Inside the world’s largest tunnel boring machine.
Inside the world’s largest tunnel boring machine (TBM).
“Bertha,” as it’s known, is the world’s largest TBM and will spend the next 14 months boring a 1.7 mile (2.7 km) tunnel under the city as part of a US$1.2 billion project to replace a viaduct damaged in a 2001 earthquake.
Inside the world’s largest tunnel boring machine (TBM).
“Bertha,” as it’s known, is the world’s largest TBM and will spend the next 14 months boring a 1.7 mile (2.7 km) tunnel under the city as part of a US$1.2 billion project to replace a viaduct damaged in a 2001 earthquake.