Tunneling began in summer 2013, just west of the stadiums. In December 2013, Seattle Tunnel Partners stopped tunneling approximately 1,000 feet into the tunnel drive after experiencing increased temperatures in the machine. While investigating the cause of the high temperature readings, STP discovered damage to the machine’s seal system and contamination within the main bearing. STP has since completed repairs and enhancements to the machine and resumed tunneling. Their latest construction schedule is available here.