The global trend in maritime cargo transport is moving toward ships with deadweight capacity, which to a certain extent implies greater draft and higher thrust produced by the ship’s main propulsion system. As a result, ports are required to accept vessels with low under-keel clearance (UKC). To remain competitive in the global maritime market, ports are facing the need to deepen access channels and harbour basins with dredging operations in order to accept ships with larger drafts. A small under-keel clearance, combined with the assistance of tugboats, leads to the resuspension of sediments from the seabed. This has negative effects on marine fauna and flora, causes erosion of sediment around the supporting piles of port infrastructure, and results in the deposition of suspended sediment in certain areas of approach channels or basins. The Port of Koper also faces this issue. This doctoral dissertation presents methods for assessing the impact of ship manoeuvring on sediment resuspension. It introduces a method that integrates a real-time nautical simulator with the processing of dynamic and static data from propulsion systems involved in the manoeuvre, based on established empirical and semi-empirical equations (PIANC, Maynord model, German and Dutch approaches). These provide output velocities of currents from the propulsion systems in the unsteady state. The results were implemented in a three-dimensional hydrodynamic and sediment transport model (MIKE 3 FM/MT) with generated bathymetry of the studied seabed area, enabling quantitative analysis of sediment resuspension under unsteady manoeuvring conditions. This includes displaying current speed and direction, vertical profiles of specific sediment concentration, changes in seabed depth, seabed density, sediment deposition, and shear stress on the seabed caused by propulsion systems. Simulation scenarios were analysed and validated using real manoeuvres of comparable container ships, including tug assistance. Experimental verification involved water column sampling and satellite imagery. Water column sampling was conducted during three manoeuvres, with six measurements at three depths using a Niskin sampler. The initial measurements, taken before the manoeuvre, showed an average of 9 mg/l in the water column, while the final measurement after the manoeuvres was 27 mg/l, indicating a threefold increase in sediment concentration. Guidelines are provided to reduce the amount of resuspended sediment over an extended period.
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