Antwerp (Brussels Morning Newspaper) – Lantis will refloat the 60,000-ton 4th Scheldt Tunnel section in Antwerp after its mid-August 2025 sinking, using cranes, pontoons, and catamarans, then store it at Doel Dock for the next immersion.
As VRT News reported, Lantis, the agency responsible, will now carry out a refloating operation of the 4th section of the Scheldt Tunnel in Antwerp to bring it back to the surface. The section is heavy and will be lifted using cranes, pontoons, and ballast systems.
Engineers will monitor the process closely to avoid further damage. The operation is expected to take around 48 hours. After reaching the surface, the tunnel section will be moved to the Doel Dock. It will remain there until conditions are right for the next immersion.
What challenges will Lantis face in refloating Antwerp’s 4th Scheldt tunnel?
According to officials, the next immersion can only take place during a neap tide. During these tides, the difference between high and low water is smaller. The weaker currents make it possible to place the tunnel section safely on the riverbed.
At other times, strong currents in the Scheldt make the operation too risky. While waiting at Doel Dock, engineers will prepare the section and plan the next attempt. They will check the riverbed, water depth, and proper alignment.
The tunnel segment weighs about 60,000 tons and is currently filled with ballast, mostly water, to keep it stable on the riverbed. Engineers from Lantis are slowly draining the water to reduce the weight and prepare the section for refloating. Once the ballast is removed, the segment will be disconnected from its temporary supports. Large cables attached to catamarans will lift the tunnel section.
“We have prepared everything well, but of course, it remains an exciting operation,”
Stuck concludes.
The Scheldt Tunnel is a major construction project in Antwerp to improve traffic under the river. Work on the tunnel started in 2022. The tunnel is built in large sections that are placed on the riverbed. The first sections were successfully immersed in early 2025. The fourth section, which sank during its first attempt in mid-August 2025, is now being prepared for refloating.
In Belgium, similar tunnel projects have taken place before. The Oosterweel Link in Antwerp began construction in 2017 and involved placing large tunnel sections underwater to connect the city’s ring road. Earlier, the Kennedy Tunnel in Antwerp, completed in 1969, was built to allow traffic under the Scheldt River, although it was constructed using traditional methods rather than fully immersed sections.
