The Northgate Link Extension construction began in late-2012 with demolition of the Roosevelt Station site. The 7 km-long project in Seattle, Washington includes 5.8 km of new light rail tunnels with two underground stations at U District and Roosevelt, and a surface station at Northgate. Tunnelling will begin in 2014. The tunnels will be bored and lined from north to south using three 6.4 m-diameter TBMs. Two of these will be launched from the Roosevelt Station site on parallel tunnels south to the University of Washington (UW) Station. The third machine will launch from the tunnel portal near NE 94th Street and bore south to Roosevelt Station, where it will be disassembled and transported back to the portal for the second tube. Cross-passages will be excavated every 250 m. The Northgate Link Extension is scheduled to open for operation in 2021. Click us/42 for tunnelbuilder archive. Visit www.soundtransit.org. 14/13.