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

[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.)