SR 99 Tunnel Boring Machine
The Washington State Department of Transportation has released photos of the world’s largest-diameter tunnel boring machine — five stories tall — being built in Japan, which will be used to dig the new State Route 99 Tunnel that will replace the Alaskan Way Viaduct.
The machine is being built by Hitachi Zosen, a company that specializes in massive tunneling equipment.
The machine won’t arrive until 2013, but the public can get a chance Thursday to look at the work zone close up. There will be a mile-long guided walking tour along the bicycle/pedestrian path adjacent to the construction site.
The tour will begin at 6 p.m. Thursday at Milepost 31 — the Alaskan Way Viaduct Replacement Program’s information center – located at 211 First Avenue S.
A self-guided tour is also available. Displays have been installed along the bicycle/pedestrian path to describe construction activities, machinery at work and the area’s history. Access to the path’s north entrance is available at South King Street and Alaskan Way South, a few blocks south of Colman Dock, or the south entrance is at South Atlantic Street and Alaskan Way South, west of Safeco Field. Maps are available at Milepost 31.