Challenging operation: installing megapumps for new pumping station Afsluitdijk

Challenging lift

This was a challenging operation because of the limited space available on the Afsluitdijk and the sheer scale of the pumps. Pumps of this size could only be hoisted if the wind was not too strong. Moreover, lifting the pumps to the right position so that they can be fixed into the concrete of the pumping station straight away, demands a high degree of precision. There is just 8 mm clearance.

The process of placing the 6 mega pumps in their assemblies has been completed in the past weeks.

Cargo from Spain

The pumps, which were built in Spain, are being shipped to the Robbenplaat sandbar at the Afsluitdijk. This load requires heavy-duty equipment, as the pumps are almost twice as tall as an average house.

The pumps needed to be tilted by cranes a few times to get them loaded, shipped and unloaded. A floating crane and a remote-controlled platform on wheels were used to move the pumps from the Robbenplaat to the 2 pump assemblies. The aim of this process was to avoid interference with road and shipping traffic.

Increased water discharge from the IJsselmeer

The Levvel construction consortium is building the new pumping station on behalf of Rijkswaterstaat. This new pumping station, together with the new sluice gates in the Afsluitdijk, will increase the possibility to discharge water from the IJsselmeer to the Wadden Sea.

This is of utmost importance, since the rivers and surrounding areas are carrying more water into the IJsselmeer, which means there is a danger of flooding. Working together, the six pumps will be able to discharge around 275,000 l/s. That amount of water is enough to fill an Olympic-sized swimming pool in about 9 seconds.

About the pumping station

The pumping station is one of the largest in Europe; together with the new sluice gates, it will increase the discharge of water from the IJsselmeer to the Wadden Sea. The sluice gates are currently the only means for the Afsluitdijk to discharge water.

These gates can only be used to discharge excess water if the level in the Wadden Sea is lower than that of the IJsselmeer (sluicing). Rising sea levels mean that we will not be able to use the sluicing process as often. In addition, more water is being discharged from rivers and surrounding areas into the IJsselmeer.

To ensure peoples safety, we need to be able to discharge more water than the sluice gates can currently cope with. The pumping station will allow us to discharge water to the side of the Wadden Sea, even when there are strong winds and high water levels.

The pumps meet the following requirements:

• The pumping station is 'fish-friendly'. The pumps allow fish to swim with the water to the other side of the Afsluitdijk.
• the energy used by the pumps in future will be generated from sustainable sources, specifically solar energy collected on and around the Afsluitdijk
• the pumping station has 2 pump assemblies, each with three pumps
• the pumps are made from aluminium bronze and steel
• the pumps can pump the water up a gradient of 3.4 m
• the discharge capacity of all the pumps, working together, is 275,000 l/s, enough to fill an Olympic-sized swimming pool in 9 seconds
• each pump weighs 90 tonnes, has a diameter of 4.6 m and is almost 12 m tall
• each dome weighs 30 tonnes, has a diameter of 9 m and is 4 m tall

These requirements keep the area safe and resilient for future challenges.