Zona Laut Jurnal Inovasi Sains Dan Teknologi Kelautan

Bridge Duty On A Ship: Study On Preventing Collisions At Sea On The Training Ship John Lie

Haryadi Wijaya — 2024-03-28

The knowledge and skills of a ship's crew can play a key role in preventing collisions. The Bridge Watchkeeping Duty becomes crucial in this context, as they are the first to detect potential threats. Given the increasing risks in maritime transportation and the need to prevent ship collisions, several steps can be taken. One of them is to effectively carry out the tasks and functions of the Bridge Watchkeeping Duty. Therefore, this study aims to analyze the Bridge Watchkeeping Duty, specifically, the efforts to prevent sea collisions conducted by the Ship's Bridge Watchkeeping Service, and how its theoretical and practical implementation is carried out in the field. This qualitative study uses a descriptive method to describe and elaborate on the study object, namely the John Lie training ship. The study will include quotations from various data sources such as interviews, field notes, memos, and other official documents. Data analysis in this study uses the techniques of Miles and Huberman. The results of this study indicate that the implementation of these duties and responsibilities must always be based on a deep understanding of various national and international maritime regulations, as well as knowledge of the characteristics of the ship and its surrounding environment. Additionally, implementing regulations such as the 2010 Manila Amendments to the STCW 2010 is also important to ensure the welfare and fitness of the watchkeepers so they can perform their duties and responsibilities optimally. This study has several limitations, such as variables that need to be explored further, such as the psychological aspects of bridge watchkeepers who bear a heavy workload, extreme sea weather conditions, and ship facilities that support collision prevention activities. Thus, this study is expected to provide constructive thoughts and suggestions for maritime transportation stakeholders, particularly sailors and crew members, regarding the importance of properly implementing the Bridge Watchkeeping Duty. Focus on the human aspect in preventing ship collisions at sea through the Ship's Bridge Watchkeeping Service.

Seakeeping Of A 60 Gt Cast Nets Fishing Vessel At Muara Angke Fishing Port

Arif Fadillah — 2024-03-28

Based on the provisions made by the International Maritime Organization (IMO), turning ability and zig-zag maneuvers are the main criteria for safety standards for every ship that will sail. This decree was made as an effort to improve sailing skills, especially for ship crew. Calculation of the turning ability of a ship is greatly influenced by the design of the ship's hull and the design of the rudder that will be used on the ship. So the analysis of turning circles and zig-zag maneuvers is the main point that will be carried out in this research. The research was carried out on cast net vessels anchored at the Muara Angke fishing port with the vessel size taken being 60 GT. The standard provisions used in the analysis of turning ability and zig-zag maneuver are based on IMO MSC 137 (76) with the main size of the vessel used as the main research material is LOA=25.7 m, LPP =22.2 m, B=7 m, H=2.3 m, T=1.7 m. With the results obtained by the movement of the fishing vessel which meets standardization based on IMO MSC 137 (76) 2002, the turning circle maneuver has a Tactical Diameter of 46.07 m, with an Advanced value of 56.23 m, with a heading transfer value of 24.48 m, the zig-zag maneuver meets the IMO standard criteria stated for angels 10°/10° and 20°/20° do not exceed 30 seconds

The Use Of Remote Sensing In Mapping The Distribution Of Chlorophyl In Belawan Waters

Alaudin Alaudin — 2024-03-28

Chlorophyll-a is one of the important water quality parameters in the sea. This research was conducted in April 2022 in the Belawan Waters of North Sumatra Province with the aim of knowing the level of chlorophyll-a concentration in these waters. The method used is survey and extraction of Aqua MODIS satellite image data into ASCII data and image data using the seaDAS application. The value of chlorifyll-a concentration obtained in Belawan waters is 3.35-5.91 mg / m³ and has an average value of about 4.65 mg / m³. Belawan waters in April 2022 experienced high chlorophyll-a concentrations.

Freeboard and Trim Measurement: a Case Study of Landing Craft Tank Conversion to Ship Power Plan

Suardi Suardi — 2024-03-28

In this research, the ship power plan which is the result of a conversion from a landing craft tank is designed to meet the electricity needs in areas affected by a disaster or electricity crisis. So far, the government has chartered a similar ship from Turkey which is used to meet electricity needs in Indonesian areas which have been affected by the disaster and electricity crisis. This ship is modified to carry an electric generator which can later be sent to areas that need it. Two main focuses are the goal of this research, the first is to find the value of the freeboard and the second is the trim of the ship after the redesign. To achieve this goal, in this study a numerical calculation method was used to calculate the freeboard and trim values according to applicable standards. The results of the analysis show that the freeboard value is still safe, with the actual freeboard value being greater than the required freeboard (0.8 m > 0.44 m). For ship trim, the bow trim condition is obtained with a smaller LCG-LCB difference than the 0.05% LPP value (0.912 < 0.923). By looking at the results of these measurements, the condition of the ship's freeboard and trim is still in a fairly good category even though it has been converted from a landing craft tank to a ship power plant. This study can provide a reference for ship design before converting the actual ship so that it can carry out trim and freeboard tests to prevent build failures.

Analysis Of Fluid Flow Conditions And Pressure Around Spar With Five Vertical Plate Damping System

Dimas Fitrawan — 2024-03-28

Spar type Floating wind Turbine is a floating structure that utilizes the speed of the sea wind to drive a turbine that can generate electrical energy .SPAR is a cylindrical floating structure that has a deep draft and is reliable in operating in the deep sea for a long time.in this study using a SPAR model with a damping system of five vertical plates located at the bottom of the SPAR structure where in this study the analysis about fluid flow conditions and pressures that are around the SPAR.this study was conducted by calculation numerical based CFD (Computational Fluid Dynamics) with four variations of fluid flow velocity used to observe changes in fluid flow conditions and pressure around the SPAR.this study aims to observe the conditions and influences around the SPAR type floating wind turbine structure which is expected to be a solution to energy problems in the world.

Along FPSO (Floating Production Storage and Offloading) Motion Analysis using Mooring Radius Variations Based on Time Domain Simulation

Muhammad Mustafa Algifari Algifari — 2024-03-28

Along with the development of technology, oil and gas exploration has begun to be carried out in the deep sea. One technology that can be used is FPSO (Floating Production Storage and Offloading). In order for the FPSO to be damped due to environmental loads during the production process, a mooring system is needed that meets standards according to the needs and environmental characteristics of the oil field. The mooring system used is a spread mooring system which is limited to 12 mooring lines. The research uses variations in the mooring line radius so that the length of the mooring line and the anchor position are different. This research is intended to analyze the effect of the mooring line radius on FPSO movement and the tension of the mooring line itself using a numerical approach with ANSYS AQWA software. From this study it can be seen that by increasing the length of the mooring line there will be a reduction in maximum tension on the mooring line, but the opposite is true there is an additional offset to the ship's movement. However, because the anchor position is further away in each radius, the tension value on the mooring line does not have a significant difference

Analysis of the Effect of Fairlead Position on the Fatigue Damage Ratio of Catenary Type FPSO Aoka Mizu Mooring Line Structures

Nur Indah — 2024-03-28

This research discusses the effect of fairlead position on the fatigue damage ratio of the Aoka Mizu Floating Production Storage and Offloading (FPSO) catenary structure during moored conditions. The FPSO is subject to the influence of ocean waves, ocean currents, and wind that can cause significant movement, jeopardize the catenary mooring system, and disrupt the production process. This study utilizes a numerical method based on the Boundary Element Method and uses environmental data from the Masela Block, which includes wave, wind, and current data. Three variations of fairlead position (0.3T, 0.5T, and 0.9T), each referring to the fairlead distance from the laden to the ship's keel, were tested with a rope length of 3100 m and a sea depth of 1000 m. The results showed that a fairlead position of 0.3T resulted in low stress and damage levels, while fairlead positions of 0.5T and 0.9T resulted in higher stress and damage. The fairlead position plays an important role in determining the stability and performance of the FPSO catenary structure. A fairlead position of 0.3T appears to be the most favorable option to reduce the risk of damage and stress to the FPSO Aoka Mizu catenary mooring system during moored conditions.

Deformation Handling Technique for Welding Supporting Elements of Ship Building Construction

Bulan Purnama — 2024-03-28

Deformation is a change in shape due to stress in the metal caused by expansion of the weld metal during the heating and cooling process which has the potential to reduce the structural strength and operational efficiency of the ship. The forms of deformation due to the welding process on supporting elements of ship construction are shrinkage deformation, corner deformation, deformationbuckling, and longitudinal deformation. This research analyzes the factors that cause welding deformation in supporting elements of ship construction, identifies existing welding deformation handling techniques, and analyzes the effectiveness of deformation handling techniques to maintain the structural integrity of ship buildings. It is hoped that this research can make a scientific contribution in improving the quality, aesthetics and safety of ship construction, as well as increasing the efficiency of the shipbuilding production process. The research method used is in the form of a literature study by accessing library documents or secondary data from existing case studies. This deformation is caused by heat in the material, the expansion coefficient and the heat propagation coefficient. Techniques for handling welding deformation on supporting elements of ship construction can be applied by heating (firing) and cooling. This will provide excellent results if carried out with the correct procedures in handling deformations that occur between supporting elements of ship construction during the fabrication process.

Keyword: Dari kata kunci abstrak

Analysis of Changes in Fluid Flow Characteristics around SPAR-3VP to Variations in Flow Velocity under Extreme Conditions

Galy Rakaziwi — 2024-03-28

This research discusses the SPAR offshore wind turbine, a floating foundation turbine used for wind power generation in the deep sea. SPARs are designed with a large-diameter vertical floating cylinder weighted at its lower end, creating a structure that is less responsive to wind, waves, and currents. SPAR foundations have advantages in deep water due to their low center of mass, simple ballast stabilization, and high stability. The purpose of this research is to gain a deeper understanding of the fluid flow occurring around the SPAR, which impacts the performance and stability of the offshore wind turbine. This research will focus on CFD (computational fluid dynamics)-based numerical modeling analysis with the help of 3D analysis software ANSYS by considering several variations of fluid flow velocity to identify the pressure, velocity, and changes in fluid flow around the SPAR. The results of this study are expected to help in reducing the risk of SPAR foundation damage, improving turbine stability, and overall increasing the efficiency of offshore wind energy generation. This research has positive implications for reducing the environmental impact of energy generation compared to traditional fossil fuel sources.

Gas Tungsten Arc Welding (GTAW) and Underwater Welding (UW) on Brass Propeller Repair

Andre Anggriawan Jaisi Djailani Putra — 2024-03-29

Over time, marine building technology has experienced very significant developments and there are several variations of improvements that can be made to suit needs and conditions. A ship's propeller is a ship component that often experiences collisions with hard objects floating in the water which can cause the blades of the propeller to experience damage such as bending, cracking or breaking. In this case, the propeller should be repaired immediately so as not to disrupt the smooth operation of the ship. Repairing broken propeller blades can be done using a welding process. Welding is a technique of joining metals by melting part of the parent metal and filler metal with or without additional metal and producing continuous metal. Underwater Welding is a welding process that occurs in wet conditions, meaning that the electrode and object are in direct contact with air, while Gas Tungsten Arc Welding (GTAW) is an electric arc welding process that uses an untreated electrode that does not melt. This research was conducted to analyze the welding measurement results of Gas Tungsten Arc Welding (GTAW) and Underwater Welding on brass materials. To support the analysis process, testing activities are carried out including tensile tests (tensile test), hardness tests (hardness test) and macrographic observations on the results of welding materials.

The Effect Of The Mooring Line Radius On Fpso Tethering Using A Numerical Approach

Adhitya Arya Prayudha Kurniawan — 2024-03-24

Floating Production Storage and Offloading (FPSO) is a floating facility in the form of a ship that is used to produce as well as a temporary storage of petroleum taken in the middle of the ocean, in its operation the FPSO is moored using mooring ropes to limit the motion of the facility. This mooring system is needed to reduce dynamic movements due to environmental loads received by the FPSO. This study was conducted to analyze the motion characteristics of FPSO that have been moored using a Spread Mooring System with a certain mooring radius and the stresses received by each mooring line using a time domain based numerical approach. The method used is a literature study and a numerical approach with the Boundary Element Method (BEM), it is concluded that the further the radius of the mooring line, the smaller the tension received by each mooring rope so that the structure becomes more stable.

Analysis of Motion Trajectory and Fatigue Damage Ratio FPSO Against Catenary Mooring Line Failure

Muhammad Alkhan Dwiki Abadi — 2024-03-28

Floating Production Storage and Offloading (FPSO) is a ship that produces floating oil and gas by having a catenary mooring type mooring system. The FPSO will produce oil and gas in the Abadi Field in the Masela Block of the Arafuru Sea (09˚ 07' 51'' S / 130˚ 28' 00'' E) where the area has sea waves, wind and currents which will affect performance FPSO ship. In this research, Response Amplitude Operator (RAO), motion trajectory and fatigue damage ratio will be tested with a ship mooring system of 12 ropes, 3 of which experienced failure. The conclusion of this research is that the more mooring ropes break, the farther the FPSO ship will move from its initial condition and the higher the maximum rope tension value, it will be directly proportional to the stress range on each mooring rope, while for the fatigue damage ratio, the higher the failure cycle value. then it will be inversely proportional to the fatigue damage ratio value for each mooring rope.

Analysis of Flow Changes in the SPAR Model (4VP)

Nurhikma Nurhikma — 2024-03-28

Research on the flow around the SPAR model was carried out with the aim of finding out how much effect the flow has
on the SPAR structure used in offshore wind turbines. SPAR is a type of floating structure that can usually be used in
deep seas and is an effective and reliable structure in terms of construction. Spar has the advantage that the buoyancy
point (KB) is above the gravity point (KG), thus providing good stability. However, there are still obstacles to the use of
SPAR structures in the deep sea, especially when environmental conditions are extreme, where SPAR structures are not
able to reduce currents at a certain speed level. Then, this research aims to test the SPAR model with a four vertical
plate (4VP) configuration system which is then modeled using Computational Fluid Dynamics (CFD) based numerical
modeling which aims to investigate the flow around the SPAR in terms of flow velocity. Especially at certain flow
velocity levels, the velocity is chosen carefully at each level starting from: V1 = 0.611m/s, V2 = 6.114, V3 = 61.144, V4
= 611.438. The addition of vertical plates to the bottom construction of the SPAR has a role in dampening the flow and
also turbulent effects due to current impacts.

Comparison Of Mooring Line Length Against Fpso Ship Movement Characteristics Using Numerical Analysis

Nadya Darwis — 2024-03-28

In analyzing moorings for FPSO (Floating Production Storage and Offloading), many things must be considered so that the mooring system can meet operability and safety standards. In this paper, we will discuss the stability of FPSO ships with varying mooring line lengths for FPSO ships with a capacity of 170218 DWT which will later be converted. The number of mooring ropes is limited to 4 with mooring rope lengths of 3100, 3200, 3300 m respectively. Variations in the length of the mooring line to clearly see the extent of the influence of changes in the length of the mooring line on the tension of each mooring line and the movement offset of the FPSO when moored and subjected to marine environmental loads (waves, wind, currents) using full dynamic analysis with the time method domain. From this study it can be seen that by increasing the length of the mooring line there will be a reduction in the maximum tension on the mooring line, but on the contrary there will be an increase in the offset of the ship's movement.

Analysis Of The Application Of Renewable Energy At The Muara Angke Passenger Port As A Means Of Supporting Thousand Island Tourism

Arif Fadillah — 2024-03-28

Kepulauan seribu are also a frequently visited destination for domestic and foreign tourists and are among the priority destinations in Indonesia. The development of the passenger port in Muara Angke is an important step in supporting the tourism sector in Kepulauan Seribu. However, this development must also consider environmental impacts, including carbon emissions and the use of natural resources. Indonesia has taken steps towards developing renewable energy and policies that support it by implementing renewable energy at the Muara Angke Passenger Port will be in line with government initiatives to achieve energy targets national renewable. The method used is primary data, secondary data, by calculating the need for solar panels and wind turbines and collecting supporting data sourced from related websites. The results are 324 solar panels placed on the roof of the main building of the port where the wind turbine is placed on the west side. with a total of 6 units, on the east side of the port there are 6 units and on the south side of the port there are 4 wind turbine units