The Netherlands: Building the Hard Seawall at Maasvlakte 2

Protect the newly sprayed-on land against the winter storms. That’s the Blockbuster. After the stormy season, the enormous crane will continue blocks in the new Maasvlakte sea defence.

To protect the land from the sea, Maasvlakte 2 will have a hard seawall that stretches over a length of 3.5 km along its northern edge. The hard seawall consists of a stony dune and a block dam. The stony dune is a sand dune with a top layer of fist-sized cobbles, similar to the natural cobble beaches found in France and England, which have proven to be extremely safe.

In front of this construction, there will be a dam of large concrete blocks in the sea that will serve as a breakwater. Around 17,000 concrete blocks from the Maasvlakte’s existing block dam will be recycled for this new dam. This both reduces waste and limits the amount of new material required for the dam.

Temporary protection from the storm

The foundation for the hard seawall is already in place. Not only has the sand bank been rainbowed on; a large number of cobbles have already been spread across the stony dune too. However, some terrible storms can blow in the autumn and winter, meaning that temporary measures are required to protect the cobbles. This has become the first big job for the Blockbuster, the enormous crane that was especially designed to place the largest rocks and concrete blocks in the Maasvlakte 2 seawall. By now, the crane is in position on the edge of the sea, along the outer rim of the new land.

It has started to apply temporary protection to the stony beach in preparation for the coming stormy season. The protection consists of heavy riprap and the same 40 ton concrete blocks that will soon be positioned with far more precision in the final version of the hard seawall. Once the temporary protection of the new land is in place, the Blockbuster can get cracking on the actual construction of the hard seawall.

Source: mv2, December 1, 2010