It will be nearly a year before the damaged tunnel-boring machine stuck under downtown Seattle can start digging again, officials said Monday.
The giant drill known as Bertha stalled in December. Its main bearing and the seals that surround it are damaged, and crews are planning to excavate a pit that will allow them to access the machine and fix it.
The timeline means a 16-month delay in boring, but the state Transportation Department says that the contractor, Seattle Tunnel Partners, hopes to shave off four months to meet the DOT’s original target for opening the new State Route 99 tunnel in November 2016.
Chris Dixon, the project manager for Seattle Tunnel Partners, says the repairs pose a significant engineering challenge and have to be done safely.
Work on other parts of the tunnel continues, including $750 million worth of work at the tunnel portals and along the Highway 99 corridor.