WWII explosives found and removed on Hollandse Kust (west Beta) cable route

Five World War II anti-tank mines were detonated in a controlled manner today by the Explosives Clearing Service Defence (EODD) in the dunes near Velsen. These explosives were found while removing some ‘obstacles’ from the beach at Velsen, on the route for two TenneT marine cables. The grid operator will use these cables to bring sustainable electricity from the Hollandse Kust wind farm (west Beta) ashore from 2026.

To ensure the safe laying of the sea cables, various obstacles have been removed from Velsen beach over the past three weeks. Excavators and so-called excavation boxes were used to dig wells measuring five by five metres to a depth of about seven metres in the beach. A total of seven ‘targets’ were involved. These were previously located with the use of a drone and radar technology during the investigation of unexploded ordnance from WWII.


Right from the first ‘obstacle’, Marvin Asveld revealed, it was a hit. As an explosives expert, he was closely involved in the investigation and excavations. “In the first pit, we found five anti-tank mines at a depth of about six metres. There were also parts of concrete barriers that the Germans placed in the low-water line to stop landing craft. These ‘tetrahedrons’ consist of six concrete beams forming a pyramid.”

Under the sand

Besides sharp points (so-called hull cutters), grenades and mines could also be attached to the barricades. Asveld: “Presumably they removed these mines from the tetrahedrons after the war and made them disappear together under the sand in one place. Many of these barricades were cleared after the war, but many were left behind. At the remaining targets, we found only the concrete posts, with no mines. All those obstacles we removed.”

Suspicious layer

The discovery of the remains from the famous Atlantic Wall was not entirely unexpected for the researchers. Similar finds were also made during previous research on the neighbouring Wijk aan Zee/Heemskerk beach. Asveld: “In Velsen, the suspected layer was much deeper because the dunes were subsequently raised, so the beach level is also two to three metres higher than in 1945.”

Laying free manually

At a depth of five-and-a-half to six metres, you are also below groundwater level on the beach. Asveld: “Once an object has been excavated to within half a metre, a diver then uses detection equipment to determine its exact location. The object is then manually exposed without stirring it. If it is an unexploded explosive device, we immediately inform the EODD. In consultation with the service, the explosives found were temporarily secured during the work. Today, the handover took place after which the service detonated the mines in a safe place in the dunes in a controlled manner.

Tangible reminder

With the excavation of the tetrahedrons, another tangible part of the local war past has come to light. What will happen to these remains is not yet known. Earlier finds from the survey for the Hollandse Kust (north) and (west Alpha) wind farms were retrieved and restored by volunteers from Rondje Wijk aan Zee. Those two tetrahedrons are now on display again in the dune area as a reminder of the wartime history of the coastal village. Source: TenneT Image: Jorrit ‘t Hoen

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