Maeslantkering
As part of the Delta Works the barrier responds to water level predictions calculated by a centralized computer system called BOS.
When closed, the barrier will protect the entire width (360 metres) of the Nieuwe Waterweg, the main waterway of Port of Rotterdam.
It is one of the largest moving structures on Earth, rivalling the Green Bank Telescope in the United States and the Bagger 288 excavator in Germany.
The construction of the Maeslantkering was a part of the Europoortkering project which, in turn, was the final stage of the Delta Works.
The main objective of this Europoortkering-project was to improve the safety against flooding of the Rotterdam harbour, of which the Europoort is an important part, and the surrounding towns and agricultural areas.
It would also mean that historic town centres, in some cases over four centuries old, would have to be broken down and rebuilt behind renewed, larger dikes.
During the closing or opening process, this ball-shaped joint gives the gate the opportunity to move freely under the influences of water, wind, and waves.
Under normal weather conditions, the two doors themselves are well protected in their dry docks and a 360-metre wide gap in the waterway gives ships enough space to pass without any inconvenience.
But when a storm surge of 3 metres above normal sea level is anticipated in Rotterdam, the barrier will be closed automatically.
The bottom has been elaborately dug and then laid with layers of broken stone, so that the gates are able to form a relatively watertight fit when submerged.
The Caland canal [nl], located just south of the Nieuwe Waterweg and the Scheuer, visible in some images on this page, is protected by the much smaller Hartelkering storm surge barrier.
In order to test the barrier in actual stormy conditions, the water level threshold at which the computer system would start the closing procedure was lowered from 3.0 m over NAP to 2.6 m, for the duration of the 2007 storm season.
[7] As the Oosterscheldekering and Hartelkering storm surge barriers were also closed, the entire Dutch coast was protected against flooding for the first time since 1976.
At 22:00 local time (CET), Dutch TV brought the news that maritime traffic on the Nieuwe Waterweg was shut off.
There were discussions to close the Maeslantkering manually before that time, and the Port of Rotterdam started reducing traffic at 16:00.
[8] At the site of the Maeslantkering, there is a visitor center where more background information on water management and the technical details of the barrier itself can be found.
