A mooring arrangement optimisation study

Ports want to ensure safe and reliable loading operations for all ships. Increase in ship sizes, especially container ships, can potentially cause unsafe mooring situations. For ships moored at quay walls, there is also a lack of international guidelines and recommendations for mooring arrangements. This paper presents a case study for a moored containership being passed by a vessel of identical dimensions. The behaviour of the moored ship is simulated using UGent’s time-domain mooring software Vlugmoor. Starting from a well-balanced arrangement used currently in daily operation, three optimisation steps are presented, aimed at lowering the ship motions, which are critical. The first step explores the impact of changing line positioning to reduce line length disparity and improve efficiency in critical force directions. The second step considers a lower fore mooring deck to reduce line steepness, as well as additional winches below the bridge and funnel. The third step proposes replacing medium stiff lines with a very stiff HMPE line, combined with an elastic tail. The effect of these optimisation steps on the ship motions are presented and compared with predictions based on efficiency parameters. These factors express the capability of the configuration to deal with positive and negative surge forces. It is shown that applying these optimisation steps can significantly improve the safety of a moored container ship during a ship passage.

Subjects

Efficiency parameters

Moored vessel safety

Mooring arrangement

Passing vessel effect

DDC Class

600: Technik

620: Ingenieurwissenschaften

Lizenz

http://rightsstatements.org/vocab/InC/1.0/

Name

paper_0022_file_0427_A_Mooring_Arrangement_Optimisation_Study.pdf

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1.61 MB

Format

Adobe PDF

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A mooring arrangement optimisation study