Late Friday morning, Sound Transit’s tunnel boring machine ‘Brenda’ holed through at the future University District station at NE 43rd St & Brooklyn Ave NE. The machine took 6 months to tunnel the mile between Roosevelt Station and the UDistrict and will be refurbished before digging the last mile of the northbound tunnel to UW Station.
The holethrough comes as Northgate Link’s TBMs have struggled with soil conditions, premature cutterhead wear, and slower than expected progress. The unmitigated success of ULink’s tunneling has set the bar very high for this project, and it’s not unreasonable to expect occasional setbacks, which is precisely what schedule float is for. The project is still well within its schedule and budget, with several months of project float remaining. (The Sound Transit Board heard a more detailed briefing on these issues at its October meeting, and those materials are not yet online.)
Meanwhile, TBM Pamela is busy digging the southbound tunnel,
and was 600′ south of Roosevelt as of the last briefing on October 22., having just passed under Ravenna Boulevard as of the last update on October 31.