Why
The Afsluitdijk was built in 1932. At the time, swing bridges were deliberately chosen so that the expected enemy could be targeted effectively from the nearby bunkers. Back then, Den Oever had just one swing bridge on the A7. In the 1970s, the original 1932 bridge was replaced by a new one, and a second bridge was added.
Now, some components are nearing the end of their lifespan. The steel structures suffer from metal fatigue, and the mechanisms that enable the bridges to open are worn out and overloaded. This makes the bridges less reliable and leads to more frequent malfunctions, often resulting in traffic delays. For this reason, Rijkswaterstaat is replacing outdated parts of the bridges to keep them safe and operational.
The bridges at Den Oever are part of the monitoring programme Rijdek Inspectie Stalen Kunstwerken (RISK). To ensure safety, the bridges are regularly inspected and, if necessary, repaired. However, in the long run, repairs alone are not sufficient. Thanks to the planned works, the bridges will remain safe for road users until at least 2050.
How
The decision to construct the Afsluitdijk was taken in 1921. This connection between Friesland and North Holland made Vesting Holland – the heart of the Dutch national defence – vulnerable. To address this, the Ministry of War built defensive structures near the Afsluitdijk, including bunkers. The choice of swing bridges was also made with defence in mind: they allowed effective fire on the enemy from the bunkers at Den Oever, and they were a smaller and more difficult target for enemy artillery than a raised bridge.
There is no reason to change this design now. Rijkswaterstaat will therefore only replace the outdated components: the movable bridge sections with the road surface and the operating mechanisms. The central supports in the water, which support and allow the bridges to rotate, will remain. After renovation, the clearance height and width for shipping will remain unchanged.
When
In September 2025, Rijkswaterstaat awarded the contract for the partial replacement and renovation of the bridges to the consortium Mobilis/Croonwolter&dros. Work is expected to start in autumn 2027. Until then, Mobilis/Croonwolter&dros, will prepare the design and execution plan in close cooperation with Rijkswaterstaat.