Northgate Link Extension TBM Cutterhead Being Lifted Out of UW Retrieval Shaft

April 8, 2016
The cutterhead measures 21 ½ feet in diameter. Sound Transit’s tunneling contractor JCM Northlink will spend the next few weeks removing the 600-ton, 333-foot long machine from the retrieval shaft at the University of Washington Station.

The cutterhead measures 21 ½ feet in diameter. Sound Transit’s tunneling contractor JCM Northlink will spend the next few weeks removing the 600-ton, 333-foot long machine from the retrieval shaft at the University of Washington Station. The TBM has been mining the tunnel that will serve northbound trains when Link light rail service to Northgate begins in 2021.