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The oil port logistics involves multiple parties including oil tanker owners, port authorities, customs, oil suppliers, and shipping companies. These parties need to exchange a significant amount of data and documentation related to cargo, such as bills of lading, customs declarations, and cargo manifests. This huge amount of data and documentation provides ample opportunities for data manipulation and corruption. Moreover, physical documentation is slow and prone to errors and manipulation. This data can be securely stored and shared between different parties in a tamper-proof and transparent manner using blockchain. Blockchain is a decentralized technology that employs secure hashing and consensus algorithms that can detect any data modification. Hence, this work proposes a blockchain-enabled immutable, and efficient framework for trade documentation in oil port logistics. The proposed framework provides timely processing of oil trade documents and ensures immutability while increasing trust among the trade entities. In addition, this work implements a private blockchain for the execution of smart contracts, which can ensure that all parties involved in the logistics process comply with pre-agreed rules and regulations. Simulation results validate the effectiveness of the proposed framework in terms of transparency, immutability, network latency, throughput, and resource utilization. [ABSTRACT FROM AUTHOR]

Maritime transport has adapted to recent political and economic shifts by addressing stringent pollution reduction requirements, redrawing transport routes for safety, reducing onboard technical incidents, managing data security risks and transitioning to autonomous vessels. This paper presents a novel approach to predictive maintenance in the maritime industry, leveraging Artificial Intelligence (AI) and Machine Learning (ML) techniques to enhance fault detection and maintenance planning for naval systems. Traditional maintenance strategies, such as corrective and preventive maintenance, are increasingly ineffective in meeting the high safety and efficiency standards required by maritime operations. The proposed model integrates AI-driven methods to process operational data from shipboard systems, enabling more accurate fault diagnosis and early identification of system failures. By analyzing historical operational data, ML algorithms identify patterns and estimate the functional states, helping prevent unplanned failures and costly downtime. This approach is critical in environments where technical failures are a leading cause of incidents, as demonstrated by the high rate of machinery-related accidents in maritime operations. Our study highlights the growing importance of AI and ML in predictive maintenance and offers a practical tool for improving operational safety and efficiency in the naval industry. The paper discusses the development of a fault detection approach, evaluates its performance on real shipboard data-through tests on a seawater cooling system from an oil tanker and concludes with insights into the broader implications of AI-driven maintenance in the maritime sector. [ABSTRACT FROM AUTHOR]

ABSTRACT Analyzing the spatial and temporal variations of offshore crude oil transportation at China's coastal ports is critical for the country's energy security. The automatic identification system provides high‐resolution real‐time data on China's offshore crude oil transportation, offering more precise spatial and temporal insights than existing statistical studies. In this study, we propose a novel method for calculating offshore crude oil transportation volumes by considering the operational status of crude oil tankers as “empty” or “full.” This approach enhances reliability and provides detailed port‐level transport data. Our findings reveal notable similarities between the centrality measures of maritime oil transportation and oil tanker networks, but significant differences in community divisions. Specifically, in the tanker networks, Chinese ports are categorized into three regions, with one region being dominant and the other two regions containing only four ports. In contrast, the oil flow networks show China divided into two major regions and two minor ones. This study offers valuable contributions to strengthening energy security in China and supports informed policy development and implementation. [ABSTRACT FROM AUTHOR]

Liquefied natural gas (LNG) exports from the United States have risen dramatically since the LNG‐export ban was lifted in 2016, and the United States is now the world's largest exporter. This LNG is produced largely from shale gas. Production of shale gas, as well as liquefaction to make LNG and LNG transport by tanker, is energy‐intensive, which contributes significantly to the LNG greenhouse gas footprint. The production and transport of shale gas emits a substantial amount of methane as well, and liquefaction and tanker transport of LNG can further increase methane emissions. Consequently, carbon dioxide (CO2) from end‐use combustion of LNG contributes only 34% of the total LNG greenhouse gas footprint, when CO2 and methane are compared over 20 years global warming potential (GWP20) following emission. Upstream and midstream methane emissions are the largest contributors to the LNG footprint (38% of total LNG emissions, based on GWP20). Adding CO2 emissions from the energy used to produce LNG, total upstream and midstream emissions make up on average 47% of the total greenhouse gas footprint of LNG. Other significant emissions are the liquefaction process (8.8% of the total, on average, using GWP20) and tanker transport (5.5% of the total, on average, using GWP20). Emissions from tankers vary from 3.9% to 8.1% depending upon the type of tanker. Surprisingly, the most modern tankers propelled by two‐ and four‐stroke engines have higher total greenhouse gas emissions than steam‐powered tankers, despite their greater fuel efficiency and lower CO2 emissions, due to methane slippage in their exhaust. Overall, the greenhouse gas footprint for LNG as a fuel source is 33% greater than that for coal when analyzed using GWP20 (160 g CO2‐equivalent/MJ vs. 120 g CO2‐equivalent/MJ). Even considered on the time frame of 100 years after emission (GWP100), which severely understates the climatic damage of methane, the LNG footprint equals or exceeds that of coal. [ABSTRACT FROM AUTHOR]

To address the challenge of measuring the dynamic characteristic parameters of the gas turbine rotor system affected by hull excitation, a vibration transmission model integrating a ship model slice, test data, and a three-dimensional entity is proposed, based on the two-dimensional slice theory, scaled ship model, and finite element model of the turbine rotor system. The transient dynamic responses of the front and rear bearing points were calculated and analyzed. Vibration response tests with significant wave heights of 0.5 m, 1.25 m, 2.5 m, and 4 m were carried out in the towing tank of the ship model to obtain the dynamic characteristic parameters of the deck position. Techniques including wavelet denoising, Fast Fourier Transform (FFT), and signal resampling were employed to filter out and reconstruct high-frequency noise, overcoming the technical challenges of a high sampling frequency and a low computational efficiency. The experimental data and simulation results were compared and analyzed, validating the accuracy of the vibration transmission model of the turbine rotor system with data and entity integration. By comparing the vibration signal values in the X and Z directions at the front and rear bearing points after vibration transmission, it is evident that the effective values of the vibration signals at the front bearing point are 0.03% to 0.1% greater than those at the rear bearing point. This model provides a theoretical basis and reference for the design of the gas turbine rotor system. [ABSTRACT FROM AUTHOR]

Research has identified volatility transmission from the oil market to the tanker freight market through external shocks. However, in the presence of intricate nonlinear structures, the academic literature often encounters difficulties in identifying cycles and their correlations across various timescales. This paper provides a multi-market analysis to comprehend the information from shock effects on different tanker routes and multi-peak fitting. Under different shock regimes, crude oil market and tanker freight rate shocks could transit bidirectly. When events occur, the crude oil market prices the expectations. However, when the actual performance of the future market differs from the traders' predictions of the future market, a price gap exists. Generally, the trade opportunity is tough to catch up on because only partial information can be found. In this study, we investigate the volatility connection of multi-markets and shock effects to clarify previously undisclosed information using multi-peak analysis. The information gathered and double-checked by cargo markets, crude oil supply-demand balance, and tanker freight prices of various tanker types could assist us in identifying prospective trends and investment opportunities. The volatility of each market, as well as the correlation of multi-markets, gives insights to crude oil dealers, tanker market participants, and energy regulators. [ABSTRACT FROM AUTHOR]

Floating production storage and offloading unit (FPSO) is an offshore vessel, producing, storing natural gas or crude oil, prior to oil shuttle tanker transport. The equivalent of natural gas is known as floating liquefied natural gas (FLNG). Robust prediction of the extreme mooring hawser tensions, during FPSO operations, is an important design and engineering reliability and safety concern. Excessive mooring hawser tensions may occur during certain types of offloading operations, posing potential operational risks. In this study, ANSYS-AQWA-software package has been used to model vessel dynamics, subjected to hydrodynamic wave loads, acting on FPSO or liquefied natural gas (LNG) vessel, under actual in situ environmental conditions. Experimental validation of the numerical results has been briefly discussed as well. This study presents novel multi-dimensional reliability method, based on Monte Carlo simulations (or alternatively on measurements). Proposed methodology provides accurate failure or damage risks assessment, utilizing available underlying dataset efficiently. Described approach may be well utilized at the vessel design stage, while selecting optimal vessel's parameters, minimizing potential FPSO mooring hawser tensions. The aim of this study was to benchmark state of the art Gaidai reliability method, proposed recently; this novel methodology opens up the possibility to predict simply and efficiently failure or damage risks for non-linear multi-dimensional dynamic offshore energy system as a whole. Key advantage of the suggested methodology is its multi-dimensionality (with unlimited number of system dimensions/components/processes, all having different physical dimensions), while classic reliability methods typically are not covering dimensions higher than two. [ABSTRACT FROM AUTHOR]

Computing the power required to meet a ship's operational needs is one of the most important tasks in naval design. The power required to propel a vessel is directly related to the resistance the hull experiences as it moves through the water. The conventional method of determining a ship's resistance involves towing tank tests of ship models at a fixed speed; however, for short-range vessels, where constant speed is not the primary mode of operation, a dynamic model is needed. This paper demonstrates a way in which different operational motion profile models can be retrieved from the acceleration stage of towing tank tests. We show that the data from the acceleration stage, often overlooked in towing tank tests, allow us to derive the gliding equations of motion. A dynamic model of a small inland ferry on the Motława River in the city of Gdańsk is developed, which enables optimisation of the required power based on different operation profiles. [ABSTRACT FROM AUTHOR]

Due to the rapid development of a global navigation satellite system and the rapid growth of ships, the traditional control algorithms are not suitable; hence, the longitudinal rocking phenomenon generated by external disturbances is more serious when a ship is sailing. This paper takes a mathematical model of the super large oil tanker "KVLCC2"'s longitudinal motion as the controlled plant, establishing a multi-input multi-output instability control system, using the root trajectory shaping method and a weighting matrix to ensure the stability of its transfer function's mathematical model. An improved closed-loop gain-shaping algorithm is utilized to design a simple robust controller. And a dual nonlinear positive feedback control algorithm is added to the control system to further improve the controller's pitching stabilization performance and reduce the controller's output energy. In order to verify that the controller has a consistently strong robustness, simulation experiments are carried out by adding a level 6, 7 and 8 wind wave model and a perturbation link to the control system, respectively. The results show that when the value of the hysteresis constant is taken as 0.25, the output values of the heave displacement and the pitch angle are greatly reduced, and the longitudinal rocking phenomenon is significantly improved. The dual nonlinear positive feedback control algorithm enhances the ship's pitching stabilization control capability and further reduces the controller's output energy, which provides technical support for the smooth and efficient sailing of super large ships under changing sea conditions. Combined with a global navigation satellite system, this algorithm provides a new method for pitching stabilization control of super large ships. [ABSTRACT FROM AUTHOR]

The influence of oblique currents in narrow and shallow channels causes the fluid flow around ships to become complex. To analyze the hydrodynamic characteristics of a ship in such channels, it is essential to examine the influence of oblique currents on the ship's hydrodynamic characteristics. In this study, current direction, ship speed, current speed, and water depth were identified as determinants affecting the hydrodynamic characteristics of a ship. Numerical simulations were conducted on a large oil tanker to investigate the effects of these factors on the ship's hydrodynamic characteristics. The viscous fluid flow was modeled using the unsteady Reynolds-averaged Navier–Stokes (URANS) equations in conjunction with the k-ε turbulence model. The URANS equations were discretized using the finite volume method. The numerical results indicate substantial differences in the hydrodynamic characteristics of ships under oblique current conditions compared to still-water conditions. At a current direction of β = −45°, the direction of the sway force is consistent with that of still water's sway force, which is an attractive force. The yaw moment at β = −45° changes from a bow-out moment under still-water conditions to a bow-in moment. Conversely, at a current direction of β = 45°, the sway force shifts from an attractive force under still-water conditions to a repulsive force. The yaw moment acts as a bow-out moment, which is consistent with that observed in still-water conditions. Furthermore, the influence of hydrodynamic characteristics on a ship varies significantly with changes in ship speed, current speed, and water depth. To ensure the safe navigation of ships, it is essential to develop and apply comprehensive strategies and countermeasures that account for practical conditions. [ABSTRACT FROM AUTHOR]

The need for an accurate inventory of ship emissions is vital for atmospheric scientists assessing the environmental impact of shipping and for policymakers aiming to regulate and incentivize emission reduction. This study used data from 189 international ports, related to ship arrivals and departures, to develop emissions inventories. Emission characteristics were examined in detail, classifying emissions by factors like ship type, month, and region. The analysis identified oil tankers and container ships as main emitters among ship categories. A detailed analysis of the monthly distribution of emissions from vessels at berth worldwide was conducted based on precise arrival and departure times. Singapore, Rotterdam, and Antwerp were the ports with the highest emissions from ships at berth. Overall, this study presents the spatial and temporal emission characteristics of ships at berth in 3912 ports around the world, which can support the development of emission reduction strategies in port management. [ABSTRACT FROM AUTHOR]

The article explores the labor theory of culture as an alternative perspective to understanding cultural texts. Unlike traditional approaches that view work and culture as opposing forces, the labor theory of culture sees them as interconnected. This theory focuses on the people, processes, and meaning behind cultural texts, emphasizing the labor involved in their creation. By studying the labor story behind cultural production, we can gain valuable insights into the social and political aspects of these texts, as well as uncover marginalized voices and collective work processes. [Extracted from the article]

The importance of marine transportation of crude oil and petroleum products significantly increases in the context of geopolitical tensions. Marine transportation of oil involves losses from evaporation during loading and unloading of tankers at marine terminals, as well as during transshipment from ship to ship. It is difficult to predict the volume and quantity of the resulting multi-component mixture of gases because of the uncertainty in the initial data. Gas-dynamic processes occurring inside the tanker and in the pipelines of gas phase affect the efficiency of oil and oil products vapor recovery systems. The paper proposes a model that allows to determine the parameters of these processes during tanker loading. Under conditions of high ambient temperatures of 25.-30 0C, it is experimentally determined that the concentration of hydrocarbons can reach up to 0.6 kg/m³ during vaporization of gasoline. The paper presents the calculation of distances for which the vapor recovery unit can accept vapors simple by pressure without using a gas blower. The developed model was verified on the basis of real loading data on the territory of a large port in the Russian Federation during gasoline transshipment. It was shown that for an operating marine terminal with a vapor recovery unit located 300 m away from the tanker, the gas blower can be turned off without the risk of opening the discharge valve. [ABSTRACT FROM AUTHOR]

The aim of this study is to optimize water resource management in the Jarrahi River Basin with an environmental sustainability approach for the Shadgan International Wetland. The Jarrahi River is one of the rivers in the Persian Gulf and Oman Sea drainage basin, with most of its course located in Khuzestan province. The river's catchment area lies on the southwestern slopes of the Middle Zagros Mountains and is located between 48°45' and 51°10' East longitude and 30°30' to 31°40' North latitude. Its area is 24,300 square kilometers. A water resource planning model for the entire Marun and Jarrahi river system was developed using an optimization approach. The entire Marun-Jarrahi watershed was simulated in a monthly time step over a 60-year period using the WEAP simulator, and five scenarios were defined. The results were then integrated and analyzed using the powerful Shahin Harin metaexploration algorithm. Based on the results, the release pattern for water utilization within the standard benchmark four and ten tank system using Harris Hawks Optimization (HHO), FPA, and SOS algorithms, the exploitation policies derived from the HHO algorithm with a more optimal release pattern yielded the highest benefit. Additionally, the model with the least water shortage was identified using this approach. These results demonstrate the superior efficiency of the HHO algorithm compared to the other meta-exploration algorithms employed. As a further innovation, study proposes and develops a novel hybrid model combining HHO and Cat Swarm Optimization (CSO) algorithms, referred to as the HHO-CSO algorithm. [ABSTRACT FROM AUTHOR]

To understand the effects of war on the diplomatic practices of nonstate actors, this article focuses on the wartime diplomacy efforts of Ukrainian think tank experts in the aftermath of Russia's full-scale invasion in February 2022. Drawing on the concept of think tank diplomacy, the study specifically examines how Ukrainian think tankers adapted their diplomacy functions – negotiation, communication, information-gathering and promotion of friendly relations with other countries – under the conditions of the full-out war. The analysis combines insights from existing studies with the authors' participant observation and original reflexive expert interviews with Ukrainian think tankers. The article reveals how Ukrainian expert professionals, unified by the goal of generating and maintaining international support for their country, adapted their diplomatic practices for asserting greater control over their agendas, engaging in cross-border collaborations and broadening their outreach efforts. By shedding light on the work of Ukrainian think tank experts in times of war, this article showcases the agency of knowledge-producing nonstate actors in wartime diplomacy. [ABSTRACT FROM AUTHOR]

We report an exploration of liquid hydrogen (LH 2) tank technology, determining if improving LH 2 tank weight, multiplicity or shape enables more hydrogen to be stored on hydrogen vessels. The improvements investigated are well beyond the current LH 2 technology state-of-the-art. The platform for this study is a monohull H 2 Baseline research vessel powered 100% by hydrogen. Regarding weight reductions, we found that the research vessel does not benefit significantly from large weight reductions of the LH 2 tanks. A 50% reduction in mass of the inner pressure vessel led to a 3.1% reduction in the total research vessel weight. Reducing the LH 2 tank weight to the asymptotic limit of zero results in a 7.1% reduction in the overall research vessel weight. This maritime application, while benefitting from a reduction in LH 2 tank weight, is not a strong driver for LH 2 tank weight improvements. The two large LH 2 tanks of the H 2 Baseline Vessel can be replaced with a multitude of smaller LH 2 tanks. In two Multiplicity design variants, the total amount of stored LH 2 was ∼5–9% less than that of the H 2 Baseline Vessel, which does not motivate conducting the needed R&D that would drive the technology to smaller high-performing LH 2 tanks. We did find a significant benefit to improving the shape of LH 2 tanks, towards prismatic tanks that would better match the vessel hullform. Considering a "Shape Variant" that included space-consuming features such as tank connection spaces, manifolding and ventilation, we found a 26% improvement in stored LH 2 compared to the H 2 Baseline Vessel. The large improvement in storage capacity could warrant further LH 2 tank R&D that can enable high performing prismatic LH 2 tanks, such as pressure vessel steel developments allowing for higher strength/ductility at 20 K, improved insulation systems, methods for efficiently building prismatic tanks with insulation systems fit for 20 K service and flare-less techniques for managing heat leak (venting). The results are reviewed considering the current regulatory restrictions as well as prevailing limitations in LH 2 tank manufacturing. • Watercraft are not a strong driver for reducing the mass of LH 2 tanks. • There is no benefit to deploying smaller LH 2 tanks with multiplicity on ships. • Improved shape of LH 2 tanks allows more hydrogen to be stored on ships. • Future LH 2 tank R&D needs to consider prevailing regulatory restrictions. [ABSTRACT FROM AUTHOR]

Low-observable technology, often known as stealth technology, hides soldiers, aircraft, ships, submarines, missiles, satellites, and ground vehicles from radar and infrared sensors (preferably invisible). Stealth coating reduces radar cross section and makes aeroplanes harder to detect. Stealth planes employ radar-absorbing polymers. Stealth technology camouflages vehicles and buildings from radar. A radar-absorbent material may alter an items radar cross section at specific radar frequencies, but it does not make it "invisible" at any frequency. Stealth technology reduces radar reflections using radar-absorbing materials and geometry. Polymer composite-based stealth are graphene, carbon black, carbon nanotubes, and carbon fibres as carbonaceous material and filler. Stealth coating resin market size is based on epoxy, polyurethane, and polyimide. It also protects automobiles against ultraviolet rays, chips, scratches. Tanks and ships employ stealth coating technology to avoid hostile radar. The coating absorbs and scatters radar radiation, hiding the device. Military aircraft uses stealth coating to avoid radar. Commercial airlines are using stealth coating technologies to improve safety and security. The coating reduces aircraft drag and weight, improving fuel economy. Stealth coating absorbs radar signals, hiding the aircraft from radar detection systems. Military and private planes utilise it for security. Stealth coating reduces radar detection by absorbing or deflecting radar emissions. Military operations need stealth and secrecy, but civilian aviation may employ this technology to avoid hijackings and identify unlicensed planes radar-absorbent polymers cover stealth aircraft. These and other design features may weaken the aircraft's radar signal. [ABSTRACT FROM AUTHOR]

The prediction of manoeuvring performance for safe navigation and effective design of ships increasingly depends on artificial intelligence (AI), mainly digital twin technology. This technology requires a digital model of the physical ship. The hydrodynamic coefficients and parameters of these models are commonly obtained through two experimental methods: the planar motion mechanism (PMM) and the circular motion test (CMT). These methods are time-consuming and expensive, which may not be feasible during the early stages of the design process. This study investigates a cost-effective alternative approach to these methods by implementing a grey box method on ships. For the first of these implementations, a full-scale tanker ship was applied with artificial training data of zigzag manoeuvres. A validation study was carried out by comparing the simulation and free-running model test results of the tanker. For the second of these implementations, a scale model of a car carrier was selected, and several numerical search methods were combined to obtain a more accurate digital model. The 3-degree-of-freedom (DOF) Manoeuvring Modelling Group (MMG) models identified through this combination were validated with simulations and compared with the free-running model test results for various manoeuvres. The contribution of this study lies in the accurate capture of the manoeuvring characteristics of the physical model, which is achieved through the use of the adjustment interval and the combination of various numerical search method of the grey box method. Consequently, the developed model can be used in future studies as a faster decision-making tool for determining the straight-line stability or instability of a ship in the ship design and in predicting the manoeuvring performance of the ship. [ABSTRACT FROM AUTHOR]

In order to investigate the impact of marine propeller wake fields on sediment siltation in shallow water channels, this study employs the unsteady RANS approach and the Volume of Fluid model. A full-scale numerical self-propulsion test was conducted on a 50,000 DWT oil tanker under the influence of a free surface. The research includes forecasting the effect of propeller wakes on sediment redeposition following the dredging of the approach channel to Jiaxing Port in the China Sea. Initially, uncertainty research was carried out on the full-scale ship and propeller system, and the credibility of the computational results was quantified. The simulated results based on the sediment transport numerical model were then compared and validated against actual data from monitoring stations. The self-propulsion performance and the velocity distribution of the propeller wake were examined under three different propeller speeds. Scenarios simulated included no ship navigation, daily single-ship navigation, and daily two-ship navigation, evaluating the siltation distribution within the channel over one month. The results demonstrate that ship propeller wakes positively influence the reduction of channel sedimentation, with the maximum monthly siltation reduction reaching 0.108 m during single-ship tidal navigation and 0.11 m during two-ship tidal navigation. [ABSTRACT FROM AUTHOR]

Heavy oil spills from stranded oil tankers are a global problem. The recovery of spilled oil must have a low environmental impact and must be capable of processing large quantities at high speeds. In this study, we investigated the application of magnetic separation for the recovery of spilled oil. Pickering emulsions were formed by heavy oil and magnetite, and recovery was carried out using a drum‐type permanent magnet. Pickering emulsions were successfully formed by stirring heavy oil A and magnetite, and magnetic separation experiments showed that up to 90% of the heavy oil A could be recovered. To recycle magnetite, a small amount of heavy oil was added to the recovered Pickering emulsions, and then a strong magnetic field of a superconducting bulk magnet was applied, which resulted in easy solid–liquid separation. The possibility of recycling magnetite after separation was also demonstrated. Finally, a small‐scale system using drum‐type permanent magnets was developed, and magnetic separation experiments were performed. The results showed that approximately 77% of the heavy oil A could be recovered. Particle trajectory simulations also demonstrated the recoverability of heavy oil at the sea surface. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Oil tankers carry large quantities of liquefied chemical cargoes that are flammable, explosive and/or toxic. Hence, a collision with a tanker that causes an oil spill poses a severe threat to the marine environment and human life. In order to quantify and analyze the risk factors of ship collision oil spill, this paper adopts a combination of knowledge element (KE) and dynamic Bayesian networks (DBN) to conduct an emergency scenario study based on the “scenario-response” model. Firstly, the key elements of “accident scenario state, human factors, emergency measures, and emergency goals” are selected to represent the accident. Then, the mechanism of accident evolution is analyzed according to the case, and DBN is used to build a scenario model of oil spills from tanker collisions. Finally, to verify the importance of human factors and the scientificity of emergency measures, the oil spill accident due to the collision between the two vessels known as MT “SANCHI” and MV “CF CRYSTAL” is used as an example for analysis. The accident model deduction results are in line with reality, and the research results help relevant decision makers to understand the deduction process of oil spills from tanker collisions, which is of great significance to enhance the safety of oil tanker shipping and marine environmental protection. [ABSTRACT FROM AUTHOR]

In response to the European Union (EU)'s sanctions on Russian oil products, tanker shipping firms may adopt two strategies to reoptimize their shipping networks. The first strategy is to switch the flag states of tankers that are not eligible to operate on certain routes. The second strategy is to reposition tankers based on their flag states, i.e., moving those tankers that are eligible from other groups to specified routes. To help tanker shipping firms minimize the total operating cost during the planning horizon in the context of EU oil sanctions, including costs of fleet repositioning, flag switching, and fuel, this study investigates an integrated problem of fleet repositioning, flag switching, transportation scheduling, and speed optimization considering the dynamic relationships among fuel consumption, speed, and load. By formulating the problem as a nonlinear integer programming model and applying various linearization techniques to convert the nonlinear model into a linear optimization model solvable by off-the-shelf linear optimization solvers, this study demonstrates the practical application potential of the proposed model, with the longest solution time of less than two hours for a numerical instance with seven routes. Furthermore, through sensitivity analyses on important factors including unit fuel prices, crude oil transportation demand, and the tanker repositioning cost, this study provides managerial insights into the operations management of tanker shipping firms. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The marine vessel performance is quite critical in the maritime applications. In addition to internal variables like fuel, propulsion type, and loading condition, external factors such as fouling, sea state, currents, and more affect ship performance. The goal of this study is to create a model to predict ship slip rate based on specified noon report data which contain sea, wind, WED, and, DAS. 30 different noon report values of a crude oil tanker have been conducted on the same route with similar loading condition and they have been analysed by the MLR and the ANN respectively. Although a meaningful relationship between the variables couldn't create among the variables by the MLR, predicted ship slip values are very close to the verified ones in the ANN. Minor differences could be caused by changes in the amount of hull fouling, vessel loading conditions, reverse or different currents, quite unsettled weather, and sea conditions. [ABSTRACT FROM AUTHOR]

An energy capture equipment is proposed, which can harvest the mechanical energy generated by the rolling motion of a tanker, and the structure of the equipment is designed. The mass-spring-damping mathematical model of the slider is established. Then, a numerical wave tank is created by Fluent to simulate the rolling motion of a typical ship equipped with equipment. According to the data of ship rolling motion and the mathematical model solved by the Newmark-β method in MATLAB, the equipment's power is obtained. Specifically, when the encounter angle is beam wave condition (90 degree), the rolling motion is violent and the equipment power reached the maximum value (187.16 W). Besides, the power generation with the quartering wave is better by comparing the equipment's power under the conditions of the bow and quartering wave. Finally, the wave height becomes bigger, the ship's rolling angular displacement and the equipment's power become larger. [ABSTRACT FROM AUTHOR]

Recommendations are given for choosing the optimal schemes for the process of inerting cargo tanks of ships carrying liquefied gases. It was determined that one of the tasks that arise during the transportation of hydrocarbon cargoes (crude oil, petroleum products, and liquefied gases) is to ensure fire safety and prevent accidental explosions of cargo vapors in cargo tanks. Processes that occur during cargo operations on ships transporting oil products and liquefied gases are considered. The critical composition of the mixture of oxygen (entering the cargo tanks with air) and cargo vapors (remaining in the tanks after the cargo is unloaded) is indicated, at which a flash and explosion may occur. It was determined that the main technological operation that prevents spontaneous ignition of cargo vapors in cargo tanks is their inerting using nitrogen. The main advantages and disadvantages of the schemes for inerting cargo tanks are considered and determined: cascade, semi-cascade and parallel. The effective use of these schemes is based on the consumption of nitrogen, the amount of which is necessary for inerting, as well as the duration of the inerting process. The results of determining these indicators for a group of gas carriers with a cargo capacity of 38,646–62,233 m³ are given. At the same time, it is stated that the lowest consumption of nitrogen is necessary to ensure the process of inerting according to the cascade scheme. It was established that semi-cascade and parallel inerting schemes require an increase in the amount of nitrogen by 1.74–2.42 times and by 1.28–1.83 times, respectively. It was also established that the cascade scheme of inerting requires more time for its implementation. The duration of inerting according to the semi-cascade and parallel scheme is reduced and is 0.43–0.64 and 0.58–0.75 times in comparison with the cascade scheme. [ABSTRACT FROM AUTHOR]

Once realized, autonomous aerial refueling will revolutionize unmanned aviation by removing current range and endurance limitations. Previous attempts at establishing vision-based solutions have come close but rely heavily on near perfect extrinsic camera calibrations that often change midflight. In this paper, we propose dual object detection, a technique that overcomes such requirement by transforming aerial refueling imagery directly into receiver aircraft reference frame probe-to-drogue vectors regardless of camera position and orientation. These vectors are precisely what autonomous agents need to successfully maneuver the tanker and receiver aircraft in synchronous flight during refueling operations. Our method follows a common 4-stage process of capturing an image, finding 2D points in the image, matching those points to 3D object features, and analytically solving for the object pose. However, we extend this pipeline by simultaneously performing these operations across two objects instead of one using machine learning and add a fifth stage that transforms the two pose estimates into a relative vector. Furthermore, we propose a novel supervised learning method using bounding box corrections such that our trained artificial neural networks can accurately predict 2D image points corresponding to known 3D object points. Simulation results show that this method is reliable, accurate (within 3 cm at contact), and fast (45.5 fps). [ABSTRACT FROM AUTHOR]

In maritime transportation systems, the stability and structural integrity of ship-mounted tanks subjected to sloshing phenomenon are critical due to economic considerations and to ensure ecological safety. During the voyage, the ships are subjected to external excitations, which induce sloshing in fluid in partially filled tanks mounted on the ship's deck. This article investigates the effect of rotational axis configurations on the slosh dynamics of a 24,000 TEU water tank mounted on an Ever-Ace container ship. Sloshing phenomena caused by different combinations of piecewise sinusoidal rotational excitations have been compared. The fluid domain was simulated using ANSYS Fluent, coupled with transient structural analysis in ANSYS Mechanical, to analyze the structural integrity of the container. The fluid pressure loads were imported on the tank structure using a one-way FSI approach. The numerical results have been validated with the experimental data available in the literature. It has been found that the effects of viscous sub-layer are insignificant on the slosh dynamics of the tank. Moreover, the transient response of the air–water interface, impact pressure, and wall moment have been presented. Wave fluctuation is observed to be small when the axis of rotation is perpendicular to the free surface. Maximum impact pressure of 7 kPa has been observed for combination of roll and pitch motions. The range of amplitude of moment is maximum for combination of roll and pitch motions that varies from − 95.6 to 92.3 kN m. Furthermore, the frequency of the moment differed from the excitation frequency depending on the configuration of the rotational axis. [ABSTRACT FROM AUTHOR]

Considering the unobserved spatial heterogeneity, this study aims to build a Bayesian spatial multinomial logistic (BSMNL) model by utilizing the geographic information from historical maritime accidents. The proposed BSMNL model can be applied to investigate the determinants of human errors involved in maritime accidents. Compared to the traditional multinomial logistic (MNL) model, the proposed BSMNL model produces a more accurate estimate of the effects of environmental and accident factors on the occurrence likelihood of human errors in maritime accidents. Results show that accidents involving cargo and container ships; tankers carrying liquefied natural gas (LNG), liquefied petroleum gas (LPG), or oil; and fishing vessels are more likely to be associated with human errors. Further, one important finding is that the involvement of fishing vessels significantly increases the occurrence probability of both negligence errors and judgment or operational errors. In addition, the occurrence likelihood of human errors is generally higher in springtime, conditions of poor visibility, the absence of strong winds or waves, and the moored or docked status. [ABSTRACT FROM AUTHOR]

The interest in flying wings dates as far as the early years of the aviation age. Early investigations of the feasibility of the concept demonstrated increased aerodynamic efficiency and reduced fuel consumption. However, structural, engine integration, and stability and control issues prevented further development. In the 1990s, a new concept, the blended wing body (BWB), was created to alleviate some of the concerns of flying wings while maintaining increased efficiency and adding further benefits, such as reduced pollutant and noise emissions. Despite the promise, technical hurdles once again proved to be a deal breaker and, as of 2024, the only successful flying wing is the B-2 Spirit, an extremely complex and expensive aircraft. Nowadays, with the world quickly transitioning towards cleaner energy, the interest in the BWB has been renewed. The latest technological advancements in the aerospace industry should make its development more plausible; however, passenger comfort issues remain. Surprisingly, the BWB development may come from an unexpected application, as a tanker aircraft. As the U.S. Air Force is seeking a replacement to hundreds of aging tankers, a startup company was recently funded to develop the concept and build a prototype. In this study, we explore the history of blended designs from its early days, highlighting its opportunities and challenges—and why the design is an intriguing fit for application as a tanker aircraft. [ABSTRACT FROM AUTHOR]