Almost exactly two years ago, our $80 million tunnel boring machine named Bertha went kaput. The machine, part of the state's $3.1 billion tunnel project to replace the aging Alaskan Way Viaduct along the Seattle waterfront, had drilled only a thousand feet (out of a planned 9,270) before hitting a steel well casing left in the ground by the state. Three days later, on December 6, the machine overheated and eventually shut down.

In the two years since the machine's breakdown, the state and its contractor, Seattle Tunnel Partners (STP), have dug a pit to reach Bertha, excavated the surprisingly damaged machine, replaced the main bearing, and added new reinforcement parts—all the while downplaying growing concerns about cost overruns and the viaduct sinking. Project delays have frustrated both Republican state senators and local Democratic legislators alike, and the state has now sued STP preemptively to try to keep its legal options open.

There's little evidence to support the idea that this project will suddenly start running smoothly on December 23, when Bertha is scheduled to restart in a kind of right-before-Christmas gift to tunnel backers. This past October, Seattle Tunnel Partners delayed the tunnel's completion date for the fourth time in two years; now the whole project is supposed to wrap up in April of 2018. Plus, Bertha's past is replete with failure.

Here's a look at more than two years' worth of reasons to be skeptical about Bertha's future success.

July 30, 2013: Bertha starts tunneling. "If Bertha was learning to ride a bike, this initial section would be her training wheels," former Washington State Department of Transportation (WSDOT) program administrator Linea Laird says in a statement. WSDOT reports that the machine is expected to surface at the end of a 9,720-foot dig at Sixth Avenue and Harrison Street in 14 months, putting the first of many later-to-be-revised tunnel opening dates at December 2015.

December 3—7, 2013: Having drilled just a little more than a thousand feet, STP finds that Bertha has recently plowed through a 119-foot-long steel pipe. Crews remove a section of the pipe, but not long after that, Bertha gets stuck. The machine overheats when it starts drilling again, and moves only in fitful four-foot segments. Ultimately, Bertha overheats one more time and is shut down.

February 7—10, 2014: It's revealed that Bertha is broken. The seals around the machine's main bearing need to be replaced, WSDOT says. Accessing the seal area and fixing the problem "will take months," according to the state. WSDOT assures everyone that they've seen no evidence "that suggests the state or taxpayers will be responsible for cost overruns associated with these repairs."

April 21, 2014: STP decides it will use a rescue pit to drill down to Bertha's broken front end. The state posts STP's schedule, which says that the damaged cutterhead will be removed from the pit by October of 2014, and that the machine will restart by late March of 2015. By now, the tunnel's opening date has been pushed back by nearly a year—from December 2015 to November 2016.

September 18, 2014: Seattle wins national recognition! Our tunnel project makes a list of 11 highway boondoggles that the United States Public Interest Research Group argues "may no longer have a compelling transportation rationale" given that Americans are driving less.

October 20, 2014: STP finally starts digging Bertha's rescue pit, which was supposed to be finished by now.

December 5, 2014: The Alaskan Way Viaduct—Seattle's monument to unnecessary earthquake risk—has sunk 1.2 inches along portions that are next to broken Bertha and the deepening rescue pit. Mike Lindblom at the Seattle Times reports that settling shows "the tunnel team is having trouble controlling the soil, crucial to protecting downtown as the Highway 99 tunnel project attempts to move ahead." Matt Preedy, tunnel project deputy administrator, acknowledges that sucking water from Bertha's rescue pit (aka "dewatering") may have caused the settling.

December 15, 2014: WSDOT tells the Seattle City Council that it has instructed STP to temporarily halt digging the rescue pit, but tunnel project administrator Todd Trepanier says that digging the rescue pit probably didn't cause the viaduct settlement. Many people, including some Seattle City Council members, are skeptical of this claim. Meanwhile, WSDOT inspects 20 buildings in Pioneer Square, and four of them show "cosmetic damage," like cracks.

And more bad news: A 16-inch water main has been damaged because of the soil sinking and will probably have to be replaced. (Who's going to pay for that? Unclear!) City council members grill WSDOT on when it would make the call that the viaduct is too unsafe to drive on—especially considering the sinking!—but WSDOT can't seem to answer any direct questions about that. Nevertheless, council president Tim Burgess says, "There's no turning back at this point."

FLASHBACK TO 2013: Here is a picture of Tim Burgess, looking pleased as punch while touring Bertha's work site. Vroom vroom!

December 17, 2014: WSDOT says that the tunnel is 70 percent complete, but The Stranger's Heidi Groover looks into it and... no. Seventy percent of the work under the state's $1.35 billion contract with STP has been finished, but the tunnel digging—the actual digging—still has 90 percent of the 9,270 foot route left to go.

January 12, 2015: The Seattle Department of Transportation uncovers an engineer's report from December 11 on the tunnel project's document-sharing website that describes a "risk of a catastrophic failure" resulting from the tunnel project's "'repair-as-we-go' method of excavation." A week later, in a revised version of that report, the "catastrophic failure" language had been removed. SDOT demands answers from WSDOT about why the City of Seattle wasn't made aware of this particular edit. Council Member Kshama Sawant says she'd like an answer from WSDOT "before there is a danger that Pioneer Square sinks into Elliott Bay like Atlantis."

January 26—27, 2015: Senate Republicans float a bill to kill the increasingly costly tunnel project and use the rest of the money to research alternatives. The chair of the senate transportation committee, Republican Curtis King from Yakima, refuses to give the idea a hearing.

January 30, 2015: STP reaches the bottom of Bertha's rescue pit!

February 12, 2015: Five workers are injured near the tunnel's north portal when a wall in an elevator shaft collapses.

February 19, 2015: Bertha finally digs through the rescue pit's concrete wall. She's crowning!

March 12, 2015: The Associated Press releases a report showing that more tunnel project workers were injured while the tunneling machine was broken in 2014 than in the two previous years put together. Oy vey.

March 20, 2015: Bertha's first troubled piece—a 270-ton part of a shield used to protect the machine's innards from water and grit—is lifted out of the rescue pit by a giant red crane.

March 30, 2015: STP workers lift Bertha's cutterhead out of the pit.

April 13, 2015: A city-commissioned study of viaduct safety concludes that the viaduct is fine. WSDOT, however, can't explain to city council members what would make the viaduct too unsafe to function. Matt Preedy, deputy program administrator for the tunnel project, announces he's leaving WSDOT for Sound Transit. (Daww! We liked Preedy.)

May 8, 2015: A dispute review board finds that the eight-inch-wide steel pipe that Bertha hit way back in 2013 was the state's fault. STP says problems caused by the pipe cost $125 million, but the review board's finding is only a recommendation. Now the state and STP have to hash it out—maybe in court.

May 18, 2015: With Bertha dug up, STP finds out that the damage to the machine was much worse than they previously thought. This suggests bad news about the soundness of the tunnel boring machine itself, and new delays will push the project schedule past an August 2015 tunneling restart date.

WSDOT also publishes two reports on the viaduct sinking. One blames dewatering. The second, commissioned by STP, blames "natural settlement" and says that dewatering contributed to sinking only in areas immediately surrounding the pit. P.S. Who's going to pay for that water main that needs to be replaced because of settlement? It's going to cost $4 million.

July 17, 2015: The project gets delayed again. Now Bertha is supposed to restart tunneling on November 23, with the tunnel ALLEGEDLY opening in March of 2018. This is at least the third time that STP has revised the tunnel completion date. It was originally set to be finished in December 2015. And the viaduct still stands!

July 27, 2015: Top tunnel project administrator Todd Trepanier announces he's going to leave the project for a regional administrator gig in Yakima.

August 6, 2015: Bertha's repaired front end will reenter the rescue pit... two weeks late.

August 24, 2015: Bertha's front end is lowered back into the pit.

August 26, 2015: Eight insurance companies sue STP to avoid $143 million in repairs. They claim the machine's design was the problem from the very beginning (!)

October 7, 2015: A letter to the insurance companies that sued STP shows that the state has racked up $3.25 million in expenses due to Bertha's two-year delay and anticipates an additional $75 million in associated costs.

October 9, 2015: WSDOT sues STP! The state says that STP is to blame for the two-year delay, but also asks for a stay in the lawsuit so that STP can finish the tunnel project first.

October 22, 2015: STP postpones Bertha's restart date another month while it conducts tests on the newly repaired machine. Now Bertha is supposed to restart tunneling on December 23. For the fourth time in two years, and millions of dollars later, the project's completion date faces another delay. But hey: Bertha will be drilling again by Christmas. Allegedly. recommended