Prince Claus Bridge: architectural eye-catcher with smart engineering

The bridge is not only hugely innovative in its design, but is also a technical tour de force. Implementation of the 140-meter long bascule bridge with rotating ballast mast commissioned by the municipality of Dordrecht is in the hands of Hillebrand, part of ASK Romein, and Dura Vermeer. 

Unique movement mechanism

"The biggest challenge with this bridge is the design by René van Zuuk architects," says Martijn Kuzee, project manager at ASK Romein. "Architecturally it looks particularly attractive, such a movable bridge with ballast mast, but such a concept has never before been applied in practice. The imposing ballast mast and pendulum rod together form the movable part (the halyard) whose halyard, when open, rises 52 meters above the water. Kuzee explains that the mechanics of all those moving elements eventually had to be concealed in the narrow spaces available for that purpose. "That required smart engineering." For this, contractor combination Dura Vermeer/Hillebrand engaged IV Group, a multidisciplinary engineering firm with expertise in technically challenging projects. "They designed all the pivot points, constantly sparring with us as contractors to see if it was technically feasible. Where necessary, they then made adjustments to the 3D model, ultimately creating a constructively feasible bridge." The 3D design of both the sub- and superstructure was drawn by Dura Vermeer. During the design and technical consultations, they used this 3D model to clarify and control the interfaces between the various disciplines.

Technical masterpiece

The unique motion mechanism, which rests on a concrete pedestal, was built so that shipping could continue even during construction. "With such an engineering feat, it is crucial that the entire design is carefully engineered," Kuzee continued. "That also applies to all assembly steps, where it comes down to both the dimensioning of the civil concrete construction and the accuracy of the steelwork." The assembly of the various components has therefore already been carried out in full modeling. Both on site and in Flushing, everything was carefully measured out and fitted together in the 3D model. "Between the fixed part (when standing) and the movable part there is only 5 centimeters of play on both sides. That's pretty little with this kind of weight," Kuzee knows. "We have also found in practice that we can work flawlessly within these close tolerances."

All parts come together

At the end of the project, the collection of colossal individual parts came together. "Many parts were prefabricated in different locations. For example, the pillars were made in Rotterdam. At the Dordrecht site itself, all the other concrete work was made, such as the attachment to the banks. At the factory in Middelburg was the steel bridge deck. The approach bridges, also built in Middelburg, still had to be welded together on site due to the transport size. The movable part and the ballast mast were made in our Vlissingen plant. Floating trestles were used for loading and assembly on site. First, the moving part, which weighs about 266 tons, was placed, and then the drive like hydraulic cylinders were connected. Next, the ballast mast (weighing about 380 tons) was installed. Finally, the electrical installation firm Langezaal & Inniger installed the electrical installation such as the controls and all the safety functions of the bridge so that it can operate safely and reliably. "We are real bridge builders with the necessary experience," says Kuzee, "but the realization of the Prince Claus Bridge has been quite a feat. We are proud that we managed to merge the architectural and technical design."