Optimisation of Load Draughts on the Middle Rhine
In the 49 km reach of the Rhine between Budenheim and St. Goar the specified fairway depth is at present 1.90 m below equivalent low water level or GlW (Gleichwertiger Wasserstand, i.e. a reference low water level that is exceeded on only around 20 days per year in the long-time mean). This means that the specified fairway depth is 0.20 m less than in the adjoining upstream and downstream reaches. As a result, this reach limits possible vessel draughts during low and mean water periods and thus the economic efficiency of shipping on the Rhine. The project Optimisation of Load Draughts on the Middle Rhine is therefore one of the projects on Germany’s federal waterways with the highest priority. The goal of the project is to adapt the navigability conditions in the reach between Mainz and St. Goar in low and mean water periods to the conditions in the upstream and downstream reaches.
As scientific advisor the BAW supports the Waterways and Shipping Office Rhine, i.e. the planning authority, with its river engineering, nautical and geotechnical expertise. Innovative investigation methods are used for the planning and evaluation of river engineering measures designed to optimise vessel draughts. This includes the combined operation of a 3D numerical flow model and a laboratory scale model with partly moveable bed . The investigations are closely intertwined with studies of ship dynamics to evaluate the impact of these measures. The focus of the studies is on the impacts the changed flow and depth conditions have on shipping. Investigating the in-situ ground conditions of the river bed serves to identify suitable methods for executing the earthworks. In addition, the geotechnical investigations provide important input data for hydraulic simulations, especially for the very heterogeneous conditions of the river bed in the mountainous reach.