Revitalisation of salmon in the Rhine: PASCHAL formwork systems enable construction of an enormous fish ladder
In order to maintain biodiversity in the animal world, it is essential for most fish species to reach their spawning grounds repeatedly, even if they must overcome difficult conditions such as strong currents or flooding in the waterways. To assist with this, an enormous fish ladder was built on the Upper Rhine, at the EDF hydropower plant near Marckolsheim in Alsace, where formwork and shoring systems supplied by the full-service provider PASCHAL from Steinach were used for the concrete work.
The contractor was DEMATHIEU BARD CONSTRUCTION from Metz (Agence Lorraine). The aim of this project is to ensure that all fish species living in the Rhine use this new ladder and that the river is revitalised for salmon species. The fish lad-der is divided into two circuits, a hydraulic circuit and a fish circuit. The fish circuit consists of an attraction flow on the left bank, another on the right bank, successive pool runs, a counting station and a fish outlet. The hydraulic circuit begins with a water inlet, followed by a pressure pipe and a micro power station on the right bank. A pumping station was also built on the left bank. An area of no less than 3,000 m² was required for all the different parts of the project, with the fish circuit having a total length of 1.0 km. A height of 13.00 metres is bridged in the process. 8,000 m³ of concrete and 700 tonnes of structural steel were processed.
The excavation work, mainly against sheet piling, was begun in July 2023 and the entire project was completed in March 2025. PASCHAL had the task of forming round walls, supporting high single-sided formwork and making difficult formwork-related adjustments to existing structures or shoring.
The variable radius circular trapezoidal girder formwork was on site for all the circular walls, which had already been pre-rounded at the factory for the first forming cycle and was therefore ready for immediate use without the need for pre-assembly on site. The LOGO.3 wall formwork, with its well-balanced assortment of panels and large-size panels, was ideal for long and high walls, as were the small panel dimensions, including plastic filler pieces for complicated floor plans. Costly additional shuttering on site was therefore avoided. The narrow panel widths could also be used together with outside corner posts as column formwork, eliminating the need for separate column formwork.
According to site manager Arthur Rudolf, single-sided walls with a formwork height of up to 8.00 metres were a particular challenge. But PASCHAL had a system solution ready here too, because the standard 4.00 m support jacks can be underpinned with two differently sized base extensions, so heights of 6.00 m or even 8.00 m are possible. PASCHAL also provided the necessary structural analyses and details for secure anchoring in the floor slab. "We have been a PASCHAL customer for a long time and were once again able to rely on PASCHAL at this construction site to always have technical solutions ready and respond quickly, even with challenging formwork tasks," says site manager Arthur Rudolf.
Project financed by France Relance and Next Generation Eu.
The LOGO.3 wall formwork, with its well-balanced assortment of panels and large-size panels, was ideal for long and high walls, as were the small panel dimensions, including plastic filler pieces for complicated floor plans.
Single-sided walls up to a formwork height of 8 metres were a particular challenge.
