Bye bye, Bertha.
The Seattle tunnel machine, which carved its way beneath the city to make way for a new waterfront portion of SR 99 to replace the Alaskan Way Viaduct, has been completely disassembled, with the final pieces being lifted out of a pit near Sixth Avenue North and Thomas Street on Wednesday morning.
The work to cut up the hulking boring machine — billed as the world’s largest — began after Bertha broke through at the end of her journey on April 4 and placed the final concrete rings that make up the outer wall of the 9,270-foot-long tunnel.
The 8,000-ton machine was moved into the 7-story-deep receiving pit at the northern end of the tunnel and crews from the contractor Seattle Tunnel Partners have been working around the clock cutting it into pieces with torches, lifting those pieces out and trucking them away.
The Washington State Department of Transportation called it “tricky, tough, and impressive work” in a new post on the SR 99 project website. The largest lift — or “pick” as crews referred to it — was 70 tons, and some pieces required additional cutting at street level to make them suitable for hauling.
WSDOT says that Hitachi Zosen, the machine’s manufacturer, will decide what to do with many of Bertha’s components. The giant steel cutterhead that was unique to Seattle’s project was cut up and trucked to a steel recycler, with the exception of some pieces that were donated to the Port of Seattle. Cutting tools and the control panel were also donated to Seattle’s Museum of History and Industry.
The video reduces the months-longs disassembly to a minute and a half. At the end, an American flag was attached to the crane by workers as a point of pride for those who worked on Bertha.
The tunneling phase of the project to replace the aging, elevated viaduct began in July 2013 but was soon plagued by a two-year delay caused by damage to the machine and repairs that followed.
Work continues on the 2-mile double-decker roadway inside the tunnel, with plans to open to traffic by early 2019. A new progress-tracker page from WSDOT shows various elements of work that is being done, including interior structures, electrical rooms and mechanical/electrical/plumbing systems.
WSDOT said it is also planning for the demolition of the viaduct, decommissioning of the Battery Street Tunnel and improving surface street connections at the tunnel’s north and south ends.
Oh, and Bertha may be gone, but her Twitter handle will live on: @BerthaDigsSR99.
