SEATTLE — Washington state transportation officials say a clogged cutterhead is one of the reasons the machine tunneling under Seattle to build a new highway tunnel got stuck
The machine named “Bertha” is only one-tenth of the way toward completing a 1.7-mile tunnel. The tunnel will carry Highway 99 traffic and allow the removal of the aging Alaskan Way Viaduct along the Seattle waterfront.
On Friday the state Department of Transportation said inspections conducted last month found that many of the cutterhead openings were clogged with dirt and other things. Officials say they also discovered the seal system protecting Bertha’s main bearing was damaged.
It’s still unclear when Bertha can begin tunneling operations again. The machine has been mostly idle for two months.