Antwerp (Brussels Morning Newspaper) – The Scheldt Tunnel project faced a setback when a 5,000 m³ sandbank blocked the sinking of the 4th section. Lantis expects about a one-month delay; full Oosterweel connection completion remains set for 2030.
As VRT News reported, work on the Antwerp Scheldt Tunnel is facing a major delay after the sinking of the 4th section failed. A sandbank of approximately 5,000 m³, equivalent to around 200 truckloads of sand, was discovered at the exact location where the tunnel piece had to be lowered.
The first 3 immersions had been completed without problems. Each part of the process takes months of planning, and engineers had even built a model of the Scheldt in a test basin in the United Kingdom to rehearse the operation.
“The Scheldt’s bottom is made up of sand waves that can reach heights of up to 3 meters,”
explains Meire.
“These waves move back and forth under the influence of the current. During a single tide, the crest of such a sand wave can easily shift several meters.”
What caused the delay in the Antwerp Scheldt Tunnel 4th section project?
Experts explain that the riverbed of the Scheldt is constantly changing, making the outcome difficult to predict and control. Sediment and sand shift with the tides and currents, and no amount of data or simulation can give perfect predictions.
Patrick Meire says such surprises are part of working with a natural river system. Lantis spokesperson Laure Stuck admits the failure is a bitter disappointment, but also proof that even the best preparation cannot remove all risks in a project of this size.
“A sandbank suddenly appeared overnight, comparable to 200 truckloads of sand.”
Laure Stuck van Lantis
Patrick Meire says the appearance of a sandbank of 5,000 cubic meters during the sinking of the tunnel part is not surprising. He explains that placing such a large structure in the Scheldt is already a demanding task.
Meire warns that no technology can predict every shift of sand and water.
“It is a huge operation,”
he says.
“The bottom changes constantly, the current is strong, and nature still decides more than humans.”
“After that initial disappointment, it’s now all hands on deck,”
she says.
“Not only in analysing what went wrong, but also in how we can solve this problem. We’re still considering whether to move the tunnel section underwater or remove it first,”
says Laure Stuyck of Lantis.
At Lantis, the company behind the Oosterweel project, the failed attempt is being reviewed step by step. Engineers are studying the situation to find out why the sandbank built up at that spot. Spokesperson Laure Stuck confirms that the tunnel part will remain underwater for 2 more weeks until the next neap tide, when the current is weaker and conditions improve. The setback will delay the schedule by about 1 month, but the project continues.
Plans for the Oosterweel connection date back to the 1990s, when Antwerp’s traffic jams and incomplete ring road were already seen as a major economic problem. The first proposals sparked decades of debate, legal challenges, and citizen protests, especially over environmental concerns and the impact on local neighbourhoods.
After years of political deadlock, a breakthrough was reached in 2017 through the “Oosterweel deal,” an agreement between the Flemish government, the city of Antwerp, and action groups. Construction of the Scheldt Tunnel, the most technically challenging part of the project, officially began in 2021, with the first tunnel sections successfully immersed in 2024. The full connection is expected to be completed by 2030.
