Earlier this week, Sound Transit achieved a historic milestone. The Link light rail train crossed the I-90 floating bridge under its own power for the first time: an essential part of the testing required for the upcoming East Link Expansion. The tests happened overnight on Monday and Tuesday, and mark the first time an electric train has ever crossed a floating bridge.
Keep reading for all the details!
What is the 2 Line extension?
The Link light rail’s new 2 Line will connect Seattle with the Eastside, hence the alternate name East Link Expansion. The Eastside includes cities and towns that are part of King County but separated from Seattle by Lake Washington. The new 2 Line will connect Seattle to Mercer Island, Bellevue, and Redmond. In April 2024, the 2 Line began service between the South Bellevue and Redmond Technology stations.
The next step is for the 2 Line to provide service across Lake Washington. It’s no easy feat, however, due to this portion of I-90 being on a floating bridge. After delays, the projected opening date for the full 2 Line is now April 2026. This week’s testing brought the completed Eastside Expansion project one step closer to completion.
What were this week’s tests on the floating bridge?
Sound Transit shared an earlier milestone back in May: the first light rail train in the world to cross a floating bridge. However, that was an unpowered tow test in which the train was pushed and pulled by a truck. This week’s testing was the first time the train crossed the floating bridge under its own power: another global first!
The light rail train crossed the Homer M. Hadley floating bridge multiple times and at various speeds, eventually reaching the full operating speed of 55 mph. The train was powered by an overhead wire. According to Sound Transit, the reason for the tests being conducted overnight was so that they could see and document “expected electrical arcing.”
In a video of Monday’s test shared on Instagram, Sound Transit CEO Dow Constantine said: “Around about midnight now, we’re here at the Mercer Island portal to the I-90 floating bridge waiting for the first train to cross under power… This is the first important step in our testing and ultimately training of our crews to get to passenger service across the I-90 bridge.”
In an Instagram post about this week’s testing, Sound Transit wrote:
This week, we reached a historic milestone: the first Link light rail train ever to cross the I-90 floating bridge under its own power. That makes this the first floating bridge in the world to carry powered trains. It’s all part of months of testing to ensure a safe, reliable ride when the 2 Line opens in 2026.”
What are the next steps?
More testing will proceed over the next few weeks and months, specifically live wire and signal testing. King County Councilmember Claudia Balducci shared that the “[Sound Transit System Expansion Committee] are hoping to conduct a four-car live wire test on the I-90 bridge as soon as next week.” You can view photos and video of the light rail’s historic floating bridge crossing here via Sound Transit.