TBM RECORDER
Seattle LRT breakthroughs
Nov 2011
TunnelTalk reporting
- November has been hailed by Sound Transit officials as "a turning point in the history of transit for Seattle's Eastside."
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First U-Link TBM drive complete
- Last week the Board received an ROD (Federal Record of Decision) to finalize funding for the East Link LRT extension and on Tuesday the Hitachi-EPBM working on the southern section of the current U-Link extension north from the downtown area holed through.
- The East Link ROD was combined with an agreement last week with the City of Bellevue to share funding of the estimated $276 million additional cost of building a tunnel under downtown Bellevue rather than the cheaper at-grade route. The City of Bellevue commits to contributing up to $160 million to the project, and establishes Sound Transit and the City as partners in its final design and construction.
- An agreement is also finalized with the Washington State Department of Transportation to use the centre of the I-90 bridge crossing of Lake Washington for the light rail. Agreement has been under negotiation since 2009 and was reached finally on November 3. Under the terms of the agreement Sound Transit will pay to add two road lanes to the crossing to compensate for the loss of the two center lanes to light rail.
- Ahead of the bridge, the LRT will run through Seattle's Mount Baker tunnel on lanes that are used today for contra flow rush-hour traffic but included in the tunnel's original design and construction for the light rail services.
- Sound Transit board member and King County Executive Dow Constantine said: "With endorsements and support from voters, the City, the State, and now the Federal Government, now it's time to finish the design and start construction."
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Seattle's East Link route is now finalized
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LRT will share the I-90 crossing
- It is hoped that construction on the East Link can begin in 2015, with passenger services being launched in 2023.
- Meanwhile back in the city centre, the Hitachi EPBM has arrived successfully into a reception shaft adjacent to the Pine Street Stub Tunnel connection to the existing Sound Transit LRT system under downtown Seattle and south to Sea-Tac Airport. Operated by the Jay Dee/Coluccio/Michels JV, the 6.5m machine started its drive south from Capitol Hill in July. It is now being disassembled and transported back to the Capitol Hill station working shaft for an expected start early next year on the parallel drive.
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Hitachi EPBM will relaunch for the parallel drive
- Meanwhile, two Herrenknecht EPBMs operated by the Traylor/Frontier-Kemper JV are driving the 3km running tunnels south from the University of Washington station to Capitol Hill.
- Performance by the EPB machines is being watched carefully in Seattle, particularly for the Jay Dee/Coluccio/Michels' machine as it is a giant 17.5m or 58ft diameter EPBM on order from Hitachi Zosen that will excavated the Alaskan Way double deck highway tunnel under downtown Seattle for the Dragados/Tutor Perini Seattle Tunnel Partners JV. The project's $1.35 billion design-build contract was signed in January and set up for excavation of the new 2.7km long tunnel has started with demolition at the southern end of the earthquake-damaged elevated highway that it is selected to replace.
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Alignment of the U-Link extension
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Hitachi U-Link breakthrough
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Dismantling beings for parallel drive
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Seattle selects East Link route - TunnelTalk, August 2011
U-Link prepares to receive its TBMs - TunnelTalk, March 2011
Owner's approach to Seattle's U-Link extension - TunnelTalk, July 2010
Hitachi EPBM for Alaskan Way mega drive - TunnelTalk, July 2011
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