After several years of delays, the lowering of tunnel elements in the Fehmarnbelt is now under way. The second tunnel element is being towed out from the production area at Rødbyhavn, 48 days after the first element was reported to be in place on the seabed off Rødbyhavn.
That brings the Fehmarnbelt project closer to its second lowering operation in the phase that will determine the pace of the remaining tunnel construction. The element had been prepared for lowering, but current conditions made it necessary to wait for a new weather window.
The Fehmarnbelt tunnel consists of 89 elements, which are to be lowered one by one into the 18-kilometre tunnel trench between Lolland and the German island of Fehmarn. Each element must be towed out from the production area, positioned in the trench and connected underwater to the preceding element.
FemernBusiness revealed as early as August 2025 that the timetable towards an opening in 2029 could not be met. That is why the pace of the lowering operation is crucial now that the first element is in place and the second is being towed out into the Fehmarnbelt.
2.5 elements a month
The original master schedule allowed 36 months, or three years, for the lowering of the tunnel elements. That means the work must, over time, maintain an average of about 2.5 elements a month.
A longer interval after the first lowering does not in itself overturn the overall plan, but it shows how sensitive the rhythm is in the phase on which the next timetable depends. The lowering operation requires several conditions to be in place at the same time. The element must be towed out, kept stable, lowered in a controlled manner and connected with great precision. Currents and weather are therefore real constraints, even in the coastal section of the tunnel trench off Lolland, where the work should be among the more manageable parts of the process.
The current lowering operation follows a longer period in which work with the tunnel elements has been at the centre of the problems on the Fehmarnbelt project. The specialised vessel Ivy, which is used to handle the elements, was delayed by two years before final approval was granted. At the same time, the tunnel trench has been one of the main points of dispute between the client and the main contractor, and Sund & Bælt has paid FLC extra to prepare the first part of the trench.
The Fehmarnbelt project has said that a revised project schedule will be presented once five standard elements and one special element have been lowered. Until then, the pace of the first lowering operations is one of the most important indicators of what the forthcoming timetable may look like.
The rest of the 18-kilometre tunnel trench remains part of the wider conflict on the project. In addition, the main contractor, Femern Link Contractors, has filed a DKr14.5bn claim against Femern A/S, which is owned by Sund & Bælt, and an international arbitration case over Covid-related delays is also under way.
Later in the process, German environmental conditions will apply farther out in the Fehmarnbelt. The working area in the Natura 2000 zone has been expanded to 1,100 metres, but the requirements on underwater noise remain in force. On the Puttgarden side, there are also specific requirements on sediment release during the summer months. The project will therefore also have to maintain its pace later in the process within a series of environmental constraints.
