July 21, 2019 at 6:00 am
By Hal Bernton Seattle Times staff reporter
GRAND COULEE DAM — When workers started pulling apart the three largest hydroelectric units in North America — capable of supplying more than enough power for all of Seattle — they found the damage far worse than expected.
They encountered large cracks, worn-out bearings and a defect in a critical weld that, if left in place, could fail, unleashing catastrophic flooding inside the powerhouse that risked killing workers and destroying the 7 million-pound generator-turbine units.
That last discovery halted work for 10 months to give engineers time to come up with a fix that would ensure a crucial covering would hold fast.
“How do we deal with the unexpected? It definitely keeps you up at night,” said Brian Clark, the U.S. Bureau of Reclamation manager for the project, which got underway in 2013 when work began on the first turbine.
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