Tunnel boring to begin on light-rail link in Seattle

A welder attaches protective shields to one of the two 21-foot-diameter tunnel-boring machines at the north end of the project near Husky Stadium. The entrance to the northbound tunnel is at upper right.

A welder attaches protective shields to one of the two 21-foot-diameter tunnel-boring machines at the north end of the project near Husky Stadium. The entrance to the northbound tunnel is at upper right.

This week, Seattle’s Sound Transit will start drilling a $2 billion, three-mile light-rail tunnel to connect the University of Washington, Capitol Hill and Westlake Center. The first TBM will be christened today near UW’s Husky Stadium and will drill the southbound tunnel towards capital hill. Another TBM will start in parallel with the first in June, excavating the northbound tunnel. A third TBM will come into service later to excavate the first tube of the 1-mile route from Capital Hill to Westlake center. It will be extracted from a pit at the end of the bore, and returned to dig the other parallel tube. [Source: Seattle Times Newspaper via ASCE SmartBrief. Image: Alan Berner / The Seattle Times]