International Journal of Marine Engineering Innovation and Research
The International Journal of Marine Engineering Innovation and Research (IJMEIR) is an open-access journal, which means that visitors around the world can publish, read, download, quote, and distribute papers published in this journal for free. The IJMEIR journal has a lot of visitors, broad impact and quite high citations. IJMEIR adopts a peer-review model, which guarantees fast publishing and convenient delivery. IJMEIR cordially invites you to contribute or recommend quality papers to us. This journal directs at the dissemination of original innovations, research and practical contributions by scientists and engineers, both from academia and industry: thesis, dissertations, research papers, and reviews related to all aspects of marine engineering. IJMEIR publishes four issues per year in March, June, September, December. 6 days Average time to first decision 13 days Average review time 15 days Average time to accepted
Department of Marine Engineering, Institut Teknologi Sepuluh Nopember
Optimization of the Number of Boat Passengers Using the Intact Stability Survival Approach
Passenger ship accidents in Indonesia’s domestic waters are frequently linked to overloading and stability failures, particularly on non-classed vessels with open decks. This study proposes an analytical method to determine the optimal passenger capacity based on intact stability survival criteria. The method begins with hydrostatic calculations of the hull to generate the KN curve, which is then adjusted for the mass distribution of the vessel and passengers to produce the actual GZ curve. Optimization is performed iteratively by comparing the calculated righting moment (Mst) with the regulatory criterion moment (Mkr), following both BKI and ISO 12217-1:2015 standards, while also accounting for the limiting condition at the downflooding angle. A case study on a V-hull boat (L = 10.5 m; B = 3.2 m; H = 1.4 m) reveals a substantial divergence between the two regulatory frameworks. Under light displacement (LWT = 1 ton), ISO permits up to 138 passengers, whereas BKI limits capacity to only 17. Conversely, at a high LWT of 8 tons, ISO does not allow any passengers, while BKI still permits approximately 29. Validation against Maxsurf software demonstrates excellent agreement (R² = 0.9993), confirming the reliability of the developed program. These findings establish that the proposed method is both valid and practical, offering a technical guideline for determining the safe passenger capacity of non-classed open-deck vessels operating in domestic waters.
Copyright (c) 2026 Institut Teknologi Sepuluh Nopember https://creativecommons.org/licenses/by-sa/4.0
Growth Performance and Osmoregulation of Vaname Shrimp (Litopenaeus Vannamei) with Cultivation Media Engineering
Production of white shrimp (Litopenaeus vannamei) in 2024 is targeted by the Ministry of Fisheries and Marine Affairs to be increased by producing 2 million tons / year. However, in fact, in 2022 white shrimp production is 1.09 million tons, so to achieve the target, new technology and innovation are needed. The obstacle experienced with freshwater cultivation is the low mineral that plays an important role in the growth of white shrimp. To be able to cultivate white shrimp in fresh water, it is necessary to first conduct a study on the manipulation of aquaculture water with freshwater, salt and bittern components as mineral sources. The purpose of this study is to test the combination of components of artificial water media for white shrimp farming and analyze the mineral content. The study will be conducted from March to April 2024. The method used is an experimental method with Completely Randomized Design (CRD). Data collection is carried out by field observation and literature study. The research procedures carried out were bittern and salt collection and white shrimp sampling, media preparation, mineral test on water as culture media, white shrimp stocking, white shrimp rearing, morphology and survival rate tests and viscosity tests to review osmoregulation in white shrimp and data analysis. Data analysis was performed using Canonical Correlation Analysis (CCA) with PAST 4.03 software. The mineral content produced is directly proportional to the amount of dose given. The best dose of bittern in this study is in treatment C with a dose of 15 ml which has a calcium content of 45.2 mg/L, magnesium 155 mg/L, and potassium 73.89 mg/L.
Probability of Deck Wetness and Bottom Slamming due to Height and Wave Directions on Klotok Boat
Sailing safety is an important aspect that must be considered to ensure the safety of the crew and passengers. One aspect that affects sailing safety is the probability of deck wetness and bottom slamming on each ship. A research object is a traditional wooden boat hull operating on the Penjam - Balikpapan route that transports passengers and vehicles. The aim is to provide information regarding wave conditions that support the safe operation of klotok ships. In this study, the variations in wave arrival directions used are 45°, 90°, 135° and 180° with a ship speed of 8 knots, and variations in wave height are based on the sea state approach, namely sea state 1 (0.488 m), sea state 2 (1.006 m), sea state 3 (1.433 m), and sea state 4 (2.012 m). Furthermore, the m0 value is obtained as an important component to measure the occurrence of deck wetness and bottom slamming through an approximation formula and validated with the NORDFORSK 1987 criteria. The results of the study indicate that the highest probability value of deck wetness occurs in the direction of wave arrival 180° with a wave height at sea state 4 (2.102 m). While the highest probability value of bottom slamming occurs in 2 variations of wave arrival direction, namely 135° and 1800. The wave height that must be considered in the direction of wave arrival 135° is 1.433 m and 2.012 m. Meanwhile, if the direction of wave arrival is 180°, the wave height that must be considered is 1.006 m, 1.433 m, and 2.012 m. With initial information on the potential for deck wetness and bottom slamming, it can be recommended that ships will tend to sail safely if waves arrive at 450 and 900 degrees, while immediately avoiding ship movements in the direction of waves at 1350 and 1800 degrees, especially at extreme wave heights. This condition will occur if the gravity concentration position is in the forecastle position. Meanwhile, if the gravity concentration position is at the stern, the passenger room and vehicle deck show a probability value that tends to be safe.
Copyright (c) 2025 Institut Teknologi Sepuluh Nopember https://creativecommons.org/licenses/by-sa/4.0
Assessment Seakeeping Performance And Operability Model A Fast Craft Using Axe Bow
Hull shape affects the characteristics of movement and operability ship itself. Operability ship is at sea the amount of time during which the structure is capable of operating in accordance with the criteria established and high correlation to wave in which criteria will be exceeded. In the research will be carried out analysis of three degrees of freedom of movement and pitch roll heave against the ship model-type crew boat planing hull and AXE Bow size 38 meters on a regular wave with future parameter (heading, speed, mass body, radius gyration, damping and etc.) are presented in the form of graphic images Response Amplitude Operator (RAO). Motion prediction in regular waves has been performed by running a mathematical model developed on the basis of a 3-liner potential theory, and further transformed into the motion in irregular waves through the spectral analysis. The calculation is performed with the help of software computing HydroSTAR Ver.7.1 will be compared with Maxsuft software. This latter analysis was conducted for all level of intensities by referring to the wave scatter data for Natuna Sea, and then correlated to the operational criteria. Results of evaluation exhibits that at full load, operational crew boat could be carried out at significant wave heights Hs ranging from 0.245m up to 3.745m, which has a proportion of occurrence as much as 97.02% to model planing hull and as much as 98.72% to model AXE Bow. Crew boat operation would not be safely conducted at wave heights higher than those, in which their occurrence in Natuna Sea is only 2.720%, model hull planing and is only 0.14% model AXE Bow
Analysis of the Implementation of the Port Concession between KSOP Class I Sorong and PT Pelindo Regional 4 Sorong
This research aims to analyze the implementation of concession policies at Sorong Port based on Government Regulation Number 31 of 2021 and Minister of Transportation Regulation Number 48 of 2021, focusing on the role of the Sorong Class I Port Authority Office (KSOP), PT Pelindo Regional 4 Sorong, and port workers. This study uses a qualitative approach with data collection techniques through interviews and field observations. The results of the study show that the implementation of concessions has provided clarity on the role between regulators and operators, but the implementation has not been optimal because there is still a gap between administrative policies and operational realization in the field. The limitations of technological infrastructure, human resource capacity, and differences in orientation between KSOP and Pelindo are the main inhibiting factors. Nevertheless, concessions have a positive impact on improving service efficiency, operational order, and the implementation of safety standards. Obstacles such as the absence of uniform Standard Operating Procedures (SOPs) and limited port facilities indicate the need for an adaptive approach that takes into account the local characteristics of the eastern region of Indonesia. This study concludes that the success of concessions at Sorong Port depends on policy harmonization, institutional coordination, and strengthening the capacity of human resources. With the support of central government policies and synergy between regulators, operators, and labor, Sorong Port has the potential to become an efficient, modern, and sustainable integrated port management model in eastern Indonesia.
Design Development Study Of Mini Trash Skimmer Boat A22 With Packing Technology In East Flood Canal
Garbage is a significant source of water pollution, particularly in the East Flood Canal (BKT) river. This study develops the design of the Mini Trash Skimmer Boat A22 as a practical solution for waste collection in polluted waters. The vessel adopts a catamaran hull to ensure stability and efficiency in skimming operations. With principal dimensions of 3.5 m in length, 2 m in breadth, and 0.8 m in depth, it accommodates a waste bin of approximately 0.4 m³. A conveyor system integrated with hydraulic press technology is applied to compact garbage, thereby increasing storage capacity. Resistance analysis using the Holtrop method in Maxsurf shows that at a speed of 21.26 knots, the vessel experiences a maximum resistance of 8.1 kN, corresponding to an engine power requirement of 8.83 kW. The boat is further equipped with an autonomous navigation module to support operational efficiency and powered by Lifepo4 lithium batteries with one-hour endurance. The results highlight that incorporating packing technology enhances waste-handling capacity, while the combination of catamaran stability and automation makes the Mini Trash Skimmer Boat A22 a promising approach for reducing water pollution in urban waterways.
Determination of Standard Time and Man Hours for Welding Process in Barge Repairs
Shipyards are facilities that play an important role in building and repairing ships. One common type of repair is replating, which means replacing damaged hull plates with new ones. This process relies heavily on welding, which needs skilled workers and a lot of electrodes. A frequent issue in the field is the challenge of estimating how many electrodes are needed, which often results in wasted materials, increased costs, and delays in completing the work. This study seeks to calculate the electrode needs, the time required for the work, and the man-hours needed for ship replating. The research involved a review of existing literature and a field study. The welding process used the SMAW method with E6013 electrodes, 160A current, and 2G and 3G welding positions. Each welding position involves three stages: root, filler, and capping. The average welding speed data for every 1000 mm is used to calculate the actual welding length in the replating process. The results showed that the average welding time for the 2G position was 39,277.89 minutes, while for the 3G position it was 17,657.54 minutes. The total electrode requirement was 1,619.69 kg, which is equal to 324 boxes, with an estimated cost of Rp. 40,240,800.00. Additionally, the number of workers needed is 27, with a total of 948.924 man-hours over a period of 5 days. In conclusion, organized calculations of electrode needs, time, and man-hours can help improve the efficiency of replating work, reduce waste, and aid in project management planning in shipyards.
Analysis Of Paint Material Requirements in the S-80 Tugboat Hull Painting Project
Calculating the paint requirements is a lengthy and meticulous process. Therefore, the company needs to calculate the painting requirements correctly and accurately. The painting process is one of the processes in shipbuilding. The coating process involves painting or layering ship steel plates with special paint to protect the vessel. This research aims to estimate the material and cost requirements for the S-80 tugboat construction project by calculating the needs, coating with 2 different products so that a comparison of materials and costs can be made, namely International and Nippon Paint. The amount of paint needed is determined based on the surface area of the underwater and topside hull of a 26-meter tugboat. This study applies a quantitative method, so resulting in final outcomes presented in numerical form. According the research, he total coating needs for the hull of the ship for the bottom part using the International brand is 111,6 L and for the Top Side is 59,43 L, while for the Nippon Paint brand, the Bottom part is 64,5 L and the Top Side is 57,6 L. For the coating process, the total cost for the bottom and topside areas with the International brand amounts to Rp31.702.000. Meanwhile, for the Nippon Paint brand, the cost for the bottom and topside areas is Rp11.238.000 in total.
Design and Development of a Command and Control Unit (CCU) on an Unmanned Surface Vehicle (USV) for Water Observation
The development of a data acquisition and control system based on modern technologies plays a crucial role in supporting aquatic environmental exploration using Unmanned Surface Vehicles (USVs). This project aims to design and implement a command-and-control unit capable of integrating water survey instruments with microcontroller-based sensors, targeting the real-time display of depth data, GPS location, and graphical visualization on an Smartphone application. The system employs the ESP32 module as the bridge between USV sensors—such as a single-beam echo sounder for depth measurement and a GPS module—and the user application. Wi-Fi connectivity is utilized for fast and efficient data transmission between the USV and the mobile interface. In this project, the Arduino IoT Cloud platform is adopted to simplify the integration of real-time data into the user interface, eliminating the need to develop an application from scratch. The system is designed to be cost-effective, portable, and user-friendly. This project is expected to demonstrate the system’s capability to process sensor-acquired data, control the USV’s movement direction, and display the results in numerical and graphical formats on the user's Android device in real time
Preliminary Analysis Of Governance, Social Norms, and Behavioral Determinants of Household Participation in Marine-Linked Waste Management in Gorontalo Province, Indonesia
This study investigates household willingness to adopt sustainable waste management practices in Gorontalo Province, Indonesia, a coastal region where unmanaged solid waste directly threatens marine natural capital such as mangroves, seagrass, and coral reef habitats. Using an extended Theory of Planned Behavior (TPB) framework, the research incorporated adaptive capacity as a governance-related antecedent to explain household pro-environmental behaviors. A cross-sectional survey of 63 respondents was conducted, and the data were analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM). The results demonstrate that attitudes had a modest effect on behavioral intentions (H4, p = 0.038), while subjective norms strongly predicted both perceived behavioral control (H2, p < 0.001) and intentions (H5, p < 0.001). Perceived behavioral control emerged as a decisive factor shaping intentions (H6, p = 0.002) and indirectly influencing behaviors (p = 0.012). Adaptive capacity significantly strengthened perceived behavioral control (H3, p = 0.028), confirming the importance of governance support in enabling household action. Finally, intentions strongly predicted actual behaviors (H7, p < 0.001), such as reducing single-use plastics and avoiding littering in coastal areas. These findings suggest that enhancing governance capacity, reinforcing social norms, and building household confidence are critical for aligning community waste practices with marine ecosystem protection.
Integration of FMEA, LTA, and Fishbone Diagrams in the application of RCM II on KN–02 Gas Compressors
Gas compressors are vital equipment in the oil and gas industry that function to maintain the smooth production and transportation of natural gas. Compressor failure can cause significant downtime, financial losses, and safety risks. This study aims to evaluate the maintenance policy of the KN-02 gas compressor at the Nibung Gas Compressor Station (SKG) using the Reliability Centered Maintenance II (RCM II) method. Engine fault data was collected in the period September–October 2024 and analyzed through Failure Mode and Effect Analysis (FMEA), Logic Tree Analysis (LTA), and Fishbone Diagram to identify critical failure modes and root causes. Furthermore, the proposed treatment strategy was formulated using the RCM II Decision Worksheet. The results of the analysis showed three critical components with the highest Risk Priority Number (RPN) values, namely cylinder oil supply failure (RPN = 671), valve suction/discharge (RPN = 662), and packing rod (RPN = 577). Based on the results of the LTA, the recommended types of maintenance include scheduled restoration, scheduled discard, and condition-directed maintenance. Fishbone's analysis indicates that the root cause comes from material wear factors, lubrication quality, and maintenance procedure errors. With the implementation of an RCM II-based maintenance strategy, compressor engine downtime is expected to be reduced by more than 40%, while improving the operational reliability of the system. This study confirms that RCM II is effective as a systematic approach in determining optimal oil and gas machinery maintenance policies.
Longitudinal Strength Analysis of a Container Ship under Sagging and Hogging Conditions Using the Finite Element Method
This study analyzes the longitudinal strength of a container ship under hogging and sagging conditions using the Nonlinear Finite Element Analysis (NLFEA) method. Numerical modeling was performed on a single frame spacing of the container ship to evaluate the stress and deformation distribution due to longitudinal bending loads. A three dimensional finite element model was developed using SHELL181 elements in ANSYS software, employing large displacement static analysis. The results show that under hogging conditions, the deck experiences a maximum tensile stress of 410.28 N/mm², while the bottom structure undergoes a compressive stress of -405.93 N/mm². Under sagging conditions, the deck experiences a compressive stress of 279.91 N/mm², and the bottom experiences a tensile stress of -387.80 N/mm². The ultimate bending moments were 1.42 × 10¹³ Nmm for hogging and -1.21 × 10¹³ Nmm for sagging, indicating that the ship is more susceptible to structural failure under sagging conditions. These findings highlight the importance of considering both loading conditions in the structural design of container ships to ensure safety and operational efficiency.
Experimental Investigation of the Municipal Solid Waste Characteristics for a Gasification Based Waste-to-Energy Power Plants
This study experimentally characterizes Municipal Solid Waste (MSW) feedstock to assess its suitability for gasification-based Waste-to-Energy (WtE) systems. Ten samples from different urban collection sites underwent thorough analysis using standardized ultimate and proximate methods, alongside bomb calorimetry on a dry basis, which helped to ensure the results accuracy. A strong positive correlation was observed between carbon and hydrogen content and gross calorific value, while oxygen, nitrogen, sulphur, and ash content exhibited a negative correlation with calorific potential. Notably, plastics and complex waste yielded the highest gross calorific values, around 30,000 kJ/kg and 31,600 kJ/kg, respectively, while high-ash content fractions recorded the lowest values at about 6,600 kJ/kg. The presence of volatile matter and fixed carbon positively impacts energy release, whereas ash dilutes fuel quality and increases heat absorption during combustion. The study suggests that pretreatment strategies, such as moisture reduction, ash fraction removal, and selective sorting for hydrocarbon-rich materials, effectively enhance fuel quality for gasification and reduce nitrogen and sulphur emission risks. The data reveal significant variability among different waste fractions, indicating that effective feedstock management and reactor design must address compositional heterogeneity to ensure reliable gasification performance.
PARIPEDAS: A Smart Rural Tourism Model Using SEM Analysis Through The Coastal Village Community Empowerment
Tourists turn to rural tourism because of its distinctiveness in relation to nature, the hospitality of the locals, and its unique food. However, Central Tapanuli Regency's tourism growth remains uneven due to a lack of infrastructure, knowledge, and policies that prioritize urban regions. The Central Tapanuli Regency Government has to create a tourist strategy that takes coastal rural development into account. In Central Tapanuli Regency, the Smart Rural Tourism Model (PARIPEDAS) encourages the growth of tourism by utilizing village potential, community engagement, natural preservation, and local knowledge. The study employs a mixed methodological approach to ascertain policymakers' perspectives, assess the function of rural communities, and develop a PARIPEDAS model using Structural Equation Modeling (SEM) analysis based on Central Tapanuli Regency's coastline potential. While the PARIPEDAS model requires more research to be in line with regional development plans, the research determined that the ideal approach was to empower and include coastal communities in the implementation of tourism and development, concentrating on the distinctive value of tourist attractions and protection of natural assets.
Implementation of Electronic E-Auction to Improve Shipyard Supply Chain Performance
Material procurement in the supply chain accounts for 60% of the ship contract value and has the highest burden with the largest portion of fund distribution, often resulting in procurement delays. This has an impact on delays in the delivery of modular ship construction. Supply chain performance delays are partly due to conventional auction methods, which result in many cases of fraud and a greater potential for material delays. The potential for losses results in delays in ship production, even though risk assessment activities have been carried out as an improvement for the shipyard. The purpose of web-based electronic auction research is to find efficient and accountable prices that can be justified. On the other hand, manual meetings are not necessary, as vendors can participate in meetings and the auction process from their respective locations, minimizing the potential risk of delays in the supply chain material procurement and enabling the production process to proceed according to the initial contract. The results of the research are in the form of an E-Auction user interface for auction processes with two functions, namely administrator login and login for partners or vendors implementing E-Auction auctions, thereby improving aspects of technology, management, marketing, and human resources.
Analysis Variation of Concentration and Pickling Time in SA-312 304 on Oxide Layer Thickness
Austenitic stainless steel SA-312 Grade 304 offers good corrosion resistance, but welding can form oxide layers that degrade its performance. Pickling with nitric acid (HNO3) and hydrofluoric acid (HF) is commonly used to remove oxides and restore corrosion resistance. This study examines the effects of varying HNO3 concentration and pickling time on oxide layer thickness. Optical and scanning electron microscopy (SEM) were performed. The optimal result was achieved with 15% HNO3 + 4% HF for 35 minutes, producing a 5.6658 µm oxide layer, while 25% HNO3 + 4% HF for 35 minutes yielded only 3.0082 µm. Results show that proper pickling parameters effectively reduce oxide scale.
The Influence of Wet Scrubber on the Performance Efficiency of Heat Exchanger at Gasification Based Waste to Energy Power Plants
This research investigates the influence of wet scrubber installation on the performance efficiency of a shell and tube heat exchanger operating in a gasification-based Waste-to-Energy (WtE) power plant located in Surakarta, Indonesia. The study was conducted using a quantitative comparative approach over a four-month operational period, comparing system performance before and after the application of a wet scrubber. Three key parameters such as heat exchanger effectiveness, fouling factor, and pressure drop were analyzed to determine the impact of the gas cleaning system on thermal performance. The results show that the fouling factor decreased from 0.003 to 0.002 J/h·m²·°C, indicating cleaner heat transfer surfaces. Meanwhile, the pressure drop on the tube side reduced from 130.374 Pa to 46.134 Pa, reflecting smoother gas flow and lower mechanical resistance. Consequently, heat exchanger efficiency increased dramatically from 34% to 83%, signifying a substantial improvement in heat transfer capability. These findings confirm that the wet scrubber effectively minimizes tar and fine particulate deposits in syngas, improving heat transfer efficiency, operational stability, and equipment lifespan. The integration of wet scrubbers is therefore proven to be a vital enhancement for optimizing gas cleaning and energy conversion processes in Waste-to-Energy systems.
Experimental Study on the Application of a Local Propeller for Improving the Propulsion Performance of FRP Fishing Vessels
This study aims to evaluate the performance improvement of fishing vessels made of fiberglass-reinforced plastic (FRP) using locally manufactured propulsion components. Two vessels, KM. Nelayan 271 and KM. Nelayan 371, were tested to identify and resolve the underperformance issue, as both initially failed to achieve the target service speed of 7 knots. The experimental approach involved field installation, configuration adjustment, and sea trials. On KM. Nelayan 271 , the original D22×P20 (three-blade) propeller was replaced with a D24×P22 (four-blade) model, resulting in a speed increase from 5.3 to approximately 7.1 knots at 2000 RPM. On KM. Nelayan 371, the gearbox was replaced from WHG17G (3:1) to MA125 (2:1), allowing the vessel to exceed 8.3 knots using the same propeller configuration. These results demonstrate that optimizing the gearbox ratio and propeller geometry effectively restores the propulsion balance and enhances vessel performance. The findings provide empirical validation that domestically manufactured components, specifically the B-Series propellers produced by BTH Surabaya, can meet the operational standards for small fishing vessels. This achievement supports Indonesia’s initiative to strengthen the TKDN policy and reduce reliance on imported marine propulsion systems.
A Machine Learning-Based Approach for Designing SEEMP on Ships: Case Study of CO₂ Emissions at a Container Port
The management of ship energy significantly affects both cost efficiency such as earnings before interest and environmental sustainability, particularly in reducing CO₂ emissions produced by ship operations. Despite the importance of this issue, research on ship energy consumption within container terminals remains limited. This study aims to estimate CO₂ emissions generated by ship activities in container ports, focusing on emission variables related to the Ship Energy Efficiency Management Plan (SEEMP). The calculation considers active ship movements in the port, including approach, maneuvering, and berthing processes. Energy consumption and CO₂ emissions were analyzed using random forest regression (RF) with default settings, and the model’s accuracy was validated through k-fold cross-validation. The results identified five major factors influencing CO₂ emissions: (1) main engine power, (2) auxiliary engine power, (3) waiting time in the port, (4) maneuvering time, and (5) berthing time. Among these, maneuvering, waiting, and berthing showed the highest significance, confirmed by attribute selection and validation results. The random forest model demonstrated a prediction accuracy of 98.89%, confirming its reliability. Moreover, operational fuel efficiency analysis indicated that combining voyage optimization, skilled operators, and cold ironing facilities could reduce CO₂ emissions by up to 20%. These findings provide valuable insights and serve as a foundation for developing a more effective Ship Energy Efficiency Management Plan to enhance environmental performance in maritime operations.
Analysis of the Influence of Structural Profile Differences Between Tambak Lorok Traditional Fishing Vessels and BKI Standard Criteria
Traditional fishing vessels in Tambak Lorok are commonly constructed based on inherited craftsmanship and empirical experience, without adherence to any formal classification standard. Consequently, variations in the mechanical strength of wooden materials due to dimensional differences require further investigation. This study aims to examine the differences in destructive stress values that occur after the vessel experiences an impact, with reference to the Bureau of Classification Indonesia (BKI) criteria. The methodology involves recalculating the structural dimensions of wooden ship components following BKI standards and conducting localised impact tests at a standard berthing velocity of 0.25 m/s, with vessel speeds ranging from 1 knot to 2.5 knots. The analytical and experimental findings reveal a construction weight reduction of 258 kg, equivalent to approximately 42% lighter than the conventional design. The safe stress limits were determined to be 102.88 MPa on the frame and around 30 MPa on the hull plating under a 2-knot collision. These results demonstrate that applying BKI criteria enhances both structural efficiency and economic value while maintaining safety under standard berthing conditions.
Analysis of the Livelihood Shift of Sea Cucumber Fishermen on Local Economic Mobility in Sitardas Village
Sitardas Village is located in Central Tapanuli Regency, a coastal area rich in marine resources, one of which is sea cucumbers (holothurians). Sea cucumbers have long been an ecologically and economically important commodity for the community, serving as the primary source of livelihood for fishermen. Sea cucumbers caught in Sitardas Village not only meet local market demand but also have significant potential in the global market, particularly in the export trade sector. Sea cucumber fishing is becoming increasingly common due to increasing demand. Given this potential, the urgency of this research is that it often faces various challenges. One such challenge is the decline in sea cucumber populations due to overexploitation. To address this issue, the aim of this research is to influence local economic mobility and how communities can adapt to these changes without compromising the sustainability of marine resources. Therefore, this analysis is crucial for providing strategic recommendations for managing natural resources sustainably while encouraging improved community welfare. This research is also expected to identify patterns of livelihood changes and their driving and inhibiting factors, so that interventions can be designed appropriately and support sea cucumber conservation efforts while strengthening the local economy in a sustainable manner.
Socio-demographic and governance drivers of sanitation participation: Preliminary Evidence from Gorontalo City, Indonesia
This study examines household willingness to participate in community-based sanitation governance in Gorontalo Province, Indonesia, where marine natural capital is increasingly threatened by inadequate sanitation. A cross sectional survey of 63 households was conducted using a structured questionnaire that measured governance performance, agency and empowerment, access, flexibility, and learning capacity. Exploratory factor analysis identified five latent dimensions, and subsequent cluster and logistic regression analyses tested the influence of socio-demographic and governance variables on willingness to participate. The hypothesis testing confirmed that socio-demographic characteristics (H1 gender, H2 age, H3 education, H4 occupation, H5 household expenditure, H6 household income) played limited roles, with only occupation and expenditure showing partial influence. In contrast, governance-related dimensions were decisive. Organizational performance (H7) and agency and governance (H8) did not reach significance in the binary model, but sanitation access (H9) strongly predicted willingness (p < 0.01), with flexibility also marginally significant. These results demonstrate that while socio-economic background shapes vulnerability, participation is primarily driven by equitable access and adaptive governance capacity. The findings underscore the urgent need for Gorontalo’s sanitation policies to integrate governance strengthening with marine ecosystem protection, ensuring that community participation contributes directly to safeguarding marine natural capital.
Numerical Simulation of Hydrodynamic and Sediment Transport in the Madura Strait
Surabaya serves as a coastal and economic center in East Java, where rapid coastal development around the Madura Strait has intensified sedimentation and shoreline change. Understanding hydrodynamic behavior and sediment transport is crucial for sustainable coastal management. This study applies a three-dimensional Delft3D numerical model to simulate hydrodynamics and sediment transport in the Madura Strait. The model accounts for tides, waves, wind, river discharge, temperature, salinity, and sediment properties to capture seasonal variations in circulation and sediment dynamics. Model validation using tidal and current observations shows acceptable accuracy based on RMSE and MAE values. Results indicate that tidal forcing predominantly controls current circulation, showing bidirectional flow with a phase lag between flood and ebb tides, leading to net sediment transport toward the Pamurbaya convergence zone. Significant wave heights (0.1–0.5 m) exhibit seasonal variation, increasing during the East Monsoon and the Second Transitional Season due to easterly winds. Sediment transport simulations show minor morphological changes (–0.02 to +0.02 m/year) but active redistribution, particularly near Pamurbaya. These findings highlight the dominant role of tidal dynamics and the need for adaptive, morphodynamic-based coastal management to ensure the long-term stability of the eastern Surabaya coastline.
Analysis and Design of Noise Barrier Based on Analytical Hierarchy Process (AHP) Method
Noise is one of the potential hazards that must be controlled to prevent occupational diseases. In one office area, the noise level exceeds the limits stipulated in the Ministry of Manpower Regulation No. 5 of 2018. Based on preliminary interviews, the installation of a noise barrier is urgently required. The selection of the type of material and the design of the noise barrier shape was carried out using the Analytical Hierarchy Process (AHP) method. The selection criteria included material, cost, aesthetics, material weight, safety, and ease of installation and maintenance. The determination of height variations was conducted using the Maekawa method. A gypsum board noise barrier with a vertical shape and a height of 1,94 meters was able to reduce the noise level in the office area exposed to 87,83 dBA down to 48,01 dBA, as validated using COMSOL Multiphysics 6.0 software. Unlike previous studies, the difference in validation results lies in the design selection using the AHP method.
Design and Construction of a Website-Based Workplace Noise Intensity Measurement
This study was conducted at the Surabaya State Polytechnic of Shipping (PPNS), where the Occupational Safety and Health Management System (SMK3) is implemented to ensure a safe and efficient work environment in accordance with industry standards. Currently, noise measurements are carried out manually and data recording is often not well documented. The main objective was to design a noise detection system for the construction workshop, focusing on monitoring environmental noise as part of SMK3's Hazard Identification and Risk Assessment (IBPR) process. The research method involved calculating decibel (dBA) values using regression, transmitting measurement data from the device to the server via a Wemos D1 Mini, and comparing the results with conventional sound level meter readings to identify machine noise sources. The outcome is a web-based noise detection system that automatically records measurements, shows results, and displays warnings if noise levels exceed the Threshold Limit Value (NAB).
Development of Virtual Reality-Based Engine Room Simulator for Marine Engineering Training
Marine engineering education relies heavily on engine room simulators to build operational competence in a safe environment. However, conventional 2D or desktop-based simulators provide limited immersion and spatial awareness, which may reduce engagement and hinder the development of situational awareness and procedural memory. This paper presents the development of a Virtual Reality-Based Engine Room Simulator (VR-ERS) aimed at enhancing marine engineering training in accordance with STCW competencies. The proposed system combines a game engine–based 3D engine room model, real-time interaction with critical subsystems (fuel oil, cooling, lubrication, and electrical power), and head-mounted display (HMD)–based immersive visualization. A modular system architecture is proposed, including hardware (VR HMD, controllers, PC), software layers (3D modeling, interaction and physics, scenario engine), and a learning management interface for instructors. A training scenario framework is designed to cover normal operation, watchkeeping routines, and selected fault and emergency cases. A preliminary usability and acceptance study with marine engineering students is outlined using System Usability Scale (SUS) and Technology Acceptance Model (TAM) constructs. The development process demonstrates that VR-ERS can provide realistic engine room familiarization and procedural training, while offering flexibility for scenario authoring and future integration with learning analytics. The paper concludes with recommendations for full-scale validation studies comparing VR-ERS with conventional simulators in terms of learning outcomes, competency achievement, and cost-effectiveness.
The Intricate Sea Borders of Batam (Indonesia), Tanah Merah (Singapore) and Johor Bahru (Malaysia)
this comprehensive report examines the technical specifications of passenger ferries operating in the busy maritime corridor between Batam (Indonesia), Tanah Merah (Singapore), and Johor Bahru (Malaysia), alongside the regulatory frameworks ensuring their safety in international waters. Predominantly high-speed catamarans equipped with waterjet propulsion systems (total power exceeding 4000 kW), these vessels accommodate 150-500 passengers and feature advanced safety systems including SOLAS-compliant life-saving appliances, GMDSS communication, ECDIS navigation, and automated fire suppression. Safety is governed by key IMO conventions such as SOLAS, STCW, and ISM Code, implemented nationally by Singapore's MPA (Merchant Shipping Act), Indonesia's DGST (Law No. 17/2008 on Shipping), and Malaysia's MDM (Merchant Shipping Ordinance 1952). Practical protocols encompass mandatory drills, STCW certified crew training, rigorous port state control inspections under Tokyo MOU, and incident analysis for continuous improvement. While robust oversight minimizes risks in high-traffic straits, challenges like human error and cross-border coordination underscore the need for enhanced trilateral cooperation. Findings highlight a mature safety ecosystem supporting millions of annual passengers, offering insights for nautical science education and policy refinement.
Comparison Analysis of the Port Business Between PT. Pelabuhan Indonesia (Persero) and PSA International Singapore
Maritime transportation, as a key element of global trade, offers significant economic advantages, with ports playing a crucial role in ensuring the smooth flow of goods. The increasing number of ship visits highlights the need for port infrastructure development to improve operational efficiency. This study aims to compare the port business between PT. Pelabuhan Indonesia (Persero) and PSA International in Singapore. The research employs a qualitative method, using the Business Model Canvas (BMC), PESTEL analysis, and gap analysis to compare key elements in both ports. The findings reveal significant differences in technology and infrastructure between Pelindo and PSA. PSA excels in the application of advanced technology, while Pelindo focuses more on domestic infrastructure development. These recommendations are expected to provide insights for Pelindo to improve its business processes and competitiveness in the international market, as well as to support the achievement of the Sustainable Development Goals (SDGs), specifically Goal 9.
A Study of Port Facilities in Supporting Throughput at Sunda Kelapa Port
Sunda Kelapa Port is a collector port that plays an important role in inter-island goods distribution, yet it still faces facility limitations and low operational efficiency. Although the number of loading and unloading activities increases each month, the predominantly manual operational processes indicate the need for facility modernization. This study aims to analyze the condition of facilities at Sunda Kelapa Port and evaluate throughput values to determine their relationship with port performance. A qualitative descriptive method was employed through an assessment of primary and functional port facilities as well as throughput calculations based on loading and unloading data from August to October 2025. This analysis was conducted to assess the capacity of the existing facilities to support increased cargo flow. The results show that the 54 percent decrease in general cargo throughput in September, followed by a limited increase in October, was influenced by inadequate conditions of the public pier, storage yard, and warehouse. For container cargo, the significant 90 percent decline in throughput was caused by the limited capacity of the container yard, insufficient stuffing– stripping areas, and the absence of modern container-handling equipment. Overall, the study concludes that the existing facilities at Sunda Kelapa Port are not yet optimal in supporting throughput growth. Modernizing port facilities is essential to improve efficiency and strengthen the port’s role within the national logistics system.
Population Dynamics of Mackerel Scad (Decapterus macarellus) Landed at the Sibolga Archipelago Fishing Port
This study analyzed the population dynamics of mackerel scad (Decapterus macarellus) landed at the Sibolga Archipelago Fishing Port, North Sumatra, Indonesia, to assess growth, mortality, recruitment, and exploitation status. Length–frequency data from 200 specimens were analyzed using the FISAT II software. The asymptotic length (L∞) and growth coefficient (K) were estimated at 40.4 cm TL and 0.51 year⁻¹, respectively, indicating a moderately fast-growing species typical of tropical small pelagics. The total, natural, and fishing mortalities were 3.91, 1.08, and 2.84 year⁻¹, resulting in an exploitation rate (E = 0.73), which exceeds the optimum level (Eopt = 0.5), signifying overexploitation. Recruitment analysis showed two annual peaks (March–April and September–October), reflecting a bimodal spawning pattern. The length at first capture (Lc = 16.2 cm TL) was smaller than the length at first maturity (Lm ≈ 17.0 cm TL), suggesting premature harvesting. The yield-per-recruit model indicated E₀.₁ = 0.607 and Emax = 0.749, reinforcing that the stock is fully exploited. These findings underscore the urgent need to regulate fishing pressure through mesh-size adjustments and seasonal closures to sustain D. macarellus fisheries in western Indonesian waters.
Bibliometric Analysis of Coral Reef Conservation and Mooring Buoy Applications in Sustainable Marine Tourism
Ship mooring at coral reef slope is a high risk for Indonesian coral reefs, particularly in tourist based coastal environment. Mooring buoy technology is a well-established component of offshore engineering but has not yet been fully adapted to shallow coral reef ecosystems. This bibliometric analysis of 2015-2024 publications was performed using Lens.org and VOSviewer in search of research trends and knowledge gaps. The study finds six main research clusters, including: environmental management, tourism, and technical aspects; conservation, ecosystem behaviour, and protected areas; sustainable development and threats; coral reefs and ecosystem resilience; fisheries and the deep sea; and sea monitoring and conditions. While coral reef conservation research also has good representation, the following are important gaps identified in this study: mooring technology is very isolated in its own network with little apparent influence on conservation or oceanographic fields. This reflects two major gaps: mooring technology are not associated with conservation objectives, and mooring designs have not been adapted to Indonesia’s unique oceanographic conditions. This research demonstrates that developing mooring buoys suitable for Indonesian shallow waters represents a strategic opportunity to bridge engineering with practical conservation. Future research should focus on three areas: site-specific hydrodynamic characterization at marine tourism destinations; numerical simulation of adaptive mooring designs; and community-based implementation frameworks for long term sustainability.
Period of Efficient Underwater Hull Cleaning
Biofouling is a collection of unwanted living organisms on surfaces submerged in water. Biofouling is a complex occurrence caused by various physical and environmental factors that can be overcome by regular hull cleaning. The main purpose of underwater hull cleaning is to remove dirt and restore propulsion efficiency. Another benefit of hull cleaning against biofouling is to restore or rejuvenate the effectiveness of antifouling paint. This study aims to determine the extent of the effect of periodic hull cleaning on the underwater area, where the results can be used to determine the most efficient period for periodic hull cleaning and the percentage of fuel that can be saved by performing periodic underwater cleaning.The effect of biofouling can be predicted by conducting simulations using Computational Fluid Dynamics (CFD) with several variations in hull roughness. The results of the CFD simulation show that the increase in resistance with the largest surge occurs in the 18th period with an average increase of 5.8%. Therefore, the effective time to perform underwater hull cleaning is in the 18th period. Performing underwater hull cleaning in the 18th period can save fuel consumption by up to 5.8%.
The Effect of Variations In The Composition And Type of Adhesive For Mixed Peat And Gelam Wood Briquettes on The Physical Characteristics of The Briquettes
South Kalimantan has quite extensive peatlands, spread across various regions such as Barito Kuala, Banjar, Tapin, and Hulu Sungai Regencies. In these peatlands, gelam trees are often found growing rapidly and possessing various benefits, both for industrial and environmental purposes. With wise management, peat can be used as an environmentally friendly raw material for briquettes, while gelam wood can be utilized to improve the quality of the briquettes. In this study, mixed peat and gelam wood briquettes were made with various compositions (100%:0%, 80%:20%, 60%:40%, 50%:50%, 40%:60%, 20%:80%, and 0%:100%) and types of adhesives (palm sugar and damar resin). To determine the performance of the briquettes, physical characteristics were tested in the form of water content, ash content, volatile matter content, calorific value, and fixed carbon. Test results show that gelam increases the calorific value and volatile matter content but reduces the fixed carbon content, while peat increases the fixed carbon content but lowers the calorific value. Damar adhesive is superior in increasing calorific value and reducing ash content compared to palm sugar. The best briquette combination is ≥60% gelam with damar adhesive for fast, high-energy combustion. For slow, stable combustion, a dominant peat composition with damar adhesive is more suitable.
IoT Application in Designing Ship Trim Reading and Monitoring Tools
The shipping industry is widely adopting appropriate technologies in various areas to overcome challenges and improve efficiency. However, ship loading and unloading efficiency remains a significant concern in terms of cost and time. Monitoring the loading and unloading process relies heavily on Android-based manual input calculations, indicating the potential for technological application in the draft survey process. This research initiates the development of an Internet of Things (IoT) application to monitor trim readings during the draft survey of a ship. The planning involved initial stability calculations to add data to the IoT module planning. The resulting tool aims to improve efficiency by providing real-time trim and ship balance data during loading and unloading operations. Additionally, this research demonstrates the potential of IoT technology in optimizing shipping logistics and can be further developed with more advanced technology to advance the maritime industry.
Coastal Waste Management Strategies to Preserve the Sea and Strengthen Fishing Family Economies in Tapanuli Tengah
The potential of marine, fisheries, and tourism resources in Tapanuli Tengah Regency is increasingly threatened by the growing accumulation of unmanaged waste. Piled-up waste in coastal settlements, mangrove forest areas, and marine waters has caused severe degradation of coastal ecosystems and a decline in environmental quality. This study aims to identify the types of waste found in the coastal and marine areas of Tapanuli Tengah Regency and to formulate relevant waste management strategies to preserve the marine environment while improving the economy of fishing households. This research employs a case study method with qualitative descriptive analysis and SWOT analysis. The findings indicate that inorganic waste—particularly plastic—dominates the coastal and marine areas, followed by styrofoam, baby diapers, and fabric waste. These types of waste were found accumulating at the research locations: Mela I Village, Pondok Batu Village, Hajoran Village, and Jago-Jago Village. Based on the SWOT analysis, several recommended waste management strategies include environmental awareness and education programs for coastal communities, the development of facilities for sorting organic and inorganic waste, the establishment of Waste Banks at the village or sub-district level, the development of handicrafts made from plastic waste, composting of organic waste, and regular community-led “clean and waste-free sea” activities initiated by the local government and residents. These strategies are expected to support marine conservation and strengthen the economic resilience of fishing families.
Evaluating the Implementation of Modern Navigation Systems to Improve Maritime Safety in Indonesia
The Indonesian archipelago is strategically located in the major vessels’ global routes and domestic shipping lanes that lead to dense ship traffic with a mix of challenging navigational conditions, which consequently raises the potential risk of maritime accidents. Modern navigational aids—and the systems used in maritime and aeronautical sectors are just two examples—are now widely recognised to be a key factor for increasing situational awareness, explaining better route planning and decreasing instances of collisions or other hazards. This research assesses the role of these technologies to enhance safety in Indonesian waters and explores legal frameworks for their introduction. Through a descriptive/analytical approach supported by regulation review and literature analysis, the study recognizes existing advantages provided modern navigation systems, in real time monitoring and hazards detection in particular. Several challenges remain, however, with the uneven technological uptake among ships and ship types, limited seafarer skills, insufficient navigational infrastructure and evidence of unsafe operation such as AIS switching off. Regulatory loopholes and insufficient harmonization with international regulations (SOLAS, MARPOL, IMO, STCW) also have impacts on the overall effectiveness of navigation technologies. It is concluded that modern navigation systems greatly contribute towards the safety of maritime navigation, but their full utilization will have to be supported by better enforcement of regulations, upgrading infrastructure, regular training of crews and harmonization with national e-navigation initiatives. Recommendations and research directions are suggested in the evaluation to enhance an effective and technological-based maritime safety system in Indonesia.
Analysis of Sedimentation Rate In Peat Lakes : Case Study of Lake Teloko, South Sumatera
Teloko Lake in Ogan Komering Ilir, South Sumatra, is a peat swamp ecosystem revitalized through dredging to increase water storage capacity and reduce flood risk. This study analyzed post-revitalization sedimentation, assessed water quality, and identified suspended particle characteristics to support lake management. Objectives included determining the distribution of Total Suspended Solids (TSS), sedimentation rates, and relationship between particle properties and hydrological conditions to assess revitalization impact. Sampling was located at five locations at depths of 0.68 to 1.30 meters during dry season in September 2025. TSS concentrations ranged between 681 and 740 mg/L, with an average of 710.92 mg/L and a standard deviation of ±9.6%, indicating uniformity across locations and no significant dredging impact. A 72-hour sedimentation test showed a very low settling rate, with particles remaining suspended without forming a clear sediment layer. This is due to the dominance of colloidal particles less than 20 µm, containing positively charged organic matter, creating repulsive forces that inhibit natural sedimentation. The results confirm natural peat water properties and lake activities have a stronger influence on sedimentation than technical revitalization. These findings support long-term conservation by recommending ecological approaches, such as natural coagulants, to maintain water storage capacity and preserve ecosystem function.
Predictive Maintenance of Hybrid Propulsion System
Hybrid propulsion systems, integrating internal combustion engines with electric motors, represent a significant advancement in maritime technology, offering improved efficiency and reduced emissions. However, their complexity introduces challenges in maintenance and reliability. Traditional maintenance strategies are often inadequate for these dynamic systems, leading to unplanned downtime and increased costs. This research develops and validates a predictive maintenance framework specifically designed for hybrid propulsion systems in maritime applications, integrating vibration, thermal, and electrical data to enhance system reliability and reduce maintenance costs. The study employs advanced signal processing techniques including Root Mean Square (RMS), Kurtosis, Fourier’s Law, and Wavelet Transforms to extract degradation features from sensor data. Multi-sensor fusion is achieved using Dempster-Shafer evidence theory and weighted entropy-based models to resolve data conflicts and provide a holistic health assessment. Failure prediction and Remaining Useful Life (RUL) estimation are conducted using Proportional Hazards Models (PHM) and Weibull distributions. The framework was validated through case studies on two hybrid-powered vessels: a 2 MW coastal cargo ship (Ship A) and a 5 MW offshore support vessel (Ship B). Results showed that Ship A achieved an MTBF of 1,440 hours and 99.45% availability, while Ship B, operating under harsher conditions, recorded an MTBF of 864 hours and 99.08% availability. The PHM-based RUL estimation achieved a Mean Absolute Error of 12.5 hours (15.6% error), demonstrating high predictive accuracy. Economic analysis indicated a potential 40% reduction in annual maintenance costs compared to traditional methods.
Analysis of the Relationship between Scrubber Performance and Engine Operational Performance on MV. Sinar Sorong
The implementation of exhaust gas cleaning systems (scrubbers) has become a critical compliance strategy for maritime vessels following the International Maritime Organization's 2020 Global Sulphur Limit regulation. However, the technical relationship between scrubber performance and main engine operational reliability remains insufficiently documented in empirical maritime research. This study aims to analyze the correlation between scrubber performance and engine operational performance on the container vessel MV. Sinar Sorong through a quantitative approach utilizing technical parameter measurements and structured questionnaires. Data were collected during operational periods from April to December 2025, encompassing chemical performance parameters of coagulant and flocculant agents, engine performance metrics including maximum combustion pressure, compression pressure, exhaust gas temperature, and specific fuel oil consumption. The research employed 29 respondents from the engine department selected through purposive sampling technique, with data analyzed using Pearson correlation and linear regression in SPSS version 26. Results demonstrate a positive and statistically significant correlation (r = 0.587, p = 0.001) between scrubber performance and engine operational performance, with regression analysis indicating that 96.9% of engine performance variance can be explained by scrubber efficiency. The scrubber system maintained optimal technical parameters with nonvolatile solid content of 34.1%, viscosity of 420 cPs, basicity level of 40%, and pH range of 3.5-8.2, effectively reducing sulfur oxide emissions while maintaining engine stability. Main engine parameters remained within optimal design specifications: maximum combustion pressure 145.4 bar, compression pressure 107.2 bar, exhaust gas temperature 333°C, and specific fuel consumption 174.0 g/kWh. This research contributes empirical evidence that scrubber systems function beyond regulatory compliance instruments, serving as technical components that enhance combustion system stability through sulfur residue reduction and corrosive deposit prevention in exhaust pathways. The findings provide practical implications for maritime operators to implement integrated preventive maintenance strategies and real-time monitoring systems to sustain the synergistic relationship between scrubber efficiency and engine reliability, ultimately optimizing operational efficiency and extending critical component lifespan.
Experimental Optimization of R-134a Refrigerant Charge in a Retrofitted Dual Function Refrigeration System for Marine Engineering Applications
This paper presents an experimental optimization of R-134a refrigerant charge mass in a retrofitted dual function vapor-compression refrigeration system designed to operate in Air-Side (AHU) and Water-Side (Water Chiller) modes. The system was evaluated after retrofit by testing four charge levels—399.5 g (85%), 423.0 g (90%), 446.5 g (95%), and 470.0 g (100%)—under multiple operating conditions: three fan speeds for AHU mode and chilled-water flowrates of 6 8 L/min for chiller mode. Performance was quantified using evaporator capacity Qevap, condenser heat rejection Qcond, compressor electrical power (PcompP_{comp}Pcomp), coefficient of performance (COP), and energy efficiency ratio (EER). The results show that the optimal charge is mode- and objective-dependent. In AHU mode, the maximum cooling capacity was obtained at 470 g (100%), reaching Qevap=4.58 kW, while the highest COPactual=3.1234 occurred at 423 g (90%), accompanied by the lowest AHU compressor power Pcomp=1.722 kW). In Water-Side mode, the highest cooling capacity was achieved at 446.5 g (95%), with Qevap=5.141 kW at 6 L/min, whereas the best energy-utilization outcome occurred at 470 g (100%) and 6 L/min, yielding EER = 2.888 with the lowest chiller compressor power Pcomp=1.6524 kW). Overall, the study provides a practical, mode-aware guideline for selecting refrigerant charge in retrofitted dual-function systems for marine engineering applications.
Influence of Ducted Propeller on Ro-Ro Vessels for Indonesia Inter-island Transportation
These Ro-Ro vessels are the backbone of inter–island transportation in Indonesia and require an efficient propulsion system to reduce fuel consumption and improve maneuvering performance. This study investigates the influence of ducted propellers on Ro-Ro vessels using Computational Fluid Dynamics (CFD) simulations. Four blades fixed pitch propeller configuration with accelerating duct are examined with different radial gaps at the propeller tip to the inner duct surface (0.1m, 0.3m and 0.5m) at rotational speed of 229 rpm and diameter of 4.202 m. the CFD model validation show average deviation of 4.06 % for KT, 7.63 % for 10*KQ and 3.11 % for efficiency compared with the experimental data. It indicated that the numerical approach is sufficiently reliable for further analysis. The open-water test results suggest that adding a duct does not necessarily improve performance. At a 0.10m gap, thrust, torque, and efficiency decrease by 39.3%, 25.7%, and 20.3%, respectively, whereas the 0.5m gap still results in noticeable performance degradation. Wake-field visualization indicates that smaller gaps produce stronger propeller–duct interaction, with more concentrated energy, sharper velocity gradients, and greater instability near the duct outlet. These findings emphasize that duct geometry and tip clearance must be carefully optimized for the vessel’s operating conditions to fully realize the energy benefits of a ducted propeller system on Ro-Ro vessels.
Hazard Identification and Risk Management at the Tuban Oil and Gas Production Unit, Indonesia