In the present study, a quasi-two-dimensional (2D) numerical model developed to model shoreline evolution under wave action near various coastal defense implementations is applied to laboratory experiments on shoreline evolution around an offshore breakwater. The model uses a spectral wave model based on the energy balance equation with wave breaking and diffraction terms. A method is proposed to distribute bulk longshore sediment transport rates over the surf zone for 2D applications. The proposed method agrees with the one-dimensional methods and 2D laboratory measurements. The model also comprises cross-shore and swash zone transport modules for maintaining the equilibrium profile, which is tested using a theoretical case governed solely by cross-shore transport. The test shows that the cross-shore transport module can restore any user-defined equilibrium beach profile. For the laboratory experiments, the model results for the nearshore wave heights and bottom contours agree well with the experimental results, especially for the initial cases of laboratory experiments. As the salient progresses through the offshore breakwater and a tombolo forms, the wave approach and local orientation angles increase, and the computed bottom contours begin to differ from the measured contours.

Safety management of maritime traffic is crucial for archipelagic states such as Indonesia, especially in areas like the connection between the Sunda Strait and the Java Sea. This study proposes a traffic lane design using the IMO routeing measures, employing the Formal Safety Assessment scientific method. The study recommends implementing Traffic Separation Schemes (TSS), precautionary areas with a recommended counterclockwise route, and inshore traffic zones. Results indicate that TSS is more effective in reducing collision frequency compared with two-way routes, with a counterclockwise flow further mitigating crossing situations. The proposed measures, particularly Risk Control Option 3, show a 54% reduction in collision frequency compared with the existing conditions. However, despite improvements, collision frequencies remain intolerable, necessitating additional strategies. The total collision frequency for all proposed measures is deemed unacceptable, requiring further methods to enhance safety. The economic evaluation shows potential savings, with estimated values for Gross Cost of Averting Fatality and Net Cost of Averting Fatality at US$ 3.21 million and US$ 2.9 million, respectively. Thus, while the proposed measures demonstrate some efficacy, additional strategies are imperative to adequately address collision risks in the designated area.

Building and maintaining social and interpersonal relationships are crucial for mental health. However, due to the unique characteristics of jobs, building and maintaining such interpersonal relationships with colleagues as well as others may not be as similar to off-shore employees like shorebased ones. On the contrary, preference towards exhibiting interpersonal relationship behaviour is another area that needs attention in the maritime sector. Such preferences may be unique while individuals pass through uncertain situations like the coronavirus disease-2019 (COVID-19) pandemic. Against the backdrop of the COVID-19 pandemic, this study investigates the linkages between personality traits and interpersonal relationship behaviours among Indian marine engineers. Data was gathered through snowball sampling from 385 marine engineers utilising the Big Five Inventory and the Fundamental Interpersonal Relationship Orientation-Behavior™ framework after necessary adaptations of these instruments. Results show that conscientiousness is linked to expressed inclusion and wanted control. Extraversion is linked with all behaviours except wanted control, while agreeableness is associated with expressed control. Neuroticism shows linkages with wanted inclusion, expressed control, and wanted control. This study fills critical research gaps by examining the missing links between personality traits and interpersonal relationships in a high-stress environment like the maritime sector and that too during the COVID-19 pandemic. These insights emphasise the need for effective communication and teamwork in high-stress maritime environments.

In the maritime world, carbon composite material has been used as a propeller on ships. Research on the use of carbon composite materials began in the early 2000s. With features including reduced cavitation and pressure fluctuations, improved acoustic attenuation, corrosion resistance, lower maintenance costs, enhanced efficiency, and longer propulsion system service life, carbon composite materials offer several benefits. The propeller’s strength and performance should increase with the use of carbon composite materials. This research uses the Fluid Structure Interaction method by conducting computational fluid dynamic simulations followed by finite element analysis. This study analyzed the deformation and stress on the propeller blades by comparing epoxy carbon fiber that was woven and unidirectional with quasi-isotropic laminate; additionally, it will be compared with other metal materials like bronze, titanium alloy, and copper alloy. Through the process of study and observation of the numerically derived data, which represent the propeller blade’s maximum deformation and equivalent stress. By comparing two types of carbon fiber, it can be analyzed from the results of maximum deformation and equivalent (Von-Mises) stress using the fluid structure interaction method. The results show that the epoxy carbon fiber is five times lighter than the copper alloy material, and the stress distribution has a similar pattern, but the deformation results of the two epoxy carbon fiber materials differ from those of the metal materials.

The study of marine lubricants using modern methods for quality control and diagnostics of engine conditions is an important task. The solution to this task determines the technical condition of ships, their performance, and accident-free operation in maritime transport. In this study, the properties of several marine motor oils were studied using broadband dielectric spectroscopy. The complex dielectric constant, conductivity, and loss tangent of base oil, Shell Rimula 15W40 oil fresh and used for 250 and 500 h were studied. The influence of the test voltage frequency and temperature on the selected electrical parameters was determined. In used oils, the DC conductivity decreases slightly, which is apparently due to the depletion of additives. The increase in the conductivity of all studied oils with increasing current frequency is caused by the displacement current. It is shown that dielectric losses increase with frequency as long as the polarization has time to follow the change in the field. A shift in the frequency at which the maximum loss occurs with a change in temperature was discovered. The activation energies of polarization and conductivity were determined. The thermal activation energies obtained from the conductivity and dielectric constant are not significantly different. For the first time, the distributions of the dielectric constant relaxation times for the studied lubricating oils have been obtained. The dielectric relaxation time distribution function depends on the composition of additives in the oil, wear particles, contaminants, and the chemical degradation of the oil during operation. For the first time, correlations have been established between conductivity and dielectric constant at different temperatures and frequencies. These correlations can be used to select frequency ranges that provide stable parameter values and maximum diagnostic ability.

Global climate change increases storm frequency and Sea Level Rise (SLR). This leads to an increased risk of coastal flooding, reduced effectiveness of protective structures, and intensified coastal erosion and retreat. The Bona and Ceinturon beaches, two beautiful sandy beaches with low-lying topography along the eastern branch of the Giens double tombolo on the western coast of Hyères Bay, have high tourist value. These areas are very vulnerable to SLR, which is believed to reduce the effectiveness of the shore protection structures built on these sandy beaches. The effects of SLR on changes in the hydrodynamic characteristics of these water bodies need to be quantified. This may help clarify the relationship between SLR and coastal erosion. This study investigated the variation of wave height and current speed due to SLR at the Bona and Ceinturon beaches using a coupled numerical model. The performance of this model was calibrated by comparing the model results with the in situ measured data. The research results are the basis for assessing the impact of SLR due to climate change on this area and provide a useful solution for coastal management in the future.

In the contemporary landscape characterized by heightened competitive pressures, adept maintenance management assumes a pivotal and strategic role in cost mitigation and profit augmentation. This paper applies the risk-based maintenance (RBM) methodology to the hydraulic system of a remotely operated vehicle (ROV) owned by an oil and gas services company. To achieve this, it was necessary to gather information on the system failures, followed by determining the critical subsystems. By analyzing the frequency and severity of identified failures, a risk matrix could be constructed. Using the “5 Whys” technique, an analytical framework was used to uncover the root causes of the failures observed in the handlers and propellant subsystems. Subsequently, a risk matrix is formulated again after the implementation of the RBM and the mitigation measures adopted by the authors to elucidate the discernible impact of the maintenance methodology on improving the availability of the ROV and the incidence of failures outlined in the study.

Container terminals are among the most critical parts of transportation systems. Reducing the ship turnaround time increases terminal efficiency and enhances global trade volumes. Such time reductions can be achieved by improving the operational efficiency of major resources at container terminals. Quay crane operating strategies are crucial for assessing the performance of container terminals. Simulation models are effective and reliable methods for interpreting and improving complex systems. This study proposes simulation models that include container loading and unloading tasks in marine container terminals implementing single-cycling and double-cycling strategies. Double-cycling is a quay crane operating strategy that attempts to improve container handling efficiency. The system was modeled using ARENA simulation software. The implementation results of the single-cycling and double-cycling strategies were compared in terms of the performance criteria, such as the utilization rates of the quay crane and yard trucks, ship turnaround time, and operating cost.

Taylor-Couette-Poiseuille (TCP) flow, characterized by the flow through an inner rotating shaft and an outer stationary cylinder, is a fundamental flow system in many industrial applications, including ship stern tubes, turbomachinery, journal bearings, and offshore drilling. Understanding the hydrodynamics of the TCP flow offers significant benefits for ensuring the robust design and operational efficiency of such systems. This paper presents the numerical modeling of turbulent TCP flow to assess the combined effects of two key control parameters-axial Reynolds number (10000-30000) and Taylor number (2.2x107-3.1x109)-on the fluid dynamics within the system. Using Reynolds Stress Modeling, this study investigates the behavior of TCP flow at high Reynolds numbers, which is relevant to real-world rotating machinery. The results indicate that the interaction between rotation and axial flow is not linear, with high rotation rates showing distinct behavior from low rotation rates, especially in the throughflow effects. At low and moderate rotation numbers (N), both the mean and turbulent variables display strong dependence on the rotational velocity and axial flow rate. However, further increases in N lead the flow field to be increasingly dominated by the contribution of rotation, and mean flow variables become relatively independent of the imposed flow rate. Furthermore, systematic deviations from the log-law in the boundary layer velocity profiles further emphasize the need to account for the combined effects of rotation and axial flow in the TCP flow system design and operation.

This article provides a model-based design method for heading control based autonomous trajectory tracking of a KVLCC2 ship. Kinematics, dynamics, and hydrodynamic force subsystems are used to represent the ship’s motion equations. By contrasting the outcomes with experimental data received from the maneuvering modelling group, the accuracy of the model is confirmed. Heading angle of the ship is controlled by a linear cascade controller, and the settings of the controller are modified by using two separate heuristic optimization techniques: particle swarm optimization and genetic algorithm. The comparison of the findings demonstrates that the particle swarm optimization approach is computationally more effective than the genetic algorithm. Performance in the presence of disturbance has been investigated using the controller parameters discovered using particle swarm optimization. A suitable guidance algorithm is incorporated into the architecture of a trajectory tracking system to establish the necessary heading angle for travel between waypoints. We use a real-time simulator to visualize the ship motion on a graphical environment.