A piece of Zaandam is back!

With the entering of the Wilhelmina Bridge and Beatrix Bridge, two major milestones of the Wilhelmina Lock Zaandam project have been completed. The Wilhelmina Lock forms the most important junction of roads and water in the heart of Zaandam. The lock in the Zaan was outdated, in poor architectural and technical condition and did not meet today's requirements. Heijmans, in collaboration with bridge builder Hillebrand and others, was commissioned by the Province of North Holland to replace the bowl lock with a new modern lock for commercial and recreational shipping. The lock has been made longer, wider and deeper.

From the very first moment, Hillebrand was involved in the design and implementation choices for both the steel structure and the superstructure of the bridge, so that the most efficient result could be achieved," says Martijn Kuzee, project manager at Hillebrand in Middelburg. Hillebrand's knowledge and expertise in the field of bridge construction, combined with the constructive attitude of both Hillebrand and Heijmans and the positive interaction between both parties, were of great importance in this project.

Smart planning ensures minimal gridlock

Kuzee: "Hillebrand has been involved from A to Z in both the production of the movable bridge parts (the so-called traps) and the electromechanical drive system. The two traps -180 tons heavy, 16 meters wide and 15 meters long- were completely prefabricated by Hillebrand in Middelburg. That is also where the railings and wear layer were installed." Although the construction is relatively simple, working with parts weighing 180 tons is a challenging activity. "That's why we enlisted the help of our partner Mammoet," Kuzee continued. "They are also the party who, through a roll-on/roll-off operation, loaded the heavy traps onto pontoons and transported them 265 km away by water." By manufacturing everything in Middelburg and delivering it just-in-time in Zaandam, as little as possible had to be done on the construction site itself. Smart planning also ensured that the blockage of shipping and road traffic was as short as possible. Still, the installation of the traps was quite a spectacle," says Kuzee.

Electromechanical drive

The electromechanical drive was also completely prefabricated by Hillebrand. "The most complex thing here was fitting the drive in the very limited space in the basement," Kuzee says. "Because the basement did not get any larger than it was before the renovation, but the standards of the drive were weighted down, it was quite a challenge to make it fit. But we managed to fabricate as slim a drive as possible and Heijmans, in turn, realized the thin concrete walls of the basement. Especially setting and pouring the anchors for the drive was a challenge for Heijmans: they were allowed to deviate by a maximum of one millimeter. This was successful with all the anchors: a fine piece of craftsmanship by the people of Heijmans and Hillebrand!"

Collaboration to be proud of

Every part of this project shows that ultimate cooperation is necessary to bring something to a successful conclusion. Kuzee confirms that this is the case: "The cooperation with Heijmans is very pleasant, with mutual respect for each other's interests. We know each other well, we often work together on projects and we know exactly what we can gain from each other. And that applies just as much to the cooperation with Mammoet." Just a little longer and then everything will be finished and the Zaan will be moving forward again.