UPDATE, 7:58 p.m. | The Highway 99 tunneling machine Bertha is expected to restart this week after being idle for nearly eight weeks, the Washington State Department of Transportation announced today. Crews will finish inspecting the excavation chamber and cutterhead by Tuesday morning, marking the completion of current hyperbaric intervention work. The next step will be to…More
Topic: Bertha; Highway 99 tunnel
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So much groundwater is flowing into the front of the Highway 99 tunnel machine that it will be another two weeks before workers can get a look at what’s blocking “Bertha,” the tunnel-boring machine, Seattle Tunnel Partners’ Chris Dixon said this afternoon. Water is spilling through the 57-foot diameter cutter head, into a sealed-off 5-foot mixing chamber…More