Fehmarnbelt Tunnel: Built in a Factory, Then Sunk

The Fehmarnbelt Tunnel is being built in giant concrete sections, floated into the Baltic Sea, and lowered into a trench. How do you make a tunnel float, sink it precisely, and seal the joins underwater? Follow the immersed-tunnel construction process linking Denmark and Germany: the factory, watertight bulkheads, ballast, immersion equipment, and the water pressure that helps close each joint. The film also examines the opening-date delays described in the project records. Construction progress and opening-date discussion reflect the research snapshot of 28 September 2026; see the project-status source for later updates. Which step seems hardest: floating, positioning, or sealing the tunnel? Share your thoughts in the comments. Like this story and subscribe to Megascale for more engineering documentaries:    / @megascale99   Chapters 0:00 A Concrete Tunnel That Floats 0:52 Why Not Dig? 2:20 The Factory 4:17 Make It Float 5:42 Sink It 7:39 The Last Push 9:20 Opening Plans and Delays Sources https://femern.com/the-tunnel/project... https://www.dmc.nl/projects/femernbel... https://www.trelleborg.com/en/marine-... https://sundogbaelt.dk/en/news-press/... Visuals are AI-generated photographic reconstructions, not archival footage. The narration is AI-generated. Quoted words are read by the narrator. #FehmarnbeltTunnel #ImmersedTunnel #Engineering