Seattle’s tunneling machine Bertha back to work

SEATTLE (AP) — The Seattle tunnel boring machine known as Bertha is back on a slightly shifted course after additional measurements confirmed it was 6 inches east of the correct site.

The Seattle Times reports (https://goo.gl/LC7l1N ) the drill resumed digging Monday following a stoppage that included three rounds of surveys.

Operators will gradually steer Bertha back on course.

Seattle Tunnel Partners used the stoppage to replace some of the 600-pound disc-shaped cutter blades.

State transportation officials say tunnel contractors are considering whether to perform additional measurements.

The $2.1 billion downtown-bypass tunnel from Sodo to South Lake Union is expected to open to traffic in early 2019, followed by demolition of the Alaskan Way Viaduct.

___

Information from: The Seattle Times, http://www.seattletimes.com