“Learning everything about hydrodynamic processes while actually making an impact.” That’s what Marguérite Willemsen (25 years old) loves about her internship at Boskalis. She’ll be finishing her master’s degree in Hydraulic Engineering at TU Delft this autumn. Her subject: the remarkable world of dredge plumes.
“Although I’m not required to do a graduate internship, I wanted to finalize my studies in a practical environment. Especially after two years of remote studying due to the pandemic. Boskalis has always fascinated me. I admire the big coastal ‘building with nature’ projects, like the Sand Motor on the Dutch west coast. Luckily, I managed to obtain a graduate position and am now working on my thesis at Hydronamic, Boskalis’ inhouse engineering company and first port of call for knowledge, design and (hydro) engineering questions.”
Trailing suction hopper dredgers are Boskalis’ largest type of dredging vessels. In the process of dredging, the dredged solid material has to stay on board. Whereas the surplus process water, containing mostly fine sediment, is released back into the water. This process leaves a cloud of sediment behind, called a dredge plume. “Now this is where it gets interesting”, Marguérite explains. “The cloud of fine sediment can take hours to sink back to the seabed, sometimes creating a long plume behind the ship. In some cases - like in and around certain ecosystems - it’s essential to keep these clouds to a minimum.”
It’s up to Marguérite to find out more about how dredge plumes spread and behave, so future dredging plans can be fine-tuned to minimize the environmental impact. Marguérite uses a ‘computational fluid dynamics model’, to analyze a series of detailed scenarios to understand the effects of various circumstances - such as water depth and flow rate - on the plume development. This understanding is used to design dredging work methods and precautionary measures.”
Marguérite is glad she got the chance to graduate at Boskalis. “This is a perfect learning environment”, she says. “I’m not just supported by my supervisor, but by the entire Morphology and Marine Environment department. It feels good to know that I can ask anyone for help. Whether it’s an error in my script or an in-depth question, there’s always someone to think along with me. My time at Hydronamic so far has inspired me to keep expanding and applying my knowledge about hydraulic engineering after graduating. Ideally, in a young and globally operating team. I won’t say no to a future career at Boskalis!”