https://www.tunneltalk.com/Accolades-Awards-Oct12-Robbins-celebrates-60-years-of-TBM-achievement.php
How many tunnels dug in 60 years?
https://www.tunneltalk.com/Accolades-Awards-Oct12-Robbins-celebrates-60-years-of-TBM-achievement.php
How many tunnels dug in 60 years?
Imagine how many miles of tunnels there are.