Construction of the world’s first light rail on a floating bridge to start next month in Seattle

2017-05-16T18:36:00-04:00

Engineers have to ensure the bridge will remain buoyant when a pair of 300-ton trains pass each other, and that the high-voltage current that powers the trains won’t stray into the bridge’s pontoons and corrode its steel rebar. They spent $53 million just to design the section across Lake Washington.

The Lacey V. Murrow Memorial Bridge is a floating bridge that stretches across Lake Washington, connecting Seattle and Bellevue through Interstate 90 freeway.

This April the final design promising to replace the center express lanes of I-90 with full speed light rail was signed off.

Subject to much controversy, Sound Transit has engineered and field-tested unique joints in order for the rail to account for the bridge's movement and weather conditions.

Rail service is projected to begin in 2023.

Seattle celebrates opening of world's longest floating bridge

2016-04-04T18:05:00-04:00

Sitting atop Lake Washington, the new State Route 520 is now the longest floating bridge in the world—beating its predecessor, the old State Route 520, by 130 feet [...]. This new bridge has stronger pontoons than the last one, and can withstand more buffeting from wind and waves. It also has a stormwater collection system, bus lanes in both directions, a path for bikes and pedestrians, and the capacity to someday accommodate a light rail system.

Archinect - News

Construction of the world’s first light rail on a floating bridge to start next month in Seattle

Seattle celebrates opening of world's longest floating bridge