Antwerp – Lantis will undertake a major operation to refloat the 60,000-ton 4th section of the Scheldt Tunnel in Antwerp, which sank in mid-August 2025. Using cranes, pontoons, and catamarans, the agency is set to lift the tunnel section and transport it to Doel Dock for subsequent immersion, reports 24brussels.
The refloating operation, as reported by VRT News, involves a complex maneuver involving heavy equipment to raise the submerged section. Engineers will oversee the process meticulously to prevent further damage, with the operation estimated to last around 48 hours.
Once the tunnel section reaches the surface, it will be relocated to Doel Dock, where preparations will begin for its next immersion. This will be contingent upon favorable tidal conditions.
Challenges Ahead for Lantis in Refloating Antwerp’s 4th Scheldt Tunnel
Officials indicated that the next immersion can only occur during neap tides, characterized by smaller differences between high and low water levels. These calmer conditions are essential for safely positioning the tunnel section onto the riverbed.
During more turbulent periods, the strong currents of the Scheldt River significantly increase the risks associated with the operation. While the section awaits at Doel Dock, engineers will conduct thorough assessments of the riverbed, water depth, and alignment to ensure a smooth operation for the next attempt.
The 60,000-ton segment is currently filled with ballast, primarily water, to maintain its stability on the riverbed. To facilitate refloating, engineers from Lantis are in the process of gradually draining the water to reduce the weight. Following this, the section will be disconnected from its temporary supports, and large cables will be attached to catamarans for the lift.
“We have prepared everything well, but of course, it remains an exciting operation,”
Stuck stated.
The Scheldt Tunnel represents a significant infrastructure project in Antwerp aimed at enhancing traffic flow beneath the river. Construction began in 2022, and initial sections were immersed successfully in early 2025. The fourth section’s initial immersion attempt faltered in mid-August 2025, prompting the current refloating operation.
Historically, Belgium has seen similar tunnel projects, including the Oosterweel Link, which commenced in 2017 to connect the city’s ring road through submerged tunnel sections. The Kennedy Tunnel, completed in 1969, was another notable project, facilitating traffic under the Scheldt River through traditional methods rather than immersion.
