Detailed view for Ramspol

CountryThe Netherlands
Concerned RiverKetelmeer and Zwarte Meer
TypeInflatable, water and air filled
Short Description

Ramspol barrier is located between two lakes, the Ketelmeer and the Zwarte Meer, in the Netherlands, and was completed in 2002.

It is a water- and air-filled inflatable barrier and it is composed of 3 span of 60 meters each, which is 180 meters in addition of the piers.

Main characteristics
Water Head (m)N/A
Upstream height (m)N/A
Downstream height (m)N/A
Discharge (m/s)N/A
Total length (m)350
Number of spans & dimensions

3 spans of 60 meters each

Weir height (m)8.2
Progress statusCompleted
Date of completion10/15/2002

Rijkswaterstaat, district Midden Nederland


Rijkswaterstaat, district Midden Nederland

Design group
  • Hollandsche Beton- en Waterbouw BV, Gouda, The Netherlands
  • Hollandsche Beton- en Waterbouw BV, Gouda, the Netherlands (project execution)
  • Bridgestone Ltd., Yokohama, Japan (fabric supplier)
Cost estimation70,000,000$


PIANC References for this project

In progress


It is known that sea storms are a major concern for the Netherlands. However, large inland water flows can be also as dangerous. In this context, Ramspol barrier was built to protect lands from inland floods.

The main concern in this project is the IJsselmeer, which contains a large amount of water and is in direct contact with the Ketelmeer. In case of strong wind, large water masses are drifted and can thread the lands. But in other situation, large amounts of water can reach the Zwarte Meer and cause water flow in the other direction. It should alos be noticed that ships travel through Ramspol.

The structure that has to be built is quite complex because it has to withstand pressure from both sides and allow ships to travel through.

Eventually, it was decided to built three identical spans and bellows with a width of 60 meters each. The barrier is in open position around 99% of the time. It is indeed expected that it will be closed once a year during around 24 hours. In this case, it lays on roller in the bottom recess. When needed, water flows into the membrane through valves located in the sill and air is also injected through the piers. The inflation time is 60 minutes and the deflation time is 180 minutes.

The membranes were built by Bridgestone and is composed of a nylon structure and a rbber matrix. Their design required a lot a complex finite elements simulations.

A great challenge was to ensure a good position of the bellows during the opening procedure. Indeed, the membrane has to go to the wanted position. As explained before, it lays down on roller supports in the sill recess. Therefore, the pressure in the membrane is decreased progressively in order to let the membrane fold properly around the rollers. That part of the design required a large friction analysis.

All these numerical analyses were validated in a laboratory in Delft.

Regarding the machinery, it was decided to automate all the operations. No human being is working for the barrier.

The structure was designed to require as few maintenance as possible. Great attention was brought to the clamping system. A special method was used for that purpose. It required a great expertise in for anchor prestressing forces.

Documents to download
  • 112- PReview WG166- Ramspol.pdf - 112- PReview WG166- Ramspol.pdf