Sea Lock Ijmuiden in Port of Amsterdam

Artist impression of new sea lock Amsterdam center

Sources: adapted from Port of Amsterdam website and Gordijn, R. (2017), Amsterdam port: building the largest sea-lock, Port Technology International, issue 75, p. 36-38.

The building consortium OpenIj constructed the largest sea lock in the world (in lock chamber dimensions) at the mouth of the 27-kilometer-long North Sea Canal (Noordzeekanaal) that links Amsterdam and its port with the sea. The new Sea Lock Ijmuiden measures 500m long, 70m wide, and 18m deep. In comparison, Antwerp’s new Kieldrechtlock measures 500m to 68m while the new Panama Canal locks measure 427m to 55m. The lock gates in Amsterdam reach almost 8m above the current water level to provide defense against rising sea levels while also strengthening flood control in the Netherlands.

Construction of the sea lock began in January 2016 with commercial operations starting in January 2022 after a short testing period. On 26 November 2021, the tanker Petrel Pacific was the first vessel to pass through the lock. The construction process was quite challenging given its proximity to existing locks which needed to stay operational throughout the construction period, and because of the complicated soil profile due to its history with liquefactions and major breaches. Total construction cost amounted to 850 million euro.

The construction process consisted of the following steps:

  • Shifting of the fairway
  • Placement of sheet piles in the former fairway.
  • Transport of dredged sand back to the lock complex to create a building site and a quay for construction equipment and materials.
  • The diaphragm wall method is used for the construction of the chamber walls instead of using more traditional steel combi-wall or sheet pile walls. The diaphragm walls are constructed in a
    trench. The first step is the construction of guide walls just inside the topsoil. During excavation, a bentonite slurry is pumped into the trench to maintain the stability of the trench while excavating
    about 40 meters deep. Once the bottom of the panel is reached, the reinforcement cage can be lowered into position. After positioning the reinforcement cage, the bentonite slurry is replaced by concrete by using vertical pipes.
  • Construction of the concrete structures holding the gate chambers using the pneumatic caisson method. The new lock uses rolling steel gates that are parked in a gate chamber when the gate is in the open position. The upper lock head (seaside) has one gate chamber, the lower lock head (landside) has two chambers.
  • The lock gates, which were built in South Korea, are fitted in the gate chambers
  • Removal of the soil at the entrance canals
  • Lock open for operation.