Journal of Engineering Science and Technology Management (JES-TM)

Analysis of the Decrease in Compressed Air Production of the Air Compressor onboard MT Seroja III

Bayhaqi Putra — 2026-06-30

The air compressor is an essential auxiliary machinery onboard MT Seroja III, playing a critical role in supporting vessel maneuverability, operational safety, and main engine starting readiness. During operations, a critical reduction in compressed air production was encountered, leading to prolonged air reservoir filling times and potential risks during ship maneuvering. This study aims to identify the root causes of decreased compressed air production in the main air compressor onboard MT Seroja III and to formulate corrective and preventive maintenance actions based on onboard observations and Fault Tree Analysis (FTA). This research employs a qualitative descriptive method, utilizing continuous monitoring parameter logs, field inspections, and semi-structured interviews with engine officers over a 12-month sea service period. The diagnostic findings using FTA indicate that the decrease in volumetric efficiency was primarily caused by high-resistance suction filter blockages, severe carbon fouling on suction and delivery valves, and piston ring degradation. Corrective maintenance involving filter purging, valve refacing, and piston ring replacement successfully restored the compressor discharge pressure to 30 bar and reduced the air receiver filling time from 45 minutes to 15 minutes. The study concludes that strict adherence to the vessel's Planned Maintenance System (PMS) is mandatory to guarantee operational safety and prevent compression loss.

Design and Feasibility Evaluation of the TAPTAP Digital Platform for Measuring Port Service User Satisfaction at KSOP Bontang

Herdandy Octabrilian Putra — 2026-06-18

This study designs and evaluates the feasibility of the TAPTAP digital platform, a Figma-based prototype for measuring port service user satisfaction at the Bontang Harbormaster and Port Authority Office (KSOP Bontang). The study used a Research and Development (R&D) approach adapted into six stages: problem identification, information collection, product design, design validation, design revision, and product trial. Data were gathered through field observation, document review, stakeholder input, and expert feasibility assessment. Two expert testers, consisting of a marine transportation lecturer and an information technology expert, assessed the prototype using a feasibility instrument covering button functionality, initial menu display, completeness and readability of satisfaction questions, presentation of satisfaction results, and overall feature functionality. TAPTAP provides public-side features for satisfaction surveys, complaints, and aspirations, as well as officer-side features for report monitoring and satisfaction-data visualization. The feasibility test produced scores of 80% from Tester 1 and 85.33% from Tester 2, indicating that the prototype is feasible for further pilot testing. The results show that TAPTAP can support more structured service feedback management at KSOP Bontang, although broader public-user testing, database implementation, data security validation, and integration with KSOP systems are still required before operational deployment

Analysis of Lifeboat Maintenance to Support Crew Safety on Board MV. Aliyah Pratama in Accordance with SOLAS Chapter III

Navire Tsabitah Lamaya — 2026-03-30

Non-compliance in the execution of lifeboat maintenance procedures significantly heightens operational risks and impairs evacuation effectiveness during maritime emergencies. This study evaluates the conformity of lifeboat maintenance and operational readiness on board the bulk carrier MV. Aliyah Pratama against the specific requirements of the Safety of Life at Sea (SOLAS) Chapter III Regulation 20 and the Life-Saving Appliances (LSA) Code. Utilizing a qualitative descriptive case study approach, data were collected over a 12-month period at Cilegon Anchorage through direct field observations, structured interviews with three key deck officers, and systematic reviews of the ship’s Planned Maintenance System (PMS) documentation. A compliance matrix was developed to benchmark observed mechanical and operational conditions against regulatory standards. The findings reveal critical discrepancies, including mechanical stiffness in the starboard gear brake, active corrosion on wire falls and winches, hardened watertight door seals, and expired emergency rations. Furthermore, abandon-ship drills demonstrated a lack of situational awareness and muster list comprehension among the crew. Root cause analysis, structured via the Ishikawa (Fishbone) framework, indicates that these non-conformities stem from superficial, visually limited inspections, high operational workloads, an aggressive saline environment, and shore-based procurement delays. The study concludes that the vessel's current maintenance execution functions primarily as an administrative formality rather than a rigorous functional safeguard. Corrective recommendations prioritize the implementation of deep-technical functional testing, expedited supply-chain logistics for safety equipment, and mandatory pre-drill tactical briefings to restore optimal evacuation.

Proper Use of Mooring Lines on Ships to Ensure a Smooth Berthing Process on The MT. Giat Armada 04

Bima Surya Pulung Sakti — 2026-07-21

This study aims to analyze the influence of the physical condition of mooring lines and supporting mooring components on the smooth berthing process of MT. GIAT ARMADA BERSAMA 04. The berthing process is a critical operational phase requiring a highly reliable mooring system to ensure the safety of the vessel, cargo, crew, and port facilities. Employing a qualitative descriptive method, data were collected through field observations across 12 berthing operations, structured interviews with deck officers, and document analysis. The findings revealed that the physical deterioration of the spring lines—specifically characterized by a visible diameter reduction, bird-caging, and surface abrasion exceeding the 10% broken strand threshold—contributed to severe operational difficulties. Furthermore, corroded deck fittings increased mechanical friction, leading to ropes jamming in the mooring chocks and significant delays in tension adjustment. Evaluated against the retirement criteria and inspection parameters defined by the OCIMF Mooring Equipment Guidelines (MEG4) and IMO safety mandates, the vessel’s mooring components operated below acceptable minimum breaking load (MBL) safety margins. Immediate replacement of degraded lines and the implementation of a strict Line Management Plan (LMP) are imperative to restore operational precision, mitigate occupational hazards, and enhance overall port efficiency.

Implementation of a Decision Support System Using the Simple Additive Weighting (SAW) Method in the New Student Admission Selection Process

Maya Oktarina — 2026-06-30

The selection process for new student admissions in secondary schools is often manual and error-prone, so a web-based decision support system (DSS) is needed to improve objectivity and efficiency. This study aims to design and implement a DSS using the Simple Additive Weighting (SAW) method at SMK Negeri 1 Tanjung Lubuk. An applied quantitative approach with the Waterfall model was used; the population was all prospective students through three admission pathways, a sample of 23 purposive applicants. Instruments included academic data documents, interviews, and web input; data analysis via SAW (matrix normalization, criteria weighting, preference values). The results showed an accurate ranking with the highest score of 1.84 (Muhamad Angga Prayitno) based on five criteria (exam scores, report cards, KIP, achievement, distance). The conclusion states that the system increases transparency and speed of selection, and replication in other schools with broader testing is recommended.

Analysis of the Effectiveness of the Marine Growth Prevention System (MGPS) in Preventing Marine Organism Growth in the Engine Cooling System of MV Ever Clear

Brian Pratama Timur — 2026-06-30

The ship engine cooling system is critical for maintaining the operational stability of main and auxiliary machinery. However, biofouling within sea chests and seawater pipelines remains a prevalent issue, leading to flow obstruction, reduced heat transfer efficiency, and potential engine malfunction. While the Marine Growth Prevention System (MGPS) is designed to mitigate this via electrolysis, marine growth persisted on MV Ever Clear, indicating suboptimal system performance. This study aims to analyze the effectiveness of the MGPS in preventing biofouling and to identify factors contributing to its performance degradation. Using a qualitative descriptive method with a case study approach, data were collected through direct onboard observation, interviews with the engineering crew, and document analysis. Results indicate that the decreased effectiveness was primarily caused by insufficient electrode maintenance, unstable electrical parameters (current and voltage), and inadequate operational monitoring. These deficiencies compromised the electrolysis process, preventing sufficient ion release. It is concluded that MGPS efficacy is contingent upon stable electrical parameters, rigorous preventive maintenance, and consistent operational supervision in accordance with established procedures.

The Effectiveness of Emergency Drill to Prepare Crew to Face Abandoned Ships on MT. Pagerungan

Daffanda Yoda Wibisono — 2026-06-30

Safety of life at sea is a paramount operational priority that heavily relies on crew preparedness in managing maritime emergencies. This study evaluates the effectiveness of abandon ship drills in improving crew readiness on the commercial tanker MT. Pagerungan. Using a qualitative case-study design, data were collected over a 12-month period through direct participant observations, structured interviews with six key personnel, and documentary analysis. Effectiveness was measured using specific operational indicators: alarm response time, correct usage of life-saving appliances (LSAs), compliance with muster list duties, and communication efficiency. The results indicate a significant gap between administrative compliance and practical readiness. Drills were conducted only four times annually, violating the monthly requirement stipulated by the Safety of Life at Sea (SOLAS) Convention. Observations revealed critical deficiencies, including the inability of junior and catering crew members to correctly don lifejackets and a lack of role awareness among specific deck ratings. Furthermore, commercial pressures and a tendency to view drills as bureaucratic formalities hindered the development of a robust safety culture. The study concludes that while incremental improvements were observed across repeated drills, overall effectiveness remains structurally fragile. Recommendations include the rigorous implementation of monthly drills, integration of pre-drill toolbox meetings, station-specific compliance checklists, and documented competency assessments to bridge the gap between regulatory mandates and actual emergency preparedness

Implementation of the Occupational Safety and Health Management System to the Daily Activities of Employees and Visitor Reception at PT X

Muh. Rifqi Aditya Harliman — 2026-07-15

Occupational Safety and Health (OSH) management in Liquified Natural Gas (LNG) terminals requires stringent alignment with both general workplace safety and process safety protocols. This study evaluates the implementation of the OSH Management System (SMK3) at PT X, an LNG logistics terminal in Indonesia, focusing on employee Personal Protective Equipment (PPE) compliance and visitor safety controls. Utilizing a qualitative case study design, data were collected through field observations, document reviews, and semi-structured interviews with nine key informants across operational and safety divisions. The data were analyzed using a formal SWOT/TOWS matrix to develop strategic interventions. The findings indicate that while PT X’s institutional procedures—such as mandatory safety inductions, daily toolbox meetings, and medical fit-to-work screenings—are consistent with ISO 45001 standards, critical field execution gaps remain. Empirical evidence highlights recurring PPE non-compliance driven by human factors (e.g., thermal discomfort), visitor violations of electronic device restrictions in hazardous explosive zones, and logistical bottlenecks due to insufficient visitor PPE inventory during peak periods. The study concludes that achieving optimal safety compliance requires moving beyond bureaucratic procedures. Practical implications include the necessity for risk-based PPE procurement, the enforcement of a controlled intrinsically-safe device management policy, and enhanced human-centric safety supervision.

Analysis of Electrical Voltage Instability Causes in Auxiliary Engine No. 2 Aboard MV. HANGLIMA

Bima Nurrahma — 2026-06-30

This study investigates the factors contributing to electrical voltage instability in Auxiliary Engine No. 2 aboard MV. Hanglima. The research was motivated by operational disruptions where the voltage output dropped significantly from the standard 440V to 290V, leading to blackouts when the generator operated independently. Employing a qualitative research method utilizing the Fishbone (Ishikawa) diagram for root cause analysis, data was collected through onboard observation, documentation, and interviews with the engineering crew. The analysis revealed that the instability was primarily caused by mechanical failure in the alternator bearings, which had approached their operational limit, leading to an unbalanced rotor rotation. This mechanical imbalance caused friction between the rotor and stator, resulting in insulation leakage (short circuits) within the windings. Corrective measures implemented included a comprehensive overhaul, re-insulating the rotor and stator windings using insulating varnish, and replacing the worn bearings. These actions successfully restored the voltage output to a stable 445V, ensuring the safety and efficiency of the vessel's electrical system.

Dynamic Modeling and Nyquist Stability Analysis of a Non-Interacting Two-Tank Series Thermal System

Yogi Yolanda — 2026-06-14

Series tank systems are vital in chemical industries but susceptible to mass and thermal disturbances, making stability analysis essential. This study models the level and temperature dynamics of a non-interacting two-tank system equipped with a heater in Tank-01, analyzing its stability via Nyquist plots. The methodology involves laboratory step-response experiments validated against mathematical models derived using Laplace Transforms and Explicit Euler methods. Results demonstrate the model closely matches experimental data; Tank-01 exhibits first-order characteristics, while Tank-02 functions as a second-order system. The physical system successfully handled +52% and -35% step disturbances within liquid height limits of 3–24 cm and feed flow rates of 40.33–136.5 cm³/s. Furthermore, Nyquist analysis confirms the open-loop thermal process is inherently stable across all tested capacities. Maximum level and thermal process gains were 0.3787 and 0.0062, respectively. Ultimately, this study confirms the non-interacting two-tank system possesses stable, self-regulating characteristics against load disturbances within operational limits.

Optimizing The Use Of Safety Equipment to Prevent Workplace Accidents at KM. Kelud

Siti Humairoh Harliman — 2026-06-30

Operational activities on board a ship constitute a work environment with a high risk of workplace accidents. One of the challenges that is still frequently encountered relates to the crew’s suboptimal compliance with safety procedures and the use of personal protective equipment (PPE), resulting in a significant potential for accidents. This study focuses on evaluating the implementation of workplace safety equipment on ships as well as examining crew behavior in support of workplace accident prevention efforts. A qualitative approach was applied in this research, utilizing observation, interviews, and documentation as data collection methods during a 12-month period of sea training aboard the KM. Kelud. Research findings indicate that the occupational safety system has been supported by the availability of safety equipment, standard operating procedures, and the regular conduct of safety meetings. However, its implementation in the field has not been consistent, as it remains influenced by individual awareness levels, established work habits, factors related to workplace comfort, and supervision that has not yet been optimized. Consequently, the use of workplace safety equipment has not been fully effective in reducing workplace accident rates, where human factors remain the most dominant cause. This situation highlights the need to strengthen safety culture through continuous training, improve the effectiveness of supervision, and enforce strict penalties to foster discipline among the ship’s crew.

Analysis of Performance Degradation of the Refrigeration System on MT Nolowati III

Sahrul Romadon — 2026-06-30

The refrigeration unit, also known as the refrigerator, is a crucial auxiliary machine on board the MT Nolowati III, as it is responsible for ensuring the crew remains healthy and refreshed. A common operational issue is the refrigeration unit's inability to reach its designated operating temperature. This includes the meat compartment (-10°C to -12°C) and the vegetable/fruit compartment (+4°C to +10°C). Suboptimal supporting components such as the compressor and thermostat, as well as a lack of standard maintenance, contribute to this issue. Analysis shows that the decline in performance is mostly caused by technical factors, such as dirt covering the condenser or thermostat errors, which disrupt the refrigeration cycle and cause temperature increases. To prevent this, preventative measures focus on regular maintenance, routine condenser cleaning, and performing maintenance work according to the manual's instructions.

Analysis of the Causes of High Internal Temperature in the TMC Type-54EWNA Control Air Compressor on MV Pan Africa

Nazha Madeza Bakri — 2026-06-30

The control air compressor is one of the important auxiliary machines in the compressed air system on board a ship, which functions to supply air for both manual and automatic pneumatic control systems. One of the problems that frequently occurs in this equipment is an increase in internal temperature (high internal temperature) in the Control Air Compressor TMC Type 54-EWNA, which can reduce compressor performance and increase the risk of damage and operational disturbances. This study aims to analyze the causes of high internal temperature in the control air compressor and to determine appropriate corrective and preventive measures. The methods used in this study include direct observation, interviews, and documentation, as well as analysis using the Fishbone analysis method. The results of the analysis indicate that the main causes of increased internal temperature include suboptimal cooling system performance, deterioration of lubrication quality, inconsistent implementation of the Planned Maintenance System (PMS), as well as the influence of environmental conditions and materials experiencing corrosion. The root cause identified is a lack of supervision and irregularity in maintenance implementation. The recommended efforts to address these problems include optimizing the cooling system, using and replacing oil, filters, and coolers according to specifications, carrying out periodic maintenance in accordance with the PMS and manual book, and improving monitoring of compressor operating parameters. By implementing these measures, it is expected that the compressor’s internal temperature can be controlled, compression pressure remains optimal, and the reliability and safety of the ship’s compressed air system can be maintained.

Optimization of Deck Crane Maintenance to Facilitate the Loading and Unloading Process on MV. Tanto Keluarga

Bimo Kartika Utama Adisa Putra — 2026-06-29

This research was conducted to analyze the implementation of deck crane maintenance, identify operational obstacles, and formulate optimization efforts to improve the cargo handling performance on MV Tanto Keluarga. The study utilized a qualitative descriptive approach supported by quantitative operational data, gathering evidence through 12 months of observation during sea practice, ship documentation analysis, and semi-structured interviews. The informants included the Chief Officer, Bosun, and an Able Seaman. The findings reveal that deck crane maintenance was significantly delayed due to the high pressure of the ship's port schedule, which disrupted the Planned Maintenance System (PMS). Consequently, the lack of timely lubrication led to critical wire rope wear and slewing gear corrosion. This chain of component degradation directly caused a heave-up system disruption, resulting in a documented 4-hour operational downtime during cargo discharging in Tobelo Port. Optimization interventions were systematically carried out through strict pre-operational visual inspections, massive re-lubrication, and schedule calibration between cargo operations and preventive maintenance. Following these interventions, subsequent loading and unloading operations recorded zero technical downtime, demonstrating a tangible improvement in equipment reliability and operational efficiency

Association Between Screw-Press Operating Pressure And Oil Loss In Press Fibre At PTPN IV Kebun Mayang Palm Oil Milll

Kevin Rolinson Manullang — 2026-06-30

Screw-press operation is a major determinant of oil recovery at the pressing station of a palm oil mill, but field comparisons may be distorted when pressure levels are observed on different machines. This study re-examined the relationship between operating pressure and residual oil in press fibre at PTPN IV Kebun Mayang using an observational dataset comprising 15 once-daily measurements from three screw presses over five recorded sampling dates in 2025. Operating pressure was recorded at the time of sampling, and press-fibre oil, moisture, and non-oil solids were measured on a wet basis using a FOSS NIRS DA1650 instrument with the installed mill calibration. Mean pressure and oil loss were 40.4 ± 1.82 bar and 3.756 ± 0.804% for Machine 1, 45.0 ± 4.00 bar and 3.404 ± 0.476% for Machine 2, and 50.0 ± 1.58 bar and 3.176 ± 0.423% for Machine 3. An unadjusted linear regression indicated a decrease of 0.088 percentage points in oil loss per 1-bar increase in observed pressure (95% CI: −0.142 to −0.034; p = 0.004). After adjustment for machine and sampling date, the estimated pressure coefficient was smaller and statistically uncertain (−0.039 percentage points per bar; 95% CI: −0.164 to 0.086; p = 0.485). The data therefore suggest an inverse descriptive relationship between pressure and oil loss, but they do not establish a causal pressure effect or identify an optimum pressure because pressure was confounded with machine identity and kernel damage, oil impurities, energy consumption, throughput, and equipment wear were not quantified.

Bit Error Rate (BER) Performance Analysis on ASK, FSK, and PSK Digital Modulation in AWGN Channels

Muhammad Ferdinand Putra Mulyadi — 2026-06-30

Digital communication systems face the challenge of Additive White Gaussian Noise (AWGN), which causes signal distortion and increases the Bit Error Rate (BER). This study aims to analyze and compare the BER performance of Amplitude Shift Keying (ASK), Frequency Shift Keying (FSK), and Phase Shift Keying (PSK) modulation techniques on AWGN channels through MATLAB simulations over an SNR range of 0–14 dB. A quantitative experimental approach was employed using Monte Carlo analysis with 100,000 bits sampled per SNR test point, validated against theoretical error probability using the Q function. The results demonstrate that PSK (BPSK) achieves the best performance, reaching a BER of at an SNR of approximately 7 dB, while FSK requires approximately 10 dB to achieve the same BER threshold — a difference of ≈3 dB — and ASK remains at a BER of approximately even at 14 dB SNR, reflecting its inherent vulnerability to additive amplitude noise. These findings confirm that PSK modulation offers the greatest power efficiency and noise robustness among the three techniques. The study recommends PSK for high-noise wireless applications such as IoT sensor networks and communication satellites where optimal power efficiency and transmission reliability are critical.

The Role of the Venus Application (Vessel Network System) as a Digital Innovation to Increase the Effectiveness of the Crew Change Process at PT Pertamina International Shipping

Siti Aurum Eka Nursasi — 2026-06-29

This study evaluates the Venus (Vessel Network System) application as an in-house digital crewing system that supports the crew change process at PT Pertamina International Shipping. The study used a quantitative descriptive approach supported by direct operational observation. Respondents consisted of 31 internal users who were directly involved in crew scheduling, document verification, approval, monitoring, and interdepartmental coordination through Venus. Data were collected using a Likert-scale questionnaire that measured the importance and performance of 12 system and service indicators, and the results were analyzed using validity testing, reliability testing, and Importance-Performance Analysis (IPA). The findings show that Venus was perceived positively by internal users, with an average importance score of 4.77 (95%) and an average performance score of 4.73 (94%). The application supports scheduling visualization, crew document monitoring, and approval coordination, thereby helping users reduce manual communication and improve operational visibility. However, IPA mapping indicates that four high-importance indicators still require priority improvement: fulfillment of crew change needs, timeliness, data security, and interdepartmental coordination. These gaps show that the effectiveness of Venus should be interpreted as perceived system effectiveness among internal users, while further improvement is needed in system quality, service quality, access control, deadline tracking, and workflow escalation. The study contributes to the evaluation of maritime human-resource information systems by combining user-perception measurement with field observation of digital crew change operations

Implementation of the Naïve Bayes Algorithm for Predicting the On-Time Graduation of Informatics Engineering Students

Erlinda — 2026-06-29

Timely graduation is one of the important indicators used to measure the quality of academic performance in higher education institutions. However, the Informatics Engineering Study Program at the Faculty of Engineering, Universitas Islam Kuantan Singingi, still faces challenges related to students who are unable to complete their studies on time. This study aims to predict students timely graduation using the Naïve Bayes algorithm with the Knowledge Discovery in Database (KDD) approach. The research process consists of several stages, including data selection, data preprocessing, transformation, data mining, and evaluation. The data used in this study were obtained from students who completed their studies in 2025 and included several academic attributes such as gender, study duration, numerical grades, letter grades, and graduation status. The Naïve Bayes algorithm was applied to classify and predict whether students would graduate on time based on the probability of previous academic data. The results show that students with good academic performance tend to have a higher probability of graduating on time. Model evaluation using cross-validation produced the best performance in the 3-fold scenario, achieving an accuracy of 88.73%, precision of 64.62%, recall of 45.72%, and a kappa value of 0.451. These findings indicate that the Naïve Bayes algorithm is sufficiently effective for predicting students timely graduation.

Optimization of Hatch Cover Maintenance on MV. Orient King

Rafigo Charisma Maulana — 2026-07-15

The hatch cover is a critical structural component of a general cargo vessel, designed to safeguard cargo from seawater ingress and maintain watertight integrity. This study evaluates the constraints affecting the execution of planned hatch cover maintenance aboard MV. Orient King. A qualitative single-case study design was employed over a 12-month onboard observation period. Data was collected through semi-structured interviews with three key deck personnel (Chief Officer, Bosun, and Able Seaman), structured operational observations, and a review of maintenance logs. Thematic analysis of the data revealed that maintenance compliance is fundamentally hindered by aggressive marine corrosion, a brittle supply chain causing 2-to-3-month lead times for critical spare parts (e.g., rubber packing, hydraulic hoses), and a dense operational tempo that routinely forces the deferral of scheduled Planned Maintenance System (PMS) tasks. Consequently, temporary repairs are frequently substituted for permanent solutions, elevating the risk of cargo damage. To mitigate these risks, this paper proposes a prioritized action plan, emphasizing strict adherence to the company's Safety Management System (Document No. JSP E41), optimized spare-part inventory control, and enhanced supervisory protocols.