Feb. 21 update: Seattle Tunnel Partners will dig access shaft to reach tunneling machine

Posted on Feb 21 2014 4:52 PM

On Friday, Feb. 21, Seattle Tunnel Partners spoke to the media about their plans to repair or replace the seal system that protects the SR 99 tunneling machine’s main bearing.

As expected, they will access the seal system through the front of the machine by digging a 100-foot-deep by 80-foot-wide shaft. Other details about the shaft and plan for fixing the seals will not be available until next week when experts from the machine’s manufacturer, Hitachi Zosen, arrive from Japan to help finalize the plan. STP has received proposals from various firms to design the shaft and will likely select a firm next week.

While STP has shared their preferred method for accessing the seal system, they are waiting until after their meeting with Hitachi to provide WSDOT with an official plan. Because this is a design-build contract, STP and their machine manufacturer are responsible for developing and implementing the plan to fix the machine and resume tunneling. 

Previous updates

Feb. 14, 2014 update – Repair plan to be finalized by the end of February

Feb. 12, 2014 update – Video of Tuesday's news conference

Feb. 10, 2014 update – Accessing the seal system inside the tunneling machine

Feb. 7, 2014 update – Two factors contributed to tunnel stoppage

Jan. 31, 2014 update – Further evaluation required before tunneling can resume