"Bertha" drill below Seattle finishes drilling tunnel 2.5 years - NBC Right Now/KNDO/KNDU Tri-Cities, Yakima, WA |

"Bertha" drill below Seattle finishes drilling tunnel 2.5 years behind schedule

Posted: Updated:

SEATTLE, WA (AP) - A tunnel-boring machine has broken through a concrete wall beneath Seattle in a troubled multibillion-dollar project to replace a waterfront highway with an underground roadway.

The machine, known as Bertha, reached the end of a 1.75-mile journey Tuesday, years behind schedule. The machine broke down soon after it started drilling in 2013 and didn't crank up again until last year.

Crews will prepare the inside of the tunnel to handle double-decker lanes of highway that will replace the Alaskan Way Viaduct, which was damaged in a 2001 earthquake.

The $3.1 billion tunnel is scheduled to open in 2019. It was supposed to be done in 2015.

Tunnel proponents say it will allow Seattle to open up its waterfront along Puget Sound, which they say has been artificially walled off by the viaduct. Critics slammed it as an expensive vanity project.

---------------------------------------------------------------------------

SEATTLE, WA (AP) - Twenty-nine months late, the massive drill boring a new Highway 99 tunnel below Seattle is almost done with its work.

The drill, known as "Bertha," is expected to chew through a concrete retaining wall in the next few days and emerge into daylight, ending a 1.75-mile dig that's part of a project to replace the elevated, earthquake-prone Alaskan Way Viaduct along the city's waterfront.

The tunnel ranks among the trickiest megaprojects in history: Bertha was the largest drill on Earth when it entered the ground nearly four years ago, and it pushed through tricky glacial soils beneath downtown Seattle.

The drill began overheating in late 2013, prompting long delays as it was repaired. Litigation is underway to determine who will pay for close to $500 million in cost overruns.

HD DOPPLER 6i
/