The World's Biggest Tunnel Machine Got Stuck Under Seattle
Seattle had the biggest tunnel boring machine in the world, and it broke down about 1,000 feet in. Bertha was 57.5 feet wide, cost about $80 million, and was digging the SR 99 highway tunnel under downtown Seattle. In December 2013 she ground to a halt and stayed out of service for about two years. Crews dug a rescue pit 120 feet (about 12 stories) deep and lifted her roughly 2,000-ton front end straight out for repairs. The contractor blamed a steel pipe left in the ground from a 2002 state tes
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