Bertha tunnel timeline: From conception to tunnel completion
Washington Gov. Christine Gregoire announces state will take down Alaskan Way Viaduct in 2012.
State of Washington, King County, city of Seattle and Port of Seattle announce agreement to replace Alaskan Way Viaduct with bored underground tunnel.
Governor Christine Gregoire signs measure authorizing $2.8 billion in state funds for tunnel project.
The world’s largest tunneling machine, now christened “Bertha,” arrives in Seattle.
Bertha begins drilling. Read more. Initial plans call for drilling to take 14 months. Bertha travels 9.270 feet of planned 9,270 feet.
Bertha components shut down during attempts to drill at high power. Drilling halted. Seattle Tunnel Partners operators try to get Bertha moving again. Drill running at elevated temperatures.
Steel pipe is blamed for tunnel stoppage. The Seattle Times reports steel pipe struck by Bertha was put there by WSDOT engineers to study groundwater and included in plans provided contractor prior to tunnel bid submission.
Bertha drills two feet each day as STP restarts drill and tries to determine cause of overheating problems. Drilling halted again.
WSDOT announces Bertha seals and bearing damaged, likely causing overheating problems, no schedule for repairs or resumption of drilling. Seattle Tunnel Partner project director Chris Dixon says contractor hopes to complete repairs and resume drilling by September 1.
STP continues working with Bertha manufacturer to determine best way to repair drill and resume operations. Plans call for 120-foot-deep pit ahead of drilling machine to facilitate repairs. WSDOT digs 60 narrow test holes to check for historic artifacts ahead of repairs.
Seattle tunnel critic files lawsuit to stop repairs on Bertha. WSDOT, STP announce tunneling will not resume until March 2015.
The Washington State Department of Transportation tells the Seattle City Council that damage to Bertha will delay its progress further. “Even though the damage is more than they were expecting to find, it’s not more than they were planning to repair at this point,” said Todd Trepanier with WSDOT. Read more.
A large crack discovered on a Pioneer Square street (on King Street near 1st Ave. S.) possibly tied to the Seattle tunnel project prompted a temporary closure as officials scrambled to respond. A map details the extent of the settlement shows the crack is just above the epicenter of the settling. Read more.
Photos: Sitting idle for two years
Crews began installing four 40-foot-tall yellow ventilation stacks at the south portal operations building. Still no word on when Bertha will resume. Read more.
Crews prepping to move Bertha forward. Bertha is still at the bottom of its access pit, but crews are beginning to treat the ground in front of the tunneling machine with water and cement. Read more.
The Washington State Department of Transportation files lawsuit against Seattle Tunnel Partners. WSDOT asked STP to agree to a stay of the lawsuit until the project is completed. Former Attorney General Rob McKenna says regardless of when the case actually goes to court, the matter will not be over any time soon. Read more.
Bertha was originally slated to resume again on Nov. 23 (three months late), but the timeline is pushed another month. WSDOT says it’s frustrated. Read more.
STP and manufacturer Hitachi Zosen completed repairs to the machine in December 2015. Seattle Tunnel Partners Project Director Chris Dixon said repairing Bertha has taken longer than anticipated. Read more.
Testing on Seattle’s tunnel boring machine was stopped temporarily due to a broken arm. Bertha resumes before Christmas. Read more.
On Jan. 13, the Washington State Department of Transportation announced a sinkhole developed shortly after Bertha began digging again. The hole was spotted about 100 feet south of Bertha’s current position. Read more.
Bertha resumes mining. The Washington State Department of Transportation has allowed the contractor, Seattle Tunnel Partners, to move forward and place a total of 25 rings. Read more.
Despite the approval to move forward, the stoppage over the past month has caused another rift between WSDOT and the tunneling contractor.
“There is a disagreement with Seattle Tunnel Partners on this. It’s not the first time we have disagreed,” said Todd Trepanier with WSDOT. “They think the stop was not appropriate, and they would like to be compensated for the time it has cost them.” Read more.
Related: WSDOT head Lynn Peterson fired
Bertha’s journey resumes on Friday, April 29, prompting the closure of Highway 99 for at least two weeks. It means at least 90,000 daily commuters had to find an alternate commute. WSDOT to closely monitor Seattle’s roads.
Bertha tunnels 292 feet since Seattle’s viaduct closed for two weeks. Read more.
Engineers determined that tunneling under the viaduct did not cause any issues with the aging structure. Read more.
Bertha nears another maintenance stop and a 3,000-foot milestone. Read more.
WSDOT asks for $60 million more in funding and more time to finish the tunnel. “We’re making good progress, we’ve had a delay that’s affected our schedule, that’s affected our budget,” acting Secretary of WSDOT Roger Millar told the state legislature’s joint transportation committee. “What we are looking at is a project that will be open to traffic in 2019.” Read more.
Bertha has tunneled 4,000 feet and approaches Zone 6. Crews have installed 607 concrete rings to form the tunnel walls. Read more.
After a two-week break, Bertha is tunneling below Seattle’s waterfront again. The tunnel machine was at a standstill 170 feet below First Avenue and Union Street for maintenance to the cutterhead. Read more.
The Seattle Times reports that the contractor who is operating the machine originally only had insurance until Aug. 31. That was the day the new SR 99 tunnel through Seattle was suppose to be completed. Bertha stops below First Avenue and Union Street for maintenance. Read more.
Bertha has bored more than 5,000 feet under downtown Seattle, and has stopped under one of the city’s more popular destinations. – Pike Place Market. Read more.
Bertha reaches one-mile mark. The machine is located 200 feet below First Avenue, north of Stewart Street. Read more.
Bertha reaches deepest point in journey and is about 60 percent complete. Read more.
Crews with Seattle Tunnel Partners resumed mining under Seattle, following 10 days of maintenance on Bertha the boring machine. Read more.
Bertha’s route had to be corrected after it was discovered that the boring machine had verred 6 inches off its alignment. Read more.
Bertha reached its final destination near the intersection of Sixth Avenue North and Thomas Street, where the drill broke through a concrete wall into a receiving pit. Washington state Governor Inslee called it a “historic moment.”
Bertha is steadily torn apart as crews remove the massive machine from the receiving pit. It will take months to completely disassemble the machine. Much of the outer shell is sent to local steel recyclers.
Half of Bertha remains standing.
The tunneling machine known as Bertha is completely dissembled and removed from the receiving pit.
State transportation officials begin discussing what tolls will be implemented once the tunnel is opened. The most popular plan sets maximum tolls at $2.50 during peak drive times. WSDOT also announces that it is moving up the tunnel’s opening day to January 2019 — two months earlier than previously forecast.