January 21, 2018

#817. The world’s largest tunnel boring machine “Bertha”!

     Seattle citizens are also excited about the world biggest tunnel excavator feat of 17.45 m in diameter, and the world is attracting attention!

“Bertha” is the largest diameter tunnel excavator in the world, and they have tunneled through the underground tunnel construction project “SR 99 Tunnel Project” in Seattle City, USA. Up to now, there were only elevated bridges that were at risk of earthquakes from the downtown to the waterfront, but they say that a safe underground road will replace this. Every completed underground road will be in 2019, but many Seattle citizens are longing for. In addition, cities around the world are paying attention to this achievement.