Research and scope determination – Keersluis Zierikzee (Zierikzee flood lock)

On behalf of the Scheldestromen Water Board, Iv conducted a detailed analysis of the technical condition of the Keersluis Zierikzee (Zierikzee flood lock), a complex and unique structure from 1956 that offers protection against high water. The water board wanted to better understand the flood lock’s remaining life and identify potential improvements to enhance operational reliability and safety. Iv divided this assignment into three steps: a desk study, an on-site inspection, and an integral scope determination.

The Keersluis Zierikzee is distinguished by its unique structure, particularly the sector gates equipped with rubber bellows filled with air to allow the gate to rotate freely. The sector gates have never been removed since construction, which raised concerns about the condition of the lower pivot points and the mercury seal. The structure requires regular maintenance, especially considering the effects of salt water on the steel structures.

One of the biggest challenges in this project was obtaining a complete picture of the condition of the floodgate, especially the wear of the lower and upper pivot points and the structure’s integrity. The various components for inflating and deflating the bellows (lower seal) and draining condensation also required improvement. Furthermore, careful consideration has also been given to the deployment and use of the floodgate from a water safety perspective. To make an informed decision about major maintenance, Iv had to accurately determine the current condition of the floodgate and the necessary measures to extend the structure’s life.

The complexity of the lower pivot points also played an important role. These pivot points, which are constantly immersed in oil and use a mercury seal to withstand pressure, are essential to the operation of the floodgate but also pose a potential environmental risk. Iv investigated whether replacing these pivot points with a more sustainable system was possible.

The research resulted in a well-founded recommendation for the Scheldestromen Water Board on how to proceed. The inspections and analysis provided insight into the remaining life of the floodgate and clarified which components needed to be addressed to ensure operational safety. By determining the scope, Iv laid a solid foundation for the next phase, where the renovation work and technical adjustments will be further developed. This research helps the water board to make a better-informed decision about the future of the flood lock and contributes to the water safety of the area.