Efficient sediment management is crucial to maintain accessibility into the port. This thesis investigates the application of the bed leveller in conditioning pre-consolidated mud, comparing its efficiency and impact on turbidity with that of the water injection dredger. The research is conducted for pre-consolidated mud from the Botlek in the Port of Rotterdam. Instead of traditionally reallocating the dredged material, the mud’s properties are modified so that it is safe for vessels to navigate through the mud. The WID is the primary conditioning vessel at the Port of Rotterdam. Since maintenance dredging is a logistical challenge, however, it is attractive to optionally deploy other vessels for conditioning purposes. The bed leveller, a type of plough normally used to level the port’s bed, could potentially be used for condition ing. It is cheaper to deploy and more easily accessible for the Port of Rotterdam. Therefore this study investigates if the bed leveller can achieve comparable results as the WID regarding conditioning dredging. To accomplish this knowledge, the research includes the design of a conditioning plough and testing and comparing it to the conventional plough and WID on a laboratory scale. The different treatments on the pre-consolidated mud are measured on density, yield stress and turbidity so the outcomes point out the differences in conditioning effectiveness and impact on turbidity. Furthermore, experiments are executed to discover what is needed to successfully condition pre-consolidated mud and the influence that frequency in a conditioning activity has. To support the findings from the laboratory, field tests are con ducted with the bed leveller and the WID as well. This experiment also gives insight into the conditioning efficiency in terms of production rate, costs and fuel consumption. The findings are that an improved design of a new piece of bed levelling equipment, based on research and experience in the field of agriculture, can increase the ability to condition mud. Stirring and mixing, breaking up cohesive bonds within the mud and suspending it, are key for successful conditioning. Increasing frequency in a conditioning activity, increases the effectiveness of conditioning as well, however this relation stagnates. Furthermore, the bed leveller can indeed condition pre-consolidated mud like the WID can. Although in comparison, a higher dredging frequency needs to be applied, for the strength and density of the mud to be reduced just as much. Thus in terms of production rate, the bed leveller is a lot less effective than the WID, resulting in higher average costs and fuel consumption per volume of effectively conditioned pre-consolidated mud. In terms of impact on turbidity, the bed leveller has less effect than the WID and the design of a new plough specifically for conditioning, contributes to reduced environmental impact. ... Read more

Kelp Blue is a company whose top priority is the well-being of the planet. Through the cultivation of giant kelp on offshore farms, they create several sustainable products, new job opportunities in regions where they are needed, enhance biodiversity in the water, and above all, sequester tons of CO2 from the air. The start-up is still in its research and development phase, but plans to be building farms on a large scale in just a few years. Despite their knowledge in engineering, the company still needs consulting on certain elements. Therefore the company invited a group of students from the Delft University of Technology to Lüderitz, Namibia for a consultancy project. The project involved creating a procedure for the company to scale up in a sustainable manner. The students decided that this complex problem should be divided into sub-problems. One workstream focused on reducing the carbon emissions during upscaling, while the other workstream focused on analyzing and improving the company’s current design and installation of the farms. Following, both parts of the project are shortly summarized: Part I: Improving the company’s current design Kelp Blue is currently in the pilot phase, in which they’re installing their first large giant kelp farms. Before, they were focusing on the complete installation, including planting the kelp on the submerged netting structure, and the review of this. For the company’s commercial phase, where they want to be able to place farms daily on a large scale, designs were still developed and analyzed. For the commercial phase, this workstream made a new design and installation method. It required an installation where buoys would need to be submerged, the structure locked in place at the desired depth, without the use of scuba divers or remote operated vehicles. Despite the fact that these requirements were challenging, an outstanding result was achieved. The main problem was divided into subproblems, and for each of those a suitable solution was created. Hopes are that the company will consider the given advice as helpful and maybe implement some parts of (or the whole) new design. Part II: Reducing carbon emissions during upscaling First, interviews and desk research were conducted to get a good idea of the challenge of sustainability. This included reading reports, speaking with employees, policy makers and experts with experience within the area. With this information, the challenge could be mapped out and the solution space became clear in terms of legislation and technical possibilities. Climate information was also requested that could later be used to run simulations. During the determination of the possible solutions, research was done on the realistic possibilities, where eventually the use of either solar or wind energy was most appropriate. After conducting a multi-criteria analysis that was put together with the management of Kelp Blue, investing in a solar plant proved to be the most appropriate solution. ... Read more