Tesla might be known for constructing tunnels for its hyperloop train, but these are nothing compared to the world's longest immersed tunnel.

The tunnel called Fehmarnbelt connects Rdbyhavn on the island of Lolland to Puttgarden in Germany.

This video explains how 360,000 tonnes of steel and three million cubic metres of concrete are being turned into an 18km-long tunnel.

 

Once completed, the tunnel will provide the fastest rout between Scandinavia and Central Europe. But what does it take to build it?

For starters, it boasts one of Europe's largest construction sites. The first step in its development is a large-scale harbour. This is where delivery will happen for the huge quantities of sand, cement, steel and gravel required for the tunnel's construction.

Behind the harbour, lies a tunnel factory with six production halls for casting the tunnel's 89 elements 24/7. Yes indeed, construction never stops in this massive development.

What other structures and elements are needed to complete this massive project? What is the science and engineering behind this monstrous tunnel? When can its completion be expected? The above video answers all these questions and more with easy-to-understand illustrations.