Inside the World’s Longest Underwater Tunnel | Japan's Trillion-Yen Underwater Bullet Train Tunnel

Inside the World’s Longest Underwater Tunnel. How Japan built $7B underwater bullet train tunnel beneath the ocean. The world's longest and luxury undersea Seikan Tunnel megaproject ever built. Built deep beneath one of the most hostile ocean channels on Earth... this is the incredible story of Japan's Seikan Tunnel. In this documentary, we unpack how engineers achieved the "impossible" task of building a massive train tunnel directly under the ocean—a project that escalated to an eye-watering $7 Billion USD (1.1 Trillion Yen). From catastrophic flooding to active fault lines, discover the extreme marine engineering and revolutionary tech used to construct this infrastructure marvel 100 meters below the seabed. If you love engineering nightmares, megaprojects explained, and high-speed rail technology, make sure to hit subscribe! #SeikanTunnel #JapanEngineering #UnderseaTunnel #MegaProjects #HighSpeedRail #EngineeringExplained #SeikanTunnelExplained #topluxury CHAPTERS: 00:00 — 00:15 OPENING INTRO. 00:15 — 01:19 THE OCEAN BARRIER. 01:19 — 02:17 BUILDING THE SEIKAN TUNNEL. 02:17 — 02:58 THE HIDDEN STATIONS BENEATH THE OCEAN. 02:58 — 04:08 A NEW VISION OF UNDERSEA TRAVEL. 04:08 — 05:10 SURVEYING THE OCEAN FLOOR. 05:10 — 05:48 MAPPING THE FUTURE ROUTE. 05:48 — 06:37 COASTAL CONSTRUCTION BEGINS. 06:37 — 07:21 EXCAVATING THE APPROACH TUNNELS. 07:21 — 08:25 BUILDING THE TRANSPARENT MODULES. 08:25 — 09:01 TESTING AGAINST THE PRESSURE OF THE SEA. 09:01 — 09:42 OFFSHORE INSTALLATION OPERATIONS. 09:43 — 10:43 CONNECTING THE TUNNEL BENEATH THE SEA. 10:43 — 11:28 BUILDING A COMPLETE TRANSPORTATION SYSTEM. 11:28 — 12:10 TESTING THE NETWORK. 12:10 — 13:37 THE FIRST PASSENGER JOURNEY & THE FUTURE BENEATH THE OCEAN.