Bertha: The big risks may lie ahead

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Will there be light at the end of the tunnel for the Bertha dig?

We’re coming up on the second anniversary of Bertha’s big break down. The tunnel diggers hope to have her boring again on Dec. 23. If she works, that would be a nice, albeit expensive, Christmas gift for the city.

Still, the problems of the last two years have turned us all into spectators, perhaps cynical ones. The big questions that loom: Will a refurbished Bertha make it to the end, or die underground again in an even more problematic location? And if she does break down again, what is Plan B?

None of us yet knows the answer, but one man predicted we’d be in this fix. Boston-based consultant Thomas Neff, who knows his tunnels and megaprojects, warned the city of Seattle in 2010 that Bertha was a high-risk project: The machine was of unprecedented size, the soil conditions were highly problematic, and the water pressure a major complication.

While some dismissed Neff’s findings as fitting all too well with Mayor Mike McGinn’s opposition to the tunnel, all those concerns have turned out to be major issues. And none of them have changed in the last two years that Bertha has been idled. The machine’s size, the soil and water conditions would still rate highly on Neff’s risk scale.

There have been other complications as well: The repair pit might have caused the damage to water mains on First and Western Avenues, requiring a major replacement. The time delay has set back work on the planned waterfront makeover, and the time frame for disruptions there and in Pioneer Square have been lengthened by years. Also, new measurements show the Alaskan Way Viaduct continues to sink and crack.

The idea of removing the Viaduct came about principally because of damage from the Nisqually quake and the risk of collapse in a quake. Unfortunately, by choosing to keep it standing during tunnel boring, not only must it totter longer than expected, but it also might be reaching its expiration date more quickly. For now, WSDOT insists it’s safe to drive.

It shouldn’t be surprising that Neff is still skeptical about Bertha’s ability to finish the job as planned. The current revised schedule has the tunnel opening in three years, in 2018, if all goes well. At least as recently as July 2013, the state envisioned having traffic going through the tunnel about now.

He points to new challenges for the tunnel machine and its operators ahead: As Bertha presses forward, it must make a turn and dig even deeper. It also has to go under the Viaduct. Water pressure issues will likely get worse before they get better. If there’s some new problem that requires reaching the tunnel boring machine, extraction becomes more difficult once it’s under downtown. It doesn’t get much easier for a while.

In a recent column for ENR: Engineering News-Record, Neff reiterated his skepticism about a refurbished Bertha completing its assignment. “Given the evidence to date, my opinion is that Bertha will not finish the tunnel, but that some other machine, or process might. The project will likely not be complete in early 2018, and much more money will be required.”

If Bertha breaks again, what happens then? Another rescue and repair? Inserting a new machine at the other end and digging toward a trapped Bertha? Neff doesn’t see the project stopping altogether — the political pressure to finish the tunnel is and will be intense. But he thinks it will take longer and be much more expensive in the end— perhaps another $1-2 billion to bail Bertha out on top of the $1.35 billion committed to the tunneling contract already. “At this point it’s way beyond precedent for a screwed up job,” Neff tells me.

In his article, he turns to Game Theory and says we’re trapped in the classic so-called “Prisoner’s Dilemma” where the tunnel builders and the taxpayers will have to shift from getting an optimal outcome and cooperate to accept a bad outcome in order to avoid “a VERY BAD” outcome.

The tunnel situation “reminds me of the famous quote from Italo Calvino’s 1979 novel, If On a Winter’s Night a Traveler, ‘You know that the best you can expect is to avoid the worst.’ In this case, the worst outcome would be two completed portals, no connecting tunnel, and a very long court battle,” writes Neff.

Pessimism? Realism? Neff tells it like he sees it, and his credibility should be enhanced by his 2010 warnings. Some might dismiss him as a Cassandra, the prophetess from Greek mythology who was cursed not to be believed. Today the term Cassandra is often synonymous with “naysayer,” but people often forget this part of the myth: Cassandra was right.


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About the Authors & Contributors

Knute Berger

Knute Berger

Knute “Mossback” Berger is Crosscut's Editor-at-Large.