Contents tagged with home

  • March 3 project update: Disassembly begins

    Bertha reached her stopping point in the SR 99 tunnel access pit on Tuesday night, clearing the way for Seattle Tunnel Partners to begin a disassembly process that will likely take weeks.
    Bertha moved forward a total of 57 feet between Feb. 17, when mining resumed, and yesterday. Along the way she built nine permanent concrete tunnel rings, which aren’t visible in the pit because they’re obscured by the ground and the machine’s exterior.
    With Bertha now in position, crews have begun the challenging task of taking apart the world’s largest tunneling machine. They will move through a number of methodical steps as they prepare to lift four pieces weighing up to 2,000 tons to the surface for repairs. Among other things, they must disconnect hundreds of hoses and cables, remove motors and weld lift points to the machine’s exterior.
    When disassembly is complete, a massive red crane (links to YouTube) will move into position above the pit. Several pieces of the machine will be removed before the cutterhead is lifted out of the pit, as illustrated in STP’s repair video (links to YouTube). 
    This Wednesday morning photo of Bertha in the pit was taken by our time-lapse camera.
    Repair plan resources:


    Previous updates

    Feb. 26, 2015 afternoon update - Bertha's next move

    Feb. 20, 2015 afternoon update - Tidying up the launch pit

    Feb. 19, 2015 morning update - Bertha reaches daylight

    Feb. 19, 2015 morning update - Bertha approaching the pit

    Feb. 18, 2015 afternoon update - Bertha digs on

    Feb. 18, 2015 project update - Bertha on the move

    Archive of previous updates


    — more —
  • Feb. 26 project update: Bertha’s next move

    After taking a break from mining to clean up the mixture of dirt, concrete and water that came into the access pit during last week’s breakthrough, Seattle Tunnel Partners has resumed Bertha’s final approach into the pit. 
    Because the cutterhead has made it through the pit wall, there isn’t any digging left to do. The focus now is on building the concrete tunnel rings that enable the machine to move forward. Bertha must build five more rings – a process that’s explained visually in this animation (links to YouTube) – before she comes to rest near the northern edge of the pit. Bertha will continue to take breaks so crews can clean up debris.
    When the machine reaches its destination, crews will begin disassembling the machine and preparing to lift pieces to the surface for repair. STP has said this process will take significant time and effort because it involves a number of steps. These steps include:
    • Installing work areas around the machine
    • Disconnecting joints, cables and hoses
    • Removing cutting tools and other parts from the cutterhead
    • Welding lift points on the body of the machine

    When the disassembly process is complete, a massive red crane (links to YouTube) will move into position. Several pieces of the machine will be removed from the pit before the cutterhead, as illustrated in STP’s repair video (links to YouTube). 

    We’ll continue to keep you posted as STP’s work moves forward. Remember to visit our access pit camera and follow Bertha on Twitter for the latest information.

    Crews clean up debris in the access pit.
    Repair plan resources:


    Previous updates

    Feb. 20, 2015 afternoon update - Tidying up the launch pit

    Feb. 19, 2015 morning update - Bertha reaches daylight

    Feb. 19, 2015 morning update - Bertha approaching the pit

    Feb. 18, 2015 afternoon update - Bertha digs on

    Feb. 18, 2015 project update - Bertha on the move

    Archive of previous updates


    — more —
  • Reminder: Long-term traffic impacts on SR 99 begin on Wednesday, March 11

    In one week, beginning Wednesday, March 11, crews building the future north portal of the SR 99 tunnel will close a single lane in both directions of SR 99/Aurora Avenue North between Valley Street and the Aurora Bridge. Two lanes will be open in each direction while crews install foundations for four large sign structures in the median and curb areas.

    Closure details and schedule

    Work is planned in two phases. View a map of the work locations. 

    • Phase 1 (approximately 8 weeks): one lane closed in both directions for median work
      • One lane in the northbound and southbound directions will be closed around-the-clock while crews install four sign foundations in the median
    • Phase 2 (approximately 4 weeks): one lane closed in southbound direction for curb work
      • One southbound lane will be closed around-the-clock while crews install two sign foundations in the southbound curb area

    Durations shown for each phase are approximate and may change due to weather or other factors. We will keep the public informed as we prepare for Phase 2 work.

    • Preliminary work scheduled for Monday night, March 9
      • From 10 p.m. Monday, March 9 to 6 a.m. Tuesday, March 10, SR 99/Aurora Avenue North will fully closed in the northbound direction between the south end of the Battery Street Tunnel and Valley Street
      • Tuesday morning, northbound drivers will notice a left-lane closure between Mercer and Galer streets.

    Bus rider information

    Because northbound and southbound buses will travel, and stop, in the outside lanes with other vehicle traffic, trips into and out of Downtown Seattle may take longer than normal. During both phases the southbound bus-only lane restriction will be lifted.

    Night work and weekend lane closures

    In an effort to balance the needs of drivers and residents, an additional lane may close in both directions at night and during some weekend days. Some of this work is unavoidably noisy and may be disruptive. Residents with concerns related to nighttime noise may call 206-305-6967.

    Driver tips

    The long-term lane closures are expected to cause additional backups on SR 99 for vehicles and buses, particularly during peak commute times. WSDOT is encouraging drivers and bus riders to: 

    • Allow plenty of extra time and expect additional congestion, especially during peak commute times, on SR 99 between the Aurora Bridge and downtown.
    • If possible, consider leaving early, delaying your trip or telecommuting to avoid traveling during peak commute times in the morning and afternoon.
    • If you must drive, know before you go and use WSDOT's travel tools or visit SDOT’s travelers information page.
    • Share a ride in a car- or vanpool, or walk or ride a bicycle.


    Contact us at or 1-888-AWV-LINE (298-5463) or visit us at


    — more —
  • Take a virtual tour of SR 99 tunnel construction

    Keeping the public informed about our work to replace the Alaskan Way Viaduct is an important part of what we do every day. Our goal is to give you as much access as possible to this amazing project, which is why we regularly post updates, photos and videos of our progress. We even offer walking tours from our information center, Milepost 31, to a viewing platform that overlooks the pit where tunneling began in summer 2013.

    Unfortunately, there’s one frequently received request … more

  • New narrated video explains Bertha repair work

    As reported elsewhere on our website, work to access and repair the SR 99 tunneling machine is coming along. We’ve heard from some people that Seattle Tunnel Partners’ repair plan is hard to picture. Enter STP’s Chris Dixon, who was nice enough to narrate a video that explains what crews are doing to resume tunneling by March 2015. Watch it on YouTube or download a WMV file.

    Other resources 

    Seattle Tunnel Partners repair work plan (pdf 4.8 Mb) … more

  • What we’re doing to keep traffic moving during the four-day SR 99 closure

    We’ve been asking you to do your part to reduce congestion when SR 99 closes for four days starting Friday night, Aug. 22. That includes things like changing your commute habits and choosing an alternate way to get around.

    But what are we, the agencies tasked with keeping traffic moving during this closure, doing to help? Quite a bit, actually. Here’s a roundup of some of the steps we’re taking to help you and your fellow commuters through the closure.

    Washington … more

  • Traffic shift underway on State Route 99 near the stadiums

    Less than three years ago, crews demolished the southern mile of the Alaskan Way Viaduct. When they did, they shifted traffic onto a new section of State Route 99 south of downtown Seattle.

    Much of that new section of SR 99 is permanent, but the piece west of the stadiums is temporary. This curving stretch of road takes drivers around the SR 99 tunnel construction site and connects to the remaining section of the viaduct near South King Street. It’s nothing fancy, but it’s … more

  • Celebrate Bike Month on our new path

    Just in time for Bike Month, we opened a new permanent connection between the on-street bike lanes south of South Atlantic Street and the shared-use path from South King Street. Here’s a map that shows the improvements, which include:

    A dedicated, 14-foot-wide shared-use path with improved paving.

    Improved lighting.

    A separate northbound and southbound path for more efficient navigation.

    Signs warning of vehicles crossing the intersection of … more

  • The SR 99 tunnel contract you’ve never heard of

    You may have noticed more construction along State Route 99, just north of the Battery Street Tunnel. That work is part of the SR 99 Tunnel Project, but it has its own name – the North Access Project. It’s also being built under a completely different contract than the one we have with Seattle Tunnel Partners, the contracting team responsible for most of the tunnel work. A map of major contracts within the program can be found here (pdf 1.1 Mb).

    Our contractor for the North … more

  • SR 99 tunnel’s north portal taking shape near the Space Needle

    A few blocks northeast of the Space Needle, crews are building the north portal of the SR 99 tunnel. It’s a huge piece of the overall tunnel project, but it’s largely invisible to the thousands of people that pass by it every day.

    About the only place you can see the north portal taking shape is from the viewing deck of the Space Needle because most of the construction is underground, inside a pit that’s every bit as impressive as the launch pit where Bertha, the SR 99 … more