The World's Largest Tunnel Boring Machine: A 400-Foot, 9.5-Million Pound Mechanical Earthworm

We've been thinking a lot today about moving earth to make pathways. Tunnels. What if you're not talking about thin, dirt tubes to move humans, though, but holes so big entire industries can flow through them? This is the world's largest tunnel boring machine: an Earth Pressure Balance (EPB) Shield developed by… »4/25/11 5:18pm4/25/11 5:18pm