Construction phases
Construction entails various activities divided into several phases over a number of years:
1. Site preparation
The construction sites at Rødbyhavn on the island of Lolland and Puttgarden on the island of Fehmarn were thoroughly prepared in the years prior to the construction phase. This particularly applies to the large construction site on the Danish side.
New channels and access roads have been constructed, utility connections installed and a number of existing buildings at the construction site have been demolished. New water holes and amphibian fences have also been established around the construction site.
2. Construction of work harbours at Rødbyhavn and Puttgarden
Work harbours were built in both Puttgarden on Fehmarn and Rødbyhavn on Lolland. Construction materials needed for the tunnel construction are delivered via them. A large part of the required construction material can thus be delivered by sea, taking the strain off the local road network on Lolland and Fehmarn.
The work harbour at Rødbyhavn is by far the larger of the two, covering 50 hectares and being about five times the size of its counterpart at Puttgarden. The harbour at Rødbyhavn is where the completed tunnel elements will be towed out of the production plant in the Fehmarnbelt.
The Danish work harbour has been in operation since summer 2022, and the work harbour near Puttgarden since summer 2023.
3. Dredging in the Fehmarnbelt and establishment of new land areas
An approx. 18-kilometre-long tunnel trench has been excavated between Denmark and Germany. The tunnel elements will be immersed into the trench, joined together and covered with gravel, sand and stone. The surplus material from the dredging will be used to construct new coastal areas near Rødbyhavn and to a limited extent on Fehmarn.
Work on dredging the tunnel trench began in 2021 and was completed in 2024.
4. Construction of tunnel factory at Rødbyhavn and the 'tunnel village'
The tunnel factory where the 89 tunnel elements will be manufactured is located to the east of Rødbyhavn. Production halls have been built for six production lines: five for the standard elements and one for special elements.
Accommodation – a “tunnel village” has also been built for around 1,300 workers and provides a good standard of accommodation and catering facilities as well as social activities.
Casting of the tunnel elements began in the summer of 2023.
5. Portal facilities
A portal building is being constructed around the descent into the tunnel on the Danish and German sides. The portal facilities will connect the tunnel railway and motorway with the upgraded and partly newly built roads and railways in the hinterland. The portal will contain a light grid in the tunnel roof to ensure a smooth transition between the natural light and the light in the tunnel.
Work on the portal buildings on the Danish and German sides began in 2022. On the Danish side, the foremost section of the tunnel portal has been under water since spring 2024, and on the German side since autumn 2024.
6. Production and assembly of tunnel elements
The tunnel elements are produced at the factory in Rødbyhavn and towed out to the Fehmarnbelt on an ongoing basis. The contractors will immerse the elements one by one and assemble them from the coast and out towards the middle of the Fehmarnbelt from the Danish and German sides.
The first element will be immersed in 2025.
7. Installing the technology and equipment
The tunnel tubes will be equipped with the technical installations, which include ventilation, communication facilities, lighting, signage and the motorway and railway installations. Work begins as soon as the first tunnel elements are in position.
8. Testing and opening
All installations in the tunnel will be thoroughly tested prior to the opening. Safety and contingency procedures will also be tested and approved by the authorities before the Fehmarnbelt tunnel opens to traffic.
The Fehmarnbelt tunnel is expected to be completed in 2029.