DNV verifies lifting system for world's longest immersed tunnel

DNV has supported Femern Link Contractors (FLC) on the Fehmarn Belt immersed tunnel project by providing independent verification of the advanced lifting appliance used to install the tunnel elements.

The Fehmarn Belt tunnel, is an 18-kilometre long immersed road and rail tunnel connecting Denmark and Germany, with the first 217-metre tunnel element successfully immersed in May 2026. An immersed tunnel is a subsea structure built by joining large, pre-made sections that are floated to the site and then lowered into a prepared trench on the seabed.

Its installation method depends on a highly specialised lifting system capable of positioning massive concrete elements with high accuracy on the seabed in offshore conditions

DNV’s work has covered verification activities across the design, fabrication and commissioning phases of the lifting appliance installed on the immersion pontoons, IVY 1 and IVY 2. The scope included assessment of technical compliance and safety performance prior to operation, culminating in certification of the complete hoisting system.

Marte Riiber de Picciotto, DNV
Marte Riiber de Picciotto, Service Area Manager, Energy Systems at DNV

“This project involves a unique application of large-scale lifting technology in a dynamic environment and a high-precision operation,” said Marte Riiber de Picciotto, Service Area Manager, Energy Systems at DNV. “Our role has been to provide independent assurance that the lifting system meets defined safety and performance requirements before they are used for tunnel installation.”

The verified lifting appliance forms an essential part of the tunnel installation process and is essential for achieving installation readiness. Independent verification supports confidence in the reliability of the equipment and contributes to safe execution during offshore operations.

Close collaboration between DNV and FLC teams has been central to managing the technical complexity associated with the project. DNV’s contribution has included technical reviews, on-site inspections and certification activities carried out in parallel with construction and commissioning.

Prajeev Rasiah, DNV
Prajeev Rasiah, Senior Vice President and Regional Director, Northern Europe, Energy Systems at DNV

Prajeev Rasiah, Senior Vice President and Regional Director, Northern Europe, Energy Systems at DNV said “The engagement builds on DNV’s long-standing experience in testing, inspection and certification, providing independent verification of complex lifting appliances and marine operations to support safety, quality and reliability across major projects.”

Femern Link Contractors (FLC) is a Joint Venture (JV) consisting of VINCI Constructions Grands Projets (France), Aarsleff (Denmark), Max Bögl Stiftung & CO KG (Germany), BAM Infra B.V (The Netherlands), BAM International B.V (The Netherlands), Wayss & Freytag Ingenieurbau AG (Germany), Solétanche-Bachy International S.A.S (France), DEME Infra NV (Belgium), DEME Dredging NV (Belgium).

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DNV is an independent assurance and risk management provider, operating in more than 100 countries, with the purpose of safeguarding life, property, and the environment. Whether assessing a new ship design, qualifying technology for a floating wind farm, analyzing sensor data from a gas pipeline, or certifying a food company's supply chain, DNV enables its customers and their stakeholders to manage technological and regulatory complexity with confidence. As a trusted voice for many of the world’s most successful organizations, we use our broad experience and deep expertise to advance safety and sustainable performance, set industry standards, and inspire and invent solutions.

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