Double Shield sees the Light in Sochi

In early March 2011, a 6.2 m (20.3 ft) diameter Robbins Double Shield TBM crossed the finish line in Sochi, Russia. The machine completed a 4.5 km (2.8 mi) long section of tunnel that will ultimately become part of the transportation infrastructure for the upcoming Olympic Games. The TBM advanced through difficult ground at average rates of 100 to 120 m (330 to 390 ft) per week for contractor OJSC Bamtonnelstroy, a division of the SK Most Company.

The section of tunnel will ultimately become a service tunnel for Complex #3-a section of Sochi’s transportation infrastructure under construction,...