Tunneling machine’s front end bolted in place

Bertha TBM cutterhead being lowered back into access shaft

The troubled Alaska Way Viaduct Replacement Tunnel TBM known as Bertha has reached a milestone in its repair. The front cutterhead has been repaired, and has been lowered back into the access shaft to be re-attached to the TBM. The time-lapse video below shows the cutterhead being lowered down into the access shaft. What caught my eye was the number of steel cables on the crane blocks…that’s a heavy lift!

Time Lapse Video

[Source: WSDOT Alaskan Way Viaduct Project Page. Image: WSDOT]