Rescuing Bertha 'Like Putting The Worm On The Hook' | KUOW News and Information

Rescuing Bertha 'Like Putting The Worm On The Hook'

Mar 9, 2015

Bertha the drill should be back at work on the tunnel to replace the Alaskan Way Viaduct by August. There’s still some unstable soil left to drill through.

Officials will be watching Pioneer Square for patches of settling. After that, the ground becomes more firm, and project managers predict smooth drilling at the maximum rate of 65 feet per day.

TRANSCRIPT

When Bertha first entered the soil in July of 2013, the machine’s cutter head was brightly colored like a new piñata. Its teeth were red and yellow, its face a lovely shade of blue-green.

The drill’s been underground for almost two years now, but it’s been stuck much of that time. 

On Monday, officials gave reporters a chance to peer down into the rescue pit.  The bright colors have all been scraped away, replaced by the reddish-gray of cement dust, soil and rust.

Chris Dixon is with the Seattle Tunnel Partners. He described the machine’s coming disassembly with an engineer’s detachment.

Dixon: “What we’re going to be doing for the balance of this month is cutting that front shield section into the three pieces that get removed by the crane you see behind me here. Those get brought up to the surface. That exposes the cutter drive unit and cutter head at the front of the machine.”

It’s kind of hard to visualize, and I told him that. So he compared Bertha to a worm for me. A worm used in fishing.

Dixon: “Yeah, we’re putting the worm on the hook to lift it out of the shaft.”

Tunnel crews work on Bertha in the rescue pit.
Credit KUOW Photo/Joshua McNichols

If the fishing expedition goes as planned, workers will have April to disassemble the parts and May to put them back together. Bertha should be digging again by end of summer.

Right now, the drill manufacturer is paying for Bertha’s repair work. Seattle Tunnel Partners, which is overseeing the project, paid for the rescue shaft. They’ve asked the state for $210 million to cover the additional work, but the state has denied three-quarters of those requests and is reviewing the rest.

The tunnel is two years behind schedule. It’s not expected to open for traffic until fall of 2017.