Bertha makes baby steps as work on Seattle tunnel repair pit continues
Sep 8, 2014, 1:59 PM | Updated: 2:19 pm
Bertha has taken some baby steps as the contractor building Seattle’s waterfront tunnel continues working to repair the world’s biggest tunneling machine.
The Washington State Department of Transportation says Seattle Tunnel Partners has now installed all 84 underground piles as part of their plan to access the SR 99 tunneling machine, which has been stalled 60-feet below the surface since December 2013.
The piles will form the walls of a 120-foot-deep circular pit in front of Bertha. Crews will drill a series of wells to lower groundwater before digging out the pit.
Once the pit is completed, Bertha will be moved into the pit, where a large crane will hoist pieces of the tunneling machine to the surface for repairs.
WSDOT says crews expect to complete well installation by mid-September so excavation of the pit can begin.
In the meantime, Bertha’s manufacturer, Hitachi Zosen Corp., has begun a series of inspections and tests as they prepare to tunnel into the access pit.
WSDOT says as part of those tests, the tunneling machine recently mined forward approximately three feet. The move allowed crews the opportunity to evaluate various systems within the machine, and positioned Bertha against the exterior wall of the access pit.
The proposed schedule calls for repairs on Bertha to be completed by the end of the year, with testing to get underway in February 2015. WSDOT says Seattle Tunnel Partners still expects drilling on the Seattle tunnel to resume in March 2015.
