Bertha, The Boring Machine
9:54 pm
Tue January 28, 2014

Tunneling Machine Bertha Moves Ahead 2 Feet

A Washington Transportation Department spokeswoman says the giant machine digging a highway tunnel under downtown Seattle has advanced two more feet, far enough to allow crews to build the next concrete ring of the tunnel.

Tuesday's progress was the first for the machine in nearly two months, since it stalled Dec. 6 some 60 feet underground.

Transportation spokeswoman Laura Newborn says workers for contractor Seattle Tunnel Partners are now "testing systems and evaluating the machine to see what maintenance might be needed before they resume tunneling."

A lengthy inspection of the machine's cutterhead has been completed but the Transportation Department has not said exactly what caused the problems that halted digging. The agency said it needs time to review inspection results.

The machine is only one-tenth of the way toward completing a 1.7-mile tunnel. The project will allow the removal of the aging Alaskan Way Viaduct along the Seattle waterfront.