After a multi-day operation, the first of the 89 elements which will be used to construct the Fehmarnbelt tunnel was successfully immersed in May.
The Fehmarnbelt tunnel will be the longest immersed tunnel in the world, spanning 18km between Rødbyhavn, on the Danish island of Lolland, and the German island of Puttgarden. The hollow concrete structures, measuring 217m long and weighing more than 73,500t, will be immersed up to 40m below the sea surface. They are divided into five tubes – two for the future motorway, two for the railway and one for technical installations.
The immersion of the first element was a significant milestone for the project, the construction of which began in 2020.
On the evening of 4 May, five tugboats and the special immersion vessel IVY transported the concrete element from the tunnel factory at Rødbyhavn to the immersion point off the Danish coast.
Around noon on 6 May, the immersion began and approximately 14 hours later the element was placed in the tunnel trench in front of the Danish tunnel portal, before being connected to the portal using hydraulic arms. Following the immersion of each element, large quantities of gravel will be placed along their sides to ensure they remain securely in position.
“It’s a highly complex operation, involving weeks of preparation and then many hours of precise execution to position the element exactly in place,” says Guy Taylor, project director for Sund & Bælt’s Fehmarnbelt scheme.
“I was on site during the operation, and there is always a moment where everything becomes very focused. You see how much preparation has gone into something that then has to work exactly as planned. When it does, it’s a very strong confirmation of the whole approach.”
Taylor is optimistic that the immersion process can be sped up in the future. “We will continue to learn from each operation. Over time, a clear immersion routine will develop, and that will help to increase efficiency. But at the end of the day, this is a process where safety and precision come first – and that ultimately defines the pace.”
When I started my career, there was much more reliance on experience and judgement on site. Today, we combine that with much more data, modelling and quality control. It’s actually fascinating to see how tools like BIM have transformed the way we design and deliver projects
New phase, new director
The project is entering a new phase – moving from predominantly on-site construction to large-scale marine operations.
“We are entering a new phase of the Fehmarnbelt project, where we will be working in a new way with our contractors to move the project forward together. This requires new skills in project management,” the CEO of client organisation Sund & Bælt Mikkel Hemmingsen said when Taylor was appointed last November.
A British national and civil engineer by training, Taylor joined the project team after spending five years as director at Singapore’s Land Transport Authority. Over the course of his career, he has been involved in the construction of over 100km of tunnels across different environments – from dense cities to large marine crossings.
Among the projects he worked on are: the Channel Tunnel between England and France, Great Belt Fixed Link and Metrocity Ring in Denmark, as well as the Söderström Tunnel in Sweden.
Over the years, Taylor has witnessed a significant change in immersed tunnel construction. “The basic concept is the same, but the way we execute it has become much more controlled and precise.
“When I started my career, there was much more reliance on experience and judgement on site. Today, we combine that with much more data, modelling and quality control. It’s actually fascinating to see how tools like BIM have transformed the way we design and deliver projects.
“This also makes it possible to evolve the elements of an immersed tunnel. We are not only building the longest immersed tunnel in the world, we are also building it by using 217m-long standard elements. It is the first time in history that series-produced tunnel elements of this size are used to build a tunnel.
“Additionally, we have 10 special elements with a basement housing the tunnel’s electrical installations. These will be positioned at approximately two-kilometre intervals to ensure stable supply and to provide maintenance personnel with easy access to all installations.
“You can clearly see how the discipline has matured. And that’s what makes projects like Fehmarnbelt so fascinating and feasible at this scale.”
As project director, he is responsible for managing the tunnel’s construction, which includes overseeing progress across contractors, interfaces and the overall delivery.
“When I first came to site, what struck me immediately was the scale – not just physically, but organisationally. You realise very quickly that this is not a ‘normal’ project,” says Taylor.
“My ambition is to help deliver something that people in our industry will look at in the future and say ‘This is how complex infrastructure projects can be done well’. With strong collaboration, a clear focus on safety, quality and risk management, and high technical standards, as well as maintaining a clear balance between time and cost.”
In terms of the advantages and disadvantages of joining a project when it is already underway, he comments: “Joining a project at this stage is quite intense. There’s a lot happening, and you have to get up to speed quickly while the project continues to move.
“At the same time, there’s a real advantage in coming in with a fresh perspective. You see things slightly differently, you ask questions that maybe haven’t been asked in a while, and you can help refocus the effort on what matters most going forward.
“In my first weeks and months, I spent a lot of time with the teams, simply listening and trying to understand where the pressure points are.”
Delays and approach changes
The client’s original plan was for the Fehmarnbelt tunnel to be fully operational by 2029, but several factors caused delays to the programme.
As reasons behind the delays, it cites the “lengthy and complex” approval and permit procedures for starting construction work in Germany, as well as challenges with the preparation and regulatory approval of the specialised vessel used for immersing tunnel elements which has set back the construction in Denmark.
With the vessel now on site and the first element immersed, Taylor says the project has taken a very important step forward.
“The next challenge is to establish a reliable and repeatable immersion routine together with our contractor FLC [Femern Link Contractors]. That will allow us to build confidence, improve efficiency and ultimately define a more robust timeline.
“On that basis, I am confident that we will overcome the current challenges. But in a project of this scale, there will always be new challenges. The key is to address them as they arise and solve them in a structured and collaborative way.”
What will be the new way of working with contractors mentioned by Hemmingsen? Taylor answers: “We are entering a new phase where close collaboration with contractors becomes even more important. The aim is to move towards a more integrated way of working, where challenges are identified early and solved together, rather than being escalated later. This requires proactive and collaborative problem solving, supported by a transparent communication culture across all partners.
“I’ve always found that projects move faster when there is a shared sense of ownership. One thing I tend to emphasise with teams is that we are all working towards the same outcome – the success of the project as a whole. That mindset is particularly important in a complex international environment like this.”
In relation to efficiency improvements, he says: “Efficiency in a project of this scale does not usually come from one big decision. It comes from improving many small things consistently.
“We are working on strengthening coordination between teams and contractors, improving planning discipline, and making sure decisions are taken at the right time.
“On previous projects, I’ve seen that even relatively simple changes – like improving how information flows between teams or how regularly interfaces are reviewed – can make a significant difference over time. That’s very much the approach we are taking here.”
Another key to project success that he has identified in his career is adaptability. “No project of this scale runs exactly as planned. The ability to respond quickly – without losing direction – is critical.”
Asked what he would like the legacy of the project to be, Taylor answers: “The obvious legacy is the tunnel itself – a major piece of infrastructure that will connect Scandinavia and Central Europe and remove a longstanding bottleneck.
“But I think there is also a more human aspect to it. Projects like this bring people together from many countries and disciplines, often working together over many years. That creates a shared experience that goes beyond the physical structure.
“And on a personal level, this project is quite special to me. I was born in Berlin, and I am married to a Dane. So, in a way, this tunnel connects two parts of my own story as well.”
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Facts Only
* The first of 89 elements for the Fehmarnbelt tunnel was successfully immersed in May.
* The tunnel will span 18km between Rødbyhavn (Lolland) and Puttgarden (Puttgarden).
* The hollow concrete structures measure 217m long and weigh more than 73,500t.
* The elements will be immersed up to 40m below the sea surface.
* The first element was transported on May 4th using five tugboats and the IVY vessel from Rødbyhavn.
* The immersion of the first element began around noon on May 6th.
* The element was placed in the tunnel trench approximately 14 hours after immersion, connected via hydraulic arms to the portal.
* Large quantities of gravel were placed along the sides of each immersed element for securing them.
* Project director Guy Taylor oversaw the operation.
* The client organization is Sund & Bælt.
* The original plan targeted full operation by 2029, which experienced delays due to approval procedures and vessel regulatory challenges.
Executive Summary
The immersion of the first concrete element for the Fehmarnbelt tunnel was successfully completed in May, marking a milestone in the project that began in 2020. This initial step involved transporting the element on May 4th and immersing it around noon on May 6th into the tunnel trench, followed by securing it with gravel. The operation required precise execution, involving five tugboats and an immersion vessel. Project director Guy Taylor described the process as highly complex, requiring careful coordination to position the element exactly in place, emphasizing that safety and precision dictated the pace.
The project is transitioning from predominantly on-site construction to large-scale marine operations. This shift has necessitated a change in working methods, requiring new skills in project management and increased collaboration with contractors like FLC [Femern Link Contractors]. The experience of project director Guy Taylor highlights the evolution of tunnel construction, noting the integration of data, modeling, and tools like BIM, which has allowed for the use of standardized 217m elements. There is an emphasis on establishing a reliable and repeatable immersion routine with contractors to improve efficiency and manage future challenges, focusing on coordinated problem-solving across all partners.
Full Take
The narrative describes a significant paradigm shift in heavy infrastructure development, moving from traditional on-site execution to large-scale marine construction, introducing new demands for project management that prioritize integrated collaboration over site-based judgment alone. The emphasis on standardized, series-produced tunnel elements signals a move toward industrialized methods in civil engineering, leveraging digital tools like BIM to achieve unprecedented precision and scale. The tension lies between the need for speed—implied by the focus on efficiency and streamlined routines—and the absolute necessity of safety and precision in an inherently complex, international setting.
The evolution described by Taylor reflects a maturation where tacit, on-site experience is now being systematically augmented by data modeling and rigorous quality control. This transition implies that future project success hinges not just on engineering capability but on establishing robust, predictable operational protocols across diverse international partners. The focus shifts from executing isolated tasks to achieving systemic coordination, suggesting that the greatest barrier to progress is often organizational friction rather than purely technical complexity.
The pattern suggests a historical trajectory where large projects are initially constrained by procedural inertia (approvals, vessel certification) before technological and collaborative advancements allow for streamlined execution. The subsequent challenge—establishing a reliable routine with contractors—reinforces the idea that technical mastery must be coupled with mastering the interface dynamics between different operational modes. This raises questions about whether the pursuit of efficiency in such large-scale endeavors necessarily risks overlooking the human element or the necessary time for adaptive, distributed problem-solving. What is the true cost of deferring deep collaboration until the critical path requires it?
Sentinel — Human
The text reads as a journalistic report blending specific engineering milestones with expert commentary on project management and innovation, displaying strong indicators of human authorship.