It was made by Hitachi Zosen Sakai Works in Osaka, Japan, and the machine's assembly was completed in Seattle in June 2013. Tunnel boring began on July 30, 2013, with the machine originally scheduled to complete the tunnel in December 2015.OverviewBertha was a 57.5-foot-diameter (17.5 m) built specifically for the 's (WSDOT) project in ,. .
The name Bertha, after Seattle's first female mayor, , was chosen by a panel (that included the Governor and Transportation Secretary) from 150 submissions from kindergarten through 12t.
[pdf] The name Bertha, after Seattle's first female mayor, , was chosen by a panel (that included the Governor and Transportation Secretary) from 150 submissions from kindergarten through 12th graders, who were asked to submit female names with Washington state heritage. The winning entry, which was submitted by two elementary schools in and , was selected in December 2012.
[pdf] Incorporated in Australia in 1990, Terratec is the world’s leading designer and manufacturer of Tunnel Boring Machines, Raise Boring Machines and other custom-engineered products for the tunnelling and mining industries, encompassing all ground conditions and boring diameters from 0.6m to 15m.
[pdf] 
