Invesis logo arc

IJmuiden sea lock officially in use

Source: Rijkswaterstaat

English translation of Dutch joint press release of Rijkswaterstaat, province of Noord-Holland, municipality of Amsterdam, Port of Amsterdam and municipality of Velsen.
Link to press release: Koning opent Zeesluis IJmuiden | Rijkswaterstaat

His Majesty the King officially inaugurated the Zeesluis IJmuiden on Wednesday 26 January 2022. With the push of a button, King Willem Alexander opened the inner door of the largest sea lock in the world from the Sluis Operation Centre (SOC). With this, the King officially gave the first ship, Bontrup  Amsterdam, access to the North Sea Canal. There the ship was welcomed by a fleet of ships, which are representative of the nautical service providers and public parties in the port, such as the Loodswezen, Svitzer, Politie, Coast guard, Royal Marechaussee, Douane, KNRM, De Koperen Ploeg and the Corps van de Vletterlieden.

Thanks to the new sea lock, the North Sea Canal area, the Port of Amsterdam and the European hinterland connections will remain easily accessible for the next one hundred years. The investment in Zeesluis IJmuiden represents a significant improvement for accessibility on the main waterway network.

The improved accessibility of the North Sea Canal area via the sea lock contributes to important changes in the ports, such as energy transition and the transition to a circular economy. With the opening of the sea lock, these can continue to develop and grow, thus contributing to the necessary sustainability of the economy and society.

Tidal-independent fences

The new larger sea lock replaces the Noordersluis built in 1929, almost one hundred years ago. Zeesluis IJmuiden is 500 meters long, 70 meters wide and 18m deep, making it the largest sea lock in the world. The depth of 18 metres makes it possible for ships to use the sea lock independent of the sea tide, and to sail smoothly and safely to the Amsterdam Port Region. As a result, the ports are accessible 24/7 via the sea access in IJmuiden. Navigating through the new sea lock is easier to plan and is more efficient. This makes shipping operations more predictable and therefore the service more reliable.

Sea lock as a flood defense

The sea lock rises above the IJmuiden lock complex. The reason for this is that the sea lock is built at a water retaining height of 8.85 meters above sea level. This means that the lock is prepared for the rise in sea level and will continue to protect the land in the northwestern part of the Randstad in the future.

Selective extraction

The Selective Extraction measure is an important part of the IJmuiden Sea Lock project. By using the new sea lock, more saltwater flows into the North Sea Canal during the locking process than by using the Noordersluis. In order to protect nature, agriculture, horticulture and the drinking water supply against salinization, a solution has been found in the selective discharge of this salt water via the flushing lock complex IJmuiden.

Rijkswaterstaat is building a dam in the Binnenspuikanaal, north of the sea lock with an opening at the bottom. Because saltwater is heavier than freshwater, only the saltwater from the deep water layers is discharged to the sea through the opening, so that water quality in the North Sea Canal and the surrounding areas is maintained.

Construction of sea lock

The construction of Zeesluis IJmuiden started in July 2016 and was completed in August 2021. An intensive period of innovative building, where space was limited. During construction, shipping could continue to pass through the lock complex via the existing locks. To prevent obstruction on the road, all materials and equipment was transported on water. Due to the limited space and the adjacent locks, the construction activities were mainly vibration free. Everything about the lock is huge. For example, the two operational lock gates and the spare lock gate weigh 3,000 tons each. They are the size of an apartment building, 72 meters in length, 11 meters wide and 24 meters high. For the construction of the lock, 300,000 cubic meters of concrete were used for, among other things, the walls, the floor and the gate recesses. The concrete was manufactured by a concrete plant on the construction site. A total of 4.5 million cubic metres of soil has also been excavated.

Testing and practice

After construction was completed, a period of practice and testing of the lock commenced in autumn. Rijkswaterstaat, together with the operators of the Centraal Nautisch Beheer, the towing services, the vletterlieden (who moor ships in the lock), the pilotage and the emergency services, tested the sea lock. An important part of testing the lock was to experience the currents in the lock chamber and the force on the hawsers as a result of the exchange of fresh and salt water.

Looking back at opening action

In light of the pandemic and the measures in place, the official opening was attended by a small gathering. This took place in the Sluis Operation Centre in the presence of parties directly involved. After the official opening, His Majesty the King spoke with, among others, the builders of contractor consortium OpenIJ and residents from the area. The King also spoke with operators of the lock and representatives of the port industry. In order to involve everyone as much as possible in the opening, the ceremony could be watched via an online stream on In the coming period, those interested can watch the opening ceremony by using the same link.


The Zeesluis IJmuiden project is a partnership between the covenant parties Ministry of Infrastructure and Water Management, the province of Noord-Holland, the municipality of Amsterdam together with Port of Amsterdam and the municipality of Velsen. Commissioned by Rijkswaterstaat, contractor consortium OpenIJ (BAM-PGGM and VolkerWessels) built the sea lock. OpenIJ will also be responsible for maintenance for the next 26 years. The project is co-financed by the CEF-fund (Connecting Europe Facility) of the European Union.

Invesis pink arc