Azimuth Stern Drive (ASD) tugboat operated from one of the four Multi-Purpose Simulators .
November 2025, no. 145
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Push tow connected to the tunnel elements on the Large Motion Simulator.
Example of a researched trajectory, clearly showing the influence of the cross-current through the Pas van Borssele.
Departure from the construction dock in Zeebrugge.
Covering the full route from Zeebrugge to the immersion site near Oosterweel, the simulations included mooring and repositioning manoeuvres at that location. The actual immersion was not part of the simulations. During transport, the tunnel elements float with a freeboard of just 20 to 40 centimetres—making them vulnerable to waves, especially in the open sea area between Zeebrugge and Terneuzen in the Netherlands. Due to their shape, the tunnel elements were not easily manoeuvrable which made it essential to define the limiting metocean (meteorological and oceanographic) conditions for safe transport
The immersed tunnel stretches 1,280 metres and is composed of eight massive tunnel elements, each measuring 159 x 41 x 10 metres. The tunnel will accommodate six car lanes (three in each direction) and have a dedicated bicycle path, significantly improving mobility near Antwerp.
All the tunnel elements were constructed in Zeebrugge but had to be transported to Antwerp via a demanding 60-nautical-mile maritime route. To ensure safe and precise execution, the project consortium ‘Temporary Partnership Combination Oosterweel Tunnel’ (TM COTU), in collaboration with Lantis, asked MARIN to perform these complex transport simulations.
Real-time simulations ensure safe transport of Oosterweel Tunnel elements
Following years of preparation and planning, one of Belgium’s most ambitious infrastructure projects—the completion of the Antwerp ring road—is making solid progress. At the heart of this development lies the Oosterweel Tunnel, a new connection across the River Scheldt. MARIN was commissioned to conduct advanced, real-time transport simulations.
Turning towards the Deurganckdok (waiting location near the immersion site with space for 4 tunnel elements).
Departure from the Kallo Lock towards the immersion site with the so-called catamaran pontoons attached for the immersion operation. The catamarans are named 'Asterix' and 'Obelix' following a naming contest held in Belgium.
These findings were validated during actual transports, where crews responded calmly and effectively to unexpected challenges, thanks to the scenarios practiced during training. As the project progresses and multiple tunnel elements have already been successfully delivered, the simulations continue to guide operations. They have become a cornerstone of the project’s safety strategy, transforming uncertainty into preparedness and enabling one of Belgium’s most ambitious infrastructure projects to move forward with confidence.
For anyone wanting to follow the complete operation, please check the website from Lantis.
Safety and preparedness
The real-time simulations conducted by MARIN confirmed that the transport of the Oosterweel Tunnel elements could be conducted safely, provided that metocean limits, speed, and turning rates were respected. Even in emergency scenarios, the towing setup proved robust, and the tunnel elements remained controllable.
The simulations served two key purposes - technical feasibility and operational training. They assessed whether the tunnel elements could be safely transported under specific metocean conditions using the chosen towing configuration. Additionally, they provided a direct opportunity for training all the involved parties— the Dutch and Belgian pilots and the experienced Tow and Tug Masters from Multraship—to ensure smooth coordination during the actual transport.
Five interconnected simulators
The setup consisted of five interconnected simulators working simultaneously to simulate the entire transport operation in real time. In a period of one year, three extensive simulation sessions were conducted to study the entire trajectory, towing configuration and operational limitations.
For the towing simulations, four Azimuth Stern Drive (ASD) tugboats (65-tonne bollard pull each) were connected via towlines and operated from four Multi-Purpose Simulators in the Seven Oceans Simulator centre (SOSc). One conventional push boat (30-tonne bollard pull) was directly attached to a push frame on the tunnel element and operated from the Large Motion Simulator (static mode).
November 2025, no. 145
Push tow connected to the tunnel elements on the Large Motion Simulator.
These findings were validated during actual transports, where crews responded calmly and effectively to unexpected challenges, thanks to the scenarios practiced during training. As the project progresses and multiple tunnel elements have already been successfully delivered, the simulations continue to guide operations. They have become a cornerstone of the project’s safety strategy, transforming uncertainty into preparedness and enabling one of Belgium’s most ambitious infrastructure projects to move forward with confidence.
For anyone wanting to follow the complete operation, please check the website from Lantis.
Example of a researched trajectory, clearly showing the influence of the cross-current through the Pas van Borssele.
Safety and preparedness
The real-time simulations conducted by MARIN confirmed that the transport of the Oosterweel Tunnel elements could be conducted safely, provided that metocean limits, speed, and turning rates were respected. Even in emergency scenarios, the towing setup proved robust, and the tunnel elements remained controllable.
Turning towards the Deurganckdok (waiting location near the immersion site with space for 4 tunnel elements).
Departure from the construction dock in Zeebrugge.
Covering the full route from Zeebrugge to the immersion site near Oosterweel, the simulations included mooring and repositioning manoeuvres at that location. The actual immersion was not part of the simulations. During transport, the tunnel elements float with a freeboard of just 20 to 40 centimetres—making them vulnerable to waves, especially in the open sea area between Zeebrugge and Terneuzen in the Netherlands. Due to their shape, the tunnel elements were not easily manoeuvrable which made it essential to define the limiting metocean (meteorological and oceanographic) conditions for safe transport
Departure from the Kallo Lock towards the immersion site with the so-called catamaran pontoons attached for the immersion operation. The catamarans are named 'Asterix' and 'Obelix' following a naming contest held in Belgium.
The simulations served two key purposes - technical feasibility and operational training. They assessed whether the tunnel elements could be safely transported under specific metocean conditions using the chosen towing configuration. Additionally, they provided a direct opportunity for training all the involved parties— the Dutch and Belgian pilots and the experienced Tow and Tug Masters from Multraship—to ensure smooth coordination during the actual transport.
Gerwin Boomaars
Project Manager
Five interconnected simulators
The setup consisted of five interconnected simulators working simultaneously to simulate the entire transport operation in real time. In a period of one year, three extensive simulation sessions were conducted to study the entire trajectory, towing configuration and operational limitations.
For the towing simulations, four Azimuth Stern Drive (ASD) tugboats (65-tonne bollard pull each) were connected via towlines and operated from four Multi-Purpose Simulators in the Seven Oceans Simulator centre (SOSc). One conventional push boat (30-tonne bollard pull) was directly attached to a push frame on the tunnel element and operated from the Large Motion Simulator (static mode).
The immersed tunnel stretches 1,280 metres and is composed of eight massive tunnel elements, each measuring 159 x 41 x 10 metres. The tunnel will accommodate six car lanes (three in each direction) and have a dedicated bicycle path, significantly improving mobility near Antwerp.
All the tunnel elements were constructed in Zeebrugge but had to be transported to Antwerp via a demanding 60-nautical-mile maritime route. To ensure safe and precise execution, the project consortium ‘Temporary Partnership Combination Oosterweel Tunnel’ (TM COTU), in collaboration with Lantis, asked MARIN to perform these complex transport simulations.
Following years of preparation and planning, one of Belgium’s most ambitious infrastructure projects—the completion of the Antwerp ring road—is making solid progress. At the heart of this development lies the Oosterweel Tunnel, a new connection across the River Scheldt. MARIN was commissioned to conduct advanced, real-time transport simulations.
Real-time simulations ensure safe transport of Oosterweel Tunnel elements
Interested? Contact us to discuss your options
Report
Create a MARIN account to stay updated
