Zinc pieces with cradles as bottom protection at De Poel pumping station

Aannemingscombinatie De Poel called on the knowledge and expertise of Van Aalsburg B.V. for soil protection for the new construction of pumping station De Poel.

"On this project, we started with dredging," says Dick van Aalsburg. "Then we profiled the bottom. After flattening, we made and sunk the bottom protection in the form of sinkers."

Specific sinkers 

"For a project like this, we choose sinkers with cots and geotextiles," says Van Aalsburg. "Those have a different construction form than classic sinkers with only willow. In fact, geotextile provides the extra safety needed at locations with deep and fast-flowing water, such as at a pumping station." Van Aalsburg imports and processes the geotextiles itself, making zinc pieces available in all sizes. 

Precise immersion

"The sinkers were knotted by us on the bank, pulled into the water and accurately -with the help of GPS- placed in the right position and sunk with pouring stones, using our crane pontoon. A specialized job," said Van Aalsburg. "In this project, colloidal concrete was applied over the sinkers. We do this particularly at pumping stations to direct the fast-flowing water before and after the pumping station in such a way that it does not erode the bottom and banks."

Decades of experience

It is the kind of project that Van Aalsburg often takes on and in which it has now built up a lot of experience. "Every few months we provide a pumping station with suitable zinc pieces and/or bank protection. The next one, the pumping station at Monnickendam, is already in the planning." Despite years of experience, Van Aalsburg is not afraid to keep a critical eye on himself. "With this project, not everything went smoothly, in such a case we try to come to the best possible agreement with our client and learn lessons for next time. It worked out quite well here and we will continue with this client again in the future as well." After all, according to Van Aalsburg, you're never too old to learn AND he takes every project seriously. "We tie more than 750,000 m² to sinkers. But whether it's a big project we're working on for a year, or a project like this one where we're working on a few hundred square meters of sinkers for a week: we tackle it."