Keersluis Kornwerderzand

Construction Alliance

On March 7th, the ‘Keersluis Kornwerderzand’ project made the news for a brief moment. (Link to news article:

In this Afsluitdijk project, the rolling gate of the Keersluis Kornwerderzand was hoisted into place. It was a remarkable and also a tense activity, considering the dimensions and weight of the gate (LxWxH = 57m x 8m x 14m, weight: over 1 million kg) and the precision required, with only a few centimeters of clearance between the rolling gate and the concrete.

A great summary is given in the following timelapse video: (Link to the timelapse video:

Along with several CI colleagues, we were responsible for designing all the concrete components.

This includes;

  • East and West lock walls (LxWxH=35m x 5m x 15m),
  • Rail beam at the bottom of the waterway on which the rolling gate moves (LxWxH = 50m x 8m x 2m),
  • The gate chamber (location in the dike body where the door ‘waits’ to come into action) (LxWxH = 60m x 12m x 1.75m),
  • The C-beams, engine room, electrical room, and gate pivot pit, all for the operation of the rolling gate,
  • Underwater concrete for the construction pits,
  • etc.

A keersluis (not to be confused with a lock=boat lift) is essentially a storm surge barrier.

The Keersluis Kornwerderzand is designed to withstand a wall of 10m of water (water level difference + wave height) and can do so across the entire 50m width of the waterway.

It is clear that this project has provided a significant professional challenge, and we are proud of the result.