Four-car trains roll across Lake Washington as Sound Transit steps up testing

[Yo_Mama_Been_Loggin]

For decades, multi-car light rail trains on Lake Washington have existed only in conceptual drawings and renderings looking ahead to a brighter transit future. But last night, they became a reality for the first time as Sound Transit ran a four-car test train back and forth across the Homer M. Hadley Memorial Bridge… again and again and again.

As with last week’s inaugural “live wire” tests, NPI’s cameras were there to capture this latest first. It’s another sign that we’re getting closer to completing the 2 Line.

I didn’t bring a Doppler radar with me, but it appeared that the train was being operated at its planned regular top speed of 55 miles per hour for some tests. This made getting photos and videos extra tough. It can be challenging to photograph a moving vehicle during the daytime; the nighttime presents a whole ‘nother level of difficulty.

But it’s a good problem to have.

https://www.nwprogressive.org/weblog/2025/09/trainspotting-with-npi-four-car-trains-roll-across-lake-washington-as-sound-transit-steps-up-testing.html

[MrWowWow]

1. Did the test engineers do a deadweight test with the actual train yet?

-Just for true dynamic load verification and validation purposes. Otherwise, there's just computer simulations and the fleet of loaded dumptrucks test. Cyclic dynamic loading may end up being a post-commissioning concern. Remember, that's a floating bridge it's traversing. Remediating and arresting structural crack propagation is probably not possible for this floating bridge. I give it 6-12 months before structural failure.
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Reference Notes:

In 2005–2007 WSDOT and Sound Transit ran full-scale load tests on the Homer M. Hadley (I-90) floating bridge using trucks loaded with concrete blocks to simulate Link’s weight. They did both static (dead-weight, parked) and dynamic (moving in “train” formation) runs to measure pontoon/balance and expansion-joint behavior, which confirmed feasibility and informed the track-bridge design.

(For context: this preceded the recent Sept. 2025 powered test runs of an actual Link train across the bridge.)