Advisories/Updates

  • 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.

    — more —

    Order: 1.0

  • 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.

    — more —

    Order: 1.2

Program Spotlight

  • A full summer for Milepost 31 before closing in November

    Milepost 31 in Pioneer Square is gearing up for a busy summer of programming. Our information center continues to offer free public viewing platform tours to see the SR 99 tunnel’s south portal construction site. Bike tours have also resumed, which follow Bertha’s tunnel route and provide a unique way of understanding the historical and engineering aspects of this megaproject. You can sign up for tours online or in person at the center.

    Our First Thursday speaker series … more