How Denmark Built the World’s Longest Undersea Tunnel to Germany

Europe is building the world’s longest undersea immersed tunnel — a $7.5 billion megaproject designed to permanently connect Denmark and Germany beneath the Baltic Sea.

But this tunnel is different.

Instead of drilling through unstable seabed geology, engineers made a radical decision:
👉 Build the entire tunnel on land, then transport and lower massive concrete elements — each weighing up to 73,000 tons — directly onto the sea floor with millimeter-level precision.

In this documentary-style breakdown, you’ll discover:

Why the Fehmarn Belt became one of Europe’s most critical transportation bottlenecks

Why traditional tunnel boring machines (TBMs) were too risky to use under the Baltic Sea

How Denmark constructed one of the largest concrete factories in history just for this project

The step-by-step process of manufacturing, transporting, and immersing tunnel elements as heavy as 200 Boeing aircraft combined

How the immersed tunnel method works — and why it’s safer, faster, and more cost-effective than bored tunnels

The engineering techniques that ensure the tunnel remains 100% watertight under extreme sea pressure for generations

Once completed in 2029, the Fehmarn Belt Fixed Link will become:
✔️ The longest combined road and rail immersed tunnel in the world
✔️ One of the most ambitious civil engineering achievements of the 21st century
✔️ A project capable of reshaping Europe’s economic and transport network for decades

If you’re fascinated by:
engineering megaprojects • undersea tunnels • infrastructure engineering • large-scale construction • civil engineering

— this video is for you.

Like, share, and subscribe for more deep-dive documentaries breaking down the world’s most extreme engineering projects.
#germany #tunnel #megaprojects
#UnderseaTunnel
#ExtremeEngineering
#CivilEngineering
#MegaConstruction
#Infrastructure
#FehmarnBelt
#EngineeringExplained