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Word of the Day: zandmotor (sand engine)

No, a ZANDMOTOR is not a modern ZEILWAGEN (sail wagon) or a motorbike designed for beach races along the Dutch coast. The sand engine is a bold and ingenious experiment to improve the protection of the fragile Dutch coastline. It is the first of its kind in the whole wide world! Between March and October 2011 a sandbar-shaped peninsula was created by pump dredgers. This new kind of coastal defence in areas where natural beaches and dunes are relatively narrow goes by the name of ‘replenishment’ or ‘sand nourishment’. 

zandmotor

 
The new peninsula, which cost 70 million euros, is situated in South Holland between Monster/Ter Heijde and Kijkduin. It has a surface of about one km² and a volume of 21 million cubic meters of sand, and is bigger than 256 football fields. The Hoogheemraadschap van Delfland (the district water control board), responsible for this region’s coastal management, expects that the waves, wind and currents move this sand along the coast over the next ten years.

The ZANDMOTOR is a ‘kunstwerk’ a fine work of art. You could see it even as a new form of Land Art. The Dutch word ‘kunstwerk’ has two meanings: it can either refer to a ‘work of art’ or to an ‘engineering structure’. In the first case it is artistic and in the second case it is artificial. Sometimes we’re lucky to find an example which is a combination of these two meanings.

The Sand Engine is such an ambiguous example. This work of art and artifice will spread slowly along the Westland coast towards Scheveningen during the next ten years, while reinforcing the coastline at the same time.

The Scheveningen Boulevard (with its built-in dike) and the artificial peninsula ZANDMOTOR are two recent state-of-the-art construction works. They herald a new era of coastal zone management. In the past the obvious solution for the protection of a fragile coast would be a DIJK, but dikes can be troublemakers. Just look at the Hondsbossche seawall which was built between Camperduin and Petten in North Holland. As you can clearly see the concrete dike sticks out into the sea while the ‘dikeless’ part of the coast keeps on eroding.

The engineer who came up with the idea for this new type of coastal zone management is Ronald Waterman (member of Zuid-Holland Provincial Council from 1978 to 2011). He called it ‘Building with nature’ in the eighties when he presented it for the first time. The basis of his plan was to restore the coastline from Hook of Holland right up to Wassenaar as it was in 1611. The coastline of 1611 was straighter, and was several kilometres further out to sea. The fishing village of Ter Heijde disappeared in the sea three times as the coastline receded. Dozens of groynes were built to stop the erosion, but they eventually had the opposite effect, as strong currents developed around the moles that caused the loss of even more sand between them. Waterman calls this kind of engineering ‘building against nature’.

Restoration is about enlarging the dunes and beach. The water managers began with the Van Dixhoorn triangle at Hook of Holland. Then they set about reclaiming the land that was to become known as the Maasvlakte. The entire Delfland coast was then to be extended, covering all the groynes with dunes and beach. After this 35 hectares of dune habitat was created along the coast at ’s-Gravenzande to compensate for the creation of the Second Maasvlakte. And in 2011 the Sand Engine was completed. It has taught the Dutch a great deal about how they can work with nature and it can profile the Netherlands as a pioneer of integrated coast and water management.

Now what about the word ZANDMOTOR. It is a name that must have been invented by an engineer, because, as you object, the name may be completely wrong. The engineer who invented it, is professor Marcel Stive of Delft University. He is considered the father of the ZANDMOTOR project.

Okay let’s look at the word MOTOR. A MOTOR is a machine which converts energy into movement. It stems from Latin ‘motor’ (literally ‘mover’). At first it was an ‘agent or force that produces mechanical motion’ in English and in the nineteenth century it became a ‘machine that supplies motive power’.

An electric motor converts electricity into movement. But does a ‘sand motor’ convert sand into movement? No. The energy needed is provided by wind, waves and the currents. This is the energy that moves the sand to those places where the coast needs to be replenished. I am confused. ZANDMOTOR, it sounds great and creative but… Maybe we have to go back to the original meaning and consider the ZANDMOTOR an ‘agent that causes the sand to be moved mechanically’.

Source photo: https://beeldbank.rws.nl/, Rijkswaterstaat

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