Third TBM to launch on Seattle light rail tunnel

16 June 2011

The Hitachi Zosen EPB machine that will excavate between downtown Seattle and Capitol Hill is in place and is scheduled to start boring in a few weeks.

Nicknamed, Brenda, the TBM is one of three being used to excavate tunnels for Sound Transit’s 3.15-mile (5km) University Link (U-Link) extension.

The JCM joint venture (Jay Dee/Cullucio/Michels) will use the 21ft diameter EPB machine to excavate 3,800ft of twin tunnels, starting with the northbound tunnel, and relaunching it for the southbound drive.

A joint venture of Traylor Bros./Frontier – Kemper is using two Herrenknecht TBMs to excavate 11,400ft (3,474.7m) of tunnels from the University of Washington to Capitol Hill. Those TBMs were dedicated at public ceremony last month.