The combined pump and hydroelectric power station in Diepenbeek has reached a new milestone. On Thursday 28 October, the three gigantic Archimedes screws were installed. Weighing 95 tonnes, with a diameter of 4.3 m and a length of 22 m, they are the largest screws in the world. The Temporary Partnership (TM) Eureka, formed by HYE and EQUANS, is leading the works and has already built similar plants in Hasselt (2018), Ham (2012), Olen (2013) and soon in Genk.
With the construction of these hydropower plants, De Vlaamse Waterweg aims to maintain the water level in the Albert Canal. The screws turn in two directions: when dry, they recover water, and when there is sufficient water, they turn in the opposite direction and act as a hydroelectric power station. In the next few years, similar installations will be built at the lock complex in Genk, and other locations, in order to reduce the overall water consumption of the Albert Canal in dry periods by approximately 50%.
As in Hasselt, the plant in Diepenbeek is being built by the TM Eureka (EQUANS-HYE). The large Archimedes screws were built by the company Vandezande from Diksmuide.
EQUANS is responsible for the electromechanical and technical equipment for the installation, including the delivery and installation of the three Archimedes screws or screw pumps.
Millimetre precision
On 28 October, the screws were delivered by cargo ship and transferred to a pontoon using two 300-tonne cranes. From the pontoon, the screw was lifted with a 500-ton and 700-ton crane and installed. This operation was repeated three times and required millimetre precision. What now follows is the further finishing of the screws, the mounting of the drives (motors, gearboxes, brakes, etc.) and the electrical finishing of the installation. The plant will be started up in January 2022 and adjusted in February/March. From April onwards, the plant should start working with the previously built plants.
EQUANS has been active on site since February 2021 but, prior to that, the electromechanics specialist also completed a great deal of work behind the scenes. Bart Van Pelt: “Behind the scenes, we worked on the construction of the operating panels, the screws and their bases. In fact, we completed all the preparation required in order to get on site, including a very detailed installation plan. The three gigantic Archimedes screws are undoubtedly the eye-catcher in this project. Weighing 95 tonnes, with a diameter of 4.3 m and a length of 22 m, they are the largest screws in the world. That’s quite a challenge in terms of controlling the forces on the installation. Another challenge is operating the plant and controlling the impact of this element on the existing water balance. Commissioning in April will therefore be a crucial moment.”
Dual use
The benefit of the hydropower plants is twofold. Thanks to the concept of a combined pumped-storage and hydropower plant, the facilities can also be used to produce electricity from hydropower for about 1,500 families when there is sufficient water available. Bart Van Pelt: “This train of thought fits perfectly with the philosophy of EQUANS. We distinguish ourselves in the multidisciplinary approach and the corresponding challenges. Our team consists of excellent technicians who are also versed in mechanics and hydraulics. In short, great profiles for this kind of work. We have the expertise for this type of complex water works entirely in-house. And I mustn’t forget to mention the great cooperation with HYE in this project too.”