Crane ship hoists mega piers for Zoutdam IJmuiden

Crane ship Gulliver successfully placed two pillars (27.5 x 8m.) weighing 3000 tons in their position in the Binnensluiskanaal near Zeesluis IJmuiden this Easter weekend. The job forms an important part in the construction of salt dam that Van Hattum & Blankevoort is currently realizing on behalf of Rijkswaterstaat. The lifting work took about 30 hours. The work was brought forward a few days because of worsening weather conditions later this week.

construction salt dam ijmuiden

The Belgian company Scaldis, familiar with projects of this magnitude, was called in to install the piers. The Gulliver is of outer category. The colossus measures 108 x 48 meters, has two cranes, each 90 meters high, and hoists a maximum of 4,000 tons. Several hundred people were involved in lowering the concrete behemoths this weekend.

Filling with sand
During lifting, the pillars were still hollow and in this way not too heavy to lift. Now that they are in place, they are filled with sand. The next milestone will be next summer, when the walls will be installed. Then, in the fall, the pocket door will be installed in the structure. This door is necessary for ships to pass through for maintenance of the pumping station. According to schedule, the salt dam will be put into operation by the end of 2024.

Salinization

The salt dam is a construction to selectively drain saltwater into the North Sea, which Rijkswaterstaat uses to prevent further salinization of the North Sea Canal through the use of the IJmuiden Sea Lock. This is because much more saltwater flows into the North Sea Canal through IJmuiden Sea Lock than through the North Sea Lock. Too much saltwater has negative effects on nature, agriculture, horticulture and our drinking water.

The salt dam is a kind of mailbox to drain the salt water again. Because salt water is heavier than fresh water, the salt water sinks to the bottom. Through an opening at the bottom of the salt dam, the salt water flows back to the sea through the Spui and Pumping Station complex. The fresh water is stopped by the salt dam and remains in the North Sea Canal.

Building Year

The construction of Salt Dam IJmuiden started over a year ago. The different parts, such as the pillars and the walls of the salt dam are pre-built on land. About 1,000 m3 of concrete per pillar was used for the piers. The piers are built in eight steps of 3.25 meters on a base of 1.5 meters high.

While pouring the concrete, anchors were also placed. The anchors, along with the lifting frames attached to the anchors, were needed to lift the piers and place them in their final location.