In high-speed ship design, accurate hydrodynamic prediction is crucial to optimizing performance and efficiency. One of the strategies is to take advantage of interceptors, which have proven to be a promising solution for resistance reduction and trim control. However, most studies focus on vessels with undisturbed stern geometries. In contrast, certain high-speed vessels, such as patrol craft or military fast boats, are equipped with tunnel propeller configurations designed to protect the propeller while ensuring optimal performance at high Froude numbers. This study investigates interceptors on hulls fitted with tunnel propellers through experimental and numerical approaches. Interceptors of various span dimensions are strategically installed on the tunnel propellers, with consistent blade height. The computational fluid dynamics approach was used to investigate the hydrodynamic characteristics of the hull, providing a comprehensive analysis of total resistance, pressure distribution, wave elevation, and dynamic trim. This study shows that interceptors can still perform effectively, even on hulls equipped with tunnel propellers. Furthermore, vessel speed and configuration play a significant role in interceptor effectiveness. The mid-tunnel interceptor configuration produced the greatest reduction in resistance, up to 9.7% at Fr=0.85.

In the last century, increasing carbon emissions have profoundly impacted efforts to mitigate climate change.Therefore, energy-intensive industries face pressure to diminish their carbon emissions.In this context, the shipbuilding industry stands out as a significant source of emissions due to its high energy consumption and raw material-based production processes.This article assesses the carbon footprint of a Turkish shipyard manufacturing tugboats, concentrating on Scope I, Scope II, and Scope III emissions as defined by the Greenhouse Gas (GHG) Protocol.Calculations utilized DEFRA 2023 emission coefficients to ascertain CO 2 equivalent emissions for each activity type.The shipyard's overall emissions comprise 55.68% Scope I, 16.81% Scope II, and 27.51% Scope III.The carbon footprint evaluation emphasizes the necessity of diminishing it and underscores the significance of prioritizing environmental sustainability.This study has explored strategies such as the use of solar energy, the transition to electric vehicles, a hybrid work model, and the establishment of local supply networks.These strategies provide practical and sustainable approaches to mitigating the environmental impact of carbon emissions in the shipbuilding industry.

Several technologies that have been employed so far to monitor IUU transshipment are Automatic Identification System (AIS), Vessel Traffic Services (VTS), and radar.AIS is an automated ship tracking system operated on ships and shore stations and functions to identify and track vessels.Unfortunately, the information contained in the AIS data has too much unnecessary data, as a consequence, information about the ship's path is often inaccurate.In 2018, Zhang et al. [3] proposed a ship path reconstruction model by eliminating noise in AIS data, thus more accurate ship path information was obtained.Research conducted by Damastuti et al. [4] regenerates data by building information from missing AIS data enabling ship monitoring able to be carried out continuously.Bal Beiki et al. [5] 2016 made

Separators are essential equipment on ships, regardless of the vessel type or the type of engine installed, whether the main, and auxiliary engines are two-stroke or four-stroke. The primary function of these separators, apart from the bilge separator, is to ensure clean fuel delivery to the main engine and auxiliary machinery by removing water and solid contaminants from the fuel. The efficiency of the separators and the level of maintenance they receive directly influence the performance of the ship's machinery, reducing the likelihood of malfunctions and power loss in systems dependent on clean fuel. However, since separators operate at high speeds using centrifugal force and are composed of numerous intricate components, they are prone to potential failures if not properly maintained. While preparing for this study, four experts were asked about the effects of failures that may occur in the separators. According to the criteria received, the fuzzy DEMATEL method, a multi-criteria decision-making method, was used to evaluate the effects of failures. When the results are examined, the most effective factors are the wear of the bearings, contamination, incorrect assembly of the bowls, and bending of the shaft. It is extremely important to have spare parts available on the ship and to maintain the equipment with sufficient authorized crew.

The maritime sector, particularly in offshore tugboat and support vessel operations, faces multifaceted strategic management challenges due to rapid technological advancements, environmental regulations, and market conditions. This paper introduces an innovative strategic decision-making framework for this industry, integrating Strengths, Weaknesses, Opportunities, and Threats (SWOT) analysis with Fuzzy Decision Making Trial and Evaluation Laboratory-DEMATEL and Order of Preference by Similarity to Ideal Solution-TOPSIS methodologies. A thorough extensive literature review and expert contributions identified 20 key factors impacting the sector across 4 SWOT categories, with balanced weights of 25.14% (strengths), 25.32% (weaknesses), 24.68% (opportunities), and 24.86% (threats). The hybrid approach uniquely highlights the interdependencies among these factors, offering a prioritized list of 8 strategic options. The analysis revealed that the WO1 strategy (focusing on cost reduction through technological innovation) emerged as the most effective strategy with a closeness coefficient of 0.798, followed by SO2 (operational efficiency enhancement) at 0.642, and ST1 (leveraging experienced crew and advanced technology) at 0.550. These results show that operational cost reduction through technological innovation and emerging market entry is a strategic priority. This study contributes significantly to the existing literature by providing a robust strategic management model tailored to address the unique challenges of offshore maritime operations. These insights are useful for improving operational efficiency for industrialists with sustainability-related concerns and for furthering their competitive advantage in an increasingly dynamic global environment. Moreover, the study also provides a replicable model that can be applied to other industries where similarly complex decisions can be made.

A fast-growing raw material is the wood of the Paulownia tree.This tree is also known as the Empress tree, Royal Paulownia, or Kiri.In one year, this tree grows an average of 4 metres in height and about 2 centimetres in width.After approximately

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.

The coronavirus epidemic, which emerged in Wuhan at the end of 2019, spread worldwide and caused more than 4 million deaths as of 2021. The cruise industry, whose goal is to maintain customer satisfaction at the highest possible level, like all service industries, has passed a difficult test with serious coronavirus disease-2019 (COVID-19) cases that emerged on various ships. The new rules of the COVID-19 pandemic are reflected in the service processes of the ships that started to sail again after a long-term pause in the sector. The main motivation of this study is to determine whether the factors affecting customers' perceived service quality have changed during the pandemic period in the cruise industry, which is one of the sectors where service quality should be maintained high. Therefore, this study aims to determine the factors affecting the perceived service quality of cruise passengers and determine the new factors that occurred during the pandemic. To achieve this goal, the online narratives of 418 passengers cruising in the European Region between September 2020 and September 2021 were analyzed using Leximancer software, and key elements of passengers' perceptions of service quality were determined. As a result of the study, it was found that cabin location, restaurant quality, and COVID-related variables became significant factors affecting the perceived service quality of cruise passengers during the pandemic period. Additionally, disembarkation and embarkation, which were important variables in the pre-COVID period, were reclassified under the COVID category. The study also determined that adherence to COVID-19 measures by cruise companies positively impacted customer satisfaction during this period.