Search Results (84)

Merchant vessels often feature numerous perforations in their web frames. To enhance the buckling resistance of these perforated panels, it is customary to install local reinforcements around the openings. This research introduces a novel approach that segments perforated panels into separated unstiffened panels (SUPs) and applies recently updated classification rules for buckling strength assessment, supplemented by inelastic FEA. This research aims to show a case study on how to reduce shipbuilding expenses by conducting a quantitative analysis of the buckling strength of such panels. The study treated perforated panels as separated unstiffened panels (SUPs) in accordance with Common Structural Rules (CSR). The authors examined web frames from various types of carriers, including those for liquefied petroleum gas, containers, products, and crude oil. They gathered data on dimensions, materials, and applied loads for 96 SUPs in total. To assess the buckling strength of these SUPs, IACS rules, eigenvalue finite element analysis (FEA), and inelastic FEA were employed. We performed element size convergence analyses on a square unstiffened panel with simple support on all four edges, ultimately deciding on a 10 mm element size for both eigenvalue and inelastic FEAs. Additionally, inelastic FEAs were performed on the rectangular, unstiffened panels with various aspect ratios, and it was decided to use the average level of initial imperfection for the inelastic FEAs. The SUPs under investigation were classified into Method A and Method B based on CSR recommendations. The ultimate buckling strengths of the categorized SUPs were evaluated by CSR and inelastic FEA. CSR rules provided more conservative ultimate buckling strengths for SUPs corresponding to Method A, while inelastic FEA did for SUPs that were classified into Method B. On the other hand, the inelastic FEAs and CSR rules provided similar ultimate buckling strengths for SUPs requiring Method B. The eigenvalue FEA confirmed that Method B can be an alternative method to inelastic FEA and CSR rules. Significant cost savings were demonstrated by selectively applying CSR and inelastic FEAs for SUPs requiring Method A. The originality of this work lies in its application of the latest classification rule logic, detailed finite element validation using real ship data, and a cost-benefit analysis of reinforcement strategies. Full article

The frequent occurrence of collision accidents between merchant and fishing vessels in China’s offshore waters not only threatens human lives and property, but also disrupts shipping and fishing activities and may cause marine environmental pollution. To effectively reduce such accidents and increase maritime safety in Chinese coastal waters, this study integrates association rules with complex networks to develop a directed weighted network of causal factors. Grounded theory and the Human Factors Analysis and Classification System (HFACS) are applied to identify and categorize causal factors from 152 collision accident investigation reports. Potential causal relationships are mined using the association rule, which is then applied to construct the causal network. Finally, the topological characteristics of the network are analyzed. The results reveal that serious negligence in lookout, failure to assess collision risks properly, and failure to adopt a safe speed significantly impact collision accidents. These findings highlight the necessity of implementing targeted preventive measures to address critical factors. This study provides valuable insights for maritime stakeholders to develop effective strategies. Full article

The electrical installation of a ship includes the generation, transport and distribution of the generated electrical energy to the electrical consumers on board. In recent years, there have been many attempts to replace traditional auxiliary generators with renewable energy sources, in particular solar panels, as this is a highly developed technology on land. Accordingly, this paper analyzes the different energy requirements on board a merchant vessel and carries out a feasibility analysis. The feasibility analysis considers technical, economic and legal aspects. Sustainable aspects are analyzed too, due to their importance nowadays. It is verified that the use of solar panels is only technically feasible for a small part of the ship’s total consumption, as the area required by the panels to cover the total demand would exceed the available area of the ship. Therefore, the possibility of installing solar panels for the fire detection system only was analyzed. This is a technically and legally feasible solution, but not an economically viable one. However, from a sustainability point of view, which takes into account economic, social and environmental aspects, this proposal is appropriate. This study concludes that, while solar panels are not a viable solution for covering all energy needs on merchant ships, they can be used for specific systems such as the fire detection network or similar small consumers, albeit with economic limitations. These findings provide valuable insights for future research and practical implementations of renewable energy solutions in the maritime sector. Full article

With over 50,000 merchant vessels and nearly two million seafarers operating globally, more than 12,000 maritime incidents in the past decade underscore the urgent need for proactive safety measures to ensure the structural integrity of aging ships and safeguard the well-being of seafarers, who face harsh ocean environments in remote locations. The Digital Healthcare Engineering (DHE) framework offers a proactive solution to these challenges, comprising five interconnected modules: (1) real-time monitoring and measurement of health parameters, (2) transmission of collected data to land-based analytics centers, (3) data analytics and simulations leveraging digital twins, (4) AI-driven diagnostics and recommendations for remedial actions, and (5) predictive health analysis for optimal maintenance planning. This paper reviews the core technologies required to implement the DHE framework in real-world settings, with a specific focus on the well-being of seafarers and offshore workers, referred to as Human DHE (HDHE). Key technical challenges are identified, and practical solutions to address these challenges are proposed for each individual module. This paper also outlines future research directions to advance the development of an HDHE system, aiming to enhance the safety, health, and overall well-being of seafarers operating in demanding maritime environments. Full article

Preventing collision accidents between merchant ships and fishing vessels has long been a significant challenge for maritime safety in coastal waters. To quantitatively analyze the relationship between the risk factors contributing to these collisions, identify the key factors leading to such accidents, and develop effective prevention strategies, the N-K model was employed to examine the risk coupling mechanisms involved. The model was based on an analysis of 132 collision incidents between merchant ships and fishing vessels in China’s coastal waters from 2013 to 2023. The characteristics of these collision accidents were investigated, and the risk factors were categorized into four distinct types: human, management, environmental, and ship factors. The coupling of collision risk factors between merchant ships and fishing vessels was mainly considered from the perspective of the overall system, and the N-K model was used to calculate the probability and risk values associated with the coupling of these four risk factors. Modeling results indicated that the coupling value of four factors was 0.1083, which was 1.5 times greater than the maximum coupling value of three factors and 2.1 times greater than the maximum coupling value of two factors. The risk of collision accidents between merchant ships and fishing vessels increases gradually with an increase in the risk coupling factors. Among the four categories of factors, the risk coupling between the ship factors and environmental factors is associated with a relatively large probability of accidents. Appropriate countermeasures were proposed to implement effective preventive measures at the source of collision accidents. Full article

Marine reactors have been applied to floating nuclear power plants, naval vessels such as submarines, and civilian ships such as icebreakers. Nuclear-powered shipping is gaining increased interest because of decarbonization goals motivated by climate change. Enhanced reactor safety can potentially reduce regulatory and liability challenges to the adoption of nuclear propulsion systems for merchant ships. This gives strong impetus for reviewing past use of nuclear reactor systems in marine environments, especially from the perspective of any accident scenarios, lest planners be caught unaware of historical incidents. To that end, a loss of coolant accident (LOCA) in a Lenin icebreaker reactor in 1965 and disposal at sea of some of its damaged fuel and reactor vessel as well as the entire tri-reactor compartment is recounted. Full article

Fishing vessels are known to have a fatality rate from accidents nearly 100 times higher than that of merchant ships. However, since most cases are resolved internally without maritime tribunals, obtaining accurate statistics on accidents is challenging, making quantitative analysis and evaluation of accident risks difficult. Studies using inconsistent analytical methods often fail to converge on unified results or preventive measures, which contributes to the persistently high occurrence of fishing vessel accidents. Therefore, this study aimed to establish a standardized method for analyzing marine accidents on fishing vessels by applying the Formal Safety Assessment (FSA) technique, originally developed for merchant ships. The research focuses on the globally prevalent trap boat fishery, specifically examining common injuries occurring on fishing vessels. Quantitative data were collected from insurance approval records, while qualitative data were obtained through surveys. The research followed the five stages of the FSA framework: hazard identification, risk estimation, identification of risk control options, cost-benefit assessment, and recommendations for decision-making. The findings suggest that the FSA framework can be effectively applied to analyze fishing vessel accidents based on insurance data, leading to selective and effective preventive measures. Full article

The 2011 Fukushima disaster and the 2020 COVID-19 pandemic are two major 21st century events that were least expected while being highly disruptive, having an immediate as well as longer-term impact on shipping operations. However, while pandemics are a recurrent phenomenon of the “known-knowns” type, the combination of phenomena which led to Fukushima had no assigned probability; hence, no preparedness was in place, as this was practically a unique occurrence in shipping. Considering significant shipping incidents of various less or more uncommon etiologies, such as the capsizing of vessels, missile attacks on merchant ships or vessel-onto-bridge collisions, this conceptual paper puts forward a consequence-based approach for assessing and managing shocks in the maritime domain, especially the ones classified in the “unknown-unknowns” or “Black Swan” categories. In the context of preparedness theory, the authors propose the adoption by shipping businesses, in parallel to any other risk approaches and tools, of the Assessment-reaction-Recovery-Conversion (ArRC) framework for managing risk and of relevant key recovery indicators which may assist in (a) increasing resilience through focusing the recovery planning on consequence-oriented, root-neutral reactions and (b) in promoting a “bounce-back-better” frame of mind and action plan, contributing to faster and easier recovery after a shock of any type. Full article

Bengala, a steamer that sank in 1889 near Capo Rizzuto, Italy, was a relatively new vessel for its time, with an unusually short 18-year service life, given that steamers of the period typically operated for 30 to 40 years. Despite its brief history, SS Bengala played a significant role in the development of Italy’s young merchant navy, undergoing multiple ownership changes and serving various Italian shipping companies. Employed mainly along the route to Southeast Asia, it transported Italian migrants overseas and also participated in troop raids during the Italian military expedition to Eritrea in 1887. Despite its historical significance, no iconographic material has yet been found to depict SS Bengala, and archival research conducted in Italy and England has not uncovered any naval plans, photographs, or drawings of the ship. To overcome this gap, the authors employed new technologies and historical information to create a virtual reconstruction. This research combined archival sources with underwater surveys, including a detailed 3D survey by divers and archaeologists. Archival research, including consultation of official documents, provided critical information on the ship’s dimensions, superstructure, rigging, materials, and construction methods. The 3D modelling of the ship’s external hull, based on precise geometric data from the wreck site, offers a first step towards virtual reconstruction. The modelling is grounded in photogrammetric surveying techniques, ensuring high accuracy in the reconstruction process. The model can be used in augmented reality (AR) applications to enhance underwater exploration, allowing divers to visualise the reconstructed ship in its original environment. Additionally, it supports museum exhibits, interactive visualisations, and educational games, making it a valuable resource for engaging the public with maritime history and archaeology. Full article

The Blue Economy is a multi-layered economy in its content, although it only reflects the relation between the sea and business. Shipping plays an essential role in this economy, as it holds the largest market share. Sustainable shipping, however, requires the sustainability of a number of the components that make it up. One of the most important components is the training of marine personnel, and particularly the ship’s crew. Over the past two decades, the Lifelong Learning strategy has been firmly established in shipping, manifested through a variety of practices. In order to ensure the continuous and sustainable training of ship’s crews, the companies have introduced annual seminars, which aim to familiarize the officers with current business topics. This article analyzes the delivery methods and quality of training in six seminars conducted by four different shipping companies carried out in three different countries. The scientific method “interview” was used for gathering the necessary information for analysis of the strengths and weaknesses of this type of training, and the way it was conducted. A significant number of deck officers and engineers, participants in all seminars, were surveyed to create a clear picture of the quality of such education and training. Collected data were used for the analysis of the strengths, weaknesses, opportunities and threats (SWOT) associated with the surveyed fleet officer’s seminars. A comparative analysis of this type of postgraduate training was made, while taking in mind higher marine education and training. The article summarizes the authors’ experience of their sea service as Officers of the Watch and Masters on board of merchant vessels, as well as participants in postgraduate education and training. Conclusions for close cooperation between shipping companies and maritime educational institutions are made. Full article

In multi-vessel collision avoidance decision-making, the collision between merchant and fishing vessels is a significant challenge. This paper proposes a fuzzy fusion method for making avoidance decisions under the influence of the navigation environment. First, C-means clustering was used to collect and analyze Automatic Identification System (AIS) data from fishing vessels. On this basis, the environment collision risk was determined using fuzzy reasoning. Second, the basic collision risk is obtained by calculating the DCPA and TCPA, and the integrated Collision Risk Index (CRI) is concluded by fuzzy logic through basic collision risk and the environment collision risk. The similar cases are extracted from the fuzzy case database, and collision avoidance decisions for merchant vessels are formulated following fuzzy adjustments. Finally, to validate the method, data from Chengshantou coastal waters is employed for verification. The results show that it can provide theoretical guidance and practical value for merchant vessels in making collision avoidance decisions. Full article

Long kept in the British Library, a liturgical manuscript from the port of Haicheng, Fujian, holds details of the rich system of beliefs that Chinese sailors held. Originally untitled, the text by the shelfmark OR12693/18 is usually referred to as “Libation Ritual (for Ship Safety)” ([An Chuan] Zhuoxian Ke [(安船)酌献科]). Formerly, it was given scholarly attention mostly due to its addended lists of maritime placenames, which follows Qing-era sea routes across China’s coasts and to the South China Sea. Further inquiry into the manuscript’s terminology, deity names, and maritime knowledge confirms its deep relation to sailors’ lore. By tracing this text into a wide range of sources, this paper demonstrates how manuscript OR12693/18 reflects a cohesive maritime system of beliefs and knowledge. Manifested within the prayer are a hierarchical pantheon, ritual practices, and a perceived sacred seascape. Moreover, it is evident that the manuscript belonged to a tradition of sailing ritual masters who were regular members of the crew onboard junks. As such, this paper offers an analysis of a religious-professional tradition with trans-local aspects, shedding new light on seafaring in pre-modern China. Full article

With an estimated 32,000 annual fatalities, fishing vessel accidents are 100-fold deadlier than those involving merchant ships. Despite ongoing safety training, accident rates remain high. Since most fishing vessel accidents occur in small fishing vessels (<12 m) and are primarily attributable to human elements, this study focuses on small fishing vessel accidents where the human element is the primary cause, exploring preventive measures for major accident types and performing a type-specific risk assessment. First, we performed a quantitative analysis of frequently occurring accidents and the indirect factors influencing the human element using maritime accident statistics and surveys, respectively. Next, we employed the fault tree analysis technique proposed by the International Maritime Organization in its Formal Safety Assessment to quantitatively assess the rate of accidents caused by the human element attributable to various indirect factors. The primary indirect factors most significantly impacting the human element were ship factors (22.8%), people factors (18.9%), and organization on board (17.4%). Secondary factors included personal negligence (14.1%), aging equipment and poor maintenance (10.3%), and harsh natural conditions such as rough waves (9.6%). Eliminating the top three secondary indirect factors reduced accidents due to the human element by 15.4% (64.5−49.1%). Full article

The melting of Arctic ice has facilitated the successful navigation of merchant ships through the Arctic route, often requiring icebreakers for assistance. To reduce the risk of accidents between merchant vessels and icebreakers stemming from human errors during operations, this paper introduces an enhanced human reliability assessment approach. This method utilizes the Dynamic Bayesian Network (DBN) model, integrated with the information, decision, and action in crew context (IDAC) framework. First, a qualitative analysis of crew maneuvering behavior in scenarios involving a collision with the preceding vessel during icebreaker assistance is conducted using the IDAC model. Second, the D–S evidence theory and cloud models are integrated to process multi-source subjective data. Finally, the human error probability of crew members is quantified using the DBN. The research results indicate that during convoy operations, the maximum probability that the officer on watch (OOW) chooses an incorrect deceleration strategy is $8.259\times {10}^{-2}$ and the collision probability is $4.129\times {10}^{-3}$. Furthermore, this study also found that the factors of Team Effectiveness and Knowledge/Abilities during convoy operations have the greatest impact on collision occurrence. This research provides important guidance and recommendations for the safe navigation of merchant ships in the Arctic waters. By reducing human errors and adopting appropriate preventive measures, the risk of collisions between merchant ships and icebreakers can be significantly decreased. Full article

Ship maneuvering in ports is increasingly reduced because the increase in ship size is not proportional to the increase in port areas. Furthermore, the number of assisted vessels and the need for tugboats working in densely populated areas make it necessary to reduce the number of involved tugboats, reducing pollution and costs. Therefore, shiphandlers must know, in addition to the pivot point, the center of lateral resistance under any circumstance to optimize the assistance from tugboats and improve maritime navigation. From the literature, it is evident that the practical determination of the center of lateral resistance is still unknown. This paper aims to propose novel mathematical models to identify the position of this point and the most important variables that determine its position. For that, data of different ships in different conditions were obtained from a full mission bridge simulator. Afterwards, 15 novel mathematical models were developed, making use of artificial intelligence tools and training neural networks. The high determination factor reached in some models shows the accuracy of the obtained models. One advantage of the presented models is that they are very easy to be applied by shiphandlers, because highly well-known parameters are involved. Moreover, original 3D charts showing the combination of the input variables were generated to identify the map of the whole process. The very simple new models obtained and the novel 3D charts shown in the present paper can be considered useful and applicable by the shiphandlers of most of the merchant fleet to improve the efficiency and safety of maritime navigation in increasingly restricted waters. Full article