The Maeslantkering is a storm surge barrier in the Nieuwe Waterweg which automatically closes when needed. It is part of the Delta Works and it is one of largest moving structures on Earth. The barrier consists of two large floating gates on both levees of the waterway. Construction of the storm surge barrier was carried out in dry docks. No vital parts of the barrier had to be placed under water. Standing upright, these arms would be as high as the Paris Eiffel Tower and each one weighs two times more than the Tower. The main purpose of the arms is transmitting the immense forces, exerted on the gates while closed, to one single joint at the rear of each gate. 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 keeping the stresses and loads low.
The Oosterscheldekering, between the islands Schouwen-Duiveland and Noord-Beveland, is the largest of the 13 ambitious Delta works series of dams, designed to protect the Netherlands from flooding. The construction of the Delta Works was in response to the catastrophic floods in 1953 in the South-Western part of Holland. The nine kilometre-long Oosterscheldekering consists of huge sluice-gate-type doors over four kilometres length. These doors are normally open, but can be closed under adverse weather conditions. In this way the saltwater marine life behind the dam is preserved and fishing can continue, while the land behind the dam is safe from the water. The Oosterscheldekering was the biggest, most difficult to build and most expensive part of the Delta works.
The storm surge barrier near Ramspol, designed and built by Royal BAM Group, was built to project the hinterland against flooding by high water from the IJsselmeer lake. The barrier consists of three inflatable, nylon-reinforced rubber dams, each 75 m long, 13 m wide and with a design height of 8.35 m. They are the largest dams of their kind ever built. The dam is inflated with air while a gravity-feed system allows water to flow in. The barrier is lowered again by pumping out the water and letting out the air.
The Thames Barrier is the world's second-largest movable flood barrier (after the Oosterscheldekering in the Netherlands) and is located downstream of central London. Its purpose is to prevent London from being flooded by exceptionally high tides and storm surges moving up from the sea. It needs to be raised (closed) only during high tide; at ebb tide it can be lowered to release the water that backs up behind it.