Work on the $8 billion Fehmarnbelt tunnel, which is planned to link Germany and Denmark as the world’s longest submerged tunnel, is progressing as crews reached a milestone last month with the successful immersion of its first precast concrete element. But Danish state-owned project owner Femern A/S says the plan is now running at least two years behind schedule and that the road and rail parts of the tunnel will be opened in two separate stages.
The nearly 11-mile-long, five-tube tunnel would cross 140 feet below the Baltic Sea between Puttgarden in northern Germany and the island of Lolland in southeastern Denmark. With four road lanes and two electrified railway lines plus an access crossing in a dredged trench, it would provide a critical new artery connecting Scandinavia with central Europe, with an estimated travel time of seven minutes by train or 10 minutes by car and halving the five-hour journey between Hamburg and Copenhagen.
Femern Link Contractors (FLC), a joint venture led by Vinci Grands Projets SAS, has previously been manufacturing the 79 standard concrete tunnel elements 712 feet long, 138 feet wide and 30 feet high, each weighing 73,500 metric tons, in addition to 10 others with housings for immersion in electrical elements and submerged in electrical elements. the dredged trench.
Photo courtesy of Femern A/S
The dredging of the 260-foot-wide, 33-foot-deep trench was carried out by a separate consortium, Fehmarn Belt Contractors, led by Royal Boskalis Westminster NV and Van Oord NV. About 60 vessels were involved in the excavation of 530 million cubic feet of material. Dredging began in 2020 and was completed in 2024. The excavated material is being reused to create more than 700 hectares of land for nature and recreation.
Equipment problems force delays
Construction continues simultaneously on both sides of the strait with a plan to eventually meet in the middle, but work on the Danish side is currently delayed by about two years due to problems with a vessel used to submerge the tunnel elements, according to Femern, the project’s owner. The tunnel was originally scheduled to open in 2029.
Other problems also affect the calendar on the German side. Last summer, German transport officials announced that the country’s approval and permitting process would not allow rail facilities associated with the tunnel to become operational in 2029. Germany’s limits on underwater noise in its waters are further affecting the timetable and will make it difficult to make up for lost time, according to Femern and its parent company, Sund & Baelt. They plan to issue an updated schedule once various elements of the tunnel have been submerged.
Due to the delays, the road part of the tunnel will now open ahead of the rail part, according to Femern.
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“A gradual opening allows the tunnel to be put into use for road traffic earlier, while reducing complexity in the final stage of the project,” Sund & Baelt CEO Mikkel Hemmingsen said in a statement.
Delaying the electrified rail portion of the road later “is unfortunate for the green transition and for rail passengers,” he added.
Project still in progress
Despite the problems, work on the Fehmarnbelt tunnel has been progressing, with thousands of workers involved, according to Femern. FLC opened a production facility in Rodbyhavn, Denmark, to precast the concrete tunnel elements. More than 2,000 people work on six production lines at the Rodbyhavn plant, while around 100 more are producing steel lattice reinforcing bar components at another nearby facility.
Photo courtesy of Femern A/S
On May 4, five tugboats began towing the contractor’s IVY 1 and IVY 2 specialized submersible pontoons with the first tunnel element. They traveled a little over a mile to the Danish side portal.
The dive itself began on May 6 and lasted about 14 hours, according to Femern. Using hydraulic arms, crews attached the precast element to the tunnel portal. Another boat then placed gravel blocking fill on either side of the element to secure it in place.
“We are happy and relieved,” Hemmingsen said in a statement about the successful dive. “Our technology, our teams and our contractors have proven their capabilities and achieved something no one has done before.”
