• 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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  • 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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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