Tunnel boring machine dedicated before mid-June start
A 21-foot diameter tunnel boring machine, a bottle of bubbly and a crowd of elected officials, Sound Transit staff and supporters marked the ceremonial start of tunneling activities from Maple Leaf Portal on Monday, April 28.
The first of two TBMs is nearly ready to begin its 3.6 mile journey from about NE 92nd Street along Interstate 5 south to the University of Washington Station. As spring comes to an end, construction crews will begin moving the TBM from where it was assembled and is being tested to the so called "head wall" where the machine will take it's first bite of an expected two-year long tunnel meal. The second machine will follow later this year.