Maintaining the condition of a vessel and its equipment guarantees the scheduled completion of voyages and the safety of the crew.
This paper presents condition monitoring techniques for early detection of faults related to piston rings in remote cylinders of two-stroke marine diesel engines. Operational sensor data from the main engine of a container ship are provided by a shipping company.
A graphical approach complimented by correlation heatmaps and feature importance from gradient boosting trees are used for feature selection. Support Vector Machine, Random Forest and Extreme Gradient Boosting Trees are tested for residual generation from the nominal behavior.
The residual time series gives a good indication of the degradation of the system and can be used for alarm raising under strict rules. It is proven that the proposed method could alert the engine crew of a change in the condition of the piston rings much earlier than existing methods.
This introductory note examines the development at the International Tribunal for the Law of the Sea for the year 2020. While there was no judgment in 2020, proceedings of two cases, the M/T “San Padre Pio” (No. 2) Case (Switzerland/Nigeria) and the Dispute Concerning Delimitation of the Maritime Boundary between Mauritius and Maldives in the Indian Ocean (Mauritius/Maldives), continue. Accordingly, this note discusses the issues of the two pending cases. Furthermore, there were some important events regarding the Tribunal in 2020. Among other things, this note focuses on an adoption of a Model Agreement between ITLOS and Singapore, the election of the seven members of the Tribunal, and amendments of the Rules of the Tribunal.
Benchmarking the energy efficiency of ships is not a straightforward task, mainly due to the diversity of operations. Although driving cycles have been used for decades in evaluating the performance of road vehicles, these do not exist in formal policy-making for maritime transport. This work builds on a previously proposed methodology. It uses noon reports of 327 vessels for 2019 to construct operational cycles for seven size classes of container ships using the main engine power as the main parameter. Concerning the main engine emissions, the resulting cycles reduce variation in the carbon intensity indicator values by more than 30% while maintaining an average accuracy of 97.7% in absolute emissions. These figures show that the concept can improve operational carbon intensity indicators in terms of robustness and their technical counterparts in optimizing ship design. The paper also proposes further work required for benchmarking applications in policy-making.
This new edition has been revised and updated to provide current and comprehensive coverage of essential issues of the international law of the sea in a systematic manner. This book presents two paradigms of the law of the sea: the law of divided oceans and the law of our common ocean. It covers contemporary issues, such as protection of the marine biological diversity, marine plastic pollution, the Arctic, and impacts of climate change on the oceans. Following the clear and accessible approach of previous editions, with many illustrations and tables, The International Law of the Sea continues to help students to best understand the law of the sea.
Abstract In the quest for a numerical method for surface waves and wave-induced effects applicable when linear or weakly nonlinear methods are insufficient, a three-dimensional numerical wave tank assuming fully-nonlinear potential-flow theory is proposed. When viscous-flow effects, breaking waves or other violent flow-phenomena are not of primary importance, potential-flow methods may have similar capability in capturing the involved physics as Navier-Stokes solvers while being potentially more accurate in handling wave-propagation mechanism and more computationally efficient. If made sufficiently accurate, efficient and numerically robust, fully-nonlinear potential flow models can therefore represent a powerful tool in the study of ocean waves and their interaction with marine structures, which is the main motivation behind the present work. The governing Laplace equation for the velocity potential is solved using the harmonic polynomial cell method, which is a field method giving high-order accuracy provided that the cells used to describe the water domain have no stretching or distortion. This can only be achieved in a grid with cubic cells, which leads to poor numerical efficiency unless measures are introduced to refine the grid locally. Here, to improve the efficiency using strictly cubic cells, an adaptive grid refinement technique is introduced. It is shown that this has the ability to improve the computational speed with a factor of up to 20 without sacrificing accuracy. Numerical results are shown to be in good agreement with highly accurate nonlinear reference solutions for regular and irregular waves of various steepness up to the limit of theoretical wave breaking. For long-crested irregular waves, significant discrepancies with a second-order theory for the crest-height distribution are identified, while the second-order theory appears to provide a better description of the crest height for the single short-crested irregular sea state simulated. Having demonstrated that the proposed numerical method accurately models nonlinear wave phenomena up to the limit of wave breaking, future work should seek to implement wave-body interaction capabilities. The adaptive grid refinement technique, which refines the grid dynamically depending on the position of boundaries of interest, is developed with this application in mind. Except from providing a robust way of dealing with wave-body intersection points, extending the method to account for wave-body interactions should therefore involve limited difficulty.
The real-time provision of high-quality estimates of the ocean wave parameters at appropriate spatial resolutions are essential for the sustainable operations of marine structures. Machine learning affords considerable opportunity for providing additional value from sensor networks, fusing metocean data collected by various platforms. Exploiting the ship-as-a-wave-buoy concept, this article proposes the integration of vessel-based observations into a wave-nowcasting framework. Surrogate models are trained using a high-fidelity physics-based nearshore wave model to learn the spatial correlations between grid points within a computational domain. The performance of these different models are evaluated in a case study to assess how well wave parameters estimated through the spectral analysis of ship motions can perform as inputs to the surrogate system, to replace or complement traditional wave buoy measurements. The benchmark study identifies the advantages and limitations inherent in the methodology incorporating ship-based wave estimates to improve the reliability and availability of regional sea state information.
Modern slavery and human trafficking present an inherent risk to workers engaged in operations surrounding shipping activities. One of the first statutes addressing the problem was the UK Modern Slavery Act [MSA], which presents several statutory sanctions for shipping companies in case of non-compliance. The article examines the sanctions available under different provisions of MSA as applied specifically to shipping activities.
As a further step, the article conducts an empirical analysis of the reporting practices of liner shipping operators, eligible for compliance under MSA. In addition to the rates of compliance, it engages in content analysis of the modern slavery statements, seeking to identify the uniform patterns of reporting and industry best practices.
The last part of the article discusses whether corporate undertakings as reported in modern slavery statements may serve as a ground for tort liability, similarly to the supply chain or ‘production liability’ emerging from group policies and codes of conduct.
This article builds on rich empirical data following our unexpected discovery of a local practice to circumvent a stressful
and counterproductive work environment due to distrust at the Port of Tema in Ghana. Using theoretical work on networks,
trust, and humor, as well as extensive ethnographic feldwork, we found that the humorous atmosphere at the regularly
held physical berthing meetings fosters a sense of community, which enables competing professions, private companies,
and public institutions to manage their mutual distrust. In an environment where trust among competitors is unrealistic, we
argue that the objective of the performance of humor and transparency at the physical berthing meetings is the management
of distrust rather than the creation of trust. The meetings have, gradually, grown to serve as a pragmatic local stakeholder
adaptation to the challenges posed by universally perceived politicized, opaque, and corrupt business practices at the Port
of Tema and beyond. In conclusion, we posit that our empirical fndings allow us to identify the potential of and gaps in
theories about trust and humor in understanding the dynamics of coping strategies among competitors in business settings
that are characterized by unethical practices.
A new power-to-X desulfurization technology has been examined. The technology uses only electricity to oxidize the hydrogen sulfide (H2S) found in biogas to elemental sulfur. The process works by using a scrubber where the biogas comes into contact with a chlorine containing liquid. This process is capable of removing close to 100% of H2S in biogas. In this paper a parameter analysis of process parameters has been carried out. In addition a long term test of the process has been performed. It has been found that the liquid flow rate has a small but notable influence on the process’ performance on removing H2S. The efficiency of the process largely depends on total amount of H2S flowing through the scrubber. As the H2S concentration increases, the amount of chlorine required for the removal process is also increased. A high amount of chlorine in the solvent may lead to unwanted side reactions.