The entire progress of the largest construction project in Danish history depends on one fundamental condition: that the tunnel trench on the seabed is ready so that the 89 elements can be lowered at a stable pace. Therefore, the trench has become a crucial point of contention in the Fehmarn Belt project, where the main contractor FLC refuses to approve it, while the client maintains that the deviations are limited.
Now Femern A/S reports that the trench work has already triggered a financial settlement. The Dutch consortium FBC, Fehmarn Belt Contractors, consisting of Boskalis and Van Oord, has paid compensation because the trench was dug too deep. The matter was settled contractually in connection with the handover, which was completed at the end of 2024.
Central bottleneck
The tunnel trench is the excavated corridor on the seabed into which the 89 tunnel elements will later be lowered. The trench is dug under a separate contract by FBC and then handed over to Femern A/S. The subsequent fine-tuning and the actual lowering are the responsibility of the main contractor, Fehmarn Link Contractors (FLC). After the handover, the trench has become a central bottleneck because FLC will not approve it in its current form.
The handover of the tunnel trench is practically the formal delivery of a partial task. When FBC finishes digging the trench, the consortium documents the actual profile and depth of the seabed with measurements, which the client reviews. Femern A/S then accepts the trench as delivered, possibly with a list of deficiencies, and a contractual final settlement is made. If it has been dug too deep or otherwise outside the tolerances, it can trigger repairs or a financial adjustment before the client takes over the trench. Once the handover is completed, the responsibility for the trench shifts from the contractor to the client, and the trench simultaneously becomes the prerequisite for the main contractor's next work.
1.8 metres too deep
This is precisely where the problem arises now. Femern has accepted the trench and settled financially with FBC, but the contractor who is to use the trench as a foundation for the lowering will not approve it in the form it has been handed over. This means that work, which has contractually been completed between the client and the trench consortium, remains a bottleneck in the next phase and thus a focal point for both the schedule and responsibility.
According to FLC's internal measurements of the first 650 metres off Lolland, the trench has been dug significantly deeper than planned in several places. The contractor states that the deviations are on average significantly below what is acceptable, and that locally it has been measured up to 1.8 metres too deep.
If the measurements prove to be representative of larger parts of the trench, it could mean extensive rectification and further delays in the next phase.
One of many conflicts
But even though the trench contract has thus been settled between Femern and FBC, the trench remains a focal point for the current conflict between Femern A/S and FLC.
The disagreement over the condition of the trench does not stand alone, however. On the large construction project, several parallel disputes are ongoing, and they also have a clear economic dimension. Femern Link Contractors has made a claim of 1.95 billion euros, equivalent to 14.5 billion DKK, citing changed conditions and the delays the contractor believes result from them. At the same time, an international arbitration is ongoing, where FLC is claiming 77 million euros in connection with delays and additional costs during the coronavirus pandemic.
