Advisories and Updates 2017

2017 Program News

  • Alaskan Way Viaduct to close Oct. 6-9 for twice-yearly inspection

    Update: The closure has ended and the Alaskan Way Viaduct has reopened in both directions.

    Alert to Seattle drivers

    The Alaskan Way Viaduct will close this weekend, Oct. 6 – 9, for the twice-yearly inspection designed to keep the aging roadway safe for everyday use. Both directions of State Route 99 will close between South Spokane Street and the north end of the Battery Street Tunnel.
     

    Closure details:

    • SR 99 closed between South Spokane Street and the north end of the Battery Street Tunnel.
    • The northbound roadway will close at 11 p.m. Friday, Oct. 6 and reopen at 5 a.m. Monday, Oct. 9.
    • The southbound roadway will be closed from 5 a.m. to 6 p.m. on both Saturday and Sunday, Oct. 7-8. 
     
    The duration of this semiannual closure is a little different from past inspections. The northbound SR 99 closure starts earlier and lasts longer than typical inspection closures. This will allow the SR 99 tunnel contractor Seattle Tunnel Partners time to complete tunnel-related work.
     
    We conduct these closures every October and March so engineers can closely inspect the elevated portion of SR 99. Drivers through Seattle should plan ahead and be prepared for additional congestion. Drivers can check WSDOT’s travel tools and follow WSDOT Traffic on Twitter for information about traffic in the Puget Sound region.

     

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  • Progress update: Transforming Bertha's launch pit

    If you’re a fan of our construction cams, this summer has been all about the pits.

    Up at the SR 99 tunnel’s north portal, our disassembly pit camera gave viewers a front-row seat for the SR 99 tunneling machine’s remarkable disappearing act. Down at the south portal, cam fans have seen something equally remarkable – the transformation of Bertha’s launch pit into a section of the SR 99 tunnel.

    The timing of these twin transformations is no coincidence. During tunnel mining, the launch pit served as the access point for delivering tunnel ring segments and supplies to the machine. The pit also housed a major piece of the conveyor belt that delivered muck from the machine to barges docked at Terminal 46 on Seattle’s waterfront.

    After tunnel mining concluded in April 2017, contractor Seattle Tunnel Partners began the transformation of Bertha’s launch pit into a section of the SR 99 tunnel. In June, after removing the conveyor belt, crews started constructing this section of the tunnel. Three months later, the transformation from pit to tunnel is nearly complete. This slideshow shows how they did it.

    Putting a lid on it

    The last phase of the launch pit transformation is underway now. Crews are building the top of the tunnel, a 4 1/2-foot-thick slab of reinforced concrete known as the lid. Building the lid makes it possible to build streets on top of the tunnel. In 2018, crews will rebuild part of Alaskan Way South directly atop what once was Bertha’s launch pit. When the tunnel opens, three levels of roadway will move people north and south across what was once the launch pit.

    This graphic shows a cutaway view of the future tunnel just west of the south portal operations building.

    Diagram showing two decks of traffic in the tunnel, with five lanes of traffic above it on the surface.

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  • Sept. 14 project update: Photos of progress inside the tunnel

    Many different elements of work must be completed before the SR 99 tunnel is ready for traffic. A previous program spotlight went into these areas of activity in detail. The linear distances of completed work are tracked on the progress tracker, which we are updating monthly (look for an update to the numbers soon). 

    But numbers only tell part of the story. This photo slideshow takes you inside the tunnel to see the recent progress being made beneath downtown Seattle.

    Drivers on the viaduct may have caught a glimpse of the recent transformation of the launch pit where Bertha began her journey (see the final photo in the slideshow). This summer, crews working for Seattle Tunnel Partners have been busy transforming the pit into the section of tunnel that will connect the bored tunnel to the SR 99 roadway near the stadiums. We will go more in-depth on this pivotal section of the tunnel in a future program spotlight.

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  • Goodbye Bertha: Final piece of the tunneling machine removed from tunnel

    Disassembly of the world’s largest tunneling machine is now complete. This morning crews lifted the final pieces of the 8,000-ton giant out of the SR 99 tunnel’s disassembly pit near Seattle Center. The lift ended more than four months of difficult work, captured in this time-lapse video:

    Bertha broke through into the disassembly pit on April 4, 2017, and shortly thereafter built the tunnel’s final ring. Though the machine’s tunneling and ring-building work was complete, crews couldn’t complete roadway construction at the north portal until it was removed. Crews from the contractor Seattle Tunnel Partners have been working around the clock, disassembling the machine to make room for the roadway coming up through the tunnel behind it.

    It was tricky, tough, and impressive work, re-positioning the machine and dismantling its 8,000 tons of steel into pieces small enough to lift by crane or pull back out of the south end of the tunnel. The largest lift (or “pick” as crews call it) was 70 tons. Larger pieces required additional cutting on the surface before hauling. Hitachi Zosen, the machine’s manufacturer, will decide what to do with many of Bertha’s components. However, her signature 57-and-a-half-foot steel cutterhead was unique to this project and was cut up and trucked to a local steel recycler. Hitachi Zosen donated pieces of the cutterhead to the Port of Seattle and donated cutting tools and the control panel to Seattle’s Museum of History and Industry.

    What happens next

    Even while Bertha was still tunneling, crews were building the roadway inside the tunnel and working on electrical and other systems. With the machine completely gone, that work can continue uninterrupted along the 9,270-foot tunnel Bertha dug beneath Seattle. You can follow the work on a new progress tracker page.

    WSDOT’s focus is on finishing the tunnel for an estimated early 2019 opening, along with preparing for the Alaskan Way Viaduct’s demolition, the decommissioning of the Battery Street Tunnel, and improving surface street connections at the tunnel’s north and south ends. With disassembly complete, we are retiring the Follow Bertha webpage and updating the program Twitter account. But we will keep the same Twitter handle, @BerthaDigsSR99, because although the machine is gone, the product of her labors remains.

    The final piece of the tunneling machine being lifted out of the tunnel

    The final lift out of the disassembly pit, Aug. 23, 2017.

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  • Viaduct demolition online open house is live Aug 3 - 14

    Demolition online open house through 17

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  • Coming soon: Alaskan Way Viaduct demolition open houses

    Demolition of the viaduct now in sight
     

    With tunnel boring complete, we’re deep in the planning stages for demolition of Seattle’s Alaskan Way Viaduct. On Thursday, we’ll launch an online open house to show what’s ahead and give the public a chance to comment on the work to come.

    Removing the seismically vulnerable viaduct will be the most visible change to Seattle’s waterfront in decades. The demolition work begins after the new State Route 99 tunnel opens, which is estimated for early 2019.

    WSDOT has successfully completed this type of work before. In 2011, we demolished the viaduct’s southern mile and built a new road in its place.  However, the remaining section of the viaduct is more challenging, as it is much closer to buildings, businesses, homes and the busy Colman Dock ferry terminal.

    Demolition is expected to take up to nine months, with the viaduct being demolished in sections to minimize localized disruptions. This contract will also involve other project elements, like filling in the Battery Street Tunnel and reconnecting several surface streets across Aurora Avenue North, which will take additional time.

    Several weeks before the new tunnel opens, WSDOT will shift Alaskan Way to the west of the viaduct, which will allow traffic to move along the waterfront before and during viaduct demolition. This new video below explains some of the planning for the demolition.

    Online open house

    The online open house will be live from August 3 - 14.

    In-person open house

    WSDOT is also hosting an in-person open house on August 10 for anyone interested in the work or who wants to speak with project staff. Representatives from Waterfront Seattle, Center City Connector Streetcar, Colman Dock, King County MetroOne Center City and Seattle Aquarium will also be available to answer questions.

    In-person open house details:

     

    WSDOT is committed to providing equal access to its facilities, programs and services for persons with disabilities. To request disability accommodations for the Aug. 10 open house event, email the ADA Office at least 7 days in advance at wsdotada@wsdot.wa.gov or call toll-free 1-855-362-4ADA (232). Persons who are deaf or hard of hearing may make a request by calling the Washington State Relay at 711.

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  • Seafair Torchlight Run to close northbound SR 99 through Seattle Saturday evening

    The Seafair Torchlight Run is back after a one year break and this year’s route includes about a three mile stretch of northbound State Route 99. 
     
    This Saturday, July 29, northbound SR 99 will close for runners between 5 p.m. and 7: 45 p.m. between South Royal Brougham Way near Seattle’s stadiums and Harrison Street just north of the Battery Street Tunnel. All southbound lanes will remain open.
     
    This map shows the entire route and additional city streets that will close for the run, which will be followed by the Torchlight Parade at 7:30 p.m.
     
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  • July 14 update: Bertha disassembly is halfway complete

    Seattle Tunnel Partners is now past the halfway point in disassembling the 8,000-ton tunneling machine Bertha. All of Bertha’s cutterhead is out of the disassembly pit and crews are working their way from top to bottom, cutting sections of the machine and lifting them by crane.

    Much of the machine’s trailing gear remains inside the tunnel, out of view of our time-lapse camera. Inside the tunnel, crews are cutting and hauling pieces of the trailing gear out of the tunnel via the south portal. This new time lapse video captures the work happening inside the tunnel.

    Work has progressed enough inside the disassembly pit to allow STP to use Bertha’s thrust rams to pull a large section of the trailing gear into the pit. Crews will now work from both outside and inside the tunnel to continue removing the trailing gear, which will help expedite work.

    Much of the conveyor system that moved extracted soils from the tunnel onto barges has also been removed. The photo below shows crews lifting the white over-water section of the conveyor last week.

    A crane removing a piece of the conveyor system

    While crews dismantle the machine, work continues on the road inside the tunnel. The photo below shows crews building the upper roadway inside the launch pit near the stadiums, where Bertha began her 9,270-foot tunneling journey underneath Seattle. You can monitor progress here.

    Concrete pours for the future roadway deck curing in the launch pit

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  • Visit us this summer at Seattle-area fairs and festivals

    This summer, members of our team will staff information booths at summer fairs/festivals. Stop by any of the fairs to make your own cardboard tunnel, see bits of Bertha and learn more about our work to replace the Alaskan Way Viaduct.

    Ballard SeafoodFest: Located in downtown Ballard. Admission is free.

    • Saturday, July 8: 11 a.m. to 7 p.m.
    • Sunday, July 9: 11 a.m. to 7 p.m.


    West Seattle Summer Fest: Located at The Junction. Admission is free.

    • Friday, July 14: 10 a.m. to 6 p.m.
    • Saturday, July 15: 10 a.m. to 6 p.m.
    • Sunday, July 16: 11 a.m. to 5 p.m.


    South Lake Union Block Party: Located at Denny Way & Westlake Avenue North. Admission is free.

    • Friday, August 11: 12 p.m. to 7 p.m.
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  • June 15 project update: New time-lapse video shows tunneling machine disassembly

    The inner-workings of the SR 99 tunneling machine Bertha are now fully visible from the camera above the pit where disassembly continues. The upper shield that surrounded Bertha is now gone – lifted and hauled away. Only a small portion of the cutterhead spokes remain. Next, Seattle Tunnel Partners plans to remove work-deck platforms, hydraulic systems, hyperbaric equipment and ring-building equipment. Remember, there’s 8,000 tons of machinery inside the disassembly pit and inside the north end of the tunnel. This brief time-lapse video shows what seven weeks of nearly non-stop work looks like as workers continue dismantling the five-story-tall tunneling machine.

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  • Northbound SR 99 closed for marathon through downtown Seattle on June 18

    The 2017 Seattle Rock and Roll Marathon will close northbound SR 99 through downtown Seattle on Sunday, June 18. Northbound SR 99 will be closed from South Hudson Street to Halladay Street between approximately 7 a.m. and 3 p.m.

    Although the marathon is scheduled to last until 3 p.m., the Seattle Department of Transportation is planning to reopen SR 99 and the Alaskan Way Viaduct as early as possible once the runners have passed this part of the course. Please refer to the event website for more specific information on other road closures and parking restrictions related to the event.

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  • June 9 project update: Disassembly continues and interior roadway progresses

    Seattle Tunnel Partners continues to work around the clock as they disassemble the SR 99 tunneling machine near Seattle Center. The face of the machine has dwindled in size as most of the cutterhead has been removed.

    Crews are also removing more pieces of the machine’s outer shield, exposing inner parts that weren’t previously visible from the pit. This includes the articulation jacks, which allowed the machine to change direction as it pushed beneath downtown Seattle.

    As work on the machine continues in the pit, disassembly is progressing from inside of the tunnel as well. STP is dismantling the trailing gear and disconnecting temporary utilities and ventilation that were necessary for the machine’s operations. These pieces are being removed through the south end of the tunnel. The below photos show disassembly progress, both in the disassembly pit and in the tunnel. Disassembly progress can also be tracked through the construction camera.

    Inside the tunnel, crews are hard at work on more than just removing the trailing gear. STP has now completed 66 percent of the southbound roadway and the corbels (wall foundations) are approaching the rear of the tunneling machine. The latest report tracking interior structures progress can be found in the information box on the Bertha page of our website.

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  • Crews finish future SR 99 off-ramp on time and on budget

    The Alaskan Way Viaduct Replacement Program is more than just the tunnel – it is 32 projects that together will replace the viaduct with a new tunnel, highway connections, and a new Alaskan Way surface street. This month contractor Interwest Construction completed the South Dearborn Street off-ramp bridge, the 24th completed project of the viaduct replacement program.

    Completed on time and on budget, this remarkable little bridge won’t have an immediate effect on anyone’s commute. The bridge currently stands isolated in the construction zone to the west of CenturyLink field. When the SR 99 tunnel is nearing completion, crews will connect this ramp to northbound SR 99, turning it into a northbound off-ramp to South Dearborn Street. After the tunnel opens, drivers heading to the stadiums or downtown Seattle will take this ramp.

    What makes this bridge special is the earthquake technology it contains. As we’ve profiled in the past, this bridge is the first in the world to pilot-test a method for making bridges earthquake resistant. Its design uses memory-retaining metal rods and bendable concrete composite so the bridge flexes when the ground shakes, then snaps back into its original shape once the shaking ends. This video explains how this new technology works:

     

     

    This off-ramp is one of several ways the AWV Replacement Program is improving Seattle’s resilience in the face of earthquakes. The viaduct is susceptible to earthquakes, and replacing it is, first and foremost, a safety project. Tunnels are one of the safest places to be in an earthquake because of the way they can move with the shifting ground, and the SR 99 tunnel is designed with earthquakes in mind. This post from 2016 explains how the SR 99 tunnel is built to withstand up to a 9.0 magnitude earthquake.

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  • May 19 project photo update: Disassembly progress

    In the disassembly pit near Seattle Center, work is continuing around the clock - cutting, lifting and removing heavy pieces of the SR 99 tunneling machine. As of yesterday, eight small spokes and the bulk of five larger spokes have been taken out of the disassembly pit. More than 50 percent of the iconic cutterhead has now been removed. These recent photos capture the progress:

    Crews are also working inside the tunnel to remove the tunneling machine and other pieces of the tunneling operation no longer needed now that the tunneling portion is complete.  Seattle Tunnel Partners is removing conveyor system components which had been used to carry the dirt underneath Seattle out to waiting barges. Temporary utilities, hydraulic lines and hoses are also coming out. And STP has started disassembling the back end of the trailing cars that carried all the equipment for tunnel-building. In all, eight thousand tons of equipment will eventually be removed from Seattle’s new tunnel to clear the path for building the rest of the double-deck road inside.

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  • Construction highlights for Friday, May 19 - Friday, May 26

    Alaskan Way Viaduct/SR 99

    • There are no high-impact closures scheduled at this time.

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  • May 8 project update: Cutterhead lifts begin

    Seattle Tunnel Partners has started lifting pieces of the SR 99 tunneling machine Bertha’s cutterhead out of the disassembly pit near Seattle Center. To date, three of the cutterhead’s eight small spokes have been cut and lifted from the pit.

    This new video shows how workers use torches to cut the 57.5-foot-wide cutterhead into pieces. More than 35 lifts will be needed to remove the cutterhead alone – which weighs more than 900 tons. The full disassembly process is expected to last up to five months.

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  • May 3 project update: Small section of tunneling machine lifted from pit

    Yesterday Seattle Tunnel Partners lifted the first piece of the SR 99 tunneling machine from the disassembly pit near Seattle Center. Crews cut a small piece of the machine’s shield to confirm its sectional weight ahead of cutting and lifting other pieces.

    Crews are also preparing Bertha’s cutterhead for a series of lifts, cutting the steel that connects the cutterhead’s 16 spokes and welding lifting-eyes (circled below) onto the spokes so they can be safely hoisted by the 400-ton crane on site.

    Zoom-in photo of cutterhead with circles highlighting two loops welded to the cutterhead

    The entire disassembly process is expected to last up to five months and can be viewed with our time-lapse construction cameras.

    New video: Bertha’s crews reflect on the tunnel journey

    Many of the workers now helping disassemble the tunneling machine are the same workers who built the tunnel. That work required long hours, including weekends and nights working underground. In this video, several members of Bertha’s crew reflect on what the end of tunneling means to them.

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  • April 21 project update: Bertha reaches her final resting spot

    With one last push from her thrust jacks, Bertha came to rest today in her final position within the disassembly pit near Seattle Center. Seattle Tunnel Partners began slowly moving the tunneling machine forward on April 13. You can watch the machine’s progress into the pit by scrolling back through the disassembly pit time-lapse camera.
     
    A crew member holding balloons in front of the TBM sitting in the disassembly pit
     

    Nowhere to go but up (and out)

     
    With Bertha’s movement complete, crews will begin disassembling and cutting the machine into pieces for removal. Some pieces will be lifted from the disassembly pit by crane, while others will be taken out south through the tunnel. A new fact sheet in our Program Library gives a brief overview of what this work entails.
     
    As Bertha moved into the disassembly pit, crews also began removing infrastructure within the tunnel that supported tunneling. More than 20 miles of pipe has to be removed, as well as the yellow ventilation duct and the conveyor belt.
     

    Video: Bertha's final push 

     
    While the time-lapse camera linked above captures the view from above the disassembly pit, this video provides an on-the-ground perspective. Watch a condensed time-lapse of Bertha's two-week move into the disassembly pit (with a pause for a group photo of the workers who built the tunnel).  
     
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  • April 13 project update: Bertha's next move

    Seattle Tunnel Partners began moving Bertha, the SR 99 tunneling machine, into the disassembly pit this morning. Crews began pushing the machine forward at approximately 9 a.m. this morning and have completed building ring 1,419.
     
    In the coming weeks, the machine will move forward approximately 80 feet before coming to rest in its final position. Along the way it will build the final rings of the tunnel, as well as a short section of temporary partial rings that the machine will use to push itself forward in the pit.
     
    Once the machine is in place, crews will begin cutting the machine into pieces and removing them from the pit. Some parts may be salvaged for use on other projects, while other parts will be recycled.
     
    Brace removal
     
    Crews spent the past several days cleaning the pit and removing the braces from the wall Bertha bored through on April 4. The time-lapse video below shows crews removing the braces.
     
     
    We’ll continue to provide progress updates on our breakthrough page and on Twitter.

     

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  • Southbound SR 99/Aurora Avenue North in South Lake Union to close this Sunday, April 9

    Crews working for the Washington State Department of Transportation will close a half-mile stretch of southbound State Route 99/Aurora Avenue North near South Lake Union this Sunday, April 9, to complete work needed to reopen Harrison Street.
     
    All southbound lanes of the highway between Valley Street and the south end of the Battery Street Tunnel will be closed from 7 a.m. to 5 p.m. Sunday. The northbound lanes will remain open.
     
    During the closure, crews will restripe access to and from of Harrison Street, which has been closed due to SR 99 tunnel construction. When the work is complete, drivers will have access to and from SR 99/Aurora Avenue North at Harrison Street.
    The forecast looks promising, but the work is weather-dependent and could be rescheduled if needed.
     
    Closure map
    Closure limits of April 9 southbound SR 99 closure
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  • Recapping Bertha's breakthrough

    Bertha's 9,270-foot journey beneath Seattle ended in dramatic fashion on Tuesday as the machine broke through into her disassembly pit near Seattle Center:

     

    On Tuesday morning all that stood between Bertha and daylight was the five-foot-thick concrete wall at the south end of the disassembly pit. Crews from Seattle Tunnel Partners began mining around 8 a.m. on Tuesday and broke through shortly before noon.
     
     
    WSDOT shared updates from the scene on Twitter, Facebook and Periscope, and hosted a livestream. (Roughly a half million people tuned into WSDOT's web channels to watch breakthrough, and another one million watched the livestream via local news outlets.)

     

    What comes next?

    In the coming weeks, STP will remove the braces in the disassembly pit and move Bertha into her final position in the pit. You can watch that work on the Bertha's Breakthrough page. The machine will be taken apart and removed from the tunnel.

    There is much work left to be done before the tunnel opens to traffic, currently scheduled for early 2019. Our recent program spotlight explains the interior structures and tunnel systems work that cres have already begun. 

    We will be transitioning the Bertha's Breakthrough page in the coming weeks to a page that tracks this progress. As always, follow the program Twitter feed and this website for updates on the work to replace the Alaskan Way Viaduct.
     
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  • Bertha breaks through: SR 99 tunneling machine emerges near Seattle Center

    Work continues inside the tunnel as crews work toward early 2019 opening 
     
    A year ago, SR 99 tunnel crews were about to face their biggest challenge: a trip beneath the Alaskan Way Viaduct they were working to replace. Today, with the viaduct and more than 9,270 feet of new tunnel safely behind them, there was nothing left to face but daylight as the SR 99 tunneling machine chewed its way into a pit near Seattle Center.
     
    Bertha’s 1.7-mile drive beneath Seattle came to a successful end Tuesday afternoon, 64 years to the day since the viaduct first opened to traffic. Led by the Washington State Department of Transportation, and designed and built by contractor Seattle Tunnel Partners, the tunnel project will move a two-mile section of SR 99 underground when it wraps up in early 2019. Crews will then demolish the viaduct, clearing the way for the city’s new waterfront.
     
    “This is a historic moment in our state’s transportation history,” Gov. Jay Inslee said. “Innovation and perseverance are the engines that keep Washington in the forefront. There is still more work ahead but this moment is one worth celebrating.”
     
    Crews will spend the next several days removing steel support braces that stand between Bertha and the interior of the 90-foot-deep disassembly pit. When the braces are gone, crews will drive the machine into its final position and begin cutting it into pieces for removal. As owner of the machine, the contractor will determine which pieces could be salvaged for use on other projects or recycled.
     
    “We were always confident that we would successfully complete the tunnel drive,” Seattle Tunnel Partners Project Manager Chris Dixon said. “The dedication and commitment of everyone on the Seattle Tunnel Partners team has been exceptional, and we wouldn’t be at this milestone without the hard work of our crews. We look forward to continuing this outstanding progress through project completion.”
     
    STP still has significant work to complete before the tunnel opens. Crews must finish building the double-deck highway within the circular walls that were built by crews inside the tunneling machine. Mechanical and electrical systems, plumbing and safety features also must be installed.
     
    Even as crews are installing these systems, crews will begin the extensive task of testing and commissioning the tunnel to ensure it’s ready for traffic. Inspectors will individually test more than 8,500 separate components before testing each of the tunnel’s various systems as a whole.
     
    “This truly is a remarkable feat of engineering,” Transportation Secretary Roger Millar said. “We've had delays and there’s still work to be done, but the individuals working on this job should be proud of this accomplishment.” 
     
    Over the next several years, the City of Seattle’s Waterfront Seattle project will build new public space and a surface boulevard in the place of the double-deck viaduct, which is scheduled for demolition in 2019.
       
    “Today is a major construction milestone in our plan to reclaim Seattle’s waterfront,” Seattle Mayor Ed Murray said. “We are one step closer to taking down the viaduct to make way for a reimagined waterfront and surrounding downtown neighborhood. We will build a waterfront for pedestrians, transit and sensible car trips without a freeway wall casting a shadow over our vision of a well-connected 21st century city.”
     
    King County Metro will continue to rely on SR 99 to route buses to Seattle after the tunnel opens, said King County Executive Dow Constantine.
     
    “The new tunnel will provide fast, reliable travel for transit and freight past downtown traffic, and reunite the city with its waterfront,” said Constantine. “The breakthrough highlights what we can accomplish when we think big, act boldly, and embrace the 'can-do' tradition of our region.”
     
    Port of Seattle Commission Commissioner Courtney Gregoire said the tunnel will work with the new waterfront surface street to accommodate freight traffic. 
     
    “This Alaskan Way route is essential to a strong port and linking our industrial lands between SODO and Ballard,” Gregoire said. “Strong, vibrant transportation connections are essential to keep our economy growing and creating middle-class jobs.”
     
    Background on tunneling machine repairs
     
    Manufactured in Japan by Hitachi Zosen Corp., Bertha arrived in Seattle in April 2013. The machine was launched from a pit near the stadiums in July of that year. In December 2013, STP stopped mining after measuring increased temperatures in the machine. 
     
    After an investigation, STP discovered damage to the machine’s main bearing. Crews completed repairs and resumed mining in December 2015. The cause of damage to the tunneling machine is in dispute and is currently in litigation. Neither WSDOT nor STP is able to comment further on ongoing legal issues.
     
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  • #BerthaBreakthrough is underway

    Bertha started mining this morning arouind 8 a.m. As of 10 a.m., water and soil conditioners had begun entering the bottom of the pit as the cutterhead began to break through.

    Due to heavy traffic, our website has been down intermitently. A livestream of the breakthrough is being carried by most Seattle-area media sites. We'll continue to provide updates here, and on Facebook and Twitter, as the day progresses.

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  • A new view at the tunnel’s north portal

    Large cranes are a common sight at the north portal construction zone, just east of Seattle Center. Some of those cranes are directly related to tunnel work, while others are simply part of the construction boom that’s swept through the neighborhood. 
     
    With Bertha wrapping up her journey beneath downtown, it’s a good time to take a look at how this area has changed since construction began. The transformation is striking, particularly when condensed into a one-minute time-lapse video. Formerly vacant lots are now home to the ramps and roads that will connect the neighborhood to the SR 99 tunnel. Meanwhile, the skyline behind the portal has grown up too. See for yourself… 
     

    This video shows the changing landscape near the SR 99 tunnel's north portal.

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  • April 3 project update: Bertha on the verge of breakthrough

    After churning through 9,240 feet of Seattle soil, the SR 99 tunneling machine is only 30 feet away from daylight. Bertha’s five-story-tall cutterhead is expected to reach the edge of the disassembly pit’s five-foot-thick wall later today, setting the stage for her breakthrough near Seattle Center.
     
    Crews will spend this evening making final preparations. Then, early tomorrow, the massive machine will begin mining through the wall and into the pit where it will be disassembled. Machine operators will proceed slowly through the wall, so it may take several hours for the cutterhead to emerge.
     
    The breakthrough will occur in several stages, as shown in the graphic below. The first two images show what is planned for tomorrow. Removing the braces will take several days, and it will be weeks until the machine is in its final position in the disassembly pit:

     

    How to watch

    Bertha's breakthrough will be streamed live on our Follow Bertha page. The camera feed will be available later today, and will remain on through tomorrow's breakthrough. We also have a new time-lapse camera that will capture images of breakthrough, and of crews disassembling the machine after it emerges in the pit. For safety reasons, the public will not be allowed in the construction zone during the breakthrough, and there will not be any public event. 
     
    We’ll continue to provide regular updates via social media as the big moment approaches.
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  • March 23 project update: Getting ready for Bertha’s breakthrough

    Seattle Tunnel Partners is making final preparations for the SR 99 tunneling machine’s arrival at the disassembly pit near Seattle Center. Because mining rates will continue to vary as crews approach the pit, we can’t predict when Bertha’s breakthrough will occur. As of this morning, the cutterhead was approximately 320 feet from the finish line. We will continue to provide regular progress updates along the way.
     
    We recognize that there is great interest surrounding this stage of the project, and we are working on ways to share this historic moment with the public. We will be activating a new time-lapse camera as well as streaming video of the disassembly pit prior to breakthrough. These cameras will offer the best view of Bertha’s arrival in the pit. We will also continue to share photos and provide frequent updates via social media, including daily progress updates. For safety reasons, the public will not be allowed in the construction zone during the breakthrough. 
     
    Look for more updates soon about the breakthrough sequence, the process for disassembling Bertha and the work that remains before the tunnel opens in 2019.
     
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  • March 9 project update: New 360-degree video takes you inside the tunnel as Bertha enters Zone 10

    The countdown is on as Bertha, the SR 99 tunneling machine, mined into the 10th and final zone of the 9,270-foot tunnel drive this week. With 1,294 concrete tunnel rings installed in the ground behind her, Bertha is less than two blocks from the disassembly pit where her journey will end.
     
    How is the interior of the tunnel shaping up? And how is Bertha doing? It’s probably best if we show you. Click below to join Program Administrator Joe Hedges on a 360-degree tour of the project. Move your smartphone up and down to move around the tunnel. Or, if you’re on a computer, grab the picture with your mouse for a 360-degree view of the work that’s happening out of sight, underneath Seattle.   
     
     
    Looking ahead
     
    It’s still too early to predict when Bertha will reach the disassembly pit. Seattle Tunnel Partners’ most recent schedule shows that tunnel boring is slated to end in May, but mining rates will continue to vary based on maintenance needs and ground conditions.
     
    There’s still plenty of work to do after tunnel boring is complete. STP will begin disassembling the tunneling machine soon after the cutterhead breaks into the pit. They will remove the machine in small pieces and haul them away by truck, a process that will take several months.
     
    Meanwhile, crews will continue building the double-deck highway inside the tunnel. This work is completed in different stages, as shown in our weekly interior structures report. The roadway deck is now at the southern edge of Pike Place Market, or nearly 50 percent complete.  
     
    Crews are also installing mechanical, electrical and plumbing systems that must be completed before the tunnel can open to traffic. This is a big job that is scheduled to last well into 2018. 
     
    As construction continues, WSDOT and STP will begin an extensive commissioning program. This involves a series of thorough inspections, tests and quality verification procedures to ensure the tunnel systems are functioning properly.  
     
    Based on STP’s schedule, the tunnel is projected to open in early 2019. Progress updates are posted on Mondays and Thursdays at our Follow Bertha page. You can also follow Bertha on Twitter @BerthaDigsSR99.   
     
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  • March 6 project update: Bertha on the move again

    Seattle Tunnel Partners resumed mining today after conducting additional survey work to verify Bertha’s position and to make necessary adjustments to complete the tunnel drive. Crews performed routine inspections and maintenance while mining was stopped, including the replacement of cutterhead tools.  
     
    As of this afternoon, Bertha was tunneling north toward the intersection of Denny Way and Sixth Avenue North, less than 1,000 feet from the disassembly pit. 
     
    STP stopped mining on Feb. 28 after survey data indicated the tunneling machine may be several inches off the tunnel alignment. Three independent surveys confirmed the 57.5-foot machine was approximately six inches off alignment.
     
    STP designers made a slight change to the tunnel alignment between the machine’s current location and the end of the tunnel drive. Adjustments are common during tunneling, including on this project. STP made a similar adjustment to correct Bertha’s course after the machine mined out of the access pit following repairs. 
     
    Crews steer Bertha (links to YouTube) based on information they receive from its onboard guidance system. The system is now set to the new tunnel alignment.
     
    According to STP’s most recent schedule, Bertha will arrive at the disassembly pit in May. Progress updates are posted on Mondays and Thursdays at our Follow Bertha page. You can also follow Bertha on Twitter @BerthaDigsSR99.
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  • March 1 project update: Getting Bertha ready for the home stretch

    Seattle Tunnel Partners has temporarily stopped mining to prepare Bertha, the SR 99 tunneling machine, for the final 1,000 feet of the 9,270-foot tunnel drive.
     
    Crews stopped mining yesterday to verify Bertha’s position along the tunnel route before making their final push to the disassembly pit. Recent surveys show that Bertha may be several inches off of the tunnel alignment. STP is conducting additional survey work and will make adjustments as needed to complete the tunnel drive.
     
    Adjustments are common during tunneling, including on this project. STP made a similar adjustment to correct Bertha’s course after crews mined out of the pit that was used to access and repair the machine.
     
    Crews will continue to perform routine maintenance on the machine for the next several days. They plan to resume mining next week. 
     
    According to STP’s most recent schedule, Bertha will arrive at the disassembly pit in May. The pit is located approximately 960 feet north of the cutterhead’s current location beneath Denny Way and Sixth Avenue North. Mining rates will continue to vary based on maintenance needs and soil conditions.
     
    Crews successfully mined under the final building of the tunnel drive earlier this week. Bertha has traveled a total of 8,310 feet and built 1,270 of 1,426 concrete tunnel rings.
     
    Progress updates are posted on Mondays and Thursdays at our Follow Bertha page. You can also follow Bertha on Twitter @BerthaDigsSR99.
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    Order: 1.2

  • Construction highlights for Friday, Feb. 24 - Friday, March 3

    North end

    Until Friday, March 10

    • Thomas Street will be closed around-the-clock between SR 99/Aurora Avenue North and Sixth Avenue North.

     

    Visit the City of Seattle page for details on Seattle DOT traffic closures.

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  • Feb. 23 project update: Bertha passes the 8,000-foot mark

    SR 99 tunnel crews have now bored 8,132 feet of the 9,270-foot SR 99 tunnel. The top of the machine’s cutterhead is located north of Wall Street, near Sixth Avenue North, approximately 100 feet below the surface.
     
    Crews successfully mined past the Seattle Center Monorail late last week. From their current location, crews will continue to mine north past the intersection of Denny Way and Sixth. The machine will emerge in a pit two blocks north of Denny, at the intersection of Thomas Street and Sixth. 
     
    Progress updates are posted on Mondays and Thursdays at our Follow Bertha page. You can also follow Bertha on Twitter @BerthaDigsSR99.   
     
    Balloons over Bertha at Wall Street
    Balloons mark Bertha's location near Sixth Avenue North
    and Wall Street on Feb. 23.
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    Order: 1.2

  • Alaskan Way Viaduct to close the first weekend in March for semiannual inspection

    The Hot Chocolate Run will also extend the closure north of the Battery Street Tunnel

    March 4 update: The viaduct inspection is now complete and the structure is open to traffic for the rest of the weekend. 

    Drivers should be aware that the annual Hot Chocolate 15k/5k Run will close SR 99/Aurora Avenue North Sunday morning, March 5 from approximately 6 a.m. to noon.
     
    ***
     
    It’s March and that means it’s time for a weekend-long inspection of the State Route 99 Alaskan Way Viaduct. Every March and October, the Washington State Department of Transportation closes SR 99 through Seattle so engineers can conduct a thorough inspection and make sure the viaduct remains safe for everyday driving. 
     
    On Saturday, March 4 and Sunday, March 5, the viaduct will close in both directions between South Spokane Street and the north end of the Battery Street Tunnel. 
     
    On Sunday, March 5, the annual Hot Chocolate Run will also extend the closure north of the Battery Street Tunnel.
     
    Drivers through Seattle should plan ahead and be prepared for additional congestion.  The Seattle Department of Transportation will post updated information on their traveler information webpage.
     
    Additionally, drivers can check WSDOT’s travel tools for information about traffic in the Puget Sound region. 
     
    Closure Details
    6 a.m. to 6 p.m. Saturday, March 4, and Sunday, March 5
    • Alaskan Way Viaduct closed for its scheduled inspection between South Spokane Street and the north end of the Battery Street Tunnel.


    Sunday, March 5

    • The Hot Chocolate Run will close SR/99 Aurora Avenue North in both directions north of the Battery Street Tunnel.


    - Southbound SR 99/Aurora Avenue North will be closed north of the Battery Street Tunnel to North 38th Street from 6:15 a.m. to 11 a.m.

    - The northbound lane closure will extend to North 45th Street from 6:15 a.m. to 11:15 a.m.

    In addition, the northbound lanes of the Battery Street Tunnel will remain closed as late as 1 p.m. for a Project Belltown walk through the Battery Street Tunnel.

     

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  • *** Canceled *** Daytime closure of southbound SR 99/Aurora Avenue North in South Lake Union set for Feb. 19

    Feb. 18 update: A planned closure of southbound SR 99 on Sunday, Feb. 19 has been canceled due to anticipated weather. The closure will be rescheduled for a later date. The original notice is below.
     
    Crews working for WSDOT will close a half-mile stretch of southbound State Route 99/Aurora Avenue North near South Lake Union this Sunday, Feb. 19. 
     
    All southbound lanes of the highway between Valley Street and the south end of the Battery Street Tunnel will be closed from 8 a.m. to 5 p.m. Sunday; the northbound lanes will remain open. 
     
    During the closure, crews will restripe and reopen a portion of Harrison Street that has been closed due to SR 99 tunnel construction. When Sunday’s work is complete, drivers will have access to and from SR 99/Aurora Avenue North at Harrison Street. 
     
    This work is weather-dependent and could be rescheduled in the event of rain.
     
    Closure map
     
    Southbound SR 99 closure map
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  • Feb. 9 project update: Bertha passes beneath the Battery Street Tunnel

    SR 99 tunnel crews successfully mined beneath the Battery Street Tunnel this week. The top of Bertha, the SR 99 tunneling machine, passed approximately 90 feet below the bottom of the 62-year old tunnel, which will permanently close when highway traffic shifts from the Alaskan Way Viaduct to the new tunnel.
     
    The ground along the tunnel route remains stable as Bertha pushes toward the finish line near Seattle Center. Crews are now less than 1,600 feet from the end of the tunnel drive, and the machine is climbing at a steady rate. The distance between the top of the machine and the surface is approximately 115 feet. The tunnel, at its deepest point, is approximately 215 feet deep.
     
    Up next for Bertha: a trip beneath Fifth Avenue and the Seattle Center Monorail. The top of the machine will pass approximately 90 feet below the Monorail’s supports.
     
    Highway construction
     
    While crews inside the tunneling machine are focused on mining, separate crews are hard at work building the double-deck highway inside the tunnel. The new roadway now stretches more than 3,800 feet into the tunnel, near the southern edge of Pike Place Market. 
     
    Work has also begun on the mechanical, electrical and plumbing systems within the tunnel. Crews began installing these systems near the stadiums last week and will continue to progress north, even after the tunnel drive is complete. 
     
    Progress updates are posted on Mondays and Thursdays at our Follow Bertha page. You can also follow Bertha on Twitter @BerthaDigsSR99.
     
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    Order: 1.2

  • ***CANCELED*** Southbound SR 99/Aurora Avenue North closure on Sunday, Feb. 5

    Feb. 2 update: A planned closure of southbound SR 99 on Sunday, Feb. 5 has been canceled due to anticipated weather. The closure will be rescheduled for a later date. The original notice is below.
     
    Drivers traveling southbound on State Route 99/Aurora Avenue North this Sunday should be prepared for a closure of a half-mile stretch between Valley Street and the Battery Street Tunnel. The closure will allow contractor crews working for the Washington State Department of Transportation to re-stripe and reopen Harrison Street west of Aurora Avenue North. 
     
    When the work is complete, drivers traveling southbound on SR 99/Aurora Avenue North will be able to turn right onto Harrison Street as well as turn right from Harrison Street onto the southbound highway. This block of Harrison Street was closed for tunnel-related work, which is now complete. 
     
    This weekend’s work is weather-dependent and could be rescheduled in the event of rain.
     
    Closure map and details 
    On Sunday, Feb. 5, all southbound lanes on SR 99/Aurora Avenue North will close between Valley Street and the north end of the Battery Street Tunnel from 8 a.m. to 5 p.m.
     
    WSDOT map showing Feb. 5, 2017 closure of southbound SR 99
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  • Jan. 17 project update: Tunneling crews resume mining

    Seattle Tunnel Partners resumed mining late Monday following 10 days of hyperbaric maintenance on Bertha, the SR 99 tunneling machine.
     
    Crews replaced approximately 300 of the nearly 500 scrapers on Bertha’s cutterhead during the hyperbaric maintenance period. As this post explains in more detail, the scrapers line the sides of the cutterhead spokes. STP also conducted other important inspections and maintenance during this time.
     
    Completing routine maintenance is an important part of ensuring that the machine continues to operate properly. STP will continue to perform inspections and maintenance as needed over the remainder of the tunnel drive.
     
    Crews are less than 2,500 feet from the receiving pit near Seattle Center where Bertha will emerge at the end of tunneling. The top of the cutterhead is located approximately 160 feet below Third Avenue in Belltown. 
     
    Progress updates are posted on Mondays and Thursdays at our Follow Bertha page. You can also follow Bertha on Twitter @BerthaDigsSR99.
     
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    Order: 1.2

  • Jan. 13 project update: Hyperbaric work continues

    Seattle Tunnel Partners is making good progress as they continue performing hyperbaric maintenance on Bertha, the SR 99 tunneling machine. Since the maintenance period began on Jan. 5, crews have replaced 250 cutterhead tools (see example below) over the course of 184 hours of hyperbaric shifts. This maintenance is critical as STP prepares for the final 25 percent of the tunnel drive.  
     
    Some of the cutterhead tools replaced during this maintenance stop
     
    The work is taking place in the chamber behind Bertha’s cutterhead, as shown in this image (PDF). As the video below explains, working in this environment is similar to performing an underwater dive.  
     
     
    STP will resume tunneling when the maintenance period is complete. The top of Bertha’s cutterhead is located approximately 160 feet below Third Avenue, about halfway between Blanchard and Bell streets. Crews are less than 2,500 feet from the receiving pit near Seattle Center where Bertha will emerge.
     
    Progress updates are posted on Mondays and Thursdays at our Follow Bertha page. You can also follow Bertha on Twitter @BerthaDigsSR99.
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    Order: 1.2

  • UPDATE: Overnight closures of northbound SR 99 set for this weekend

    Update: Repair work is complete and northbound SR 99 is open to traffic south of the stadiums.
     
    Drivers headed into downtown Seattle on Friday and Saturday nights should prepare for a full closure of northbound State Route 99 near the stadiums. Contractor crews working for the Washington State Department of Transportation will use the closure to repair damaged pavement. 
     
    Friday, Jan. 6 to the morning of Saturday, Jan. 7
    From 8 p.m. until 8 a.m. the following morning crews will close all lanes of northbound SR 99 between South Spokane Street and South Royal Brougham Way.
     
    Saturday, Jan. 7 to the morning of Sunday, Jan. 8
    From 10:30 p.m. until 8 a.m. the following morning crews will close all lanes of northbound SR 99 between South Spokane Street and South Royal Brougham Way. 
     
    Detour
    • During the closures all northbound SR 99 traffic must exit at East Marginal Way. 
    • Eastbound West Seattle Freeway ramp to northbound SR 99 will be closed.
    • Drivers wanting to continue north on SR 99 will use the on-ramp at South Royal Brougham Way.
     
    This weekend’s work is weather-dependent and could be rescheduled in the event of heavy rain or snow.
     
     

     

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  • Jan. 5 project update: Bertha reaches next planned maintenance stop

    During the holiday break, Seattle Tunnel Partners performed routine maintenance and inspections on Bertha, the SR 99 tunneling machine. This included inspection of some of the machine’s cutterhead tools under normal atmospheric pressure. STP decided to begin a hyperbaric maintenance stop this week to inspect the other cutterhead tools on the machine under hyperbaric conditions (this post explains the different types of tools in more detail).  
     
    Crews plan to spend between one and two weeks inspecting the tools, and replacing them as necessary. However, the duration of the stop could be longer or shorter depending on the number of tools that need to be replaced. STP’s most recent hyperbaric maintenance stop in late October lasted one week. 
     
    The top of the cutterhead is located approximately 160 feet below Third Avenue, about halfway between Blanchard and Bell streets. Crews are less than 2,500 feet from the receiving pit near Seattle Center where Bertha will emerge at the end of her tunnel drive.
     
    Progress updates are posted on Mondays and Thursdays at our Follow Bertha page. You can also follow Bertha on Twitter @BerthaDigsSR99.
     
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    Order: 1.2