Why This $30M Steel Monster Is Stuck in the Mountain Forever!

Deep beneath the Swiss Alps, a $30 million steel monster sits permanently entombed in solid granite. Here is the hand-drawn engineering breakdown of why tunnel boring machines can never back out. When excavating the 57 km Gotthard Base Tunnel under 2,500 meters of rock, engineers faced a brutal geometric trap: as the 9.5-meter TBM drill head grinds forward, it seals the tunnel behind itself with an 8.8-meter concrete ring. Pulling it back is physically impossible. Discover the sacrificial cavern method that turns a 3,000-ton machine into a permanent structural support pillar. 👇 Subscribe to Groundwork for weekly engineering breakdowns:    / @groundwork-uzb  \_confirmation=1 🎬 Watch our full Megaengineering Playlist:    / @groundwork-uzb   CHAPTERS: 0:00 The $30M Machine Entombed in Granite 0:22 Drilling the 57km Gotthard Base Tunnel 1:12 2,500 Meters of Crushing Mountain Pressure 1:42 62 Alloy Discs: How the Cutterhead Micro-Fractures Rock 2:24 Hydraulic Grippers and the Geometric Lock 3:22 Why Pulling the Cutterhead Back is Impossible 3:46 The Shrinking Concrete Support Ring Trap 4:28 The Sacrificial Cavern: Driving Into a Dead End 4:45 Turning a 3,000-Ton TBM Into Concrete Support 5:31 The Economic Reality of Deep Underground Mining 6:26 Sleeping in Darkness Forever SOURCES: • Gotthard Base Tunnel AlpTransit Gotthard AG Engineering Archives • Tunnel Boring Machine Geometry & Excavation Reports (Herrenknecht AG) 🔔 New engineering breakdowns every week. Subscribe for more of what holds things up! 📩 Business inquiries: murodbest19@gmail.com #tbm #engineering #gotthardtunnel #megaprojects #howitworks #geology #underground