Ship Operation Research Articles

A risk assessment of an autonomous navigation system for a maritime autonomous surface ship

thorough reformation in multiple domains, one of which is ship navigation and operation. Significant efforts have recently been targeted towards the research and development The maritime industry is undergoing a of Marine Autonomous Surface Ships (MASS). It is expected that, with the introduction of maritime autonomous technologies the safety performance of maritime operations increases. Nevertheless, the safety of the MASS must be properly planned and then demonstrated. This applies to the functionality of any Autonomous Navigation System (ANS). The nature of the risks related to an ANS might differ significantly from the traditional maritime risks. Therefore, mitigating these risks before applying an ANS to real-world operations is critical. This study analyses and assesses the risks of a currently developed ANS by integrating the System-Theoretic Process Analysis (STPA) and Bayesian Networks (BN) into a two-stage process. The study results provide a holistic view of the underlying risks in the ANS and the functionality of formulated Risk Control Options. The risk levels of loss events are computed within a model to represent the effects that each loss may have on the safety of the ship’s navigation and the company’s overall reputation. The assessed Risk Control Options provide information to system developers to elaborate an ANS that is safe by design.

A New Approach to Risk Assessment Model and Management for Jetty Fuel Terminal Industrywide Using Risk Priority Number

Jetty is an essential part of a fuel terminal and oil distribution process in terms of loading and unloading oil from and to tanker. Jetty has been widely used in fuel supply point facilities in archipelago countries like Indonesia. The increase in the importance given to maritime transportation has not only resulted in the development of the structure of safety issues but has also led to new investigations into the design of ships, the configuration of ports, and the operations conducted, all of which are essential components. However, it is not possible to ignore the risk inherent in jetty fuel terminal operations. Most of the reseach have pre-dominantly focused on the operation and impact of ship maneuvers and ship operations. But focusing on the jetty fuel risk itself is also very important as a whole part of reliability of a fuel receiving facility. FMEA is frequently used as a risk analysis method in determining risks arising from oil and gas sector. Each category of Severity, Occurance, and Detection from each risk factor can be rated to obtained the Risk Priority Number value. Mooring facilities assessment furthermore provides the implementation of assessment (grading) of operational suitability of jetties, based on the results of a visual assessment and special inspections. This paper aims to identify the risk associated with and to analyze these risk using Risk Priority Number ranking.

Controlling Engine Load Distribution in LNG Ship Propulsion Systems to Optimize Gas Emissions and Fuel Consumption

The increasing emphasis on environmental sustainability and stricter gas emissions regulations has made the optimization of fuel and emissions a crucial factor for marine propulsion systems. This paper investigates the potential to improve fuel efficiency and reduce emissions of LNG ship propulsion systems by using different load sharing strategies in Dual-Fuel Diesel-Electric (DFDE) propulsion systems. Using data collected from on-board cyclic measurements and an optimization model, the effects of different load sharing strategies for various types of fuel, such as HFO, MDO, and LNG, under different engine load conditions were investigated. The results of these strategies are compared with those of on-board power management systems (PMS), which evenly allocate power among the engines, irrespective of fuel usage and emission levels. The results show that load adjustments according to the optimization model can considerably increase fuel economy and contribute to the reduction of CO2 and NOx compared to standard practice at the equal load in different ship operating modes. Our approach introduces an innovative optimization concept that has been proven to improve fuel efficiency and reduce emissions beyond standard practices. This paper demonstrates the robustness of the model in balancing environmental and operational objectives and presents an effective approach for more sustainable and efficient ship operations. The results are in line with global sustainability efforts and provide valuable insights for future innovations in energy optimization and ship emission control.

TCN-MBMAResNet: a novel fault diagnosis method for small marine rolling bearings based on time convolutional neural network in tandem with multi-branch residual network

Abstract Centrifugal pumps are key components of marine systems, and the health of their internal rolling bearings is critical for the normal operation of ships. In small ship replenishment systems, the rolling bearings of centrifugal pumps often have short failure times, making it difficult to gather balanced failure data. This paper addresses the challenges in extracting fault features from centrifugal pump bearings in ship water replenishment systems and the low accuracy of fault identification caused by unbalanced data samples. We propose a fault diagnosis method that combines a Time Convolutional Neural Network (TCN) with Multi-branch Mixed Attention Residual Networks (MBMAResNet). This paper introduces TCN to capture dependencies in long time series and optimize the feature distribution of raw data. The captured multi-channel 1-D feature sequences are converted into 2-D feature maps to provide spatially correlated features for the designed MBMAResNet. Multiple Single Path Fusion Residual Blocks (SPFBs) with different scales are designed in the MBMAResNet to further extract effective fault features from the unbalanced samples, and a feature fusion structure is utilized for further feature enhancement. Additionally, improved Convolutional Block Attention Modules (CBAMs) are integrated into the network to increase the significance of valid channels and spatial locations. Experiments on an unbalanced public dataset and a private centrifugal pump faulty bearing dataset achieved diagnostic accuracies of 99.71 and 98.50, respectively, demonstrating that our method offers higher accuracy and generalizability compared to other methods.

Maritime Autonomous Surface Ships: Architecture for Autonomous Navigation Systems

The development of Maritime Autonomous Surface Ships (MASS) has seen significant advancements in recent years, yet there remains a lack of comprehensive studies that holistically address the architecture of autonomous navigation systems and explain the complexity of their individual elements. This paper aims to bridge this gap by conducting a literature review that consolidates key research in the field and presents a detailed architecture of autonomous navigation systems. The results of this study identify several major clusters essential to MASS navigation architecture, including (1) autonomous navigation architecture, (2) decision-making and action-taking system, (3) situational awareness and associated technologies, (4) sensor fusion technology, (5) collision avoidance subsystems, (6) motion control and path following, and (7) mooring and unmooring. Each cluster is further dissected into sub-clusters, highlighting the intricate and interdependent nature of the components that facilitate autonomous navigation. The implications of this study are vital for multiple stakeholders. Ship captains and seafarers must be prepared for new navigation technologies, while managers and practitioners can use this architecture to better understand and implement these systems. Researchers will find a foundation for future investigations, particularly in filling knowledge gaps related to autonomous ship operations. This study makes a substantial contribution by filling a critical gap in the maritime literature, offering a detailed explanation of the elements within autonomous navigation systems.

Development of a Multidimensional Analysis and Integrated Visualization Method for Maritime Traffic Behaviors Using DBSCAN-Based Dynamic Clustering

Automatic Identification System (AIS) data offer essential insights into maritime traffic patterns; however, effective visualization tools for decision-making remain limited. This study presents an integrated visualization processing method to support ship operators by identifying maritime traffic behavior information, such as traffic density, direction, and flow in specific sea navigational areas. We analyzed AIS dynamic data from a specific sea area, calculated ship density distributions across a grid lattice, and obtained visualizations of traffic-dense areas as heat maps. Using the density-based spatial clustering of applications with a noise algorithm, we detected traffic direction at each grid point, which was visualized in the form of directional arrows, and clustered ship trajectories to identify representative traffic flows. The visualizations were integrated and overlaid onto an S-57-based electronic nautical map for Mokpo’s entry and exit routes, revealing primary shipping lanes and critical inflection points within the target area. This integrated visualization method simultaneously displays traffic density, flow, and customary routes. It is adapted for the electronic nautical chart (S-101) under the next-generation hydrographic information standard (S-100), which can be used as a tool to support decision-making for ship operators.

Redesign of User Experience in Inaportnet Using the User Experience Questionnaire Method TND User-Centered Design

The Directorate General of Sea Transportation, under Indonesia's Ministry of Transportation, developed Inaportnet as a digital platform mandated by Ministerial Regulation Number PM 8 of 2022 to streamline ship service procedures and enhance e-government implementation. This study evaluates the user experience (UX) of the Inaportnet website, focusing on its usability, security, and overall design using a user-centred design (UCD) approach and the User Experience Questionnaire (UEQ) method. Data were collected from 56 respondents, including stakeholders such as ship operators, port authorities, and service users. The findings reveal critical shortcomings: 95% of respondents encountered frequent bugs affecting usability, 65% highlighted security concerns, 60% criticised the cluttered interface, 40% experienced access failures, and 50% expressed low engagement with the platform's features. To address these challenges, the website was redesigned using UCD principles, resulting in significant improvements. The redesigned platform achieved "Good" ratings for attractiveness, stimulation, and novelty, and "Above Average" ratings for clarity, efficiency, and accuracy in UEQ metrics, indicating enhanced usability and user satisfaction. This study underscores the importance of iterative UX design in optimising digital government systems, offering actionable insights for improving public service platforms in developing countries.

The digital twin of complex shipboard DC microgrids: The high‐performing synergy of compiled models and HIL platform in the dynamics emulation of zonal power electronic power distribution systems

AbstractNowadays, resilience is a crucial attribute to be pursued in advanced shipboard DC microgrids. When the power distribution is zonal, the presence of autonomous‐controlled converters guarantees both power use and resiliency improvement. The adoption of bidirectional controlled devices ensures power routing among generating units, storage, and loads. Moreover, zonal electrical distribution systems are effective in applying the optimization algorithms for green, safe, and high‐performing ship operation. In zonal DC microgrids, real‐time cooperation among controlled converters through properly set communication protocols enables the ship mission achievement. To this aim, functional tests are to be done on such complex power infrastructure. The digital twin approach provides the de‐risking step before the onboard deployment for controlled systems and communication. A zonal DC shipboard microgrid is the case study to test the synergy between compiled models and power converters on two hardware in the loop platforms, then verified by experiment in this paper. The first platform exploits the Linux real time application interface on the average value models of converters. This solution is then compared with a platform that utilizes the Typhoon hardware in the loop environment, proposing a combination of average value models and detailed switching models for the real‐time emulation of controlled grid.

Sustainability for ship operations in seaport areas: Technical solutions and environmental assessment.

The International Convention for the Prevention of Pollution from Ships (MARPOL) has prohibited ships using of HFO in ports. For this reason, during in port operations, different strategies must be adopted, based on the use of cleaner fuels or on the transition towards marine electrical technologies. In this context, the purpose of the present research is to analyze and compare, from an environmental and economic points of view, different technical solutions for in port operations. Four alternative configurations have been proposed: Solution 1, Battery & Internal Combustion Engine (ICE); Solution 2, Battery & Fuel Cell (FC) with yellow hydrogen; Solution 3, Battery & Fuel Cell (FC) with green hydrogen, and Solution 4, Battery & Cold Ironing (CI). From the environmental perspective, the Well-to-Waves (WTW) analysis has been carried out; from the economic point of view, the investment costs and the operating costs have been calculated and compared. Moreover, an economic performance indicator, the Economic-Environmental Correlation specific Index (ECI), has been introduced and evaluated. Results highlighted that from environmental point of view, the best solution is achieved implementing the Battery & Fuel Cell (FC) solution. On the other hand, the Battery & Cold Ironing (CI) solution represents the best solution from the economic point of view, allowing to obtain the lowest ECI.

수상레저 활성화를 위한 수상레저기구 운항 및 금지구역에 대한 비교연구

As the technology of water leisure craft develops, safety is improved and related standards suitable for domestic coastal terrain should be reviewed for the purpose of suitable craft facilities and reasonable operation of the navigation zone system. and the criteria for setting operation/prohibited areas that reflect the characteristics of each area and craft need to be reestablished.. The concept and definition of water leisure craft need to be improved as a water leisure “activity area” that performs leisure activities differently from ship operation.. In addition, it is thought that the water leisure activity prohibited zone should be reviewed in consideration of the current method of designating an area where entry is prohibited, as well as the standards for the accessible distance and equipment speed for human risk factors(swimming, skin scuba diving etc.), physical risk factors(navigation ships, other water leisure craft, breakwaters etc.).

The Influence of Community Empowerment Training for Inland Water Transport Ship Loaders on Students’ Knowledge and Skills

The causes of shipping accidents, as identified by the KNKT investigation, included technical, weather, and human factors. As a result, community empowerment training was conducted in 2023 for loaders of inland waterway transport vessels Class I. This training aimed to enhance participants’ knowledge, insight, and skills regarding loading arrangements and stability testing of inland waterway vessels. The study employed a quantitative descriptive method using primary data from evaluations, including pretests and posttests administered to 30 training participants. The analysis technique utilized was the paired t-test. Results obtained through the Wilcoxon Matched Pair test indicated a significant difference between pretest and posttest scores, leading to the conclusion that participants’ knowledge improved after completing the training. The findings revealed that, out of 30 training participants, only 2 experienced a decrease in scores. Conversely, 28 participants showed positive results (positive rankings), indicating an increase in scores. The average pretest score was 73.67, which increased to an average posttest score of 92.50 following the training. These results were further supported by the significant difference shown in the paired t-test analysis. In conclusion, there was a significant improvement in participants’ knowledge after the training. It is recommended that the program be expanded to include more participants to ensure that the broader community, particularly ship operators, benefits from increased knowledge of shipping safety and proper ship loading practices.

A conceptual model of autonomous ship remote operators' competency

Abstract The Shore Control Centre (SCC) is being developed and tested as an autonomous ship vessel with remote control. However, since the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers (STCW) regulation's competency standard has yet to be altered, it must be revised and modified. Therefore, this study aims to define the competency of remote operators on an autonomous ship from ashore and develop a conceptual model of remote operators' competency. This study used both primary data by interviewing executives from four groups of maritime experts, and secondary data from academic databases, IMO, classification society and maritime companies. Academic databases are employed to conclude the academicians' view on remote operators’ (ROs’) competency and the other data sources are used to conclude the industrial view on the RO's competency. The content analysis technique was used to determine the presence of keywords or concepts from secondary data and develop a conceptual model. The study's findings present four main dimensions to indicate the development of future training and development programs for RO officers: navigation, cargo handling and stowage, controlling the ship's operation and care for persons onboard, and information technology; and present 45 competencies of ROs for managing autonomous ships from ashore, which a conceptual model can explain.

Mechanism of Wear-Out of Sounding Pipes in Ship Ballast Tanks

During the operation of ships in the global commercial fleet, measurements of the current ballast level in ballast tanks are taken under various cargo and ballast conditions. As a result of repeated measurements, the structure at the bottom of the sounding pipes is damaged. The main cause is the impact of the weight at the end of the measuring instruments on the bottom of the pipe. Once the bottom of the pipe is destroyed, the impact is transferred to the hull or double bottom of the ship. In some cases, if timely measures are not taken to limit this phenomenon, the watertight integrity of the ship's hull is compromised. The article examines a possible mechanism of wear of the measuring pipes during the ship's operation. Repairing this type of wear takes a significant part of the ship's repair time and is accompanied by many associated tasks, the cost of which exceeds that of the repair itself. Approximate estimates of the time required for this type of wear to occur have been made. Measures to reduce this adverse effect are proposed.

Risk performance analysis model of escort operation in Arctic waters via an integrated FRAM and Bayesian network

Escort operation is an effective mean to ensure the safety of ship navigation in the Arctic ice area and expand the window period for ship navigation. At the same time, the operation mode between icebreaker and escorted ship may also causes collision accident. In order to scientifically reflect the complex coupling relationship in the escort operation system in Arctic waters and effectively manage the navigation risks. This study proposes to use the functional resonance analysis method (FRAM) to identify the risk factors of ship escort operation in Arctic waters, and uses the Bayesian network (BN) method to establish a risk assessment model for escort operation collision accident. The cloud model is used to process the uncertain data information. The proposed method is applied during the actual escort operation of a commercial ship on the Arctic Northeast Passage. According to the model simulation results, the risk performance of ship escort operation in Arctic waters is quantitatively analyzed, and the key risk causes are further analyzed. This study has positive significance for better understanding the risk evolution mechanism of ship escort operation in Arctic ice area and helping relevant management departments to take risk control measures.

Prosedur Pengurusan Rencana Pengoperasian Kapal (RPK) Menggunakan Sistem SIMLALA Oleh PT. Dian Bahari Perkasa Dumai

This paper aims to describe the Procedure for Managing Ship Operation Plans (RPK) using the SIMLALA System implemented by PT. Dian Bahari Perkasa Dumai. This research uses field research and library research methods. The RPK processing process through the SIMLALA system has been running smoothly, starting with a submission from the shipping company appointed by the ship owner to manage the RPK. The ship agent then attaches all the documents and requirements needed to submit the RPK via the SIMLALA system. After that, officers from the Harbormaster's Office and Port Authority checked the documents that had been uploaded to the system. If all documents have been checked, the Harbor Master's Office and Port Authority can issue a Ship Operation Plan (RPK) certificate through the SIMLALA System.

Early Fault Diagnosis and Prediction of Marine Large-Capacity Batteries Based on Real Data

The inconsistency of battery voltages in all-electric ships is a significant issue for electric vehicle battery systems, leading to numerous safety concerns during vessel operation. Therefore, timely fault diagnosis and accurate fault prediction are crucial for the safe operation of ships. This study examines the fault alarm system of marine battery management systems in conjunction with the unique operating conditions of ships, focusing on the system’s latency. To facilitate prompt fault detection, a fault diagnosis method based on the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm is proposed, utilizing the voltage data of battery clusters. Results indicate that the DBSCAN clustering algorithm demonstrates superior effectiveness and accuracy in identifying irregular battery clusters. Furthermore, the fault prediction method based on the iTransformer model is introduced to forecast variations in battery cluster voltages. Experimental findings suggest that this model can effectively predict consistency faults and over-/under-voltage conditions based on battery cluster voltage values and corresponding fault thresholds.

A Data-Driven Approach to Analyzing Fuel-Switching Behavior and Predictive Modeling of Liquefied Natural Gas and Low Sulfur Fuel Oil Consumption in Dual-Fuel Vessels

International shipping is responsible for approximately 2.7% of the global greenhouse gas emissions, a share expected to rise by as much as 250% by 2050. In response, the International Maritime Organization (IMO) has set ambitious targets to reduce these emissions to near-zero by 2050, focusing on alternative fuels like LNG. This study examines the energy consumption patterns of dual-fuel engines powered by LNG and develops machine learning models using LightGBM to predict fuel usage for both fuel oil (FO) and gas (GAS) modes. The methodology involved analyzing operational data to identify patterns in fuel usage across different voyage conditions. The FO mode was found to be predominantly used for rapid propulsion during speed changes or directional shifts, while the GAS mode was optimized for stable conditions to maximize fuel efficiency. Additionally, a mixed mode of FO and GAS was occasionally applied on complex routes to balance safety and efficiency. Using these insights, LightGBM models were trained to predict fuel consumption in each mode, achieving high accuracy with R2 scores of 0.94 for the GAS mode and 0.98 for the FO mode. This model enables ship operators to optimize fuel decisions in response to varying voyage conditions, resulting in reduced overall fuel consumption and lower CO2 emissions. By applying the predictive model, operators can adjust fuel usage strategies to match operational demands, potentially achieving notable cost savings and meeting stricter environmental regulations. Furthermore, the accurate estimation of fuel usage supports CO2 emissions management, aligning with the Carbon Intensity Indicator (CII) and providing ship operators with actionable data for fleet management optimization. This research provides essential data to support carbon emission compliance, improves fuel efficiency, and offers practical insights into fuel management strategies. The predictive model serves as a valuable resource for ship operators to optimize fuel use and aligns with the IMO’s environmental targets, aiding the maritime industry’s transition toward carbon neutrality.

Data-driven model for marine engine fault diagnosis using in-cylinder pressure signals

Effective diagnosis of marine engines that is crucial for safe and reliable ship operations requires fidel tools for the identification of critical faults. However, the unavailability of extensive measured data-sets corresponding to engine faulty conditions renders the development of such tools challenging. This study aims to develop a data-driven fault estimation model considering information extraction methods and regression techniques of low computational effort, namely multiple linear and polynomial regression. The required data-sets for healthy and faulty conditions for four critical faults and their combinations are generated by employing a calibrated zero-dimensional thermodynamic model representing a marine four stroke medium speed diesel engine, which is validated against engine shop trial measurements. Fourier analysis of the derived in-cylinder pressure profiles is employed to calculate the coefficients of the harmonic orders. Several harmonics coefficients sets are used as input to the regression models to estimate the severity of the four considered faults. The results demonstrate that initial 20 harmonics are sufficient to effectively estimate the severity for each fault, whereas polynomial regression is highly effective, exhibiting R 2 values greater than 98 % . This study provides insights on the data-driven simultaneous faults severity estimation, and as such it impacts the advancement of cost-effective diagnostic methods for marine engines.

Research of assessing the reliability of containers securing taking into account the actual metacentric height of the container ship

The study focuses on the impact of the metacentric height of container ships on the reliability of container securing systems in order to prevent container loss overboard, which is a significant issue in the shipping industry. It is noted that the increase in ship capacity is achieved by increasing the number of layers of containers stacked on deck. Dynamic loads on the securing means of containers stowed in the upper tiers of container stacks are increasing, that can be particularly dangerous in the intense rolling conditions. It is noted that the international shipping community is well aware of the significance of this issue and is working to develop solutions. Assessment of the expected reliability of securing systems and prevent container loss through a comprehensive analysis of relevant factors is considered. The complexity of this assessment lies in the presence of many uncertainties in the calculation algorithm. These uncertainties are supposed to be quantified taking into account the accumulated experience and statistical data within the framework of the TopTier industry project. Existing methods and calculation algorithms do not take into account the fact that the actual height of the center of gravity of containers differs from the accepted value. The goal of this article is to study the effect of the actual metacentric height of a container ship on the parameters of rolling and the loads on containers and their securing means depending on it. To do this, using the example of a real ultra large container ship, a comparative analysis of the effect of metacentric height on the rolling acceleration was performed. The effect of the rolling acceleration on the loads acting on the deck container stack has been shown. The necessity to take into account the actual height of the center of gravity of containers is justified for the correct determination the metacentric height of the container ship and calculation loads in order to ensure the safety of operation of container ships and prevent containers from being lost overboard.

Towards sustainable energy selection for ships in response to maritime regulation

Ship owners and operators are continuously seeking financially viable ways to comply with the Sulphur emission limits set out by the IMO, which calls for a reduction of sulphur content in ship fuel to less than 0.5 % in 2020. The prudent decision in managing required energy sources by shipowners/operators will lead to an efficient ship operating decision, subsequently resulting in long-term financial return. The study aims to identify the factors influencing ship owners and operators to select the energy types in operating their vessels. Furthermore, the research explores the most desired energy sources to address the IMO Sulphur Cap Regulations 2020. One operation research method, namely the Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE), and one econometrics tool, namely the conditional logit model, have been used to explore the research objectives. The PROMETHEE analysis suggests that clean fuel (VLSFO) is the best alternative to respond IMO 2020, followed by scrubber installation. The conditional logit analysis suggests almost the same, indicating clean fuel as the only alternative for responding to regulation. The decision is driven by the vessel's age negatively and the size of the vessel positively. The study will enormously impact the ship’s energy procurement practices in Bangladesh.