VINCI's Fehmarnbelt Consortium Just Placed Tunnel Element 3 of 89. It Is Also Billing Denmark EUR 1.95bn for the Trench It Sits In

On 2 August, five tugboats towed a 217-metre concrete box weighing more than 73,500 tonnes about 500 metres off the coast of Lolland and lowered it onto the seabed. It was the third of 89 elements that will make up the Fehmarnbelt tunnel between Denmark and Germany. The first was immersed on 6 May, the second on 29 June. Three elements in 88 days. Eighty-six to go.

Femern A/S, the Danish state-owned client, described the operation as a demanding precision task and said its contractor gains useful experience with each immersion. Both statements are accurate. Neither addresses the arithmetic.

Three down, 86 to go: the run rate is the schedule

Take the observed cadence at face value and roughly one element goes in every 29 days. Hold that flat and the remaining 86 take just under seven years, putting the last one on the seabed around 2033. Nobody expects the rate to stay there. Immersion campaigns are seasonal, crews climb a learning curve, and Sund & Bælt has said it will publish a revised schedule once the first elements are in and it has seen how the standard and special elements behave in practice.

That is the honest position: the programme does not yet have a defensible completion date, and the next four immersions will produce one. For anyone underwriting the corridor, the metric to track from here is days between immersions, not tonnes placed. Femern already concedes that work on the Danish side is running about two years late because of problems with the specialised vessel used to sink the elements.

The EUR 1.95bn argument is about a hole in the seabed

Running alongside the marine campaign is a commercial dispute large enough to be a project in its own right. Femern Link Contractors, the joint venture led by VINCI Construction Grands Projets, has lodged a claim of DKK 14.5bn against Femern A/S — roughly EUR 1.95bn, or a quarter of the project's approximately EUR 7.4bn capital cost. A separate international arbitration over Covid-era delay is running at around DKK 570m.

The subject of the big claim is the trench. The 18-kilometre channel on the seabed was dredged between 2020 and 2024 by a different consortium, Fehmarn Belt Contractors, led by Royal Boskalis Westminster and Van Oord. Femern A/S accepted that work from the dredging contractor. FLC, which has to place 89 elements into it, has declined to take it over. Sund & Bælt has since paid extra to have the first 650 metres of trench prepared to FLC's satisfaction; the remaining seventeen-plus kilometres sit in negotiation.

Strip away the specifics and this is the oldest failure mode in split-package delivery. Two contracts, one physical boundary, and a client standing between them holding an interface it never priced. Whoever signs off package A's work owns the argument with package B. On a project where the boundary is a dredged trench under forty metres of water, that argument costs EUR 1.95bn to have.

Germany's clock runs on permits, not concrete

The Danish end is not the only constraint. In July 2025 Germany's federal transport ministry confirmed that the rail land facilities on the German side would not be operational in 2029 as planned, citing approval and permit procedures. The German plan approval also sets hard limits on underwater noise and on when and where marine work can take place in German waters, which removes most of the flexibility a delayed marine programme would normally use to claw time back.

On 17 May 2026 Sund & Bælt drew the obvious conclusion and split the opening in two. Road first, rail whenever the German land facilities are ready. Chief executive Mikkel Hemmingsen called the rail lag unfortunate for the green transition and for rail passengers, and framed the split as a way to get the asset earning sooner while simplifying the endgame.

What a phased opening buys, and what it costs

The commercial logic is sound. Fehmarnbelt is user-financed, so opening the four road lanes brings toll revenue forward against a debt stack that accrues interest either way. It also decouples two commissioning programmes that would otherwise have to succeed at the same moment.

The cost sits in the case that justified the tunnel. The EU has committed roughly EUR 1.3bn of Connecting Europe Facility money to the construction phase, and the rail link is the reason: a seven-minute crossing that halves the Hamburg to Copenhagen rail journey and closes the Scandinavian gap in the TEN-T network. A road-only Fehmarnbelt is a faster ferry. The corridor benefit arrives with the trains.

For contractors and sponsors elsewhere in Europe, the transferable lesson has nothing to do with immersed tunnels. It is that on any programme split into separately procured packages, the handover between them is a priced risk somebody has to carry, and the party holding it is rarely the party best placed to manage it. Rail Baltica, CPK, the German Generalsanierung and every Baltic grid build-out have the same seam running through them. Denmark is currently paying to find out what that seam is worth.