Oosterweel Link: Final tunnel Scheldt Tunnel element departs Zeebrugge dry dock
An exceptional journey with a tight deadline
Since May 2025, the eight tunnel sections have been transported one by one by tug boats via the North Sea and the Scheldt to Antwerp. Four of these have already been carefully immersed beneath the River Scheldt. But before these complex operations could take place, the elements first had to be constructed in a specially built dry dock in the port of Zeebrugge. Construction began in 2021.
The deadline had been set years in advance: the first tunnel element had to be immersed by the summer of 2025. “Negotiating the schedule was out of question,” says Dieter. “We had to be ready.” With a team of 200, he tackled the enormous challenge of building a tunnel 100 kilometres from its final destination.
 "The dry dock in July 2024")
Why Zeebrugge
“There simply wasn’t enough space in Antwerp,” Dieter explains. “We needed room to build a massive dock that could accommodate all eight tunnel segments. So we went to Zeebrugge.”
The figures are staggering: each segment is 160 metres long, 42 metres wide and 10 metres high. Weight per element? Around 60,000 tonnes! Yet, they are able to float, thanks to the Archimedes’ principle. "We added ballast tanks to each element and filled them with water, allowing the elements to settle at the bottom of the dry dock. When the water is removed, they float to the surface. It’s a simple application of physics."
Twenty metres of tunnel a week
Nature laws were under serious time pressure. “We had exactly three years,” Dieter recalls. “The date for the first element’s immersion was fixed from the outset. There was no room for any delays.”
Each week, the team had to build 20 metres of tunnel. “That’s 3,000 m³ of concrete and 700 tonnes of steel. Week in, week out. And it had to be sport on each time.”
What’s more, the Scheldt Tunnel makes a slight curve, which added to the complexity. “This bend had to be incorporated during construction of course. We had to factor it in for every element. A true technical feat,” Dieter adds.
Naturally, there were tough days too. “There were some tense moments,” Dieter admits. “But I try to keep that tension to myself. Not let it trickle down to the team. If I stay calm, they can stay focused.”
What kept him going? “The team. Their dedication, precision and pride. We also welcomed many visitors: schools, industry peers, people passionate about engineering. That was heartening. Hopefully we’ve inspired some young minds to pursue a career in construction.”
Looking ahead
The final tunnel element is arriving at the at the Doel dock on Monday 29 September 2025, where it will be prepared for its immersion beneath the River Scheldt. Meanwhile, TM COTU is gearing up to immerse the fifth element, which is scheduled for 15 October 2025*.
The story in Zeebrugge isn’t over just yet. The site is being readied for future use by Port of Antwerp-Bruges. These preparations include the removal of the sheet piles and relocation of the concrete plant.
Vital link in the Oosterweel project
The Scheldt Tunnel comprises two tubes for motorised traffic, an emergency passage and a six-metre-wide cycle path. This new tunnel provides an additional crossing beneath the Scheldt, which will complete the Antwerp Ring Road in the north. Cyclists will be able to use the tunnel from 2028, with motor traffic following in 2030. The entire Oosterweel Link is set for completion in 2033.
TM COTU stands for ‘Tijdelijke Maatschap Combinatie Oosterweeltunnel’ (Temporary Partnership Combination Oosterweel Tunnel). The consortium includes Belgian construction firms BESIX, Stadsbader Contractors, DEME and Jan De Nul.
*Schedule subject to change due to factors such as weather, wind, currents and tides.
Watch the interview with BESIX colleague Dieter Van Parys:
Travel through time with us as TM COTU realised the dry dock in Zeebruges and the eight Scheldt Tunnel elements:
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