Merchant Ships Research Articles

A combined experimental and numerical approach to predict ship resistance and power demand in broken ice

Despite its remoteness and hostile environmental conditions, the Arctic holds significant shipping lanes, such as the Northern Sea Route (NSR) and the Northwest Passage (NWP). Typically, merchant ships operate along these routes in summer only, when the dominating type of ice is broken ice. A challenge of operating in such ice conditions is that there is no cost- and time-efficient method for predicting the resulting ice resistance, which makes route planning difficult, among others. To address this challenge, we present and analyze two complementary approaches to predict ship resistance in broken ice, of which one is experimental and the other numerical. The experimental approach makes use of a type of non-refrigerated synthetic model ice made of polypropylene, which makes it possible to test how a ship behaves in broken ice using a conventional non-refrigerated towing tank rather than an ice tank. The numerical approach, in turn, is based on the CFD-DEM method and can be used to consider fluid effects, such as the changes in fluid velocity and ship waves, while the ship is moving ahead. Validation calculations against established empirical approaches indicate that both approaches are reasonably accurate.

Piracy in the Gulf of Guinea and the Role of African Regional Organisations in Ensuring Security of Maritime Shipping

The first decade of the XXI century witnessed a rise in piracy in some regions of the world, including the Gulf of Guinea. The purposes of this article are to find out historical reasons of the emergence of piracy in off the West coast of Africa and to analyse the participation of African regional organisations in the struggle for ensuring security of maritime shipping in the Gulf of Guinea. The initial surge in incidence of attacks against merchant ships was caused by anti-governmental groups, which adopted pirate tactics. Later, piracy off the shores of Central and West Africa turned into a profitable type of organised crime. Pirates of the Gulf of Guinea inflicted significant damage to economic development of the countries of the region and began to pose a threat to shipping off the West African shore of the Atlantic. The article describes how interregional cooperation with external partnership was organised to counter transborder nature of pirate activities. Based on regional organisations, specifically, the Economic Community of Central African States (ECCAS) and the Economic Community of West African States (ECOWAS), the maritime security summit held on June 24–25, 2013 in Yaoundé adopted the Code of Conduct, which contained a list of measures to combat piracy. The Code of Conduct envisaged close cooperation among the nations of Central and West Africa with help of “external” partners in order to ensure rapid reaction to counter pirate attacks. Research of the problem indicates that only consecutive realisation of these measures allowed to reach a tangible result almost 10 years later, namely, in 2022. Nevertheless, if control over waters of the Gulf of Guinea is weakened, piracy may resurge, because its social and economic roots still exist.

About the need for an assessment on the risk of pollution from the fuel on board the shipwreck of the former USS Peacock in the Bay of Cartagena de Indias

The tugboat USS Peacock was sunk near the tip of the Castillogrande peninsula in the Bay of Cartagena when it accidentally collided with the Norwegian-flagged merchant ship MS Hindanger on 23 August 1940. Almost split in two, it quickly sank, killing three crew members while 23 were rescued. Since it started to be monitored in 1992, it has been noted that fuel drops sporadically come out of the shipwreck and its position coincides with the measurements of the highest concentration of hydrocarbons in the bay. The Diving and Salvage Department of the Colombian Navy has been monitoring this situation that is still ongoing. Therefore, this article suggests a research project to evaluate of the amount of fuel that the shipwreck may have on board and to study the alternatives to remove it in order to allay the environmental risk.

The Dimple Effect on Flettner Rotors for the Wind Power Drive System of a Sailing Merchant Ship

Wind-powered ship propulsion is investigated in relation to reducing ship exhaust emissions, such as the application of Flettner rotor systems. How to increase rotor thrust's contribution to ship speed is an intriguing research question. This paper investigates the influence of dimples on the surface of a Flettner rotor on its ability to generate thrust for a ship. The CFD code, which includes the Reynolds average Navier-Stokes equation and the k-ω model for turbulent flow, is utilized to analyse three rotor designs: one with a smooth surface and two with dimple surfaces of varying diameters. Lift and drag are computed by taking into account varying spin ratios and the incoming wind angle. The CFD results are validated by comparing them to experimental data gathered in a wind tunnel and determining that their error is less than 5%. The addition of dimpled surfaces to the rotor increases lift by 69.6% and decreases drag by 14.8% due to the smooth surface. For the case study, the two rotors are mounted on the sailing ship 900 DWT and can generate the most thrust to give the ship a speed of 8.5 knots with a spin ratio of 4 and apparent wind angles of 90o or 270o relative to its speed.

Detection of SARS-CoV-2 in aerosols in long term care facilities and other indoor spaces with known COVID-19 outbreaks

Coronavirus outbreaks are likely to occur in crowded and congregate indoor spaces, and their effects are most severe in vulnerable long term care facilities (LTCFs) residents. Public health officers benefit from tools that allow them to control COVID-19 outbreaks in vulnerable settings such as LTCFs, but which could be translated in the future to control other known and future virus outbreaks. This study aims to develop and test a methodology based on detection of SARS-CoV-2 in aerosol samples collected with personal pumps that could be easily implemented by public health officers. The proposed methodology was used to investigate the levels of SARS-CoV-2 in aerosol in indoor settings, mainly focusing on LTCFs, suffering COVID-19 outbreaks, or in the presence of known COVID-19 cases, and targeting the initial days after diagnosis.Aerosol samples (N = 18) were collected between November 2020 and March 2022 in Castelló (Spain) from LTCFs, merchant ships and a private home with recently infected COVID-19 cases. Sampling was performed for 24-h, onto 47 mm polytetrafluoroethylene (PTFE) and quartz filters, connected to personal pumps at 2 and 4 L/min respectively. RNA from filters was extracted and SARS-CoV-2 was determined by detection of regions N1 and N2 of the nucleocapsid gene alongside the E gene using RT-PCR technique.SARS-CoV-2 genetic material was detected in 87.5% samples. Concentrations ranged ND-19,525 gc/m3 (gene E). No genetic traces were detected in rooms from contacts that were isolated as a preventative measure. Very high levels were also measured at locations with poor ventilation. Aerosol measurement conducted with the proposed methodology provided useful information to public health officers and contributed to manage and control 12 different COVID-19 outbreaks.SARS-CoV-2 was detected in aerosol samples collected during outbreaks in congregate spaces. Indoor aerosol sampling is a useful tool in the early detection and management of COVID-19 outbreaks and supports epidemiological investigations.

An incremental singular value decomposition approach for large-scale spatially parallel & distributed but temporally serial data – applied to technical flows

The article presents a strategy and its algorithm to compile a simulation-accompanying, incremental Singular Value Decomposition (SVD) for time-evolving, spatially parallel discrete data sets. The framework addresses state-of-the-art PDE solvers for computational science and engineering applications. An important characteristic of such applications is that the spatial size of the data is often time-invariant and significantly exceeds the temporal size due to the large computational grid in 3D applications. Typical examples, which are also considered in this article, relate to results extracted from unsteady flow simulations. Herein, the flow data, which progresses over time, is frequently calculated spatially parallel based on domain decomposition strategies, which allow to parallelize the simulation on distributed memory machines following a Single Instruction Multiple Data (SIMD) concept.With a view to the memory-efficient reuse of (compressed) simulation results and their CPU time-saving, sufficiently accurate generation, the paper scrutinizes the efficiency of incremental/parallel SVD approaches for such simulation examples. To improve the computational efficiency, the introduction of a bunch matrix is proposed, which enables the aggregation of multiple time steps and SVD updates, and significantly increases the efficiency. The suggested strategy is verified and validated by simple 2D laminar single-phase flows and subsequently applied to more complex 2D and 3D turbulent two-phase flows. Emphasis is given to (a) the accuracy of SVD-based reconstruction, (b) the physical realizability of the reconstructed quantities, (c) the independence of domain partitioning, (d) an efficient snapshot bunching, and (e) related implementation aspects. In addition, the influence of lower and (adaptive) upper rank thresholds on the effort and accuracy is evaluated. A final application renders the practical benefits of the approach and refers to a merchant ship in head waves at Re = 1.4×107 and Fn = 0.26. The simulation involves 2880 processor cores and the related full-rank snapshot matrix has (108×104) entries. With a numerical overhead of O(10%), this snapshot matrix can be incrementally generated and compressed by O(95%). The compression is accompanied by only small errors in the integral force and local wave elevation of O(10−2%). This qualifies the method for an efficient subsequent data processing.

Novel marine ejector-compression waste heat-driven refrigeration system: Technical possibilities and environmental advantages

A novel combined ejector-compression refrigeration system for provision rooms of merchant ships was conceptualized and analyzed. The principle possibility of recovery of onboard low-grade heat (85–95 °С) of jacket cooling water was confirmed. Two ejectors of different geometries to ensure the ejector stage operation when the seawater temperature varies in a wide range were designed and proposed to install in parallel. The performance of the combined system was compared to a vapor-compression one and the choice of the rational temperatures in the condenser-evaporator tC/Ev was performed. The combined system COPtotal is considerably higher than the vapor-compression system, and it weakly depends on heat source temperature. At condensing temperature tC = 34 °С the decreasing in tC/Ev from 20/15 to 10/5 °С results in increasing of COPtotal up to 13.5 % at generation temperature tG = 80 °С and up to 15.6 % at tG = 90 °С. Utilizing the combined system for the onboard cold production will contribute to fuel savings of 25 to 33 % per voyage (operation and transport) vs. vapor-compression system. The combined system inherent the lower specific CO2 emission per 1 kW h of cooling energy emrefr than the standard system for all considered operation modes. The value of emrefr for combined system at tC/Ev = 10/5 °C, tG = 80 °C and tC = 36 °C or tC = 42 °C is 23.1% or 18.3%, respectively, less than for the vapor-compression one. The approach to analysis proposed can be used for assessment of the feasibility of utilization of low-grade heat and the retrofit of ship refrigeration systems.

Challenges for Seafarers Education and Training in the Context of Autonomous Ships Development

Education and training of seafarers are defined in the provisions of the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers (STCW Convention) and elaborated by the set of the International Maritime Organization (IMO) Model Courses. These documents represent minimum requirements for the education and training of seafarers at the international level. IMO member states shall integrate these requirements as appropriate into their maritime high school and college training programs and into training programs leading to STCW certification. Although there are different views in the literature and in practice about the existing seafarers training system, this system is standardized worldwide. This allows consistent acquisition of knowledge, skills, and competences for seafarers on merchant ships. The development and gradual introduction of autonomous ships raises numerous questions about the future trends of world shipping. Various researches are currently being conducted on autonomous ships. This technological progress brings with itself many challenges and one of them is the education of the personnel who will control and monitor these ships. It is clear that a new approach to seafarer’s education needs to be developed. The development of this concept opens numerous questions from different segments of shipping and maritime security in general, particularly in the context of maritime cyber security. The paper analyses the education concept for seafarers in the Republic of Croatia, paying special attention to trends related to the development and deployment of Maritime Autonomous Surface Ship (MASS).

The relationship between potential ergonomic hazard with complaints of musculoskeletal disorders

Introduction: The potential risk of ergonomics can cause musculoskeletal disorders (MSDs) is one of the causes of work accidents with complaints in various parts of the skeleton that are felt by a person, these complaints can be in the form of damage to joints, ligaments, and tendons. The purpose of this study was to develop potential ergonomic hazards and analyze complaints of Musculoskeletal disorders in thin plate, pipe, and machinery workshop workers of the commercial ship division of Shipbuilding Methods: This study used an observational research design with a cross-sectional design. The population used was 57 people from the thin plate, pipe, and machinery workshops in the merchant ship division, and used 50 people as samples by accidental sampling. The variables in this study were age, years of service, part of work, potential hazards of the ergonomics, and complaints of muscle disorders. The instruments used are questionnaire sheets and observation sheets contained in SNI 9011:2021. Analysis was carried out using the chi-square test using SPSS ver. 25. Results The results of this study indicate that all respondent workers are male with an age range of 21 to 45 years with a percentage (54%) aged 21-34 years, working period of 5 – 10 years a percentage (48%), and workers in the cutting or fit as much (42%). 38 respondents have a value of 7 potential ergonomic hazards which are dangerous. The neck, shoulders, lower back, and, calves are the parts that workers often complain about because they work in a sitting position with the lower back and looking down. Conclusion: There is a significant relationship between the level of risk of musculoskeletal disorders and potential ergonomic hazards. Further studies with more comprehensive designs are needed to validate these findings so that can be used as protocol or in further analysis.

Russia — Africa: old friends and perspective partners (on the example of Angola and Mozambique)

The article analyzes diplomatic, trade and economic relations, as well as military-technical cooperation between Russia and Angola, Russia and Mozambique caused by the growing role of African countries in world politics and economy. These African states traditionally hold a special place in the Russian, and previously Soviet, foreign policy. In the 21st century Africa is one of the most dynamically developing and promising regions in the world, which is reflected in the Concept of the Foreign Policy of the Russian Federation. This is evidenced by Foreign Minister Sergey Lavrov’s recent activity. In the first months of 2023, he has already toured Africa twice: from January 23 to 27 and from February 6 to 9. Russian-Angolan and Mozambican bilateral relations have been always seen as “reliable and timetested”. It was 1975 when the USSR established diplomatic relations with Angola and Mozambique after they gained independence from Portugal. During the Soviet Union ties between our countries were actively developing. After the collapse of the USSR bilateral cooperation signifi cantly decreased, while military-political collaboration continued, including the settlement of the armed conflict in Angola. At the present stage, our relations are developing in many directions. These are, in addition to military assistance, Russia’s participation in the development of Angolan diamond deposits, cooperation in the field of education, merchant shipping, as well as exploration and use of outer space for peaceful purposes. A new impetus to the development of relations is given by high-level visits “on the sidelines” of BRICS and the Russia-Africa Summits.

Observation and Modelling on the Shipping Noise in Shallow Waters with Complex Islands and Reefs of the East China Sea

The impact of the noise radiated from merchant ships on marine life has become an active area of research. In this paper, a methodology integrating observation at a single location and modelling the whole noise field in shallow waters is presented. Specifically, underwater radiated noise data of opportunistic merchant ships in the waters of Zhoushan Archipelago were collected at least one day in each month from January 2015 to November 2016. The noise data were analyzed and a modified empirical spectral source level (SSL) model of merchant ships was proposed inspired by the RANDI-3 model (Research Ambient Noise Directionality) methodology. Then combining the modified model with the realistic geoacoustic parameters and AIS data of observed merchant ships, the noise mappings in this area were performed with N×2D of Normal Mode calculations, in which the SSL of each ship was estimated using the modified model. The sound propagation at different receiving positions is different due to the shielding effect of islands and bottom topography. The methodology proposed in this paper may provide a reference for modelling shipping noise in shallow waters with islands and reefs.

Maritime Trade Regulatory Framework In India: Current Landscape, Historical Evolution, Challenges, And Future Directions

This comprehensive article explores the multifaceted regulatory framework governing maritime trade in India. Beginning with a historical overview of maritime regulation in India, tracing its roots from ancient civilizations to colonial rule and post-independence reforms, it provides a contextual backdrop for understanding the current landscape. The article meticulously dissects the key components of India's maritime regulatory framework, highlighting the significance of laws such as the Merchant Shipping Act, 1958, and the Major Port Trusts Act, 1963. It also sheds light on the role of customs regulations, the Directorate General of Shipping (DGS), and international conventions in shaping this framework. Recognizing the challenges that the maritime sector faces, the article discusses pressing issues such as infrastructure bottlenecks, bureaucratic inefficiencies, safety concerns, and the need for regulatory reforms. It underscores the urgency of modernization and adaptation to international standards and security protocols. Furthermore, the article delves into recent initiatives and reforms, including the Sagarmala Project and the National Maritime Policy, aimed at revitalizing the maritime sector and enhancing its competitiveness. It also discusses the digitalization efforts and ease-of-doing-business measures undertaken to streamline processes and reduce red tape. Lastly, the article contemplates the future prospects of India's maritime regulatory framework. It emphasizes the importance of infrastructure development, sustainability, digitalization, security, regulatory flexibility, and the promotion of coastal shipping as essential components of India's maritime strategy. In conclusion, this article paints a comprehensive picture of India's maritime regulatory landscape, from its historical evolution to its current challenges and future aspirations, emphasizing the nation's commitment to fostering a dynamic and thriving maritime trade ecosystem.

Mining and Analysis of the Traffic Information Situation in the South China Sea Based on Satellite AIS Data

The loading of Automatic Identification System equipment on low-orbiting satellites can adapt to the demand of exchanging data and information with greater “capacity” brought by the AIS data information of ships in deep waters that cannot be covered by land-based stations. The information in the satellite AIS data contains a large number of potential features of ship activities, and by selecting the ship satellite AIS data of typical months in the South China Sea in 2020. Data mining, geographic information system, and traffic flow theory are used to visualize and analyze the ship activities in the South China Sea. The study shows that the distribution of ship routes in the South China Sea is highly compatible with the recommended routes of merchant ships, and the width of the track belt is obviously characterized. The number of ships passing through the southern waters of the Taiwan Strait has increased significantly, and the focus of traffic safety in the South China Sea should also focus on major route belt and important straits.

The Use of Private Contracted Armed Security Personnel (PCASP) As A Measure and Solution of Anti-Piracy

The sea route is one of the best options chosen by national and international traders because of lower cost when we compare it to using air freight and the increasing use of merchant ships for international trade, makes people take advantages such as sea piracy and armed robbery and a solution to protect from these things commercial vessels use the services of the Private Contracted Armed Security Personnel (PCASP) and the Private Maritime Security Company (PMSC). The absence of international regulations regarding the use of these services raises pros and cons between coastal states and with special policies in particular regarding the territorial sea of ​​a coastal state. Thus, there is a big question that the use of PCASP and PMSC is in accordance with international law with existing regulations and how Indonesia as a coastal state sees the use of such services as a solution to avoid piracy. The formation of soft laws and agreements is a way out at this time in order to maintain maritime security from the dangers of sea piracy and armed robberies.

The maritime consequences of peace: The impact of treaties with the Barbary states on Venetian shipping in the eighteenth century

From a maritime-history perspective, little is still known about eighteenth-century Venice, especially in non-Italian literature. Classic interpretations of eighteenth-century Venetian shipping suggest that the Venetians never regained a significant role as carriers in the Mediterranean after the sixteenth century. Although Venetian shipping was heavily impacted by the arrival of the ‘Northerners’ in the Mediterranean at the end of the sixteenth century, its capacity for long-term recovery has yet to be clarified. The primary impediment to Venetian maritime activity was the high threat of attacks by the so-called ‘Barbary corsairs’ on their merchant ships, which drove up transport costs. The Republic of Venice signed treaties with Algiers, Morocco, Tripoli and Tunis from 1763 onwards, but historians remain sceptical about the effects of this peace. This article seeks to demonstrate that the treaties with the Barbary states represented a groundbreaking turning point for eighteenth-century Venetian shipping: from the 1760s onwards, liberated from the burden of high risks and high protection costs, Venetian shipping made a vigorous and lasting resurgence on all routes in the Mediterranean and beyond. Following the treaties, the Venetians became significant carriers in the Mediterranean sea trade and were able to rival other competitors in international markets. From this standpoint, the Venetian shipping sector not only recovered but also flourished until the ultimate dissolution of the Republic in 1797.

Determining The Main Criteria Required for The Green Transition of The Maritime Industry in Terms of MTME

In this study, the main criteria for the green transition of the maritime industry have been determined, taking into account the criteria determined by the International Maritime Organization (IMO) for the year 2050 and beyond. The criteria were prioritized using an AHP approach and the DEMATEL technique. The aim of the study is to determine whether the green conversion can meet the operational requirements of merchant ships. For this purpose, quantitative and qualitative research techniques were used as a hybrid. The ultimate goal of the study is to evaluate the impact of merchant ships, which will be built in the green concept, on the operational needs, within the framework of maritime transportation management engineering (MTME). At the end of the study, a gradual roadmap was presented to the maritime industry, which will prepare a strategic target plan within the scope of the green transition of the maritime industry.

Book Review: The Merchant Ship in the British Atlantic, 1600–1800, Continuity and Innovation in a Key Technology. Technology and Change in History by Phillip Reid

Book Review: <i>The Merchant Ship in the British Atlantic, 1600–1800, Continuity and Innovation in a Key Technology. Technology and Change in History</i> by Phillip Reid

Tozaltı Ve Gazaltı Kaynak Yöntemleri İle Birleştirilen Gemi İnşa Çeliğinin Kaynak Bölgesinin Mekanik Özelliklerinin İncelenmesi

Merchant ships are generally built by joining steels with various welding methods. When the welding methods used in shipyards are examined, it is seen that gas metal arc welding (GMAW), submerged arc welding (SAW), covered electrode arc welding and tungsten inert gas (TIG) welding come to the fore. In the assembly of ship hull sheets, GMAW and SAW are generally preferred. In this sense, it is extremely important to characterize the mechanical properties of the weld zone after welding of the shipbuilding steel joined by these two welding methods. When the studies examined, although there are few studies on the joining with GMAW and SAW of shipbuilding steels, no study has been found on the comparative examination of these two welding methods. In this context, within the scope of the study, 3701 shipbuilding steel, which is used extensively in shipbuilding, was joined with SAW and GMAW methods and the hardness, tensile, impact and bending properties of the welding zone were examined comparatively. In consequence of the tests, it was determined that higher mechanical properties were obtained than the base metal in both welding methods. Also, it was found that the welding zone of the shipbuilding steel joint by the SAW method had relatively better mechanical qualities.

Penerapan Terhadap Kepatuhan Konvensi Ballast Water Management Dari Awak Kapal Niaga Di Indonesia

The International Maritime Organization (IMO) through the Environmental Protection Committee (MEPC/Marine Environment Protection Committee) since 2004 has established the international Convention on the Control and Management of Ship's Ballast Water and Sediments (BWM 2004), which seeks to protect marine waters from the impact of water discharge. commercial ship ballast The aim of this research is to determine the extent of implementation of the 2004 BWM Convention in Indonesia through questionnaires and interviews given to seafarer respondents in Indonesia. The compliance of commercial ship crews with PTES shows that the ship crews have not implemented the Ballast Water Management Convention, namely exchanging ship ballast water at sea according to standard D 1. The results of a questionnaire conducted on Indonesian merchant ship crews consisting of student crew members and student officers show that water exchange Ballast in the middle of the sea by merchant ships is only worth 14.5%. Commercial ships that have documents related to Ballast Water Management are also obtained below the 24% figure. PTES managers should manage ballast water at ports as the cheapest and most efficient solution compared to managing ballast water by commercial ships.

Parametric Modelling of Rousselier ́s Damage Model Parameters with Instrumented Charpy Tests

This work presents Rousselier´s damage model parameters effect and their physical meaning on Charpy fracture propagation curves. Therefore, instrumented Charpy tests were performed at room test temperature to measure the load-displacement curve. The parameters were measured from a Grade A ship plate steel, employed for the construction of merchant ships. The effect of Rousselier´s model parameter was done by performing cellular automata finite element (CAFE) modelling, where Rousselier’s damage model was coded, and therefore Rousselier´s model parameters were incorporated using random number generators in the ductile arrays of cells, using Weibull distributions. Consequently, in each CAFE simulation, the model evaluates random values of Rousselier´s damage model parameters performing a more physically based modelling. The results showed that the present CAFE modelling was able to reproduce the hardening and fracture propagation regions of instrumented Charpy data. Furthermore, the present work showed a suitable Rousselier´s damage model parameters calibration procedure with Charpy data, and how each Rousselier´s model parameter can affect the hardening and fracture propagations regions when they are not properly calibrated, producing unrealistic results. Additionally, it can be observed that the present results can be used as a template for a better calibration of Rousselier´s damage model parameters in CAFE modelling.