The two purpose-built vessels Ivy 1 and Ivy 2 are absolutely critical to the Fehmarnbelt link. They are the ones that will hold and control the massive tunnel elements as they are lowered onto the seabed of the Fehmarn Belt. The vessels have been completed and delivered, but without the necessary approvals they cannot be put into operation. The case has developed into a lengthy process involving exemptions, special rules and technical assessments. Several authorities have been involved, and decisions have been made gradually over four years.
It is the Danish Maritime Authority that must approve the vessels before they can be taken into use.
“The approval process for the units is well advanced but, as far as the Danish Maritime Authority is informed, it is awaiting the completion of technical testing with satisfactory results. The Danish Maritime Authority is not aware of a timetable for this,” the authority states.
The authority refers to Det Norske Veritas, which is responsible for the actual certification. Det Norske Veritas has no comments on the approval process.
Based on access to documents from the approval process, FemernBusiness can outline the following timeline:
2021:
Paperwork begins
In August 2021, the Danish Maritime Authority, Det Norske Veritas (DNV) and Femern Link Contractors (FLC) meet to find a way to approve the two purpose-built pontoons Ivy 1 and Ivy 2. FLC is the main contractor behind the tunnel construction. DNV is the classification society that, on behalf of the state, verifies that the vessels comply with international maritime rules, while the Danish Maritime Authority has the final say.
Why the delay?
The short explanation is that Ivy 1 and 2 are not ordinary ships. They are floating steel structures built for one purpose only: to manage the submersion of the tunnel elements. This makes them difficult to fit into the rules normally used for ships.
Ballast water and rescue equipment were resolved early through exemptions. But stability, freeboard, and load line - the very foundation of safety - were only approved in the winter and spring of 2025 after long negotiations and special regulations.
Thus, the delivery in 2024 could not be followed by operation. And therefore, the project still lacks the necessary sea trials and certificates before the vessels can be put into use on the Danish side.
Already at that time it was clear that the pontoons were so unusual that standard rules could not simply be applied. Special solutions were required – essentially exemptions – which had to be documented and approved step by step.
2022:
Work on special rules continues
Throughout 2022, Femern Link Contractors, the Danish Maritime Authority and Det Norske Veritas continued working to establish the specific rules under which Ivy 1 and 2 could be approved. The vessels were under construction at the Crist shipyard in Poland, while the classification society and authorities discussed documentation requirements and initial drafts of alternative solutions. The main issues concerned how the pontoons should be registered and how stability and safety could be described in a way that matched the vessels’ unique design.
2023:
First major approval falls into place
In August 2023, the Danish Environmental Protection Agency grants a five-year exemption from international ballast water treatment requirements. The justification is that the pontoons operate only locally between Denmark and Germany and that all ballast water is discharged in Danish waters. This allows FLC to avoid installing costly treatment systems – and a key piece falls into place.
2024: Delivery approaches – but technical issues remain
The plan was for Ivy 1 and 2 to be delivered in June 2024, towed to Denmark and ready to lower the first tunnel elements in the autumn. However, delivery was postponed to August 2024.
While the vessels could be physically completed, approvals lagged behind. Stability – meaning the safety that the pontoons will not capsize in rough weather or in case of damage – had still not been approved. Freeboard and load line – the rules determining how deep a vessel may sit in the water – could not be finalised until stability was resolved.
Other issues were settled. In September, the Danish Maritime Authority accepted that the vessels do not need their own lifeboats, as they will always be surrounded by other vessels with rescue capabilities. In October, DNV issued a ballast water certificate for Ivy 1 based on the Environmental Protection Agency’s exemption.
2025:
Approvals fall into place but sea trials are missing
At the beginning of 2025, the most important regulatory decisions begin to fall into place. The Danish Maritime Authority approves an alternative stability concept in November 2024 and, in February 2025, a special load line and freeboard concept. In March, the construction of the bottom pontoons is approved, and in April the solution proposed by FLC and DNV for emergency power supply is accepted.
This means that almost all technical conditions are in place: stability, load line, ballast water, rescue equipment, structural design and emergency power have been approved. A few technical details remain, such as lifting equipment, noise measurements and working environment requirements. However, the vessels still lack the certificates required to enter into operation.
In March 2025, FLC must request a temporary permit for sea trials, as the Danish Maritime Authority maintains that the vessels are formally detained until the final certificates are issued. Sea trials can only be carried out if Det Norske Veritas declares the vessels seaworthy for testing and FLC submits a detailed plan to the Danish Maritime Authority.
October: After a prolonged period of standstill, movement resumed in the certification process. On 17 October, a temporary load line certificate (ILLC-IC) was issued, defining the freeboard and making it possible to carry out the necessary load and sea tests. At the same time, an additional certificate related to environmental and working conditions was issued. These were the first new certificates since the spring and marked that the approval process was back on track.
November: An International Anti-Fouling System Certificate (AFS-IC) and a Danish National Cargo Ship Safety Certificate (DNK-CS-C) have now been issued. This means that several formal requirements have been met, but the classification certificate is still missing.
December: The authorities withdraw the vessel’s temporary navigation certificate. As a result, a planned first immersion in February 2026 is abandoned.
2026:
2 April: The vessel is approved by the Danish Maritime Authority
