Determining viscous damping of large ships moored next to a quay wall

Safe mooring of ships at quay walls has become increasingly more challenging. Large container ships, car carriers and cruise ships have a significant side wind area and the combination of bollards located at the quay edge and high mooring deck levels, make that short, steep lines can often not be avoided. This results in unsafe mooring situations where high line tensions could occur. Ultimately, this increases the risk of slipping winches, snapping lines, or even overloading bollards. As a consultant for port authorities and terminal operators, Haskoning analyzes the behaviour of various mooring configurations in ports with scientific models developed by MARIN. We provide valuable numerical insight in the behaviour of moored ships and find possibilities to ensure safer mooring. Haskoning has contributed to the new PIANC Guidelines: Mooring of large ships at quay walls - Pianc, which addresses the mooring safety of ships at quay walls. When a ship is moored in close proximity to another object such as a quay wall or revetment, interaction effects play a significant role in the prediction of the motions and mooring loads. Not only will high water velocities occur between both bodies, but also shallow water conditions at low under keel clearances affects mooring responses. The complexity is increased by the fact that both effects will interact as well. These viscous effects can be incorporated in our numerical models, but currently there is insufficient understanding in this phenomenon. This may lead to under- or overly conservative results.

The purpose of this graduation is to quantitatively analyze the effect of viscous damping on vessel motion and mooring line forces by means of model tests at TU Delft. These model tests will need to be designed and executed by the student in the (small) towing tank at the faculty of ME. For simplification, it is anticipated to represent the container ship by a rectangular box. The main focus of this thesis is understanding how viscous damping depends on the underkeel clearance at the berth and the gap between quay and ship based on physical model tests. Similar tests have been done by MARIN in the past with a LNG carrier next to a gravity based structure, see De Boer & Buchner (2005): Viscous Damping of Vessels Moored in Close Proximity of Another Object.

What do we offer you?:

• Haskoning has a significant track record in Dynamic Mooring Analysis (DMA) for over 20 years. By working in our office, you can learn much about mooring analysis in port engineering in a short time.
• You will learn how to use engineering software, developed by MARIN (DIFFRAC | MARIN, aNySIM XMF | MARIN), that is used in our mooring analyses. We have dedicated workflow for DMAs in place, including cloud computing, pre- and post-processing.
• Our new office in Delft (open: 6 May) is conveniently located next to the TU Delft campus. You can easily divide your time between working at faculty of ME and our new office at the Mijnbouwstraat. In our office, you will get the opportunity to work at an international engineering consultancy firm in port consultancy.

Contact If you like to take up a challenge in the field of port engineering and mooring analysis, this is your chance! For additional information please contact: Dr. Ir. Alex van Deyzen (alex.van.deyzen@rhdhv.com)
Dr.-Ing. Sebastian Schreier (S.Schreier@tudelft.nl)