How America Built a Highway Tunnel Under Seattle With a Broken Giant Drill

Bertha, a tunnel boring machine 57.5 feet wide, was the biggest in the world when it started digging beneath Seattle in 2013. A thousand feet in, it stopped. To save it, engineers dug a 120-foot pit from the street and lifted 2,000 tons of machine into the daylight. #Bertha #Seattle #TunnelBoringMachine #SR99 #Engineering #Megaproject #Tunnel DISCLAIMER ____________________________________ This is not engineering advice. Everything here is for informational and entertainment purposes only. Contact an engineer licensed to practice in your area if you need professional advice or services. All non-licensed clips used for fair use commentary, criticism, and educational purposes.