International Journal of Marine Engineering Innovation and Research
International Journal of Marine Engineering Innovation and Research A Sinta-2 accredited open access journal advancing original research and innovation in marine engineering, committed to fast peer-reviewed publishing for academia and industry worldwide. Submit Your Manuscript About the Journal Promoting the innovative marine engineering research and knowledge through open-access, peer-reviewed global collaboration. P-ISSN: 2541-5972 | E-ISSN: 2548-1479 Focus and Scope The International Journal of Marine Engineering Innovation and Research (IJMEIR) is a peer-reviewed, open-access journal dedicated to disseminating original research, innovations, and practical contributions in marine engineering. We welcome high-quality papers from both academia and industry covering all aspects of marine science, technology, and related fields. IJMEIR publishes quarterly issues and offers a fast publication process with broad international visibility and high citation impact. IJMEIR commitment is to provide a free platform for researchers worldwide to publish, read, and share valuable knowledge. IJMEIR scope includes marine engineering, marine technology, marine sciences, environmental engineering, and associated interdisciplinary areas. We invite you to contribute and advance marine innovation with us. Detailed Scope
Department of Marine Engineering, Institut Teknologi Sepuluh Nopember
Analysis of Ethylene Propene Cargo Loss During Discharge Using Root Cause Analysis
The transfer of ethylene-propene cargo from LPG/C vessels to onshore storage tanks is a critical operation in which measurement accuracy, temperature correction, and transfer system efficiency influence cargo integrity. This study analyses cargo loss during the discharge process using quantitative calculations and Root Cause Analysis (RCA). Cargo quantity was determined by calculating the apparent liquid volume (13,465.454 KL) from tank sounding data, followed by temperature correction using the shrinkage factor equation 1+α(t−T) with 𝛼 = 0.0000348. The corrected liquid volume obtained was 13,463.632 KL. Using an average density of 561.1 kg/m³, the calculated liquid mass reached 7,598.525 MT. Vapour volume was obtained by subtracting the liquid volume from the total tank capacity, producing 3,027.235 KL, which, after thermal correction, became 3,026.339 KL. With a gas factor of 0.0200851, the vapour mass was calculated as 59.207 MT, resulting in a total cargo mass of 7,657.732 MT. Comparison between ship and shore tank measurements showed a discrepancy of 78.482 MT or −2.294%, indicating cargo loss during transfer. RCA results identified suboptimal vapour return systems and temperature-induced density variations as dominant causes. Recommended improvements include optimising vapour recovery performance, implementing Automatic Tank Gauge (ATG) systems, and standardising temperature-corrected cargo calculations.
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Characterization of Gelam Wood Pellets: Effects of Compaction Pressure and Binder Type
Wood pellets represent a mechanical densification technology that enhances biomass density for more efficient utilization. In this study, Gelam wood was used as the raw material, with variations in binder type (palm sugar and molasses) and compaction pressure (40, 60, and 80 kg/cm²). An experimental approach was employed to directly evaluate the physical and combustion characteristics of the produced pellets. The results indicate that pellets without binder (C3) exhibit superior physical properties, particularly lower moisture and ash content. In contrast, pellets with binders—molasses (C1) and palm sugar (C2)—demonstrate higher calorific values that meet standard requirements. The increased volatile matter observed in C3 suggests a faster ignition and more reactive combustion behavior. Furthermore, combustion characteristics reveal that ignition time, ignition point, and combustion temperature increase proportionally with higher compaction pressure, while the combustion rate shows an inverse trend. Among the tested binders, molasses provides the most favorable combustion performance. Overall, pellets with higher density tend to produce shorter but more stable flames, indicating improved combustion stability. These findings highlight the significant role of compaction pressure and binder type in optimizing the quality and performance of Gelam wood pellets for energy applications.
Quality of Friction Stir Welding on High Density Polyethylene-Polypropylene Polymer
One solid-state welding technique that shows great potential in joining polymer materials is Friction Stir Welding (FSW), especially for various polymers like HDPE and PP. FSW can join materials with different mechanical and thermal characteristics without melting the material. The parameters used were a tool rotational speed of 1460 rpm, a feed rate of 30 mm/minute, a plunge depth of 3.84, and a tool tilt angle of 0 degrees for triangular, threaded cylindrical, and tapered groove cylindrical tools. To determine the quality of the welding, the methods used are Non-Destructive Testing (NDT) and Destructive Testing (DT). For NDT, the methods used are visual and radiographic testing. For DT, the tests used are tensile testing, bending testing, hardness testing, and macrostructure testing. From the research results, data were obtained, and the interpretation of the radiographic test showed that the FSW joint of the threaded and grooved tool had no defects, indicating that the FSW joint had good quality. This is supported by tensile strengths of 8 MPa and 4.2 MPa. Meanwhile, the triangular FSW tool showed defects from radiographic testing, such as voids or lack of fusion, with a tensile strength of 1.7 MPa. The highest bending strength obtained from the three tools was for the groove tool, with a bending strength of 16.6 MPa, because the increased material distribution during the welding process created a strong, uniform, and homogeneous surface flow. The bending strengths for the triangular and spiral tools were 15.2 MPa and 5.4 MPa, respectively. The hardness values for the three tools (threaded cylindrical, tapered groove cylindrical, and triangular) were 57.6 SHD, 57.7 SHD, and 60.1 SHD, respectively, which is because the heat from the triangular tool was the highest. The results of the visual test, NDT (Radiography test), are consistent with the macrostructure results: there are no defects in the threads and grooves of the FSW tool, while the FSW tool with a triangular shape has defects in the form of voids.The use of FSW for joining polymer materials in this study is in line with Sustainalbe Development Goals (SDGs) number 4 (Quality Education), 7 (Affordable and Clean energy), 8 (Decent Work and Economic Growth), and 9 (Industry, Innovation and Infrastructure)
Analysis of Fishing Vessel Queueing Models for Optimizing Palabuhanratu Fishing Port Operations
This study is motivated by the importance of operational efficiency in fishing ports in addressing the dynamics of vessel arrivals and limited service facilities. The objective of this study is to analyze a fishing vessel queue model to optimize port operations at the Palabuhanratu Port based on existing facility conditions. The methods used include field observation, interviews, and quantitative analysis using a queue model with a Poisson distribution approach for vessel arrivals and an exponential distribution for service. The results of the analysis show that the queue system follows the (M/M/5):(FCFS/~/~) model with five service points operating in parallel. The vessel arrival rate is relatively low compared to the service capacity, so that the port is in an under capacity condition with a high probability of an empty system and almost no waiting time in the queue. To improve optimization, scenarios were carried out to increase the number or frequency of vessels in several vessel size categories, namely 21 vessels (21–30 GT), 63 vessels (5–10 GT), 12 vessels (11–20 GT), 123 vessels (5–10 GT), 7 vessels (51–100 GT), 5 vessels (101–200 GT), 31 vessels (5–10 GT), and 4 vessels (11–20 GT). Simulation results show that the addition is able to increase the utilization of port facilities without causing significant queues, so that operational efficiency can be improved sustainably.
Effect of Hydrofoil Angle of Attack on Resistance Reduction and Lift Generation in a Planing Hull
Abstract¾Hydrodynamic resistance remains a key factor governing the performance of high-speed planing vessels, as it directly determines propulsion power requirements. Despite extensive studies on hydrofoil performance, the application of the NACA 6409 profile in planing hull vessels remains limited. In particular, its potential as a fixed hydrofoil configuration, which may reduce design complexity and enhance practical implementation, has not been thoroughly investigated. Therefore, this study aims to evaluate the effect of hydrofoil angle of attack on resistance reduction and lift generation in a small planing hull vessel. Numerical simulations were conducted using Computational Fluid Dynamics (CFD) in ANSYS Fluent with the SST k–ω turbulence model. Angles of attack of 0°, 5°, 10°, and 15° were analyzed at operating speeds of 15 and 20 knots under foilborne conditions. The results show that low angles of attack, particularly 0° and 5°, provide the greatest resistance reduction, achieving up to 63.3% lower total resistance compared to the non-hydrofoil configuration at 20 knots. In contrast, higher angles of attack (≥10°) increase resistance due to induced drag and flow separation. The hydrofoil configuration also reduces propulsion power requirements and enables foilborne operation at speeds above 15 knots with a minimum angle of attack of 5°. These findings identify the optimal operating range of the NACA 6409 hydrofoil and provide practical design guidance for improving the efficiency of hydrofoil-assisted planing vessels.
The Effect of Structural Configuration on the Effectiveness of Double Pontoon Floating Breakwater: A Review
The need for flexible and environmentally friendly coastal protection has driven the development of floating breakwaters (FBs), particularly the double pontoon floating breakwater (DPFB), which offers adaptive capabilities to varying wave conditions. Despite their widespread application, the effectiveness of DPFBs remains highly dependent on structural configuration, highlighting the need for a comprehensive literature review to understand wave attenuation mechanisms and the influence of design parameters on the transmission coefficient (KT) and reflection coefficient (KR). This review examines the fundamental principles of wave structure interaction for floating systems, energy dissipation mechanisms, and analyzes four key parameters that influence system performance: pontoon geometry, porosity, the presence or absence of inter-pontoon connectors, and gap spacing. The findings indicate that pontoon geometry is the dominant factor governing the initial hydrodynamic response, while porosity plays a significant role in creating effective internal energy dissipation. Gap spacing controls wave interference and resonance, whereas connector use affects the system's dynamic stability, though comparative studies on this aspect remain limited. Overall, wave attenuation effectiveness is not determined by a single parameter but by the combined interactions among these four aspects in influencing KT and KR values. This review emphasizes the need for further research on multi-parameter evaluation and the development of more realistic hydrodynamic models to achieve optimal, adaptive DPFB configurations across diverse marine environments.
Technical Language Barriers and Engineering Communication Challenges Among Marine Engine Officers: Implications for STCW Certification and Onboard Safety Performance
The engine room represents one of the most technically demanding and communicatively complex environments in maritime operations, yet engineering communication among marine engine officers remains substantially underexplored relative to the well-documented study of bridge communication. This study investigates technical language barriers and engineering communication challenges among marine engine officers within Indonesian maritime institutions, examining their implications for STCW certification outcomes and onboard safety performance. Using a mixed-methods design incorporating a validated technical communication assessment rubric, structured questionnaires, and semi-structured interviews with 115 participants comprising marine engineering educators, engineering cadets, and certified engine officers, the study identifies a pronounced proficiency deficit in machinery-related technical language, particularly in watch handover protocols and emergency engineering communication. Quantitative findings reveal that engineering cadets achieve an overall mean proficiency score of 2.05 on a four-point scale aligned with STCW Chapter III competency standards, falling within the Developing range across all four communication domains assessed. Qualitative analysis attributes this deficit to the dominance of Bahasa Indonesia as the medium of technical instruction, the absence of engineering-specific communication simulation, and a systemic disconnect between language training and technical training programs. The study contributes a theoretically grounded assessment framework specific to engine room communication and advances evidence-based recommendations for curriculum integration, simulator-based pedagogy, and regulatory quality assurance in Indonesian maritime engineering education.
Standardized Marine Communication Proficiency Among Deck Officers: A Competency-Based Assessment of SMCP Implementation Under STCW Convention Frameworks
Maritime communication failures remain a critical contributor to navigational accidents globally, yet the extent to which the IMO Standard Marine Communication Phrases (SMCP) are effectively implemented within maritime education institutions — particularly in major seafarer-supplying nations — remains underexplored. This study examines SMCP proficiency among deck officers and cadets at Indonesian maritime institutions through a competency-based assessment aligned with the STCW Manila Amendments. Using a mixed-methods design incorporating a validated four-domain proficiency rubric, structured questionnaires, and semi-structured interviews with 120 participants drawn from maritime educators, deck officer cadets, and certified officers, the study identifies a systematic proficiency gap between institutional training outcomes and STCW-mandated communicative standards. Results indicate that the majority of cadets perform at the Developing level, with particularly pronounced deficiencies in Distress and VTS Communication domains. Qualitative findings attribute this gap to the dominance of declarative instructional approaches, limited simulator access, and insufficient integration of communicative simulation in curriculum design. The study contributes a validated assessment framework and contextually grounded findings with direct implications for maritime curriculum reform, STCW quality assurance, and seafarer safety in Indonesia.
Anchorage Offset Sensitivity Analysis of a Single Point Mooring System with a Moored Crude Oil Tanker in the Gulf of Guinea
Deepwater Single Point Mooring (SPM) systems increasingly integrate Steel Catenary Risers (SCRs) to enable high-pressure hydrocarbon transfer in water depths exceeding 500 m. While SCRs provide structural robustness, their high axial stiffness introduces strong coupling between seabed anchors and the surface buoy, significantly influencing system stability. This effect becomes critical in swell-dominated regions such as the Gulf of Guinea (GoG), where long-period waves (Tp ≈ 12–20 s) induce low-frequency surge motions of moored Very Large Crude Carriers (VLCCs), generating substantial loads that are transmitted through the tanker hawser to the buoy. This study numerically investigates the influence of anchorage offset on the mechanical response of a deepwater SPM–SCR system using a six-degree-of-freedom time-domain model developed in ANSYS Aqwa. The system comprises a cylindrical SPM buoy connected to a VLCC via a polyester hawser and restrained by six symmetrically arranged SCRs. Parametric simulations were performed for anchor offsets ranging from 500 m to 2,000 m under representative environmental conditions. Results reveal a pronounced nonlinear response governed by the transition of SCRs from seabed-supported catenary behaviour to a semi-taut configuration as offset increases. Beyond offsets of approximately 1,000–1,500 m, rapid amplification of riser tension occurs in offset-aligned legs, accompanied by large horizontal restoring forces and significant downward loads acting on the buoy. These vertical components can exceed the available buoyancy restoring capacity, indicating potential loss of hydrostatic stability. The polyester hawser exhibited slackening under large offsets, suggesting susceptibility to snap loading during dynamic excitation. The findings demonstrate that anchorage offset strongly governs load redistribution and stability in SCR-connected SPM systems, highlighting the need for optimized mooring footprint design to maintain structural compliance and safe offshore loading operations in deepwater swell environments.
Intelligent Engine Mismatch Detection in Detroit Diesel Alusion DW.6WE Using Artificial Neural Networks
The maritime industry plays a strategic role in supporting international trade, particularly in the distribution of goods between countries. The main engine, as the primary component that powers a ship, is crucial for its smooth operation. Therefore, monitoring engine condition is crucial. Indicators such as main bearing temperature, exhaust gas temperature, and engine rotation speed are used to assess engine health. Preventive maintenance approaches that rely on fixed schedules are unable to identify damage early. Therefore, Artificial Neural Network (ANN) technology is used to analyze sensor data in real time. Data is sent to the PLC, processed by the ANN, and classified into Normal, Alert, or Danger conditions. This information is displayed visually and accessible to the ship's crew via the node-red platform with the Modbus TCP/IP protocol. Results show that the system has a classification accuracy of 94.11%, is capable of activating automatic alarms, and sends data in real time via the MQTT protocol. This demonstrates the effectiveness of ANN in an intelligent and adaptive ship engine monitoring system.
Innovation in Occupational Health And Safety Through Gamification to Improve Safety Compliance
Occupational safety is a critical aspect in the construction sector, particularly in transmission network construction projects that involve high-risk activities such as working at heights and operating heavy equipment. Despite the implementation of established safety standards, work accidents remain a major concern, largely caused by unsafe actions performed by workers. This study aims to examine the effectiveness of gamification in improving safety compliance at PT Surveyor Indonesia, Surabaya Branch, specifically in transmission network construction projects. This research employs a quantitative approach with a descriptive correlational design. Data were collected using a Critical Behavior Checklist (CBC) to record unsafe actions and a questionnaire to measure workers’ perceptions of gamification elements. The testing of this application was conducted over a one-month period. The results indicate that the implementation of gamification was effective in significantly reducing the percentage of unsafe actions, which decreased from 69% before implementation to 24% after gamification was applied. The paired sample t-test results show a significance value (2-tailed) of 0.000, indicating a statistically significant difference between safety compliance levels before and after the implementation of gamification. Furthermore, the findings demonstrate that gamification elements such as point systems, rewards, and leaderboards enhance worker motivation and engagement in adhering to safety procedures, thereby reducing unsafe actions. This study contributes to occupational health and safety practices by providing empirical evidence that gamification can serve as an innovative and effective strategy to improve safety compliance in high-risk construction projects.
Design Optimization of a Modern Catamaran Using Dynamic Stability Criteria for Improved Safety in Jeneberang River Transport
River transportation in Sungai Jeneberang plays a vital role in supporting daily mobility between Kabupaten Gowa and Kota Makassar. However, the existing traditional vessels (katinting) exhibit low safety standards due to poor stability and the absence of adequate safety equipment. This study aims to optimize the design of a modern catamaran based on dynamic stability criteria to improve river transport safety. The research applies a Parent Design Approach combined with geometric modeling using AutoCAD and stability analysis using Maxsurf. The design process is based on field data and evaluated under three loading conditions: lightship, half load, and full load. The resulting principal dimensions are LOA = 12,00 m, B = 5,00 m, T = 0,55 m, with ratios L/B = 2,4, B/T = 9,09, and H/T = 2,91, indicating favorable stability characteristics. The results show that all loading conditions meet the IMO Intact Stability Code (IS Code) requirements, with positive metacentric height (GM) and stable righting arm (GZ) curves. The final 3D design accommodates 20 passengers, 15 motorcycles, and safety equipment, ensuring improved operational safety and comfort. This study contributes to the development of small-scale river transport design by integrating empirical data with stability-based optimization, offering a practical and safer alternative for sustainable river transportation systems.
Effect of Bilge Keel on The Resistance Characteristic of Fishing Vessels in Benoa : A CFD Simulations Study
Bilge keels are commonly installed on fishing vessels to improve stability and operational safety; however, their influence on calm water resistance remains insufficiently documented for hull forms representative of Indonesian fishing vessels. This study investigates the effect of bilge keel installation on the total resistance of a 33.5 m tuna longline fishing vessel reconstructed from field survey data in Benoa, Bali. The resistance performance of bar hull and bilge keel equipped configurations was evaluated using steady state CFD based on the RANS equations and validated against towing tank data at 3, 6, and 9 kn. Simulations were conducted over a range of Froude numbers from 0.09 to 0.271. Results indicate that both configurations exhibit the expected non-linear increase in resistance with speed. Under the investigated numerical conditions, the bilge keel equipped hull was predicted to produce lower total resistance than the bare hull across the evaluated speed range, with the largest reduction of approximately 18% at 6 kn. These findings suggest that, for the investigated hull and appendage arrangement, bilge keel installation may induce favorable local hydrodynamic interactions that partially offset appendage related drag.
The Influence of Shipyard Layout on Sustainability Performance Based on the Triple Bottom Line through Operational Efficiency Mediation: A SEM-PLS Approach
This study examines the effect of shipyard layout on sustainability performance based on the Triple Bottom Line, with operational efficiency as a mediator. The main issue is a layout that evolves without integrated planning, reducing material flow efficiency and operational performance. The method used is Structural Equation Modeling–Partial Least Squares (SEM-PLS) based on questionnaire data with purposive sampling. The results indicate that layout has a significant effect on sustainability performance, both directly and through operational efficiency as a key mediator. These findings confirm that layout optimization not only enhances efficiency but also improves environmental and social performance. This study positions layout as a strategic determinant in a sustainable production system.
Environmental Risk Assessment of Fuel Oil Spill Incidents in Indonesian Archipelagic Waters: Vulnerability Mapping and Mitigation Strategies
Indonesia's position as the world's largest archipelagic state — operating domestic shipping networks through the globally significant Coral Triangle and other ecologically sensitive marine environments — creates one of the world's most consequential maritime pollution risk landscapes. This study conducts a comprehensive environmental risk assessment of fuel oil spill incidents in Indonesian archipelagic waters, integrating accident probability modelling, ecosystem vulnerability mapping, and response capacity analysis into a spatially explicit Integrated Spill Risk Index. A mixed-methods methodology was applied, combining negative binomial regression analysis of 1,847 domestic shipping incident records (2015–2024) with AIS traffic exposure data across six geographic zones, composite marine environmental sensitivity mapping from Allen Coral Atlas, Global Mangrove Watch, and BPS Indonesia livelihood data, NOAA GNOME drift trajectory modelling, and stakeholder interviews with 28 maritime safety and environmental stakeholders. Results identify the Makassar Strait (risk index 0.89) and Banda Sea (0.84) as Critical priority zones requiring immediate investment. Despite having lower incident probability, the Banda Sea registers the highest environmental vulnerability score (0.96) due to its Coral Triangle location, extensive seagrass and mangrove coverage, and coastal communities with over 80% fish dependency. Three immediate priority recommendations emerge: establishment of dedicated OSRO pre-positioning at Makassar Port and Ambon; mandatory AIS-based vessel traffic management with speed restrictions through ecologically sensitive Makassar Strait segments; and strengthened SMS verification and P&I insurance requirements for domestic tankers and bulk carriers operating Critical-zone corridors. The study provides the first integrated spill risk index for Indonesian domestic shipping routes, offering a prioritization framework for the Ministry of Transportation, KPLP, and environmental authorities.
Design and Initial Performance Characterization of DC Electric Motor as a Propulsion System for Small-Scale Fishing Vessels
The majority of fishermen in Indonesia, approximately 95.6% are small-scale fishermen who operate daily using small vessels powered by outboard engines. This reliance on fossil fuels and the environmental impact, including air and noise pollution, highlights the need for more sustainable alternatives such as electric motors. This study aims to design an electric propulsion system for small fishing vessels by adapting electric motors commonly used in electric scooters and evaluating their initial performance. The performance test was conducted to assess the system's feasibility and to estimate energy requirements and optimal battery capacity. The results indicate that electric motors can be utilized as a propulsion system with essential components including a dynamo, battery, controller, shaft, and propeller, reaching Technology Readiness Level (TRL) 2. The initial performance is not yet optimal and requires further refinement of components. The estimated energy requirement is 282.24 Wh, with a recommended battery specification of 24 V 12 Ah for further testing.
Augmented Reality-Enabled WebGIS for Navigation and Decision Support of Potential Kawakawa (Euthynnus affinis) Fishing Zones
Efficient identification of potential fishing zones is crucial for sustainable coastal fisheries. This study presents the integration of oceanographic data analysis, spatial modeling, and Augmented Reality (AR) technology to predict and visualize suitable fishing locations for Euthynnus affinis in the waters of Panjang Island, Banten, Indonesia. Sea surface temperature (SST) and chlorophyll-a concentrations were derived from MODIS satellite imagery and processed using Google Colaboratory to generate spatial distribution maps of key environmental parameters. These maps formed the basis for predicting potential fishing zones, which were implemented in NaviAR, a WebGIS-based platform with AR features that provides interactive visualization, real-time coordinates, distance measurements, and directional markers toward predicted fishing locations. The system’s main features, including the Home page, AR Camera, and WebGIS modules, were tested using black-box testing, achieving a 100% functional success rate. These results indicate that NaviAR effectively supports decision-making for fishermen by providing spatially explicit and actionable information on potential fishing zones
Validation of a Sensor-Based Digital Anthropometer for Standing Height: Accuracy, Reliability, and Time Efficiency
Accurate standing-height measurement is fundamental to ergonomic assessment, informing workstation design, equipment fit, and occupational health surveillance. Manual Anthropometer, while considered a reference standard, is susceptible to operator-dependent variability, transcription errors, and procedural inefficiency. This study aimed to design, develop, and rigorously validate a sensor-based digital standing-height measurement system by comparing its performance against a calibrated manual anthropometer. A randomized crossover experimental design was employed with 50 healthy adult participants. Primary outcomes included measurement agreement assessed via Bland-Altman analysis (95% Limits of Agreement threshold: ±0.5 cm), test-retest reliability evaluated using Intraclass Correlation Coefficient (ICC 2,1), time efficiency, and user acceptance. Bland-Altman analysis revealed a negligible mean bias of [-0.1] cm with 95% LoA ranging from [-0.8] cm to [0.6] cm, confirming non-inferior accuracy. The digital system demonstrated excellent test-retest reliability (ICC = 0.90), surpassing that of the manual method (ICC = 0.75). Measurement time was reduced by 64.7% (p < 0.001; Cohen's d = 33.50). Ninety percent of participants preferred the digital system. The sensor-based digital anthropometer provides a valid, reliable, and highly efficient alternative to manual standing-height measurement, supporting its potential application in occupational health surveillance and ergonomic assessment.
Socioeconomic Analysis of Octopus Handline Fishers in Aceh Besar
This study examines the social and economic conditions of octopus handline fishers in Gampong Lamteungoh, Aceh Besar. The research was motivated by declining catch production, which potentially affects fishers’ household welfare. The study aims to describe social conditions and analyze economic conditions based on income levels. Data were collected in April 2025 using a census method involving 30 fishers through observation, interviews, and documentation. Social conditions were analyzed descriptively using welfare indicators from Statistics Indonesia (BPS), while economic conditions were analyzed using income analysis. The results show that 97% of fishers have high social welfare and 3% moderate welfare, based on housing, education, and access to basic services. However, economically, fishers remain vulnerable, with an average income of IDR 1,909,365 per month, which is below the regional minimum wage. High household expenditures and declining catches contribute to this condition. The study highlights the need for improved fisheries management and economic support for small scale fishers.
Root Cause Analysis of Compression-bar Failure on Manual Pontoon Hatch Cover Systems
Hatch covers are critical structural components that maintain cargo hold watertightness and operational safety. This study investigates non-conformities in the compression bar of a manual pontoon-type hatch cover on a Gearless Multi-Purpose Vessel constructed at PT. KTU Shipyard. The analysis evaluates construction conditions and the conformity of fabrication and installation processes with MacGregor standards and ClassNK requirements. Root causes were identified using the Root Cause Analysis (RCA) method within a qualitative descriptive case study approach. Data were obtained through visual inspection, manual measurement with an acceptable compression tolerance of 14–24 mm, ultrasonic testing with a leak acceptance limit of <10% OHV, and review of design drawings and technical specifications. RCA was performed using fishbone diagrams and the five-why method, addressing human, method, material, measurement, environment, and machine factors. Findings show that improper installation beyond manufacturer tolerances caused uneven gasket contact pressure, reducing sealing performance. The primary causes were inadequate fabrication and installation practices and inconsistent tolerance verification. Recommended corrective actions include standardizing procedures, strengthening technical competence, and implementing systematic inspection and measurement control at all work stages.
Design and Development of Web-Based USV Ground Control Station for Ocean Observation
Ocean observation increasingly relies on Unmanned Surface Vehicles (USVs) for wide-area maritime data collection, yet existing Ground Control Station (GCS) systems remain limited by desktop-based accessibility constraints, high-latency HTTP communication, unoptimized relational databases, and the absence of integrated oceanographic sensor visualization. This study aims to design and develop a web-based GCS that unifies telemetry monitoring, bidirectional remote control, CTD and ADCP sensor visualization, and waypoint-based mission planning within a single browser-based interface. The system was developed using the Rapid Application Development (RAD) methodology, with MQTT and WebSocket adopted for low-latency communication and PostgreSQL with TimescaleDB for time-series data management. Functional testing confirmed that all core features operated correctly. Performance evaluation under 4G-LTE field conditions showed an average command round-trip latency of 178 ms and end-to-end monitoring latency below 250 ms. TimescaleDB hypertable conversion improved write throughput by 2.5×, reduced long-range query latency by 3.75×, and achieved a storage compression ratio of 875×. The proposed architecture provides a replicable reference for web-based USV GCS development across ocean observation applications.
Social Behavior in the Working Relationship Between Ship Owners and Fishermen in Kupang City
Indonesian fishing communities possess unique social characteristics due to their dependence on the sea as their primary source of livelihood. Despite abundant coastal and marine resources, fishers often remain trapped in cycles of structural poverty. The primary factors contributing to this include limited human resource quality, restricted access to technology, and limited market and capital control. Fishermen face low income due to challenges in employment relationships because the fishermen’s social dependence on ship owners, which results in unilateral control over market access and selling prices. Additionally, issues persist regarding competency enhancement, occupational safety, and facility support. This study aims to identify social behaviors that require intervention to improve social norms in the working relationships between ship owners and fishermen in Kupang City. Employing a soft systems methodology, the research identifies social issues necessitating intervention in the interaction patterns among fishermen, ship owners, and other stakeholders. The study yields three root definitions. First, local governments, fishing ports, along with ship owners are creating a competency improvement program for fishermen, through the implementation of independent training to achieve enhanced skills, workplace safety, and professionalism of fisheries human resources. Second, the local government, ship owners and fishermen's organizations, established a mediation and labor relations management system through a fair profit-sharing mechanism and clear work regulations. Third, local governments, fishermen's organizations and related institutions, are designing a system of protection and independence for fishermen through strengthening market access, financial management, and alternative livelihoods, to improve welfare and reduce vulnerability.
Study on Kalina Cycle Performance Under Operating Temperature Variations for Ship Waste Heat Recovery
Energy inefficiency in marine diesel engines remains a significant challenge due to substantial waste heat losses. This study aims to evaluate the thermodynamic performance of a Kalina cycle for waste heat recovery from a low-speed marine diesel engine under varying operating temperature and ammonia-H2O compositions. A thermodynamic model is developed based on mass and energy balance principles to analyze system behavior across different conditions. The analysis focuses on key performance aspects, including evaporator heat input (Qin), pump work, expander work, thermal efficiency, and energy losses for ammonia concentrations of 30%, 45%, and 60%. The results show that increasing ammonia concentration significantly reduces the required heat input, while expander work decreases with rising condenser temperature due to a reduced enthalpy drop. Thermal efficiency is found to decrease with increasing evaporator temperature, as additional heat input is not effectively converted into useful work, leading to higher irreversibility. The highest efficiency of 11.9% is achieved at 60% ammonia concentration under lower temperature conditions. In contrast, energy losses increase consistently with higher heat input, particularly at elevated temperatures. Overall, the findings demonstrate that optimal system performance depends on a balanced combination of operating temperatures and working fluid composition.
Development of a Clean Energy-Based Information System for Mapping Marine Environmental Conditions and Navigational Safety to Support Sustainable Marine Tourism
Marine tourism development requires accurate information regarding marine environmental conditions and navigational safety. However, many coastal tourism areas in Indonesia still rely on conventional observation methods that are limited, fragmented, and difficult to access in real time. This study aims to develop a clean energy-based information system capable of mapping marine environmental conditions and supporting navigational safety for sustainable marine tourism. The system integrates environmental sensors, Global Positioning System (GPS), Geographic Information System (GIS), and renewable energy sources through solar-powered monitoring stations. The research employed a Research and Development (R&D) method consisting of needs analysis, system design, prototype development, implementation, and evaluation. Data were collected from temperature, salinity, wave height, wind speed, water level, and vessel route monitoring. The resulting system provides spatial visualization, hazard alerts, route recommendations, and environmental status information through a web-based dashboard. The implementation results indicate that the system can improve the effectiveness of marine environmental monitoring and increase navigation safety in tourism areas. Furthermore, the use of solar energy supports sustainable operation in remote coastal locations with limited electricity access.
Suitability Of Physical Oceanographic Conditions To Ministerial Decree No. 64/Kepmen-Kp/2020 On The Establishment Of Gili Ketapang Marine Protected Area
Marine conservation areas in small island environments require compatibility between management zoning and local physical oceanographic conditions to function effectively and sustainably. Gili Ketapang, located in the Madura Strait, has been designated as a Marine Conservation Area under the Decree of the Minister of Maritime Affairs and Fisheries No. 64/KEPMEN-KP/2020. However, evaluations of zoning suitability based on physical oceanographic characteristics remain limited. This study aims to assess the suitability of zoning within the Gili Ketapang Marine Conservation Area using key physical oceanographic parameters, including currents, waves, tides, and wind. Tidal analysis was conducted using the Admiralty method to determine tidal type and sea level characteristics. Wave and current data were obtained from Copernicus Marine Reanalysis with a 3-hour temporal resolution over a ten-year period, while wind data were used to support seasonal analysis. Zoning suitability was evaluated by comparing the analyzed oceanographic conditions with relevant criteria for coastal and marine utilization. The results indicate that the waters of Gili Ketapang are characterized by a mixed, mainly semidiurnal tidal regime, with a Formzahl value of 1.3. Seasonal variability in currents and wave conditions reveals periods that are less favorable for utilization activities in certain sub-zones, particularly within the Aquaculture Sub-Zone. These findings suggest that zoning suitability is dynamic and strongly influenced by seasonal oceanographic variability. This study highlights the importance of integrating long-term physical oceanographic analysis into the evaluation and management of marine conservation zoning, especially in small island environments with high hydrodynamic dynamics.
Fuel Oil Consumption and Carbon Intensity Indicator (CII) Monitoring of Container Ship Using Automatic Identification System (AIS) Data
The IMO has introduced the Carbon Intensity Indicator (CII) to reduce carbon emissions, and it will be mandatory for ships sailing internationally from 1 January 2023. Implementing CII should be a top priority for reducing greenhouse gas emissions from ships sailing in Indonesia’s territorial waters, the world’s largest maritime country. This study aims to determine the constant in the empirical formula for monitoring fuel consumption and CII implementation using Automatic Identification System (AIS) data from MV. Meratus Padang. The Holtrop method is used to calculate the ship’s basic resistance, and the STAWAVE method is then applied to account for environmental conditions during sailing to obtain more accurate results under actual conditions. The total resistance of the Holtrop and STAWAVE methods can be used to calculate the power supplied to the propeller. Furthermore, the propeller’s power can be used to calculate fuel consumption. The fuel consumption calculation showed differences of 0.41% on the Surabaya-Banjarmasin route and -0.35% on the Banjarmasin-Surabaya route, with a propeller efficiency of 0.5 and an engine degradation of 9.5%, as the average CII is “E”.
Probabilistic Gas Dispersion Analysis Due to Natural Gas Pipeline Leakage Using ALOHA: A Case Study of Transmission Pipeline from Custody Metering to Tire Plant
Gas leakage in pipeline systems represents a critical hazard in the oil and gas industry, posing significant risks to human safety and the environment. This study aims to perform a probabilistic analysis of natural gas dispersion resulting from pipeline leakage using ALOHA (Areal Locations of Hazardous Atmospheres) integrated with statistical wind data analysis. Meteorological data over 25 years (2000–2024; 219,167 observation hours) were analyzed using Weibull distribution and wind rose methods to characterize the dominant wind regime. The results indicate that low wind speeds (0.5–2.5 m/s) dominate site conditions (77.1%), limiting gas dilution and increasing accumulation near the source. The dominant dispersion direction is identified in the southwest-to-south sector (213.75°–236.25°). Under these conditions, the red zone (≥30,000 ppm, 60% LEL) extends approximately 89.6 m, while in worst-case scenarios it reaches up to 198 m. Vapor Cloud Explosion (VCE) overpressure remains below 1.0 psi. Probabilistic integration of all scenarios produces a consequence probability map identifying high-risk zones along the right-of-way (ROW). These findings support improved risk assessment and provide a basis for targeted mitigation strategies in pipeline safety management.
Comparative Evaluation of Critical Path Method and Critical Chain Project Management for Ultra Low-Pressure Compressor Installation in the Oil and Gas Industry
Project delays remain a persistent challenge in the oil and gas industry, where conventional scheduling methods such as the Critical Path Method (CPM) fail to adequately address resource constraints and duration uncertainty. This study evaluates the effectiveness of Critical Chain Project Management (CCPM) as an alternative scheduling approach for Ultra-Low Pressure (ULP) compressor installation projects. A case study methodology was applied using actual project data from Pamaguan Plant, PT Pertamina Hulu Sanga Sanga, involving Work Breakdown Structure analysis, critical chain identification via Microsoft Project, and buffer sizing using the Root Square Error Method (RSEM). From 1,096 activities, 86 critical activities formed the critical chain, yielding a project buffer of 28 days and 27 feeding buffers. Buffer utilization reached 171%, placing the project in the red zone, indicating the planned buffer was insufficient to absorb delays caused by duration variability, resource limitations, and behavioral phenomena including Student Syndrome and Parkinson's Law. These findings confirm that CCPM offers a structurally superior scheduling framework compared to CPM, yet its effectiveness depends on disciplined execution and proactive buffer monitoring. This study contributes quantitative evidence on buffer utilization effectiveness in oil and gas project scheduling, providing practical guidance for managing high-complexity installation projects.
Integrated Fire Safety Model for Ship Engine Rooms
Engine room fire remains one of the most critical threats to ship safety because it involves the interaction of fuel systems, lubrication systems, hot surfaces, electrical installations, confined-space operations, and emergency response constraints. Although international regulations such as SOLAS, STCW, and IMO Model Courses have established a comprehensive normative framework, fire incidents in ship engine rooms continue to occur. This condition indicates a persistent gap between regulatory standards, technological capability, and operational implementation onboard. Previous studies have examined engine room fire from different perspectives, including technical failure, fire detection, suppression systems, human factors, and safety barriers. However, most of these studies remain fragmented and do not sufficiently explain how technical readiness, managerial implementation, and human capability interact in real ship operations. This article aims to develop an integrated fire safety model for ship engine rooms by synthesizing those three dimensions into one analytical framework. The study applies an integrative literature review and conceptual model development approach based on maritime safety regulations, peer-reviewed maritime fire studies, and organizational safety theory. The results show that effective fire prevention and response depend on the simultaneous strength of technical systems, procedural discipline, and crew capability. The proposed model offers practical implications for shipping companies, maritime education institutions, and safety regulators in strengthening evidence-based fire safety in commercial vessels.
Compliance Analysis of Fiberglass Boat Construction by CV. Roni Marine with BKI Standards
Technological developments have encouraged the shift in the main material from wood to Fiber Reinforced Plastic (FRP) because of its light weight, noncorrosive, lower price, and simple production process. However, traditional FRP boat production in Indonesia generally has not implemented the construction standards set by the Indonesian Classification Bureau (BKI), including those of CV. Roni Marine boat production. This study aims to describe the construction of FRP boats produced by CV. Roni Marine and assess its compliance with BKI standards. The research was conducted through direct observation at CV. Roni Marine, measuring the dimensions of the 9.5 m FRP boat construction, and literature studies of the BKI standard documents. The main components of boat construction analyzed include the boat's skin, keel, frames, longitudinal stiffeners, and deck beams. The results showed that the CV. Roni Marine uses a combination of transverse and longitudinal construction systems with laminated materials, including CSM300 and WR600 fibers. The thickness of the hull laminate is 2.13 mm. The spacing between frames is 580 mm, length of the longitudinal stiffeners is 8,700 mm, the width of the keel lamination is 60 mm, and the spacing between the deck beams is 2,900 mm. The results show that 100% of the boat construction does not comply with BKI standards
Numerical Analysis of Forward-Facing Reverse-V Step Hull Angle on Resistance Characteristics of Planing Hull
This study investigates the hydrodynamic resistance characteristics of a forward-facing reverse-V stepped planing hull using a Computational Fluid Dynamics (CFD) approach under high-speed planing conditions. Five reverse-V angle configurations consisting of 180°, 165°, 150°, 135°, and 120° were evaluated at a constant speed of 27 knots (13.9 m/s) using the Reynolds-Averaged Navier–Stokes (RANS) and Volume of Fluid (VOF) methods. Unlike conventional aft-facing stepped hulls, the proposed reverse-V geometry redirects the flow inward toward the forward centerline region beneath the hull bottom, modifying pressure redistribution, cavity interaction, and wetted surface formation. The numerical simulations employed a Poly-Hexacore meshing strategy and demonstrated stable convergence behavior with excellent mesh-quality characteristics. The results show that the 165° and 150° configurations increased hydrodynamic resistance due to stronger turbulence interaction and larger wetted surface development around the step region. In contrast, sharper reverse-V configurations improved hydrodynamic performance through stronger inward pressure convergence and more compact cavity formation. The 120° configuration generated the lowest resistance value of 7463.052 N and achieved the highest resistance reduction of 2.02% compared to the baseline model.
Eco-Friendly Antifouling Coating Technologies for Marine Vessels: Material Science Advances and Environmental Compliance Under IMO Regulations
Marine biofouling — the progressive accumulation of microorganisms, algae, barnacles, and other aquatic organisms on submerged vessel hull surfaces — imposes a 25–40% fuel consumption penalty at the macrofouling stage and simultaneously facilitates the transport of non-indigenous invasive species across biogeographic barriers, constituting both a significant GHG emission driver and a global ecological threat. This study examines antifouling coating technology adoption and compliance in the Indonesian domestic fleet, evaluates alternative antifouling technologies against environmental performance, fuel saving benefit, and IMO regulatory compliance dimensions under Indonesian tropical operating conditions, and develops prioritized technology adoption and regulatory implementation recommendations. A mixed-methods design was employed, combining hull inspection and documentary review of 84 domestic vessels across four vessel type categories at three Indonesian port areas, stakeholder interviews with 46 participants across operator, shipyard, regulatory, industry, and NGO groups, and comparative technology performance assessment of four antifouling system categories. Results reveal that while 86% of vessels achieve AFS Convention (TBT prohibition) compliance, only 6.5% fully comply with IMO Biofouling Management Guidelines. A full fleet eco-upgrade across the 84-vessel sample would deliver annual fuel savings of 12,980 tonnes HFO and 40,500 tonnes CO₂ at a positive 15-year fleet NPV of USD 16.6 million. Cost barriers — with eco-friendly coatings carrying a 2–4× unit price premium — are identified as the primary adoption constraint. Three priority policy recommendations are proposed: mandatory Biofouling Management Plan documentation for all vessels exceeding 400 GT; a green maritime financing facility for eco-coating upgrades during drydocking; and mandatory hull fouling performance reporting within the CII monitoring framework.
Marine Engineering Innovation for Environmental Compliance: An Integrated Environmental Engineering Framework for Indonesian Domestic Vessel Operations
Marine engineering is undergoing a fundamental redefinition — from a discipline optimized primarily for propulsive performance and fuel economy to one in which environmental engineering is integral to every shipboard system domain. This study develops an Integrated Environmental Engineering Framework (IEEF) for Indonesian domestic vessel operations, synthesizing marine engineering innovation literature across propulsion, thermal management, exhaust treatment, waste management, and hull systems into a structured, evidence-based environmental technology portfolio. A mixed-methods methodology was employed, combining quantitative Environmental Engineering Audit Protocol (EEAP) assessment of 72 Indonesian domestic vessels across 10 MARPOL-relevant engineering domains with AHP-TOPSIS multi-criteria technology assessment involving 24 domain experts. The audit reveals critical compliance gaps in CII monitoring systems (36%), waste heat recovery installation (10%), and eco-compliant antifouling coatings (35%), alongside high-severity deficits in NOₓ treatment (42%), sewage treatment (44%), and ballast water management (50%). AHP-TOPSIS ranking identifies waste heat recovery and CII digital monitoring as equal top-priority investments (composite score 0.83), followed by nano-hybrid antifouling (0.79), Annex IV sewage treatment (0.77), SCR/EGR NOₓ reduction (0.72), and LNG dual-fuel conversion (0.68). The IEEF organizes these priorities within a three-horizon implementation roadmap — Horizon 1 (2025–2027) deploying proven compliance technologies, Horizon 2 (2027–2032) advancing NOₓ reduction and hybrid system integration, and Horizon 3 (2032–2050) transitioning toward hydrogen, ammonia, fuel cell propulsion, and on-board carbon capture — providing a structured engineering trajectory aligned with IMO 2050 net-zero ambition.
Marine Pollution Prevention Policy and Port State Control Enforcement in Indonesia: Implementation Gaps and Regulatory Recommendations
Indonesia, as a signatory to MARPOL 73/78, holds binding international obligations for vessel-source pollution prevention across all six annexes. Port State Control (PSC) is the primary enforcement mechanism for realizing these obligations operationally, yet evidence consistently indicates a wide and persistent gap between regulatory obligation and enforcement practice. This study provides a systematic assessment of marine pollution prevention policy and PSC enforcement in Indonesia through a mixed-methods methodology combining quantitative benchmarking of 4,218 IOMOU PSC inspection records (2019–2024), 44 semi-structured stakeholder interviews, and comparative regulatory framework analysis. Results reveal that Indonesia's PSC performance falls significantly below both IOMOU regional and Paris MoU benchmarks across all key indicators: the detention rate of 4.8% is double the Paris MoU average, mean deficiencies per inspection exceed the Paris MoU figure by 1.97, and a repeat deficiency rate of 38.4% — 23.6 percentage points above the Paris MoU — confirms that enforcement is not generating the corrective response it should. MARPOL Annex IV (sewage) and Annex I (oil) deficiency gaps against Paris MoU benchmarks reach 13.2 and 10.8 percentage points respectively, both classified as critical. Six primary implementation gaps are identified: PSC officer capacity deficit, absence of digital inspection systems, inter-agency coordination failure, inadequate penalties, domestic fleet MARPOL exemptions, and port reception facility insufficiency. An Integrated Marine Pollution Prevention Reform Framework addressing all six gaps through a phased four-pillar architecture is proposed, offering a structured pathway for Indonesia to close its enforcement deficit and fulfill its international maritime environmental obligations.
Determination of Ship Accident Risk in Indonesia: Contribution of Crew Member Competence and Job Stress Through Safety Culture Moderated by Communication Effectivity and Supervision
this paper investigates how human factor variables determine ship accident risk in Indonesian domestic shipping. Drawing on accident investigation reports and international literature, the study proposes and tests a structural model linking deck crew competence, supervisory quality, and work stress to perceived ship accident risk, with safety culture as an intervening variable and work stress and competence as moderators. National data from Indonesia’s National Transportation Safety Committee (KNKT) for 2020–2025 indicate that human error remains the dominant contributing factor in marine accidents, with high fatality rates despite the implementation of SOLAS, STCW, and the ISM Code. Relevant studies confirm that inadequate training, fatigue, miscommunication, and weak supervision are among the most critical contributors to marine casualties. A quantitative survey will be conducted among Indonesian seafarers working on domestic Roro ferries and passenger/ cargo vessels, focusing on major inter-island routes. The proposal model will be tested using Partial Least Square–Structure Equation Modelling (SEM) to assess direct, indirect, and moderating effects of competence and job stress on the relationship between safety culture and perceived accident risk. The expected contribution is twofold: theoretically, it integrates Human Factor Analysis and Classification System (HFACS) Maritime and safety culture perspectives into a comprehensive human factor risk perception framework tailored to an archipelagic developing country; practically, it provides evidence=based insights for regulators and shipping companies regarding priority interventions in crew training, work-rest scheduling, supervision, and safety culture development.
Physico-Thermal Characteristics of Coconut Coir–Latex Composites for Thermal Insulation in Fishing Vessels
Maintaining low storage temperatures on fishing vessels is strongly influenced by the insulation performance and durability of fish-hold lining materials, especially under humid and splash-exposed marine conditions. This study investigates latex–coconut coir composites as a lightweight, locally available, and bio-based candidate for insulation applications in small fishing vessels. Composite specimens were fabricated using a controlled formulation series from neat latex (100/0) to 50/50 latex–coir, with intermediate ratios of 90/10, 80/20, 70/30, and 60/40. The work emphasizes manufacturability, mass-related properties, and moisture behavior relevant to shipboard service. Water absorption was evaluated after 24 h immersion following the general procedure of JIS A 5908, while specific gravity and density were determined using an Archimedes-based method (ASTM D 792) at 23°C. The results show that increasing coir content reduces the dry specimen mass, supporting lightweight panel development, but significantly affects moisture uptake. Neat latex exhibits minimal water absorption (0.846%), whereas coir-containing composites show higher absorption with a non-linear trend, peaking at the 80/20 formulation (17.345%) and decreasing at 50/50 (10.410%). In contrast, specific gravity (~0.498–0.500) and density (~497–499 kg/m³) remain nearly constant across formulations, indicating that moisture performance is governed primarily by microstructure (porosity and latex–fiber interfacial sealing) rather than bulk density. These findings highlight the feasibility of latex–coir composites for marine insulation, while underscoring the need for processing optimization and/or surface sealing to improve moisture resistance.
The Effect of Chlorophyll-a and Sea Surface Temperature on Skipjack Tuna Fishing Areas in FMA 714
Skipjack tuna (Katsuwonus pelamis) is a high economic value pelagic commodity in FMA 714, whose distribution is highly responsive to oceanographic parameters, particularly sea surface temperature and chlorophyll a. This study aims to analyze the influence of sea surface temperature and chlorophyll a distribution on the characteristics of potential skipjack tuna fishing areas in the waters of FMA 714 in 2022. The approach is a quantitative, descriptive method using simple linear regression to correlate NOAA datasets with fish catch statistics. Temporal analysis revealed that oceanographic dynamics are controlled by the monsoon cycle, particularly the upwelling process during the East Season. This period was marked by a drastic decline in sea surface temperature to 28°C in August, in contrast to a sharp surge in chlorophyll a concentration in July-August, reaching 0.48-0.50 mg/m³. Although these water conditions produced dynamic productivity, linear regression analyses showed that sea surface temperature was positively associated with fish catch, while chlorophyll a was negatively associated, though very weakly. Sea surface temperature and chlorophyll a did not have a significant effect on fish catch (p=0.239), indicating that these parameters explained only 23.9% of the variation in catch, with the remaining 76.1% influenced by factors outside the research model. Catch production is largely influenced by fishing gear. Purse seine with a single boat is the most widely used fishing gear, with as many as 2,328 fleets using it. This is another factor in the production of skipjack tuna catches in FMA 714.
Household Financial Management and the Welfare Level of Coastal Communities in Pasar Sorkam Village, Tapanuli Tengah
Communities that are still considered poor often identify with fishermen's households. This impression arises due to the simple condition of their houses and a lifestyle that often appears unbalanced between their income and expenses. This research focuses on exploring the level of welfare of the Pasar Sorkam community in Tapanuli Tengah from the aspect of their household financial management. The research employs a mixed methodology approach, supported by measurements of the community's welfare index. The research results indicate that the income level of the fishing community is classified as low, while the expenditure level is high. The fishing community in Pasar Sorkam Village has a welfare index value of 55.6, indicating that they fall into the low welfare category. The research is expected to serve as a reference for relevant future studies and as a guideline for policy formulation for the local government of Tapanuli Tengah Regency.
Energy Management Strategies for Hybrid Ship Propulsion: A Systematic Review of MPC, ECMS, and Predictive Control
Effective energy management is critical for maximizing the efficiency and environmental benefits of hybrid propulsion systems (HPS) in ships. This systematic review evaluates various advanced energy management strategies (EMS) applied to marine HPS, focusing on model predictive control (MPC), equivalent consumption minimization strategy (ECMS), sequential quadratic programming (SQP), predictive power-split, and rule-based approaches. Based on an analysis of recent international literature, findings indicate that MPC-based EMS improves fuel efficiency by 10-20% and extends battery life through optimal power distribution under dynamic load conditions. Meanwhile, ECMS reduces equivalent fuel consumption by up to 25% under varying operational cycles. Predictive power-split algorithms achieve 15-20% energy savings by anticipating propulsion load changes up to 30 minutes in advance. Compared to conventional rule-based systems, advanced EMS reduces CO₂ emissions by 20-45% and NOx emissions by 20-60%, especially during harbor maneuvering and low-speed cruising. However, challenges remain, including high computational demands for real-time MPC, dependence on accurate load prediction models, and the lack of standardized interoperability protocols. This review concludes that integrating artificial intelligence and digital twins into EMS represents the most promising research direction. For ferries, patrol boats, and research vessels, implementing MPC or ECMS with adaptive tuning can significantly enhance operational performance while complying with IMO EEDI and CII regulations.
Evolution and Innovation of Ship Propulsion Technology: From Paddle Power to Electric and Wind-Assisted Hybrid Systems for a Sustainable Maritime Future
Ship propulsion has evolved significantly over thousands of years, from the use of simple paddles around 40,000 BCE to modern advanced systems driven by diesel engines, steam turbines, nuclear reactors, electric motors, and wind power. This systematic literature review aims to synthesize current knowledge on ship propulsion systems, highlighting technological advancements, energy efficiency, and environmental impacts. By analyzing various studies through a qualitative approach and the PRISMA framework, this research identifies three main themes: advanced propulsion systems, propulsion optimization, and hybrid technology integration. The results show that while diesel engines remain dominant, Integrated Full Electric Propulsion (IFEP) systems coupled with induction motors and Permanent Magnet Synchronous Motors (PMSMs) offer higher efficiency and lower emissions. Furthermore, wind-assisted technologies, such as Dynarigs, Flettner rotors, and towing kites, demonstrate great potential to reduce fuel consumption by up to 50% compared to conventional systems, while nuclear propulsion enables higher operational speeds with minimal fuel replenishment. However, key challenges remain, including high initial investment costs, control system complexity, and regulatory acceptance. In conclusion, the future of ship propulsion lies in hybrid configurations that optimize the combination of electric and wind power, supported by predictive computational models and fault-tolerant control to achieve cleaner, safer, and more sustainable maritime operations. Interdisciplinary collaboration is essential to accelerate this transition.
Intelligent Energy Management and Hybrid Propulsion for Ships: A Review of Configurations, AI-Based Strategies, and Decarbonization Potential
Stringent IMO regulations targeting a 40% GHG reduction by 2030 and net-zero by 2050 have driven the maritime industry to adopt cleaner technologies, as conventional diesel propulsion often operates inefficiently with high fuel consumption and emissions. This paper presents a descriptive-comparative literature review of hybrid propulsion systems for ships, analyzing peer-reviewed journals published in the last five years. The study examines system configurations (series, parallel, series-parallel), key components (diesel engines, fuel cells, batteries, supercapacitors), and energy management strategies (EMS), with a focus on artificial intelligence-based approaches such as Deep Reinforcement Learning (DRL) and Nonlinear Model Predictive Control (NMPC). The findings indicate that hybrid systems can improve energy efficiency by 15–30% and significantly reduce CO₂, NOₓ, and SOₓ emissions compared to conventional systems, especially during zero-emission port operations. Advanced EMS, particularly DRL algorithms like Proximal Policy Optimization (PPO), enable real-time multi-objective optimization that balances fuel economy, battery health, and component longevity. However, challenges remain, including high initial investment costs, optimal sizing of hybrid energy storage systems, and limited charging infrastructure. This review concludes that despite these barriers, the convergence of intelligent EMS, falling battery prices, and tightening environmental regulations positions hybrid propulsion as a key technology for sustainable maritime transportation, with future potential from waste-heat recovery systems and alternative fuels.
Performance Mapping and Fuel Efficiency Analysis of an LSCS Piston Diesel Engine under Injector Pressure Variation for Marine Applications
Fuel efficiency and stable engine performance are important issues in small diesel engines used for marine-related applications, such as auxiliary power units, generator sets, and small vessel systems. This study investigates the effect of injector pressure variation on the performance and fuel efficiency of a four-stroke single-cylinder diesel engine equipped with a Lateral Swirl Combustion System (LSCS) piston. The injector pressure was varied at 170, 180, and 190 bar, while the engine was tested at different speeds of 1000, 1200, 1300, and 1400 rpm under electrical loads of 2000, 3000, and 4000 W. The evaluated performance parameters included output power, torque, brake specific fuel consumption (BSFC), brake mean effective pressure (BMEP), and performance map characteristics. The results show that injector pressure significantly influenced the combustion performance and fuel utilization of the LSCS piston diesel engine. Among the tested conditions, the 190 bar injector pressure produced the best overall performance, with a maximum power of 2.72 kW, torque of 18.65 N·m, BSFC of 371.06 g/kWh, and BMEP of 1.95 bar. Compared with the 180bar setting, the 190bar injector pressure increased power by 1.87%, increased torque by 1.96%, reduced BSFC by 7.32%, and increased BMEP by 2.09%. The performance map also indicated that the 190bar setting provided the most favorable operating region, characterized by relatively low BSFC and higher BMEP. These findings suggest that injector pressure optimization combined with LSCS piston geometry can improve combustion effectiveness and fuel efficiency in small diesel engines for marine-related applications.
Hydrodynamic Optimization of a Patrol Vessel: Evaluating Stern Foil Configurations on Resistance and Seakeeping via CFD
The operational efficiency and safety of patrol vessels critically depend on minimizing hydrodynamic resistance and enhancing seakeeping performance. This study explores the effect of stern foils with different NACA airfoil sections on a patrol vessel. Employing Computational Fluid Dynamics (CFD), we assessed water resistance in calm conditions and seakeeping traits in regular head seas. Based on the results obtained, the total resistance value (RT) without stern foil shows a value of 202,112 N. Findings show that stern foils lead to a considerable reduction in total resistance, with the NACA 2412 profile achieving the greatest reduction at 14.85%, followed by NACA 64-212 (14.70%) and NACA 4412 (11.67%) at 20 knots and Fn 0.418. Additionally, seakeeping assessments revealed a significant mitigation of pitch and heave motions across all foil designs, notably a marked decrease in pitch Response Amplitude Operator (RAO) at the dominant frequency of 0.13 Hz. This work provides significant contributions to the optimization of patrol vessel design through advanced hydrodynamic additions, contributing to better fuel economy and greater operational stability in challenging maritime environments.
Decarbonizing Short-Sea Shipping: A Comparative Analysis of Diesel-Mechanical, Diesel-Electric, and Hybrid Propulsion Systems
The role of short sea shipping in regional logistics operations is very important. With pressures from IMO regulations (EEXI and CII) growing, the maritime industry must adopt more efficient propulsion. The impact of marine technology choice on the shipping industry and its effect on the entire economy is often overlooked by society. In this paper, a techno-economic and environmental comparison of three propulsion architectures for a 5000 GT Ro-Ro passenger ferry is presented. These architectures include conventional diesel-mechanical (DM), diesel-electric (DE), and parallel hybrid (PH). The project developed a simulation framework leveraging operational profiles that were obtained from Automatic Identification System (AIS) data through the national AIS archive Marine Cadastre. The fuel consumption, emissions (CO₂, NOₓ, and SOₓ), and life-cycle cost (LCC) of all three systems were evaluated over a 20-year planning horizon. The findings demonstrate that PH approach is responsible for a 25.0% decline in yearly fuel consumption and CO₂ emission as compared to DM baseline and 14.3% compared to DE system. While the PH system necessitates 31% more CAPEX than the DM system, its payback period is approximately 2.15 years because of significant savings on operating cost. This framework, combining quantitative evidence and systematic decision-making processes, will help ship owners and other policy makers choose the best propulsion technologies to decarbonise short-sea shipping fleets.
Structural Strength Analysis of a High-Density Polyethylene Floating Jetty under Ship Collision
Floating jetties are increasingly used in marine infrastructure because of their adaptability to water-level fluctuations and ease of installation. Recently, High-Density Polyethylene (HDPE) has attracted attention as an alternative construction material due to its corrosion resistance, lightweight characteristics, and impact-absorption capability. However, information regarding the structural behaviour of HDPE floating jetties under ship collision loads remains limited. Therefore, this study aims to investigate the structural response and deformation characteristics of an HDPE floating jetty subjected to vessel berthing impacts. The analysis was conducted using the Finite Element Method (FEM). A floating jetty with dimensions of 10 m × 2.5 m × 1.5 m was modelled and subjected to collision loads generated by a 5-ton vessel approaching at a 20° berthing angle. Berthing energies were calculated according to PIANC recommendations and converted into equivalent static impact loads under favourable, moderate, and unfavourable berthing conditions. The calculated berthing energies were 88.4 J, 198.9 J, and 353.6 J, corresponding to impact loads of 15.2 kN, 22.7 kN, and 30.2 kN, respectively. The maximum deformations obtained from the FEM analysis were 12.11 mm, 18.21 mm, and 24.22 mm. The results showed a nearly linear relationship between impact load and structural deformation, indicating stable elastic behaviour throughout the investigated loading range. Even under the most severe berthing condition, the maximum deformation represented only 0.24% of the jetty length. The study demonstrates that HDPE floating jetties possess adequate impact resistance and deformation capacity for small-vessel berthing operations. These findings provide additional insight into the application of HDPE as a structural material for floating marine infrastructure subjected to collision loading.
The Effect of Variations in the Side Skeg Angle on Drag and Seakeeping of a Barge
This study aims to analyze the effect of variations in the side skeg angle on the total resistance and motion response of a barge. The research subjects consisted of a barge model without a skeg and a barge model with a triple-skeg configuration at side skeg angles of 140°, 150°, 160°, and 180°. Numerical simulations were conducted using Maxsurf Resistance software to obtain total resistance values and the Hydrodynamic Diffraction method to evaluate sway and yaw motion responses. Resistance tests were performed under two loading conditions full load and light load with a speed range of 2 to 6 knots. Seakeeping analysis was performed at a speed of 6 knots with regular waves 1 meter high and wave incidence angles of 0°, 45°, 90°, 135°, and 180°. The results of the study show that the addition of a skeg increases total resistance by a relatively small percentage, namely 1.68% - 1.74% under full-load conditions and 2.60% - 2.83% under light-load conditions. From a seakeeping perspective, the addition of a skeg tends to slightly increase the sway response but effectively reduces the yaw response, particularly at a transverse wave angle of 90°. Based on the balance between increased resistance and reduced yaw response, the 150° side skeg configuration can be considered the most balanced option for improving the barge’s directional stability without introducing significant additional resistance.
A The Analysis Of Performance Solar Panel Placement on the Deck House Fishing Vessel (30 GT) on Fishing Operation
The integration of renewable energy systems in fishing vessels has increasingly attracted attention as an alternative approach to improving operational sustainability and reducing dependency on conventional energy sources. However, additional equipment installed above the deckhouse may influence vessel stability and operational performance. This study aims to investigate the effect of solar panel installation on the deckhouse of a 30 GT fishing vessel in terms of stability characteristics and fishing operational capability. The analysis was conducted using secondary vessel data and numerical simulations through Maxsurf software. Stability performance was evaluated using the A.N. Krylov method with verification based on International Maritime Organization intact stability criteria, while seakeeping performance was assessed using strip theory combined with the Joint North Sea Wave Project wave spectrum under various loading and wave conditions. The results indicate that solar panel installation slightly changes the vessel’s weight distribution but does not significantly affect stability performance, as all loading conditions satisfy the required stability criteria. Seakeeping analysis further shows that vessel performance is strongly affected by wave conditions, with the most favorable operational performance achieved at wave heights below 2 m. These findings demonstrate that solar panel integration can be implemented on fishing vessel deckhouses without significantly compromising vessel safety and operational performance under appropriate environmental conditions.
Design and Implementation Independent Battery and Lost-Link Fail-Safe Module for USV Safety
This study presents the design and implementation of an independent battery and lost-link fail-safe module to improve the navigational safety and operational reliability of Unmanned Surface Vehicles (USVs). Previous studies on USV fail-safe systems mainly focused on battery monitoring or communication recovery separately and generally relied on the main onboard controller or autopilot system. Such approaches may reduce system reliability when the primary controller experiences malfunction or communication interruption. To address this limitation, the proposed system integrates a Jetson Orin Nano, a CUAV autopilot, and an independent ESP32-based monitoring module capable of autonomously monitoring battery and communication conditions. Communication reliability is evaluated using MAVLink heartbeat signals, while battery condition is assessed using a progress-based energy estimation method to predict mission feasibility according to the remaining battery capacity and mission progress. When abnormal conditions such as low battery or communication loss are detected, the system autonomously activates fail-safe actions, including return-to-home and loiter modes, to prevent mission failure and vehicle loss. Experimental results show that the proposed system achieves a voltage measurement accuracy of 99.87%. In addition, the fail-safe mechanism successfully detects low battery conditions within 2.5–3.0 seconds and communication loss within 6–15 seconds, demonstrating improved USV operational safety and reliability.
Risk Management of Subsea Pipeline Integrity and Failure Prevention
Subsea pipelines are critical offshore infrastructures for transporting oil, gas, and produced fluids, but they are exposed to structural degradation, environmental loading, and third-party interference that may lead to leakage or failure. This study evaluates subsea pipeline damage risk by integrating Fault Tree Analysis (FTA), Event Tree Analysis (ETA), and Bowtie Analysis. Risk identification classified the main hazards into pipeline structural integrity failure and third-party interference. The FTA results show that the probability of subsea pipeline damage as the top event is 0.0297492, with pipeline structural integrity failure contributing 0.0179766 and third-party interference contributing 0.0119882. The dominant basic events are failure to conduct periodic inspection, corrosion, gasket failure, emergency anchoring, and severe weather conditions. ETA was applied to assess consequence pathways after pipeline damage through six safety barriers: detection and alarm, alarm verification and decision making, emergency shutdown and isolation, pressure and inventory control, area control and secondary impact prevention, and emergency response, inspection, and repair. The results indicate that minor damage with no significant fluid release has the highest probability, whereas catastrophic loss of containment has the lowest probability but the most severe impact. Bowtie Analysis integrates the causal and consequence pathways into preventive and mitigation controls for integrity.
Spatial and Socio-Economic Determinants of Public Acceptance and Management of Domestic Wastewater Treatment Plants
Wastewater treatment systems are vital to secure the public health and environment by processing wastewater to be less harm. This research aims to analyse the domestic wastewater management system and develop strategic management steps specifically for the Lhokseumawe City area. The method employed is a quantitative analysis using a cross-sectional approach. Primary data were collected through field surveys, questionnaires, and interviews, while secondary data included population and city maps. Data analysis utilized the Chi-Square test to determine correlations between respondent characteristics, such as age, education, and income, and their knowledge or attitudes regarding wastewater treatment plants (WWTP). Results and discussion reveal that Lhokseumawe residents generally hold positive knowledge (75%) and attitudes (86%) toward wastewater management. Significant correlations were found between education levels and management knowledge (α < 0.05). While Muara Satu residents showed the most positive engagement, otherwise the Blang Mangat community requires further educational intervention. The conclusion suggests that local governments should strengthen community-based training and awareness campaigns, particularly targeting youth, women, and low-education groups, to ensure sustainable and effective wastewater management.