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Bertha, the tunnel boring machine, isn’t quite ready to get moving again.
Inspections during the planned maintenance stop are expected to take several more days before the tunnel’s contractor can keep drilling under the city, the Washington State Department of Transportation reports.
Crews have completed 10 hyperbaric shifters in the chamber behind the machine’s cutterhead. Most of the work has involved cleaning and building platforms crews use to stand on during the maintenance.
Seattle Tunnel Partners, the contractor, will determine how long the maintenance will take based on its current inspections.
Once the machine is given the OK, Bertha will make its trip under the Alaskan Way Viaduct. There will be a two-week closure of the viaduct for safety purposes.
Meanwhile, photos show how far Bertha has gone since tunneling resumed in February. Seattle Tunnel Partners has built almost 300 feet of the SR 99 tunnel.