Milestone Achieved: Four Tunnel Elements Successfully Immersed

This week, TM COTU and IMMONTEC reached an important milestone in the construction of the Scheldt Tunnel: the fourth tunnel element, weighing 60,000 tonnes, was successfully immersed and accurately positioned on the riverbed of the Scheldt. With this, the tunnel immersion operation is now halfway complete.

Work began in July 2025 with the first immersion operation. Four tunnel elements, each weighing 60,000 tonnes, are now in their final positions on the riverbed. The focus has shifted to immersing the remaining four elements to bring the tunnel project closer to completion.

Sequence of Remaining Tunnel Elements

The remaining elements will be immersed in the following order: 5, 6, 8, and finally 7. The last element is intentionally placed last for technical reasons: element 8 connects directly to the fixed tunnel section on the Right Bank. If element 7 were placed first, there would not be enough depth to position element 8 correctly. By placing element 7 between 6 and 8, the tunnel section can be aligned within the permitted tolerance of 35 mm, allowing the closure joint formwork for the final element to be installed precisely.

Planning

If all goes according to plan, the final immersion operation will take place at the end of 2025, marking an impressive achievement in maritime engineering and precision work.

This milestone once again highlights the craftsmanship, teamwork, and technical expertise required to deliver one of the region’s largest infrastructure projects.

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