Seattle’s Floating Bridge Welcomes Historic Electric Train

Something extraordinary happened on Lake Washington in September 2025. Under the cover of night, steel met water in a way never before seen anywhere in the world: an electric train glided across a floating bridge under its own power. This wasn’t just a test – it was a bold demonstration of innovation, determination, and decades of engineering expertise. The historic crossing not only marked a world-first achievement, but also signaled the dawn of a new era in public transportation, one that will soon unite Seattle, Bellevue, and Redmond with faster, cleaner, and more reliable connections.

Gateway to Regional Connections

The successful bridge crossing unlocks the final piece of Sound Transit’s East Link Extension, soon to be known as the 2 Line. When passenger service begins in early 2026, commuters will enjoy a 30-minute ride between downtown Seattle and downtown Bellevue – regardless of highway traffic conditions.

This achievement represents more than just a transportation breakthrough. It symbolizes the region’s commitment to sustainable transit solutions that connect communities while reducing carbon emissions.

Despite facing multiple delays throughout its development, the project’s completion will transform how people move throughout the Puget Sound region. The floating bridge segment creates a vital link in what will eventually become a 116-mile regional light rail network.

As the 2 Line prepares to open, anticipation is growing among residents and businesses alike. For many, the project is not just about saving time on commutes, but about reshaping daily life – expanding access to jobs, education, and cultural opportunities across the region. The bridge crossing stands as both a practical solution and a powerful symbol of the Puget Sound’s future.

Engineering Marvel on Water

How do you run a 300-ton electric train across a bridge that literally floats on water? Engineers faced unprecedented challenges in designing a rail system capable of handling the bridge’s constant movement with waves and weather changes.

Special track bridges called “track bridges” were installed at transition points where the floating section meets land. These innovative connections allow the tracks to flex and adjust as the bridge rises and falls with water levels and traffic loads.

Electrical systems required special corrosion protection against the lake’s salt water. The power distribution system needed to maintain consistent voltage despite the bridge’s movement – a challenge never before solved anywhere in the world.

The result is not only a feat of engineering, but also a world first – proving that heavy rail can safely and reliably operate on a floating bridge. Beyond solving immediate technical hurdles, the project sets a precedent for future transit systems facing similar geographical challenges worldwide.

Midnight Journey Makes History

Under the cover of darkness on September 8, 2025, a single Link light rail vehicle glided across Lake Washington’s Homer M. Hadley Memorial Bridge. Starting at just 5 mph, engineers gradually increased speeds until reaching the full 55 mph operating speed during multiple overnight crossings.

Testing crews carefully monitored the expected electrical arcing between overhead power wires and the train – a normal occurrence during this phase. The nighttime schedule minimized disruption while maximizing safety during this critical milestone.

This wasn’t just another test run; it represented the culmination of decades of planning, engineering, and collaboration between Sound Transit and the Washington State Department of Transportation.

For many in the region, the sight of light rail crossing the lake symbolized more than a technical achievement – it was a glimpse into a future of faster, more sustainable connections between Seattle and the Eastside. The successful trial run marked a turning point, bringing the long-anticipated expansion one step closer to serving thousands of daily commuters.