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The greenhouse effect contributes to sea level rise and influences coastal conditions in Indonesia. Dalegan Beach, characterized by intense human activity and environmental sensitivity, requires an assessment of coastline changes and its vulnerability level. The Coastal Vulnerability Index (CVI) is a straightforward and practical method for evaluating coastline vulnerability to sea level rise and shoreline alterations. This approach supports long-term coastal planning and management by incorporating physical and geological parameters, including coastal relief, morphology, shoreline change, tidal range, sea-level change, wave height, land subsidence, and land use. Since the CVI incorporates both vulnerability and hazard factors, such as wave height and sea level rise, it functions more as a coastal risk index than a pure vulnerability measure. Consequently, this study focuses on analyzing coastline changes at Dalegan Beach and the nearby Panceng District, followed by a coastal vulnerability assessment using the CVI method, considering multiple variables. The results show that the studied coastal area is categorized as very vulnerable, with a score of 39.5.

A classic-type SPAR has a natural heave period in the range of 25–30 seconds, making it vulnerable to resonance when wave periods approach this range. To reduce resonance effects, this study investigates the influence of a spring-mass type Tuned Mass Damper (TMD) on the SPAR’s heave motion response. Simulations were performed using a frequency-domain numerical method with Nemoh software to obtain the heave Response Amplitude Operator (RAO). Key parameters evaluated include the TMD mass ratio to SPAR displacement, spring stiffness coefficient, and damping coefficient. Results indicate that TMD parameter variations significantly affect the RAO curve, altering the height of resonance peaks, generating new peaks, and shifting the resonance frequency. The most effective configuration reduced the maximum RAO from 2.216 m/m without TMD to 1.536 m/m. However, in spectral response analyses under 1-year and 100-year wave conditions at the West Seno site, the TMD showed limited effectiveness due to a mismatch between the structure’s critical RAO frequency and the dominant energy regions of the wave spectrum. This highlights the importance of aligning TMD design with site-specific wave characteristics for optimal performance.

Offshore structure, particularly fixed offshore structures, should be kept in the performance for the fit-for-purpose condition during their operating lifetime. For fixed offshore structures that exceed their designated life years, the proper Structural Integrity Management System (SIMS) should be developed and applied. Despite the fixed offshore platforms have their service life, there are still platforms that continue to operate exceeding their service lifetime. These ageing platforms should be taken care thoroughly to avoid the consequences that could take casualties. This paper will propose the proper initiation of SIMS development for ageing fixed offshore platforms in Indonesia, by taking an example at Bekapai Field Platforms in East Kalimantan. Using HAZID technique and several ranking criteria, the platforms are assessed and ranked. Platforms that categorized in critical condition are grouped based on similarities in geometry and function. The highest rank is analyzed in computer Finite Element Analysis (FEA) Software with modification based on latest inspection result. This method is proven to be a proper method to be used as a maintenance program for ageing fixed offshore platforms in Indonesia.

Evaluation is carried out on the operability of a 87,900 ton Sevan Stabilized Platform (SSP) functioned as an FPSO in the hypothetical operational site of Masela Block. This is to observe the critical conditions when side-by-side (SBS) offloading is performed between the SSP and a 35,000 DWT shuttle tanker. The first stage of analysis conducted on the moored SSP as a single floating body indicates the capability to withstand a 100-year wave, designated by the significant height of 8.0 m. Largest motions are experienced when SSP contains 75% load capacity, resulting in the mooring tension range from 2,000 kN up to 7,000 kN, portraying ample safety factors of 2.0 up to 3.0. The second stage of analysis is conducted for execution of SBS offloading from SSP to shuttle tanker, positioned in a 3.3 m distance. Observation is made when SSP is loaded with 100%, 83%, and 75% capacities correlated to the shuttle tanker loading of 10%, 60%, and 90% capacities. This reveals critical conditions arise when the wave exceeds 2.0 m in height, or the operability level of some 88.5%. Safer operation and higher operability level could be achieved by increasing the distance of SSP and shuttle tanker.

Remotely-located small islands face huge challenges. Nearly all aspects of life are at low level. Lack of adequate physical infrastructure, healthcare, education, transportation and prosperity may require a massive investment and operating costs. Soft infrastructure, implemented by choosing appropriate ICT implementation, opens a window of opportunity to address the above challenges effectively. This paper outlines how the Digital Island aims to contribute in achieving sustainable development in small islands, with a case study, Maratua Island.

This research aims to determine the fatigue life of the structure near the chain stopper of a storage tanker using the spectral fatigue analysis method. The wave spectrum is developed based on six significant wave height and period variations from the site wave scatter data using a modified spectrum of JONSWAP. The stress analysis is carried out using finite element analysis software. It can then be processed into Stress RAO from each loading direction. The response spectra are generated from the wave spectrum, multiplying with the square of the Stress RAO. These response spectra will determine the stochastic values of each stress range variation in obtaining the number of cycles that occur in each variation (nL). The accumulation of each ratio obtained from all existing variations will produce a fatigue index value (D). The American Bureau of Shipping’s S-N curve D-Class is used in this fatigue life analysis. The Gamkonora Aframax tanker operated as a temporary storage tanker at Papa’s field area is used as the case of this study.

The increasing demand for oil and gas requires the continuous development and revitalization of offshore platforms. One of the common methods for the installation of these platforms involves the utilization of crane barges for lifting operations. However, one of the main concerns is the longitudinal strength of these barges under various loading conditions, particularly during heavy lifting operations which can induce changes in trim. This research intends to perform a comprehensive analysis of the longitudinal strength of a crane barge during heavy lifting operations under different trim conditions. This study will employ advanced modelling and simulation techniques using software to accurately simulate the variations in loads and their subsequent impact on the structural integrity of the barge. The results will show the changes in load distribution, which will be systematically compared across different trim conditions. This analysis included calculations of shear forces and bending moments to compare the conditions of the even keel up to 1-meter trim by stern. Furthermore, this study will compare the ultimate shear force and bending moment obtained with its allowable as defined by the applicable standards and regulations to verify the structural integrity of the crane barge under the specified conditions.

From 1996 to the end of 2015, the Health and Safety Executive of Liverpool John Moores University recorded a total of 176 incidents resulting from collisions between ships during operations with jacket platforms. A jacket platform structure capability of withstanding unforeseen accident loads, such as potential ship collisions with the platform structure, is essential. The boatlanding structure must be designed to absorb energy from ship collisions with the platform structure. This study analyzes ship collisions with the boatlanding structure to examine its strength capacity in resisting potential loads during ship impacts on the boatlanding. This analysis was conducted with scenarios involving collisions between a vessel and a boat landing, varying the ship’s speed, the direction of impact (bow/stern and broadside), and variations in sea surface height due to tides. Under broadside collision conditions during operations, maximum stress reached 310 MPa, while bow/stern collisions saw maximum stress up to 9743 MPa. The most critical condition occurred during stern collision at minimum water depth, resulting in damage to the boatlanding structure.

Over the last few decades, studies found that relying on conventional fossil fuel sources has been giving so many negative impacts to the environment. Depletion of coal along with natural gas and crude oil are also the reasons why we need some new energy alternatives that less harmful and sustainable. Offshore wind energy can be an effective solution due to abundant wind resources and space availability. Unfortunately, the cost of offshore wind energy is expensive. Therefore, an innovative concept of FOWT integrated with an aquaculture is proposed here. This concept is expected to evolve continuously because of the huge profit gained from offshore aquaculture trade. To be qualified, its dynamic behaviour should be evaluated and investigated while considering various environmental conditions. Arafura Sea, which has both fish and wind potential, is chosen as the suitable location for this innovative concept. The environmental conditions, representing different sea state are adopted for the analyses. One incident angle of combined wind, current, and wave loads are being considered in this paper for dominant wind direction. Similarly, a numerical model with dynamic simulation is carried out. Then, the dynamic responses of the FOWT integrated with fish nets, including the periods, motions, tower loads, and mooring tension are numerically examined. While the maximum mooring line tension in the FOWT with fish nets is observed, the expected maximum tension should occur at the mooring line aligned with the direction of the environmental load. Additionally, the highest mooring line tension should occur during operational conditions. This is due to the wind turbine system actively generating electricity during operation, with the rotor facing the incoming wind, resulting in relatively substantial aerodynamic load along with hydrodynamic load. The FOWT with nets motions result shows decreased amplitudes compared with those without nets. This reduction of all the motion amplitudes is the result of the damping effect caused by the presence of nets.

The marine transportation of crude oil from tankers to final terminals is facilitated using pipelines and oil terminals. The predominant form of the terminal is the Single Point Mooring system. The system is crucial as it anchors tankers and transfers crude oil from the ship to the system using floating hoses. Thus, periodic inspections are needed on the Single Point Mooring structure during its lifespan. In an inspection, there was a finding the Single Point Mooring 17,500 DWT vessel required rapid overhaul. Acquiring a substitute Single Point Mooring (SPM) system with 150,000 DWT in capacity is necessary to ensure the uninterrupted continuation of crude oil loading and unloading activities. However, a different mooring system was found between these two. Thus, a redesign of the mooring system is configured and analyzed in this paper. This paper investigates the strength of the mooring lines and the triangle plates. The different positions of triangle plates are also compared to give recommendations for the mooring system. The research findings indicate that the mooring system design satisfies the API RP 2SK criterion, both intact and damaged.