A year after the tunnel machine Bertha broke down on the Seattle waterfront, state transportation officials said Thursday the target date for restarting the dig has been pushed back again.
In response to an inquiry from KIRO 7, the Washington State Department of Transportation said contractor Seattle Tunnel Partners now estimates Bertha will resume tunneling in April 2015.
STP had previously said it would dig again at the end of March.
On Dec. 3, 2013, the world's largest tunnel-boring machine chewed through a steel pipe.
On Dec. 6, contractors stopped the machine.
The cutterhead became clogged, the machine overheated, and seals around the vital main bearing were damaged, requiring them to be replaced.
By now, repairs were supposed to be well underway but construction of the access pit to fix Bertha still isn't done.
The pit will be 120 feet deep, but WSDOT said Thursday it is so far only 74 feet deep.
STP's schedule had called for excavation to begin in July and be completed in September.
Contractors ran into complications building the walls and the discovery of shell fragments stopped excavation for 10 days for an archaeological review.
WSDOT wrote to KIRO 7 "STP has also talked about difficult soil conditions that require dewatering and careful monitoring.
We knew building the pit for these repairs would not be an easy task and it's important that they take the time they need to do this work properly and safely."
WSDOT officials also said that contractors now plan to tunnel into the pit and lift the front end of the machine out this month.
State officials added that "a significant amount of work still needs to be completed to achieve that goal."
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