Completion reported on August 22nd, 1999 of 18 km-long twin tunnels in remote region using drill/blast for one tube and two Wirth 8.8 m hardrock TBMs from the portals for the other. The TBMs drove a total of 10.9 km in 19 months and the drill/blast teams completed 25 km, all in extremely hard granite and gneiss formations of UCS averaging between 150 and 250 Mpa and peaking at 325 Mpa. TBM average progress was 338 m/month with a best of 518 m. Best day, 35 m in 9.3 hours. The drill/blast teams completed their own tunnel and broke back onto the TBM tunnel alignment in order to meet the advancing machines and speed up completion. Sept 1999.
