Four enormous cables, 2,500 trucks of sand and a ‘socket’: the energy transition comes ashore at Wijk aan Zee

Imperturbably, the bubbling seawater rolls over the place where three taps should have been. But where the beach should have given the machines solid ground under the wheels, the water is now churning, pushed up by a sharp northwesterly and high tide.

A little further on, builders shrug their shoulders at the situation from their shed. The fact that the water is so high is a disappointment, sure, but it will fall again. If not this afternoon, then tonight or tomorrow morning. You can still make such beautiful calculations, they know, in the end Mother Nature decides.

Mother nature decides on Friday that the water will not sink. So they are there again on Saturday morning, the men with their cranes. It won’t be the last free morning they have to sacrifice for this project. But in the afternoon the time has finally come.

Sea, wind and huge machines to get electricity ashore

This project is one in the Dutch Glory category. Of sea and wind and huge machines. Here on the coast near Wijk aan Zee, energy will come ashore next year, generated by two new offshore wind farms. To get the electricity ashore, four huge cables are needed. They have to be drilled under the dunes to reach the high-voltage grid via a new transformer station a few kilometers away, after which the electricity continues to flow towards homes and factories.

To make this possible, the huge machines are now pulling the last of four so-called casing pipes through the dunes; a tube hundreds of meters long through which a power cable will soon run. The kilometer of pipe, which was rolled out over the beach like a huge garden hose on Friday, must be pulled under the dunes in one go. Site manager Folkert van Eijk: ‘Once we get started, it has to go through.’ The dunes will consume the tube at 150 meters per hour, until after six hours of pushing and pulling, it beeps out at the back.

Drilling over this distance is normally a routine job for driller Cor Versluys and his colleagues from contractor NRG. What makes this challenging is the difference in height between the end of the dunes, at the Meeuweweg, and the beach. Because the beach is lower, the liquid needed to lubricate the drill and support the tunnel that was dug could run off on the beach side, Versluys explains.

To prevent this, the height difference had to be eliminated. This was done with a mountain of sand of 50 thousand cubic meters, the same as 2,500 dump trucks, walled by steel plating. The ‘sand banquet’ towers six meters above the beach.

Its construction seems simpler than it is: sand in abundance on the beach, you might think. But that turned out not to be the case: the beach and the dunes are part of the primary flood defense system and just removing something from somewhere can disrupt the balance.

It was resident and pavilion owner Jeroen van Son who came up with a bright idea: in front of his beach tent is a hefty heap of sand (‘a million cubic meters’, he says), deposited there by the wind that revolves around the pier of IJmuiden. 50 thousand cubic meters can easily be removed from that, he thought. After a study by Deltares showed that it was possible, Rijkswaterstaat and the Water Board agreed.

Three of the four pipes were pulled last week, the fourth was successfully laid on Saturday. Soon the sand hump will be dismantled and the sand will be moved. The bathers will be able to return next spring, although part of the site will remain closed off for the time being, until the cables have been laid and completely buried.

The German bather with pit ambitions does not have to fear that he will encounter one of the cables. They will soon be six meters deep, says site manager Van Eijk.