In Seattle, US, TBM Pamela has arrived at Roosevelt Station and TBM Brenda is expected at U District Station in early-Autumn.

On 13.07.2015  the Robbins EPBM Pamela arrived at the future Roosevelt light rail station for the Northgate Link light rail extension at Seattle, completing the second 2.4 km-long segment of a 5.5 km-long tunnel from Northgate Mall to the University of Washington, to open in 2021 (click here for the video). This is the second of six tunnels being mined by Sound Transit tunnelling contractors.

The TBM Pamela, launched last November from the Maple Leaf Portal just east of Interstate 5 and south of Northgate Mall, will be refurbished before continuing to the U District station site and later connecting with the completed University of Washington Station.

The second  TBM, Hitachi Zosen EPBM Brenda, launched from the Maple Leaf Portal last July, reached the Roosevelt site in March and is expected to arrive at the U District site this Autumn.

Both tunnels are expected to be complete by mid-2016. Cross-passages and tunnel finishes are scheduled for completion in early-2018. When service starts in 2021, light rail trains will enter and exit the tunnels at the Maple Leaf Portal.

Each TBM weighs 600 t and is more than 91.44 m long with trailing gear. The cutter heads are 6.4 m in diameter. By the time tunnelling is finished, a total of more than 382,277 cu m of soil will have been excavated and over 7,200 concrete rings used to line the tunnels.

When complete, the EUR1.94 billion Northgate Link Extension will connect the University of Washington Station at Husky Stadium to underground stations in the U District and Roosevelt neighbourhood, and to an elevated station at Northgate. Click here and us/42 for tunnelbuilder archive. Visit http://www.soundtransit.org and http://www.therobbinscompany.com/. 30/15.