Erik Sugianto

Indonesia possesses dense and strategic shipping lanes, where seasonal ocean currents in the Java Sea frequently impact vessel transit times. On palm-oil shipping routes from Kumai to various ports in Java, route efficiency is paramount as fuel constitutes the largest operational expense. Due to the variability of ocean currents, conventional routes are not always the most efficient choice. This study utilizes 2024 ocean-current data from the Copernicus Marine Service alongside the technical specifications of the MT Nusaniwe to calculate effective speed, travel time, and fuel consumption. The Ant Colony Optimization (ACO) algorithm is applied to evaluate alternative route combinations under varying seasonal current conditions. The methodology encompasses current analysis, effective-speed formulation, fuel-consumption modeling, and route-optimization simulations for both the northwest and southeast monsoon seasons. Previous literature has not integrated ACO with seasonal oceanographic data for route optimization, which defines the research gap addressed herein. The results demonstrate that ACO-based routes integrated with oceanographic data outperform conventional routes, achieving significant reductions in transit time and fuel consumption. Consequently, this model proves that leveraging seasonal currents can enhance vessel operational efficiency and support data-driven voyage planning.

The design of a ship's propeller is very important as it directly affects the fuel efficiency, speed, and stability of the ship. Commonly, propellers are designed using expensive commercial software. This research aims to design a ship propeller using open-source code based on lifting line theory and using MATLAB application. The ship data used is a container ship with a length of 397 meters and a width of 56 meters. The propeller design results were propeller performance such as design performance, induced velocity, inflow angle, expanded blade, blade thickness, lift coefficient, performance curve, 2-D and 3-D outlines. A qualitative and quantitative comparison was conducted between a real-world manufactured propeller, a redesigned propeller developed using open-source software (OpenProp), and a commercial design tool (PropCAD). The comparison reveals that while the overall geometry and blade shape of all three propellers are similar, consisting of 6 blades with comparable radial profiles, key differences emerge in the expanded area ratio (EAR), skew angle, and surface modeling quality. The OpenProp design features an EAR of 1.0876 and a high skew angle of 39.9°, indicating an emphasis on hydrodynamic efficiency and cavitation mitigation. In contrast, the PropCAD model presents a slightly lower EAR of 1.077 with a more moderate skew angle of 20.5°, offering a balanced compromise between performance and manufacturability. This distinction highlights a potential optimization opportunity and demonstrates the capability of the open-source design approach to approximate real-world propeller characteristics with high fidelity, while also offering flexibility for further refinement. In summary, the findings suggest that the open-source design approach can approximate real-world propeller characteristics with high fidelity and provide flexibility for iterative optimization.

In this study, the variation of piezoelectric and solar panel positions on a marine debris collection vessel is investigated for stability using maxsurf stability. The inner flat catamaran ship model with different piezoelectric and solar panel position variations, namely at the bow of the ship, at the centerline of the ship, and at the stern of the ship. The criteria used in conducting the analysis carried out are in accordance with the stability criteria contained in the International Maritime Organization (IMO) regulations. The effect of piezoelectric and solar panel positions has a less significant difference on ship stability in each model. All aspects of design and use are carefully considered so as not to interfere with the process of collecting marine debris. Model 1 has better stability results because the stability arm is larger and produces better performance. From these results, the stability arm in model 1 has a larger area than the other models. This is due to the difference in load from the piezoelectric position at the stern and the solar panel at the centerline. This condition causes the GZ at a certain angle to be larger which results in a larger stability.

Using Ketapang Seed Oil Biodiesel as an Environmentally Friendly Renewable Alternative Energy to Improve Diesel Motor Performance

In this paper an attempt has been made to assess how effective waste-collecting use monohull ship with conveyor in the front. Numerical investigation based on Reynolds Averaged Navier Stokes (RANS) for predicting the flow pattern characteristics, velocity contour, and ship resistance. The focus of the present study is the impact of mohohull ship front shape on waste collection in calm water through the application of numerical methods. The three variations of the front of the monohull used are hardchine type, round bilge type, and monomaran type. It is done using speed variations of 1 to 4 knots. The results show round bilge type has the smallest total resistance value than others. In addition, analysis of the flow pattern in front of mohohull shows that monomaran type is the easiest to make waste closer to conveyor. From analysis of velocity contours also shows that monomaran type has fastest to make the waste close to conveyor.

Annex IV Marine Pollution (MARPOL) Application for Pollution Prevention on Ketapang-Gilimanuk Route Crossing Vessels with Analytical Hierarchy Process (AHP) Method

The coastal region is characterized by dynamic changes in its coastline, which can be attributed to various factors. However, the main causes of change along the Gresik coast have yet to be thoroughly studied. Therefore, this research aims to examine the patterns of coastline change along the Gresik coast around the Madura Strait and the influence of wind-generated waves on them. Specifically, the study focuses on four coastal zones: Ujung Pangkah, Sidayu, Bungah, and Manyar districts. The research utilizes satellite imagery and geographic information systems (GIS) as well as methods for calculating ocean waves to analyze the coastline change patterns. The study also examines the impact of ocean wave energy on coastal abrasion and accretion. The findings revealed that the accretion rate in the study area was higher than the erosion rate. The accretion in the coastal area of Gresik is attributed to the flow of the Bengawan Solo River, which carries sediment from upstream. The accretion and abrasion areas for the entire period from 2002 to 2019 were 1063.16 ha and 425.23 ha, respectively. The study also found that the mangrove areas exhibit a higher rate of accretion than abrasion, indicating their potential as a reliable indicator of the effects of sea level rise resulting from global warming.This study revealed that the northern part of Ujung Pangkah District and Bungah District experienced the highest abrasion patterns, whereas no abrasion was observed in Sidayu District. Between 2002 and 2019, the abrasion areas in Ujung Pangkah and Bungah districts totaled 243.96 ha and 178.29 ha, respectively. Wind-generated waves were likely the primary cause of the abrasion in these areas, though other factors may also have contributed to coastline changes. It is essential to consider these factors for effective coastal management in the region.

The continuous flow of marine debris in the sea has been a problem until now. Previous research on garbage collection vessels was conducted in calm water conditions, without waves and waves due to wind. This is different from the real conditions in the sea which are choppy and bumpy. In addition, research on the effect of wave length and amplitude on marine debris collection on garbage collection vessels does not yet exist. This study aims to determine the effect of wave length and amplitude on velocity contours, flow patterns, and ship resistance. The ship uses a circular hollow wing conveyor. Modelling using Rhinocheros software, then numerical simulation using Computational Fluid Dynamic (CFD). Verification of the simulation process uses grid independent by varying the mesh size, then validation of the results is done by comparing with previous experimental research. The results show that the best velocity contour in front of the conveyor is at a ship speed of 1.028 m/s (2 knots) using an amplitude of 0.5 T and a wavelength of 0.5 L. The velocity value in front of the conveyor is 1.551 m/s. This affects the speed of collecting marine debris. This affects the speed of collecting marine debris. The model that has a laminar flow pattern at the bow and at the stern is a speed of 1 knot at an amplitude variation of 0.1 T and a wavelength of 0.1 L. This is the best because it is easy to collect garbage. The smallest drag is the speed of 0.514 m/s (1 knot) at amplitude variation of 0.1 T and wavelength of 0.1 L. At this condition, the fuel consumption is the least. Thus, the greater the wavelength and amplitude of the waves the greater the drag and the smaller the speed.

The Mayangan Beach Fisheries Port (BFP) in Probolinggo City is a fishing port that was established using a combination of funds from the APBN, APBD of East Java province and APBD of Probolinggo city. Equipped with basic and functional facilities to support various fishing activities, fishing vessels generally use a mechanical propulsion system driven by a diesel engine. The results of the government's decision to increase fuel prices by 8,000 rupiah per liter, were then supported by a survey which showed that fishermen needed as much as 110 liters of fuel for a journey of approximately one hour for one trip, with these conditions making fishermen, especially in the Mayangan district, Probolinggo very objection by increasing the price of fuel that will be used to go to sea, so that with the problems complained of by fishermen on the Mayangan coast, Probolinggo about rising fuel prices, this refers to researchers planning a hybrid propulsion system to reduce consumption of the use of fuel that will be used for purse seine fishing boats. The results showed that the main engine specifications for the Mitsubishi ship were 6D24-Mpt (A) with 228 Kw power, then the Yanmar Ytg 15 Tlv generator, while the electric motor specifications that would be used were Weg Tru Metric 132 Kw / 175 HP, as well as batteries for storing battery energy which had specifications J185-Agm Vrla Agm / Non-Spillable. The difference in fuel consumption in the conventional system and the hybrid system looks quite significant. Using a hybrid propulsion system can produce fuel savings of up to 30% when compared to using a conventional engine.

In this paper an attempt has been made to assess how effective waste-collecting use catamaran ship with conveyor in the front. Numerical investigation based on Reynolds Averaged Navier Stokes (RANS) for predicting the flow pattern characteristics, velocity contour, and ship resistance. The focus of the present study is the impact of catamaran ship hull front shape on waste collection in calm water through the numerical methods. The three variations of the front of the hull used are symmetrical hull type, inner flat, and outer flat. It is done using speed variations of 1 to 4 knots. The results show inner flat hull catamaran has the smallest total resistance value than others. In addition, analysis of the flow pattern in front of catamaran shows that outer flat hull catamaran is the easiest to make waste closer to conveyor. From analysis of velocity contours shows that outer flat hull catamaran also has fastest to make the waste close to conveyor.