Crews lift Scuffed and Rusty Disc-Shaped Front End of Broken Tunnel-Boring Machine

The scuffed and rusty disc-shaped front end of the broken tunnel-boring machine has been lifted by Crews from the ground in Seattle. Crews have pulled it out of a 120-foot-deep pit to do repair work.

According to the Seattle Times, it seems that the process is going smoothly with the 2,000-ton machine segment emerging from the ground. The Dutch lift company, contractor Seattle Tunnel Partners and machine maker Hitachi have been praised by Matt Preedy, deputy Highway 99 tunnel administrator for the Washington State Department of Transportation (WSDOT), for devising a good lifting plan and carrying it out.

The tunnel-boring machine called Bertha stopped working in December as it worked to construct a tunnel under Seattle in order to replace the Alaskan Way Viaduct that was damaged in a 2001 earthquake. It is expected that that drilling will begin again in August. The Washington State Department of Transportation has taken decision to keep the viaduct open to traffic at the time of the delicate operation.

There is a possibility that the deep access vault around Bertha could be damaged by major failure of cables or the tower beams. It can also put the Alaskan Way Viaduct at risk. Laura Newborn, spokeswoman for the Washington State Department of Transportation, said that the crews carried out incremental tests so that they can confirm that the motors and cables are up to the task.

"By doing it on the way out, they were able to save some time and they were able to keep the center of mass lower, which is always a good thing," said Matt Preedy.