Video: Travel On Site In 2019, Editor-in-Chief Scott Blair visited the Brenner Base Tunnel. Watch how it all began. The Brenner Base Tunnel is down to its final two tunnel boring machines. When TBMs Olga and Wilma finish their remaining combined 6 km beneath the Austrian Alps, mechanized excavation will be complete on the 55-km, $11.5-billion rail tunnel connecting Innsbruck and Fortezza—and one of Europe's most technically challenging infrastructure projects will move fully into its systems phase before its scheduled 2028 opening. BBT SE reported in early February that Olga had reached the 4-kilometer mark in the east main tunnel of the H53 Pfons-Brenner lot, passing the halfway point of her 7.6-km northbound drive. Wilma has exceeded 5 km in the west main tunnel. Together, the machines have constructed more than 9 km of tunnel, leaving fewer than 6 km remaining between them. "With only 3.6 kilometres still to be excavated, Olga is coming down the home stretch," BBT SE said.…