on November 6th, 2023

Europe’s ambitious €10 billion (nearly AU$16.7 billion) Fehmarnbelt Fixed Link, the world’s longest underwater rail and road tunnel, promises to enhance transport between Germany and Denmark, yet stirs environmental debates.

Engineers Behind the Fehmarnbelt Tunnel

Before diving into the intricacies of the Fehmarnbelt project, it’s crucial to understand the multidisciplinary team of engineers and experts involved in bringing this ambitious project to fruition.

Here’s a look at some of the critical engineering disciplines contributing to this engineering marvel:

Structural Engineers

Structural engineers are responsible for designing the tunnel’s structural components, ensuring its stability and durability under the immense pressure of the Baltic Sea.

Construction Engineers

Construction engineers oversee the construction process, including logistics, site management, and coordination of various construction activities.

Electrical engineering will be a big part of the tunnel’s electrical systems’ operation

Electrical Engineers

Electrical engineers focus on the tunnel’s electrical systems, including lighting, power distribution, and safety.

Environmental Engineers

In addressing the project’s ecological impact, environmental engineers are pivotal in minimizing harm to the sensitive Fehmarn Belt area.

Geotechnical Engineers

They are tasked with understanding the geological conditions at the tunnel site; geotechnical engineers help design safe and stable foundations for the tunnel.

Conservation vs Progress

At over 18 kilometers in length, the tunnel is an engineering marvel of colossal proportions. This tunnel will significantly shorten the rail journey between Hamburg and Copenhagen, cutting it from 4.5 to 2.5 hours and facilitating connections to Sweden, Norway, and Finland.

The European Commission, recognizing its importance, has allocated a substantial €1.1 billion (about AU$1.8 billion) to support its construction. However, while the promise of speed and interconnectivity is celebrated, environmental concerns have raised their heads.

Environmentalists, led by the German organization NABU, express fears about the potential damage to biodiversity in the Fehmarn Belt, an EU-protected area. They argue that the benefits of the tunnel may not outweigh the ecological consequences. Malte Siegert, the head of NABU, questioned whether the project aligns with the European Commission’s green ambitions, mainly due to its inclusion of road traffic lanes.

In response, Henrik Vincentsen, the CEO of Femern A/S, the Danish company responsible for building the tunnel, emphasizes the creation of new natural habitats as a conservation effort.

He told Euronews Next: “Vast areas of new nature will be established due to the project. On land, 300 hectares of coastal wetlands will be created, and at sea, we are establishing 42 hectares of new reefs.”

Vincentsen’s argument rests on the belief that the construction’s impacts are temporary, and the tunnel will ultimately benefit passengers and the climate.

Carbon Calculations

One of the key concerns surrounding the Fehmarn Belt Link project is its carbon footprint. While the exact carbon cost remains uncertain, an environmental impact assessment from 2013 estimated that the project’s construction could emit the equivalent of two million tonnes of CO2.

However, the actual carbon reduction benefit will emerge over the tunnel’s 120-year lifecycle.

The tunnel’s lower-carbon concrete and high-speed electrified railway are designed to reduce the need for flights and shorten road journeys, effectively cutting down emissions.

This shift towards sustainable transportation aligns with the European Commission’s environmental objectives and aims to make the tunnel more ecologically friendly in the long run.

Carbon calculations: the tunnel’s carbon footprint is a key concern
Animated video of Europe’s largest construction project

Largest Construction Project in Europe

The Fehmarn Belt Link is no ordinary construction project. It currently holds the title of the largest construction project in Northern Europe.

This extraordinary feat of engineering will span the Fehmarnbelt, a strait connecting the Danish Island of Lolland and the German island of Fehmarn. The tunnel will accommodate a four-lane motorway with northbound and southbound compartments and a high-speed electrified railway.

Femern A/S, which is also a subsidiary of the Danish state-owned transport management firm Sund & Bælt, oversees this mammoth endeavor. The project is considered a strategic continuation of the Øresund Link, the bridge and tunnel system connecting Sweden and Denmark.

Once complete, combining these two projects will offer a faster route from Scandinavia to Central Europe, revolutionizing transportation between the regions.

Delivery and Challenges

The project has faced its share of challenges, from the disruptions caused by the COVID-19 pandemic to weather-related delays. However, progress continues. Dredging, a significant construction phase, is almost halfway complete, and work on the tunnel entrance at Rødbyhavn has commenced. 

Femern has also started seeking input from the rail industry in preparation for the bidding process for the railway delivery. Despite the challenges, Vincentsen remains confident in the project’s timely completion, with the expected delivery date of 2029. 

An illustration of the World’s Longest Underwater Tunnel. Image by Femern A/S

A journey between Denmark and Germany involves an hour-long ferry crossing of the Fehmarnbelt or a 160-kilometer detour via the Storebælt bridge. With the Fehmarn Belt Fixed Link, travel times will be slashed by at least two hours, with the ability to cross the strait in just 10 minutes for vehicles and seven minutes for high-speed trains traveling at 200 kilometers per hour.

Vincentsen expressed his enthusiasm for the project’s legacy: “We’re building a world record tunnel, and with a lot of the things we’re working on, we’re going to create a lot of new best practices that everyone can benefit from.” 

The tunnel project represents an unprecedented engineering achievement that promises to enhance transportation, reduce travel times, and support environmental conservation. However, the debate between progress and conservation persists. 

With its environmental impacts, carbon footprint, and potential benefits in mind, the Fehmarn Belt Fixed Link symbolizes the delicate balance that engineers, environmentalists, and policymakers must strike when pursuing ambitious infrastructure projects. 

Ultimately, the world will be watching as this colossal tunnel takes shape, observing the real-world consequences of this grand engineering endeavor. 


Fehmarn Belt Link: Are the benefits of the world’s longest underwater rail tunnel worth the damage? 

Future of Tunnelling | How contractors are gearing up to build record-breaking Fehmarnbelt immersed tube 

The Insane Scale of Europe’s New Mega-Tunnel 

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