Bertha completes final approach to pit
Feb 26, 2015, 11:27 AM | Updated: 3:23 pm
Bertha is done digging for now and will be disassembled and removed from the pit. (Photo courtesy of Washington State Department of Transportation)
(Photo courtesy of Washington State Department of Transportation)
Bertha is done digging for the time being.
The boring machine dug a little further Wednesday night, reaching the access pit that it will be disassembled in.
Workers are building concrete rings that will allow the machine to move out of the tunnel, according to the Washington State Department of Transportation. Five more rings must be built.
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Workers will continue to clean debris from the machine as it moves forward.
Once the machine reaches the northern edge of the access pit, it will be disassembled before being lifted to the surface for repair. A crane will hoist Bertha out of the pit in pieces.
Seattle Tunnel Partners say the process will take “significant time and effort,” because of the following steps: installing work areas, disconnecting joints, cables and hoses, removing cutting tools, welding lift points on the body of the machine.
Bertha broke through a 20-foot concrete wall Feb. 19 to reach the access pit. It sat idle for more than a year before that.
The tunnel being dug by Bertha, which will run about 2 miles under the city, is designed to replace the Alaskan Way viaduct, damaged in a 2001 earthquake. The project is two years behind schedule.
If all goes as planned, the tunnel is expected to open to traffic at the end of 2017.
