Maeslant Barrier is an enormous storm surge protector on the waterway leading to Rotterdam port. It protects the region from disastrous floods. Bouwkombinatie Maeslantkering, a construction consortium, built the barrier between 1991 and 1997. The cost was €450 million.
History of Maeslant Barrier
A terrible North Sea flood in 1953 killed over 1,800 people in the Netherlands. This lead to the creation of the Delta Works. However dikes and dams would block the busy shipping lanes of Rotterdam. Therefore engineers designed two massive hollow steel floating gates. The gates stay open during normal circumstances and swing shut only during severe storms.
The Design Concept
Its unique design uses two massive, pivoting floating steel gates that close automatically by computer commands. The gates do not obstruct the movement of ships during normal weather conditions. Two curved hollow gates, each 210 m wide and 22 m high, are fixed to huge 237 m steel trusses.
Each arm connects to a colossal 680 ton ball and socket joint on the shore. This permits multi-directional movement during extreme hydrodynamic loads. The gates rest in recessed dry docks on both the banks during non-emergency periods and maintain the shipping lane fully open.
Automatic Operation
- Trigger Threshold: Programmed to close automatically when water levels near Rotterdam are predicted to reach 3 m above normal sea level (NAP).
- Closing Sequence: Dry docks fill with water, causing the hollow gates to float off their supports. Self-propelled locomotives push the gates into the channel where they rotate inward to meet.
- Sinking Phase: Once aligned across the river, the valves open to let water flood the gate chambers. The gates sink securely onto a prepared stone sill on the river bed to form a solid wall against North Sea surges.
- Duration: The entire automated process consumes about two hours and requires no human intervention.
Construction of the Maeslant Barrier
The construction of the barrier started in 1991. The dry docks came up on both the banks and a ridge was constructed at the bottom of the Nieuwe Waterweg. Then the two steel gates were built. After this they welded 237 m long steel trusses on to the gates. The arms weigh 6,800 tonnes each.
The main purpose of the arms is to transmit the immense forces exerted on the gates, while closed, to a single joint at the rear of each gate. The ball-shaped joint powers free movement of the gates during opening and closing.. It moves like a ball and socket joint. Skoda Works in the Czech Republic produced the ball joints. The joint is the largest in the world. It has a diameter of 10 m and weighs 680 tonnes. The total cost of the Europoort barrier project was €660 million.
Computer Control of the System
A computer system named BOS controls the Maeslant Barrier. It operates sans human intervention by continuously tracking weather forecasts and live water level data.
How the Control System Works
- Autonomous Decision-Making: The BOS system monitors weather stations and water pressure gauges in real-time. If water levels are projected to reach a critical threshold, the computer triggers the closure sequence.
- Double Redundancy: To ensure fail-safe reliability, the system runs on dual fault-tolerant computers. It attains an elite Safety Integrity Level under IEC 61508 standards.
Getting There
From Rotterdam Centraal station, Maeslant Barrier is a drive of 30 km (34 min) via A20.
Alternatively take Metro Line B from Rotterdam Centraal to Hoek van Holland Haven station. Conclude the final 4 km stretch by taxi, bus or rented bicycle.
Visitor Centre
Keringhuis features an exhibition on Dutch water management. It has a restaurant and several viewpoints overlooking the huge barrier gates. Standard working hours on weekdays are from 10:00 to 16:00 hrs an d on weekends from 11:00 to 17:00 hrs. Guided tours are available for groups and individuals. Our guide spoke well in English and German.
Well explained.
Innovative solution for the problem.
Good job by the Designers.
Thanks