BESIX Unitec and Croonwolter&dros: essential partners in ZEEKR for renovation Krammer locks

23 May 2024

The contract for the renovation of the Krammer Locks complex has been awarded by Rijkswaterstaat to the combination ZEEKR. A joint venture between main contractor BESIX and its partners BESIX Unitec, Croonwolter&dros, Demako, Iemants and Bosch Rexroth. With this renovation, Rijkswaterstaat is making Krammer Locks future-proof again. The renovation will start in 2025 and is scheduled to be completed in 2028.

The renovation of the Krammer Locks will make the locks more modern, faster, sustainable and fish-friendly in addition to future-proofing them. Among other things, the project will renovate drive motors, lock gates, motion works and electrical installations, and make the lock remotely operable. The most special parts of the project are the new fresh-salt separation with air bubbles in the pusher locks and the addition of a culvert.


The renovation of the Krammer Locks has been awarded to the combination ZEEKR, a joint venture between main contractor BESIX and its partners BESIX Unitec, Croonwolter&dros, Demako, Iemants and Bosch Rexroth. The contract was awarded for EUR 417 million.

Director-General Martin Wijnen of Rijkswaterstaat says: "Rijkswaterstaat is dealing with an outdated area and thus a large maintenance task. The successfully tendered renovation of the Krammer Locks is therefore a nice step in the right direction to get all that work done. We are very happy with that, also because of the great importance of the Krammer Locks."

Project director Dieter Behaeghel of BESIX: "We are very pleased to be able to start this gigantic job together with Rijkswaterstaat. The renovation of this impressive complex is an integral task in which safety, availability, sustainability and reliability are paramount. The strength of ZEEKR is in the people, together with our partners we have the right people on board to make this multifaceted project a success."

Project manager Henk van den Bosch: "ZEEKR's offer contains a thorough approach and a smart and robust planning. In addition, it also looks closely at disturbance reduction and its coordination with the users of the Krammer Locks. With the proposal, BESIX has shown that they have the experience, knowledge and skills to carry out the renovation and modernisation of the Krammersluizen complex. I look forward to the cooperation."

Renovation of electrical installations

Within the ZEEKR combination, BESIX Unitec ans Croonwolter&dros are responsible for the full scope of Electricity and Industrial Automation. This means that, united in the VOF EnVastKrammersluizen (EVK), they will replace almost all electrical installations of the Krammer Locks. This includes the entire energy supply, where a significant reduction in energy consumption is a prerequisite for making the property more sustainable fot he future. In addition, the entire control system will be replaced, making the entire object remotely operable from the Neeltje Jans control house. 

Tom Haesebrouck, project manager at BESIX Unitec and also responsible for the entire technical management of EVK:
"It is an honour to contribute to the renovation of this lock complex. With our technical expertise, we will significantly improve the efficiency and reliability of the facilities, which is essential for the sustainability of this infrastructure."

Benjamin Mooijaart, project manager at Croonwolter&dros and also responsible for EVK's project management on this new partnership:
"We are immensely proud that by combining our years of knowledge and strenghts, we are jointly contributing to keeping the busy shipping route between Zeeland and the major rivers available and safe. Together we are creating progress!"

Importance Krammersluizen

The Krammer Locks are on the border of Brabant, Zeeland and South Holland, near Bruinisse. Some 60,000 ships pass through the locks every year. Therefore, they are of great importance for the flow on the Rotterdam-Antwerp-Ghent international corridor.

The Krammer Locks complex is located in the Philipsdam, one of the thirteen Delta Works that protects the southwest of the Netherlands from high water from the sea. The complex was completed in 1987, and after 35 years is in need of a major renovation. Many parts of the locks have reached the end of their lifespan and need to be replaced, overhauled or modernised.

Maintenance table

Rijkswaterstaat is facing a major maintenance challenge. Many locks, bridges, roads and tunnels were built in the 1960s, 1970s and 1980s. Over the years, they have been intensively loaded by more and more and heavier traffic and therefore need to be replaced or renovated. The government is therefore investing heavily in major road and waterway maintenance in the coming years.

(picture: Rijkswaterstaat)

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