Maritime security in the Gulf of Guinea is a challenge that straddles multiple players and sectors, and crimes like piracy cause disruptions to international trade and shipping. During the COVID-19 pandemic, the global shipping industry tried to keep maritime security on the agenda, while advocating for global security assemblages, specifically, transnational policing initiatives as part of the maritime security governance. Using the notion of narratives and assemblage thinking, it is argued that although global shipping and Ghanaian state agents agree on the problem, they differ on which maritime security governance infrastructure to deploy, resulting in tensions between the two parties.
Determining the key characteristics of a ship during the concept and preliminary design phases is a critical and intricate process. In this study, we propose an alternative to traditional empirical methods by introducing a model to estimate the main particulars of diesel-powered Z-Drive harbor tugboats. This prediction is performed to determine the main particulars of tugboats: length, beam, draft, and power concerning the required service speed and bollard pull values, employing Bayesian network and non-linear regression methods. We utilized a dataset comprising 476 samples from 68 distinct diesel-powered Z-Drive harbor tugboat series to construct this model. The case study results demonstrate that the established model accurately predicts the main parameters of a tugboat with the obtained average of mean absolute percentage error values; 6.574% for the Bayesian network and 5.795%, 9.955% for non-linear regression methods. This model, therefore, proves to be a practical and valuable tool for ship designers in determining the main particulars of ships during the concept design stage by reducing revision return possibilities in further stages of ship design.
The Nordic countries are ranked among the most gender equal countries worldwide. Equality, political, and civil rights, leading to the high participation of women in the workforce, have paved the way for this egalitarian view. However, women remain the minority in managerial positions in general, and they are also strongly underrepresented in many male‐dominated sectors of the blue economy. The aim of this article is to introduce and discuss gender equality in the blue economy, and to assess the status of gender research in the Nordic context. To achieve this, a purposive interdisciplinary literature review resulted in three encompassing themes on how women’s participation is hindered, overlooked, and undervalued. Using these themes as an analytical lens, we propose that the underlying mechanisms are similar within fisheries, aquaculture, and maritime transportation in how they affect women’s participation. Still, there is a lack of statistics and research within parts of the blue sector. To move forward, there needs to be a shift in focus from policy to practice. One starting point could be to implement current knowledge, e.g., regarding workplace design and tailoring equipment to fit a diverse workforce. We call for scaling up best practices and evaluating policy performance and effectiveness. These are prerequisites for sustainable recruitment and retention of the blue sector workforce and the only way forward for countries aspiring to be truly gender equal.
Power-to-X plants can generate renewable power and convert it into hydrogen or more advanced fuels for hard-to-abate sectors like the maritime industry. Using the Bornholm Energy Island in Denmark as a study case, this study investigates the off-grid production e-bio-fuel as marine fuels. It proposes a production pathway and an analysis method of the oil with a comparison with e-methanol. Production costs, optimal operations and system sizing are derived using an open-source techno-economic linear programming model. The renewable power source considered is a combination of solar photovoltaic and off-shore wind power. Both AEC and SOEC electrolyzer technologies are assessed for hydrogen production. The bio-fuel is produced by slow pyrolysis of straw pellet followed by an upgrading process: hydrodeoxygenation combined with decarboxylation. Due to its novelty, the techno-economic parameters of the upgraded pyrolyzed oil are derived experimentally. Experimental results highlight that the upgrading reaction conditions of 350 °C for 2h with one step of 1h at 150 °C, under 200 bars could effectively provide a fuel with a sufficient quality to meet maritime fuel specifications. It requires a supply of 0.014 kg H2/kgbiomass. Modeling results shows that a small scale plant constrained by the local availability of and biomass producing 71.5 GWh of fuel per year (13.3 kton of methanol or 7.9 kton of bio-fuel), reaches production costs of 54.2 €2019/GJmethanol and 19.3 €2019/GJbio-fuel. In a large scale facility, ten times larger, the production costs are reduced to 44.7 €2019/GJmethanol and 18.9 €2019/GJbio-fuel (scaling effects for the methanol pathway). Results show that, when sustainable biomass is available in sufficient quantities, upgraded pyrolysis oil is the cheapest option and the less carbon intensive (especially thanks to the biochar co-product). The pyrolysis unit represents the main costs but co-products revenues such as district heat sale and biochar as a credit could decrease the costs by a factor three.
Accurate estimation of the roll damping of a ship is important for reliable prediction of roll motions. In particular, characterization and prediction of parametric roll incidence and other events associated with large roll angles require detailed knowledge about the damping terms. In the present paper, an approach to identify the stability parameters, i.e. linear and nonlinear roll damping coefficients in conjunction with the natural roll frequency, based on onboard response measurements is proposed. The method starts by estimating the encountered wave profile using wave-induced response measurements other than roll, e.g., heave, pitch, and sway motions. The estimated wave profile is then fed into a physic-based nonlinear roll estimator, and then the stability parameters that best reproduce the measured roll motion are identified by optimization. In turn, in-situ identification can be achieved while simultaneously collecting the response measurements. A numerical investigation using synthetic response measurements is made first, then follows an experimental investigation using a scaled model ship. Good results have been obtained in both long-crested and short-crested irregular waves.
This work extends an existing seakeeping tool (OceanWave3D-seakeeping) to allow for the efficient and accurate evaluation of the hydroelastic response of large flexible ships sailing in waves. OceanWave3D-seakeeping solves the linearized potential flow problem using high-order finite differences on overlapping curvilinear body-fitted grids. Generalized modes are introduced to capture the flexural responses at both zero and non-zero forward speed, but we focus on the zero speed case here. The implementation of the hydroelastic solution is validated against experimental measurements and reference numerical solutions for three test cases. The ship girder is approximated by an Euler–Bernoulli beam, so only elastic bending deformation is considered and sheer effects are neglected. Some controversy has long existed in the literature about the correct form of the linearized hydrostatic stiffness terms for flexible modes, with Newman (1994) and Malenica and Bigot (2020) arriving at different forms. We provide here a complete derivation of both forms (including the gravitational terms) and demonstrate the equivalence of the buoyancy terms for pure elastic motions.
As ocean space increasingly is used for production purposes, such as for the production of food and feed, renewable energy and resource mining, competition for space becomes a concern. A spatial solution to this is to co-locate activities in a multi-use setting. Next to the direct (financial) costs and benefits of multi-use and the societal cost and benefits, there are other factors, in the realm of legal aspects, insurance, health and safety issues and the overall governance of multi-use, that determine whether multi-use can be implemented successfully. This includes transaction costs that arise when for example non-adequate regulation, governance and insurance schemes are in place. Based on the analysis of five case studies across Europe these combined/collective transaction costs of multi-use are analysed and suggestions how to reduce and/or overcome these transaction costs are presented.
Background: Autonomous ships have the potential to increase operational efficiency and reduce carbon footprints through technology and innovation. However, there is no comprehensive literature review of all the different types of papers related to autonomous ships, especially with regard to their integration with ports. This paper takes a systematic review approach to extract and summarize the main topics related to autonomous ships in the fields of container shipping and port management. Methods: A machine learning method is used to extract the main topics from more than 2000 journal publications indexed in WoS and Scopus. Results: The research findings highlight key issues related to technology, cybersecurity, data governance, regulations, and legal frameworks, providing a different perspective compared to human manual reviews of papers. Conclusions: Our search results confirm several recommendations. First, from a technological perspective, it is advised to increase support for the research and development of autonomous underwater vehicles and unmanned aerial vehicles, establish safety standards, mandate testing of wave model evaluation systems, and promote international standardization. Second, from a cyber–physical systems perspective, efforts should be made to strengthen logistics and supply chains for autonomous ships, establish data governance protocols, enforce strict control over IoT device data, and strengthen cybersecurity measures. Third, from an environmental perspective, measures should be implemented to address the environmental impact of autonomous ships. This can be achieved by promoting international agreements from a global societal standpoint and clarifying the legal framework regarding liability in the event of accidents.
Background: Evidence on workplace safety and health promotion interventions shows that the
interventions have failed to demonstrate substantial benefits for seafarers. It is therefore important to explore what is the evidence of interventions with empowering elements regarding seafarers’ safety and health. This study aims to examine what is known about health promotion interventions in a maritime setting and whether they include an empowerment perspective. And secondly, what were the effects of these efforts. Methods: We systematically searched PubMed and NLM Gateway (for MEDLINE), Institute of Scientific Information/Web of Science (ISI/WOS), and SCOPUS up to July 2022 by using standard keywords including empowerment in the maritime setting. Data extraction was done by three independent reviewers. The quality of included studies was assessed by using the critical appraisal checklists from Joanna Briggs institute. Results: From 3313 studies initially identified, 10 articles met the inclusion criteria and were included in this review. Interventions covered a wide range of topics such as educational interventions on safety, first aid training, weight management, healthy eating, sexual harassment, alcohol abuse, and cancer prevention training. None of the studies applied a specific theory or definitions of empowerment
even though their aim was to increase seafarers’ empowerment in these areas. Conclusion: The studies focused on improving the safety and health status of the seafarers, however, they had no explicit focus on participation and empowerment. Increasing research with an empowerment approach in maritime sector is recommended to enhance the feasibility and
success of the programs in this hard-to-reach occupation.
This paper presents a detailed risk assessment framework tailored for retrofitting ship structures towards eco-friendliness. Addressing a critical gap in current research, it proposes a comprehensive strategy integrating technical, environmental, economic, and regulatory considerations. The framework, grounded in the Failure Mode, Effects, and Criticality Analysis (FMECA) approach, adeptly combines quantitative and qualitative methodologies to assess the feasibility and impact of retrofitting technologies. A case study on ferry electrification, highlighting options like fully electric and hybrid propulsion systems, illustrates the application of this framework. Fully Electric Systems pose challenges such as ensuring ample battery capacity and establishing the requisite charging infrastructure, despite offering significant emission reductions. Hybrid systems present a flexible alternative, balancing electric operation with conventional fuel to reduce emissions without compromising range. This study emphasizes a holistic risk mitigation strategy, aligning advanced technological applications with environmental and economic viability within a strict regulatory context. It advocates for specific risk control measures that refine retrofitting practices, guiding the maritime industry towards a more sustainable future within an evolving technological and regulatory landscape.