The IJmuiden sea lock is located at the mouth of the North Sea Canal overlooking the island of Fort. It is 500 meters long, 70 meters wide and 18 meters deep. This makes IJmuiden the largest sea lock in the world. The lock will be put into operation for shipping in 2022.
There are several locks in the lock complex. The Zuidersluis for pleasure boats, the Middensluis and the Noordersluis. To date, the Noorder lock, built in 1929, was the largest. However, this was no longer sufficient for economic and technical reasons. What will happen to the Noordersluis after the new sea lock is built is still unknown.
There is also a spui and pumping station complex on the north side of the locks. Here the salt water is returned to the sea through selective suction. This is necessary so that the water in the hinterland does not become too salty. Every time a ship passes through the locks, salt water enters the canal. Too much salt water in the North Sea Canal has a negative impact on our drinking water, nature and agriculture. A kind of umbrella was built at the beginning of the Binnenspuikanaal. Salt water is heavier than fresh water. By leaving an opening at the bottom of the umbrella, most of the salt water disappears, leaving fresh water behind.