Why was the tunneling machine built in Japan?

Tags: sr99

As WSDOT's design-build contractor, Seattle Tunnel Partners was responsible for procuring the SR 99 tunneling machine. Hitachi Zosen Corp. was selected as the SR 99 tunneling machine manufacturer ahead of three other American and international firms based on overall technical requirements, support capabilities, price and schedule. Based in Osaka, Japan, Hitachi has successfully built more than 1,300 tunneling machines, a number of them for large-diameter tunnel projects such as this one.