Why Israel Needed an 1,800-Ton Monster to Cut Through Jerusalem’s Mountains | Grand Structures

To connect Tel Aviv and Jerusalem in just 28 minutes, engineers couldn't simply lay tracks over the hills. High-speed trains are strictly limited to a 2.5% grade, meaning the only way forward was straight through the solid rock. In this documentary, we break down the extreme civil engineering of Israel's 7.4-mile twin-bore rail tunnel. Discover how 1,800-ton Tunnel Boring Machines (TBMs) chewed through uniform rock continuously, why the crews were forced to abandon the machines and switch to dangerous drill-and-blast methods as the rock grew harder near Jerusalem, and why digging two parallel tunnels is vastly safer than building one massive cavern. Subscribe to Grand Structures for deep dives into extreme civil engineering, architectural physics, and hidden megaprojects #GrandStructures #CivilEngineering #MegaProjects #TunnelBoringMachine #Israel #Infrastructure #Engineering #Railway Chapters 0:00 — The Mid-Mountain Switch 0:45 — The 2.5% Grade Problem 2:20 — The 1,800-Ton Tunnel Boring Machine 4:10 — Drill & Blast: When the Mountain Fights Back 5:50 — Why Build Two Tunnels Instead of One? 7:00 — The Scale of Concrete and Steel 7:50 — The Right Tool for the Mountain & Next Time