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Bertha Gets a Visit from SR 99 Tunnel Project Leaders

SR 99 Tunnel Project leaders tour the control room inside Bertha. The December 2012 tour was part of a daylong event in Osaka, Japan, where the machine is being manufactured. (Photo courtesy of WSDOT)

Just before the holidays in December, Washington State Department of Transporatation (WSDOT) and Seattle Tunnel Partners representatives working on the SR 99 Tunnel Project traveled to Osaka, Japan to view testing of “Bertha,” the tunnel boring machine that will be used to bore the tunnel that will replace the waterfront section of the SR 99 Alaskan Way Viaduct in Seattle next summer. Bertha stands at about five-story high and was built by Hitachi Zosen Corporation. Testing should be completed early this year. Seattle Tunnel Partners will then authorize the shipment of the machine, which will need to be disassembled into 41 separate pieces to travel across the Pacific Ocean to the Port of Seattle.

  This is a short video of the ceremony in Japan on December 20, when SR 99 Tunnel Project leaders witnessed the testing of the machine: SR 99 tunnel boring machine ceremony in Japan .

The tunnel is scheduled to open to traffic in late 2015.

A 10-foot-long interactive model of Bertha is on display at Milepost 31, the project’s information center in Pioneer Square. For more information about the SR 99 Tunnel Project, visit


Looking south at pit where the SR 99 tunneling machine will begin its journey in summer 2013. Crawler cranes and excavators do the heavy lifting and digging while crew members survey progress from struts spanning the top of the pit. In the distance the two bridges that were built to replace the Alaskan Way Viaduct’s southern mile are visible. This new section of SR 99 opened in September 2012, one year ahead of schedule. (Photo courtesy of WSDOT)