The Seattle Times

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Mike Siegel / The Seattle Times
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Saturday, July 20, 2013

Highway 99 tunnel machine Seattle’s biggest grind

The giant tunnel drill, nicknamed "Bertha," is seen nestled in its launch pit. The white structure at left is a covered conveyor belt to transport excavated dirt to a barge at Terminal 46. At lower right, the white crane will lower thousands of arc-shaped concrete segments that will become the tunnel tube.