning complete, crews began installing track on the bridge in late 2018.
