BESIX renovates Mercator lock in Ostend

In Ostend, the Mercator lock is currently undergoing a major renovation and BESIX is at the helm of the transformation. Located in the heart of Ostend, the lock provides access to the Mercator dock where visitors can see the famous sailing ship Mercator, a three-master dating from 1932. Since 10 November, the team has been working on site to replace mainly the existing ebb and flood doors. With these works, BESIX is not only helping this lock stand the test of time, but also adding a a new chapter to the history of this marine monument.

The lock's upstream ebb doors have long stood up to the forces of the sea but are in need of a renovation.

Jasper Degraeuwe, Project Manager at BESIX, details the works: "Our tasks include removing the existing lock gates, replacing the pivots by locally dry-docking using caissonhalss, adjusting, conserving, and repositioning the hinge points at the top, also known as the neck brackets. We are also taking on the production of new wooden lock gates, sourced from the Netherlands, fitted with new steel fittings. The preservation of steel components, supply and installation of cathodic protection, and the precise installation and adjustment of the new doors are also among our responsibilities."

The project is not just a routine operation. Jasper explains:

"Replacing the 4 heavy lock doors (2 on each side) poses two specific challenges: the attachment points to lift the doors and the bridge cellar that is close to the location of the lifting crane." To make sure this was handled correctly, the Ostend team consulted the BESIX Engineering Department. "The lifting points with which the doors were once hoisted are no longer there," clarifies Wim Dewilde, Expert Engineering & Methods at BED. "So, we had to look for a safe and cost-efficient way to do this. We ended up using the second beam of each door to place the fixing points, to reduce the risk."

And then there is the location of the bridge basement. The doors have to be lifted out along a bascule bridge. Under the legs that allow that bridge to swing open is a basement, perilously close to the location of the lifting crane. Here, the team could count on Hans Verbraken, Project Manager at BED.

"My job was to determine exactly where to place the crane to ensure that the doors could still be lifted in a way that the basement wall could handle the pressure of the weight of that crane. In the end, we found the right solution to do this safely, using the right spacing and plates under the crane's outriggers that distribute the weight."

As the project is located in the centre of Ostend, things can get busy there sometimes. A number of traffic flows around the dock, such as the buses from ‘De Lijn’ and the pedestrian passage, will therefore be diverted during the works. The Mercator dock is also completely blocked. However, maritime traffic can only be stopped there during the winter period, so the team is working to a tight schedule. The works should be completed by February 2024.