BBC:
A record-breaking tunnel is being built under the Baltic Sea between Denmark and Germany, which will slash travel times and improve Scandinavia’s links with the rest of Europe.
Running for 18km (11 miles), the Fehmarnbelt will be the world’s longest pre-fabricated road and rail tunnel.
It’s also a remarkable feat of engineering, that will see segments of the tunnel placed on top of the seafloor, and then joined together.
The project’s main construction site is located at the northern entrance to the tunnel, on the coast of Lolland island in the south east of Denmark.
The facility spans more than 500 hectares (1,235 acres), and includes a harbour and a factory that is manufacturing the tunnel sections, which are called “elements”.
“It’s a huge facility here,” says Henrik Vincentsen, chief executive of Femern, the state-owned Danish company that is building the tunnel.
To make each 217m (712ft) long and 42m wide element reinforced steel is cast with concrete.
Most underwater tunnels – including the 50km Channel Tunnel between the UK and France – burrow through bedrock beneath the seafloor. Here instead, 90 individual elements will be linked up, piece by piece, like Lego bricks.
“We are breaking records with this project,” says Mr Vincentsen. “Immersed tunnels have been built before, but never on this scale.”
