Danish planning company Femern has reportedly initiated the construction work on Fehmarnbelt Tunnel, which will connect Denmark and Germany.

Fehmarnbelt Tunnel is officially known as Fehmarnbelt Fixed Link.

CNN reported that the 18km-long immersed tunnel will entail an investment of more than €7bn ($8.2bn). It is claimed to be the world’s longest immersed tunnel descending up to 40m beneath the Baltic Sea.

In addition to being the world’s longest immersed tunnel, the tunnel is said to be one of the largest infrastructure projects in Europe.

Upon completion in 2029, Fehmarnbelt Tunnel is expected to significantly reduce travel times between Denmark and Germany.

Fehmarnbelt Tunnel will be built by immersing pre-built tunnel sections across the Fehmarn Belt, which is a strait between the German island of Fehmarn and the Danish island of Lolland.

Weighing 73,000mt, each section will be 217m long, 42m wide, and 9m tall.

Positioning the sections will take roughly three years.

The new tunnel is set to serve as an alternative to the existing ferry service from Rødby and Puttgarden, which takes 45 minutes to move passengers from one end to another.

The company claims that the new road will enable people to reach the other end in just seven to ten minutes by car.

In addition, Fehmarnbelt Tunnel will also be the world’s longest combined road and rail tunnel.

The tunnel will feature two double-lane motorways and two electrified rail tracks.

Femern technical director Jens Ole Kaslund was quoted by CNN as saying: “Today, if you were to take a train trip from Copenhagen to Hamburg, it would take you around four and a half hours. When the tunnel will be completed, the same journey will take two and a half hours.

“Today a lot of people fly between the two cities, but in the future, it will be better to just take the train.”

During the construction period, the project is expected to create 2,500 jobs.