Kill Bertha’: Why senators in the US want to terminate Seattle’s gargantuan tunnelling project

Bertha isn’t boring, and that’s her problem.

The tunnel boring machine (TBM) has been stuck 60 feet underneath Seattle, in Washington State, for just over a year now, and two state senators want to just call the whole thing off, even though they say the ambitious project has cost $2bn so far.

The project has failed, say senators Doug Ericksen (R-Ferndale) and Michael Baumgartner (R-Spokane). Pressing on with it will only cause more heartache and waste more taxpayers’ money, they argued in a bill that was due for first reading yesterday.

Bertha had only dug around 1,000 feet when she ran into trouble in December 2013. She had over 10,000 (two miles) feet to go to complete the tunnel, which is the centrepiece of a $3.1bn scheme to to replace the SR 99 Alaskan Way Viaduct, a double-deck highway that has crossed Seattle’s waterfront for more than 60 years.

According to local media, Bertha’s teeth got caught on a long steel pipe that no one had accounted for, although the Washington State Department of Transportation, the agency in charge of the project, prefers to say that Bertha heated up, and sustained damage to her system of seals.

Now the contractor, Seattle Tunnel Partners, is building a 120-foot-deep pit in front of the machine. The idea is, Bertha will limp into the opening so crews can take her apart and fix her. Bertha was supposed to have finished her work in December 2015, but the estimated completion has been pushed back to August 2017.

Senators Ericksen and Baumgartner just want Bertha terminated. They say the rescue plan itself has been plagued by delays due to artifact-finds, water levels and soil conditions. They say the dewatering of downtown Seattle is causing subsidence. And they say the tolls to be charged would either be too low to cover the costs of the new scheme, or too high, and would cause congestion on other roads. In their bill they say the project has already cost $2bn.

Anatomy of a tunnel boring machine (Washington State Department of Transport)

"Due to these overwhelming circumstances, the project has created great anxiety and frustration, and has lost the political support of the people of Seattle," they claim in their bill. They insist that "the most prudent way forward is to cease all construction" and "prohibit the continued expenditure of funds on this project". 

Instead, they say, the old viaduct should be retrofitted, or a new one built.

Their defeatist bill faces stiff opposition, however. Senator Curtis King (R-Yakima), said it would not even get a hearing in the Senate Transportation Committee, which he chairs. "Now is not the time to be talking about, let’s bury it, let’s save ourselves," King told local media. "I will tell you it’s going to take you a heckuva lot of money to find another solution."

So maybe Bertha will be spared. 

Like ships, TBM’s are usually given female identities. Bertha’s tunnelling face is 17.5m (57ft) in diameter, and she was the largest TBM in the world when shipped to Seattle to start work in the spring of 2013. Hitachi Zosen Sakai Works of Japan made her specially for the project, and she was named after Seattle’s only female mayor, Bertha Knight Landes. She is reported to have cost $80m.

Photograph: The cutting head of ‘Bertha’, the huge tunnel boring machine now stuck under Seattle (Washington State Department of Transport)

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