Seattle’s “Big Bertha” tunneling machine — or SR99 if you’re nasty — is finally drilling again three years after breaking down just 1,019 feet into the project.
It cost Japan’s Hitachi Zosen company $143 million to repair the drill it manufactured, and Big Bertha is now hardened with bearing seals and reinforced steel on its cutterhead. It wasn’t an easy job, as the five-story high drill was trapped beneath Seattle, where it was boring a 1.7-mile-long toll tunnel to replace the elevated highway.
Bertha — named after former Seattle Mayor Bertha Knight Landes — has already mined 73 more feet since resuming operations on December 22.
Its new fortifications will get a test when it meets the sand and clay packed 80 feet beneath the buildings of downtown Seattle.
Digging is projected for completion by January 2017 and the tunnel will open to drivers in April 2018.