Currently, work is underway in Washington to replace the SR 99 Alaskan Way Viaduct with an incredible two-mile-long tunnel situated directly under Seattle’s downtown.
The decision to replace the viaduct was made in an effort to reduce closures and impacts to traffic. After the tunnel opens, the viaduct will be removed as part of the Waterfront Seattle program to provide more public space for visitors and locals alike.
This underground tunneling project is possible thanks to a massive tunneling machine nicknamed Bertha, which was specifically manufactured for this project by a Japanese firm that specializes in large-diameter tunnel projects.
According to the Washington State Department of Transportation, Bertha has mined a total of 1,560 feet.
The Waterfront Seattle project is expected to be completed in 2017.