"It's like a practical joke at this point, right?" That's what Heidi Groover asked me after I opened the e-mail from the Washington State Department of Transportation (WSDOT). It announced that Bertha's restart and completion dates would be postponed another month behind schedule. This is the fourth time the state's contractor, Seattle Tunnel Partners, has pushed back the tunnel project's end-date.

Bertha is the world's largest, broken tunnel boring machine. Mayor Ed Murray, the Downtown Seattle Association, and a number of other politicians in charge of running a sane 21st-century city had decided it would be a grand idea to use Bertha to build a 9,270-foot-long, four-lane tunnel for cars beneath downtown Seattle. The $3.1 billion project would replace the Alaskan Way Viaduct, a decrepit elevated highway positioned in a city at severe risk for earthquakes.

Bertha overheated and stalled in December of 2013, not long after hitting a steel well casing left in the ground by WSDOT. Since Bertha's breakdown, parts of the machine have been exhumed, repaired, and reassembled, all the while racking up an estimated $143 million in repair costs that insurers are now rejecting in court.

Earlier this year, Seattle Tunnel Partners (STP), the state's contractor, scheduled Bertha's restart date for November 23. Now the restart date is December 23.

STP’s latest schedule, which was posted Thursday afternoon, shows that mining will resume on Dec. 23, 2015 – one month later than the date shown in the previous schedule. Accordingly, the tunnel opening date in the new schedule also has moved by one month, to April 2018. STP has told us the changes in the schedule reflect the current emphasis on giving crews the time they need to complete the tunneling machine repairs successfully.
 
Like all large construction projects, the schedule for this project changes frequently. WSDOT cannot verify any of the dates shown in this schedule.

April 2018 is 28 months later than December 2015, when the tunnel was first supposed to be finished. Since then, eight insurance companies—and now WSDOT—have sued STP. In January, state senate Republicans floated a bill to kill the Bertha project. (That bill was killed not long after.) In May, a now-dissolved oversight panel recommended that the steel well casing incident was WSDOT's fault.

"Given the evidence to date, my opinion is that Bertha will not finish the tunnel, but that some other machine, or process might," Thom Neff, an infrastructure management consultant who performed a 2010 assessment of the tunneling project for the Seattle Department of Transportation, wrote back in September. "The project will likely not be complete in early 2018, and much more money will be required."

To repeat:

Like all large construction projects, the schedule for this project changes frequently. WSDOT cannot verify any of the dates shown in this schedule.