Keep on boring: Bertha almost to Washington Street in downtown Seattle
Mar 3, 2016, 3:28 PM | Updated: 5:18 pm
Bertha is still boring under conditional permission from WSDOT, but has made steady progress toward downtown Seattle. (WSDOT)
(WSDOT)
Bertha continues to dig underneath Seattle and has moved 110 feet since it restarted on Feb. 23.
That puts Bertha’s total traveled distance at 1,391 feet. The massive boring machine is now approaching South Washington Street in downtown Seattle.
Related: Bertha allowed to move forward under certains conditions from WSDOT
The Washington State Department of Transportation has allowed Bertha to move ahead and install a total of 25 concrete rings. So far, crews have put 17 rings into place.
The 25-ring allotment is part of conditional permission that WSDOT gave the contractor, Seattle Tunnel Partners, after a sinkhole developed behind the boring machine on Seattle’s waterfront. If WSDOT believes that tunneling crews have proven they can safely operate within the 25-ring period, then Bertha will be allowed to move forward to a planned maintenance stop south of Yesler Way.
That stop is slated for several weeks of maintenance jobs. After that, Bertha is expected — with WSDOT approval — to dig underneath the Alaskan Way Viaduct and downtown Seattle.
Soils removed during the tunneling process are being trucked away, instead of moved via barge, which was previously done. A barge recently damaged a pier and dumped dirt into Elliott Bay. WSDOT wants to review barging operations before the contractor uses Elliott Bay again. The damaged pier was repaired last month.
