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Improvements experienced by incumbent "old" technologies when threatened by new ones, potentially supplanting them, are often addressed as the "sailing-ship effect." The latter phrase points to the eponymous case that consists of the 60-year or so technological battle between sail and steam in ships' propulsion during the 19th century, which led to unexpected large advancements in sail technology. Paradoxically, until today, the only work which addressed quantitatively that technological battle actually found a lack of evidence of the occurrence of the sailing-ship effect. In this paper, through fresh statistical analysis, we find instead confirmation of the existence of the effect in the original case. This finding contributes to the theoretical debate that explains technological persistence through mechanisms such as path dependence, cumulativeness, localized technical progress, competence and cognitive traps, the presence of complementary assets and tributary innovations, as well as institutional features. Policy dimensions are considered in Section 7 of the work. [ABSTRACT FROM AUTHOR]

Voyage charterparty arrangement (VCA) for river shipping is a common agreement between a shipowner and a charterer regarding the transportation of specific cargoes from one port to another via a tramp vessel. Optimizing VCA with the essential terms such as laytime and sailing speed of the vessel, is a crucial task for both parties to reduce potential disputes and achieve win-win outcomes. This paper models the problem from two perspectives: the VCA negotiation stage and execution stage. Firstly, according to the given probability distribution of port time, the theoretically optimal laytime is obtained by using textbook formulation of newsvendor problems (NVP). On this basis, considering the concerns about the inaccuracy of the given probability distribution and the adjustment measures taken by charterers and shipowners in reality, an integrated adjustment model is constructed to determine the optimal laytime in the VCA negotiation stage. Secondly, taking into account the vessel's uncertain lock crossing time, an operations coordination model with information sharing of the berth plan is established to obtain the optimal sailing speed under a certain confidence level in the VCA execution stage. Finally, a case study of chartering tramp vessels on the Yangtze River validates the applicability and effectiveness of the models proposed in this paper, and some important management insights are derived. The results show that establishing lower optimal speed limits and relatively shorter laytime when signing a contract with the shipowner of green river vessels is reasonable for the charterer. By notifying the shipowner of the berth plan after the green river vessel crosses through the lock, the charterer can avoid higher demurrage costs due to speeding-up. Operations coordination would be mutually beneficial without abusing the contract terms. Compared to traditional river vessels, it's more reasonable to reduce the benefits allocated to charterers from the deceleration of green river vessels by shipowners. • Optimizing voyage charterparty arrangement (VCA) for river tramp shipping. • Combining with judgmental adjustments in the optimal laytime model. • Establishing an operations coordination model by considering streamflow and uncertain lock crossing time. • Providing differentiated VCA strategies for green and traditional river vessels. [ABSTRACT FROM AUTHOR]

Large container ships are the main means of maritime trade transportation, and transportation safety and efficiency directly affect global economic development. The complex maritime navigation conditions make it difficult to ensure the safety and efficiency of large container ships. In order to improve the safety and transportation efficiency of large container ships sailing at sea, a Maneuvering Motion Generator (MMG) is proposed. Based on the existing four degree of freedom model, a six degree of freedom ship maneuvering motion model is constructed to simulate and analyze the sea maneuvering of large container ships. The results showed that the constructed model accurately simulated the changes in pitch angle and roll angle during ship navigation, and the error between roll angle and pitch angle did not exceed 0.2°. When the relative wind direction was 120°, and the wind speed was 13m/s, wind interference had the greatest impact on ship navigation. At this time, the lateral deviation was more than 120m, and the heading deviation angle was more than 4°. When the wind speed was 16m/s, the influence of wind interference on the ship's heading was significantly reduced after the ship's steering, and the deviation angle reduced from 0.3° to almost no effect. The designed simulation model for large ship maneuvering compensates for the lack of upper and lower wave states in ship maneuvering simulation, accurately simulating the sea motion state of large ships. This result helps operators make optimal decisions in strong winds and other disruptive environments, improving the safety and efficiency of large ships navigating at sea. [ABSTRACT FROM AUTHOR]

Transport of cargo by short-sea shipping is at the forefront of the European Union's transportation policy. It has the promise to alleviate congested land transport and decrease pollution [European Commission. 2021. Putting European transport on track for the future]. However, the shortage of qualified personnel might impede this solution. Autonomous sailing of ships could help, especially if the whole trip is automated. In this study a control system is designed that is capable of sailing a round-trip with a model-scale feeder vessel in Marin's Seakeeping and Manoeuvring Basin. The Guidance-Navigation-Control framework is used to sail this journey with attention given to smooth switching between the operational modes. A set of experiments is conducted to validate the controller and identify crucial parts in the operation. The experiments showed that the controlled vessel can sail a round-trip with different levels of waves and wind disturbances coming from different directions. Furthermore, the round-trip can be modified such that the approach angle to the quay changes and the ship still successfully docks at the quay. It was found that the approach to the quay is most difficult during transition from high to low speed, when the bow thrusters have yet to become effective, and a large change in course is needed. This can be circumvented by changing the trajectory to the quay to have a longer straight approach, or it can be corrected when the bow thrusters become active. [ABSTRACT FROM AUTHOR]

As basic structural components of the ship hull, stiffened plates suffer both thrust and shear loads while ships sail in rough sea environments. In order to guide the scaled model design effectively, the similarity law is investigated in this paper. The parameters that determine the nonlinear behaviour of the stiffened plate under compression and shear loading are defined and the nonlinear similarity method is improved. This method is applied to design a scaled model under combined bending and torsional moment, and the collapse test is conducted to research the collapse characteristics. The collapse behaviour of actual ship structures under combined loads predicted by the model test is compared with that obtained by the nonlinear finite element analysis. The good agreement represents the capability of the newly improved nonlinear similarity law. The present research provides a proper way to investigate the collapse characteristics of actual ship structures through a model test. [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 Yangtze River's substantial variation in water depth and current speeds means that inland ships face diverse operational conditions within a single voyage. This paper discusses the adoption of controllable-pitch propellers, which adjust their pitch to adapt to varying navigational environments, thereby optimizing energy efficiency. We developed an optimization framework to determine the ideal pitch angle and rotation speed (RPM) under different sailing conditions. The energy performance model for inland ships was enhanced to account for the open-water efficiency of CPPs across various pitch angles and RPMs, considering the impacts of current and shallow water, among other factors. The optimization approach was refined by incorporating an improved genetic algorithm with an annealing algorithm to enhance the initial population, applying the K-means clustering algorithm for population segmentation, and using multi-parent crossover from diverse clusters. The efficacy of the optimization method for CPP operations was validated by analyzing three operational scenarios of a Yangtze sailing ship. Additionally, key components of the ship performance model were calibrated through experimental tests, demonstrating an anticipated fuel consumption reduction of approximately 5% compared to conventional fixed-pitch propellers. [ABSTRACT FROM AUTHOR]

This study aims to address the problem in tracking technology in which targeted cruising ships or submarines sailing near the water surface are tracked at low frame rates or with some frames missing in the video image, so that the tracked targets have a large gap between frames, leading to a decrease in tracking accuracy and inefficiency. Thus, in this study, we proposed a water surface dynamic multi-target tracking algorithm based on the fusion of YOLOv7 and DeepSORT. The algorithm first introduces the super-resolution reconstruction network. The network can eliminate the interference of clouds and waves in images to improve the quality of tracking target images and clarify the target characteristics in the image. Then, the shuffle attention module is introduced into YOLOv7 to enhance the feature extraction ability of the target features in the recognition network. Finally, Euclidean distance matching is introduced into the cascade matching of the DeepSORT algorithm to replace the distance matching of IOU to improve the target tracking accuracy. Simulation results showed that the algorithm proposed in this study has a good tracking effect, with an improvement of 9.4% in the improved YOLOv7 model relative to the mAP50-95 value and an improvement of 13.1% in the tracking accuracy in the DeepSORT tracking network compared with the SORT tracking accuracy. [ABSTRACT FROM AUTHOR]

In this paper, the numerical approach for the structural assessment of tall ship rigs is presented. It allows investigating complex sailing vessel structural rig layouts, composed of different types of masts (armed with both square and Lateen sails), yards, stays and spreaders. For these types of vessels, Classification Societies do not provide any direct calculation approaches, but only a mere comparison between cross sections and thicknesses with reference values as a function of the mast length. The provided approach can overcome this lack and it is based on considerations and calculations of real aerodynamic forces and the experimental evaluation of the pretension load of stays and shrouds. The herein proposed approach is very practical and can be adopted as a reference for this type of vessel, also with different mast configurations. [ABSTRACT FROM AUTHOR]

Polar transport ships frequently traverse in the brash ice channel opened by icebreakers. Although the substantial ice resistance caused by direct collisions with the level ice is avoided, the hull still encounters collisions with the brash ice, leading to periodic damage and exacerbating the fatigue issues of the hull structure. To address the fatigue challenges faced by ships sailing in the brash ice channels, this paper proposes an ice-induced fatigue damage assessment method based on the CFD-DEM-FEM. Referring to the brash ice model test conducted at the Hamburg Ship Model Basin (HSVA), a discrete element ice model and a numerical brash ice tank are established using the CFD-DEM coupling method. The simulated ship-ice interaction is compared with HSVA's experimental results to validate the reliability of the numerical brash ice tank and ice load. The ice load time history resulting from the ship-brash ice collision is applied to the hull, and the hot spot stress time history under each fatigue subcondition is calculated using the FEM. The improved rain-flow counting method is employed to determine the stress level of the hot spot stress time history, and the S-N curve method based on the linear cumulative damage criterion is used to calculate the total fatigue damage of hot spots. Finally, the results of the proposed method are compared with those of the LR method. This study can serve as a valuable reference for the ice-induced fatigue assessment of ships navigating in brash ice channels. [ABSTRACT FROM AUTHOR]

Inland waterway transport is considered a critical component of sustainable maritime transportation and is subject to strict legal regulations on fuel quality. However, crew members often prefer cheaper, inferior fuels for economic reasons, making government inspections crucial. To address this issue, we formulate the ship selection and inspection scheduling problem into an integer programming model under a multi-inspector and multi-location scenario, alongside a more compact symmetry-eliminated model. The two models are developed based on ship itinerary information and inspection resources, aiming to maximize the total weight of the inspected ships. Driven by the unique property of the problem, a customized heuristic algorithm is also designed to solve the problem. Numerical experiments are conducted using the ships sailing on the Yangtze River as a case study. The results show that, from the perspective of the computation time, the compact model is 102.07 times faster than the original model. Compared with the optimal objectives value, the gap of the solution provided by our heuristic algorithm is 0.37% on average. Meanwhile, our algorithm is 877.19 times faster than the original model, demonstrating the outstanding performance of the proposed algorithm in solving efficiency. [ABSTRACT FROM AUTHOR]

Evidence from more than 40 000 voyages shows that labour productivity growth for sailing ships in the London coal trade was rapid but quite irregular between 1700 and 1860. These granular data permit us to examine various dimensions of change, showing that ships made more voyages per year, had smaller crews, carried more coal per ship ton and had longer working lives. Some changes resulted from what happened on land rather than on the sea, notably a marked reduction in the seasonality of trade as wagonways were built in the northeast in the early eighteenth century and a pronounced dip in voyages per year due to congestion in the port of London during the 1830s and 1840s, partly caused by the operation of the coal cartel. These results for the coal trade suggest that shipping, being neither spectacularly modern nor doggedly traditional, made a respectable contribution to British economic growth. [ABSTRACT FROM AUTHOR]

At the end of the 19th century, a new framework of references was proposed that introduced substantial variations for Spain in the Moroccan question, in such a way that what was now at stake was an imminent threat to national security Both liberals and conservatives understood that the Rif was a region of vital geostrategic interest in the defense of the Peninsula. And the control of the Rif began to be questioned to the Majzén by the French imperialist interference. The events had a fortuitous origin, and were originated by the smuggling practiced by some members of the Kabyle of Bocoya. Swindled by the Europeans with whom they trafficked, they assaulted some ships sailing near the Moroccan coast and took their crews hostage. This is what has been wrongly called the conversion of the Bocoyas into pirates. French diplomacy then forged large-scale intervention projects, and moved a diplomat to the territory, the Algerian Si Al.lal, who tried to convert the Central Rif into a republican protectorate. In this work, using diplomatic documentation preserved in Alcalá de Henares, we analyze how the Hispanic government response resolved this problem with notable success. [ABSTRACT FROM AUTHOR]

As of 19th century, foreign trade developed rapidly in the Ottoman Empire. The developments that started in Europe affected the whole world in a short time. Transitioning from sailing ships to steam ships brought about significant changes, particularly in the maritime industry and economically. The rapid proliferation of steam ships in the Ottoman Empire caused a change in Ottoman maritime trade. Şirket-i Hayriye caused important developments in the economic and social fields in the Ottoman Empire. It was established in 1850 as the first joint stock company in the Ottoman Empire. Since Şirket-i Hayriye was established on the Bosphorus, it played an important role in passenger and freight transportation and led to the developments in the maritime transportation in the country. In this study, we aimed to illustrate the needs addressed by the company and the key tasks it undertook upon its establishment. The changes in the company's income and expenses between 1857 and 1909 will be analyzed in relation to the economic and political conditions of the country. How the company increased its revenues by increasing its fleet of ships over time will be analyzed. [ABSTRACT FROM AUTHOR]

Autonomous sailing is seen as one of the possible solutions to cope with the decrease in qualified personnel and to minimise the risk to humans and ships in challenging conditions. Autonomy is not limited to sailing a vessel safely through the seas, but it also includes docking the vessel. A feeder vessel distributes cargo and spends a relative large percentage of its time on (un)docking. Automating this part of the operation is expected to help save on resources. The objective of this work is to automatically approach a dock with an underactuated vessel. It comprises of both the design of a time-dependent trajectory, and a controller that can track this trajectory. The solution is tailored for our 71 m long feeder vessel designed for the eu-h2020 Moses project. The focus is on approaching the dock from cruising speed until the speed of the vessel is near-zero. The result of the study is a high-fidelity time simulation that shows the behaviour of the vessel in combination with the control system when it approaches a dock. The simulations show that the ship can approach the dock with coupled azimuthing thrusters to a speed when the bow thrusters become effective. The vessel then becomes fully actuated and can safely dock with its dynamical positioning system. [ABSTRACT FROM AUTHOR]

When a ship sails in shallow water, it will show different hydrodynamic performance from that in deep water due to the limitations of water depth. The shallow water effect may lead to hull sinkage and trim, increasing the risk of bottoming or collision. In this study, a new design scheme of a shallow-water seismic survey vessel is proposed to solve the problems of traditional seismic survey vessels in shallow-water marine resources exploration and safety. The RANS (the Reynolds-Averaged Navier–Stokes) method combined with the Overset Mesh and DFBI (Dynamic Fluid Body Interaction) method is used for numerical simulation to analyze the influence of ship type, water depth, and speed on ship sinkage and trim, as well as the influence of the shallow-water ship's attitude on resistance. The results show that with the decrease in water depth and the increase in speed, the pressure distribution around the hull becomes uneven, which leads to the aggravation of the sinkage and trim of the hull. In response to this problem, the shallow-water seismic survey vessel significantly improved the sinkage and trim of the hull in shallow water to ensure its safe navigation. The research also shows that navigation resistance can be effectively reduced by appropriately adjusting the ship's attitude. Therefore, this study provides a reference for the development of shallow-water ships in the future. [ABSTRACT FROM AUTHOR]

Managing Shipping Emission Control Areas The design of emission control areas (ECAs) is crucial for reducing global shipping emissions and protecting the environment. In "Shipping Emission Control Area Optimization Considering Carbon Emission Reduction," Zhuge, Wang, and Zhen focus on the ECA optimization problem for sailing legs with ECAs. First, a case with a no-ECA policy and a case with the current ECA policy are discussed. Then, two new voyage-dependent ECA policies with sulfur limits, designated sailing paths, and speed limits are proposed, under which Stackelberg game models with the ECA regulator and a shipping company are developed. The authors extend the research problem from a sailing leg to a shipping network to improve the practicality of the findings. They also develop a dynamic programming-based algorithm to optimize the ECA policies for the shipping network from the perspective of the ECA regulator. The effectiveness of the proposed policies in reducing social costs is validated by numerical experiments. Sulfur emission control areas (ECAs) are crucial for reducing global shipping emissions and protecting the environment. The main plank of an ECA policy is usually a fuel sulfur limit. However, the approaches to setting sulfur limits are relatively subjective and lack scientific support. This paper investigates the design of ECA policies, especially sulfur limits, for sailing legs with ECAs. The objective is to minimize the social costs of shipping operations, local sulfur oxides (SOx) emissions, and global carbon dioxide (CO2) emissions. First, a case with a no-ECA policy and a case with the current ECA policy are analyzed. Then, two new voyage-dependent ECA policies with sulfur limits, designated sailing paths, and speed limits are proposed. Stackelberg game models are developed to solve the research problem with the two proposed policies and two players: the ECA regulator and a shipping company aiming to minimize social costs and company costs, respectively. The ECA regulator determines the sulfur limit, sailing path, and speed limit, and the shipping company optimizes the sailing speed accordingly. We also compare and analyze each type of cost under different ECA policies (i.e., no ECA, the current ECA policy, and the proposed ECA policies). The research problem is then extended from a sailing leg to a shipping network to improve the practicality of the findings. A dynamic programming-based algorithm is developed to optimize the ECA policies for the shipping network from the perspective of the ECA regulator. Mathematical derivation shows that the proposed ECA policies can reduce the social costs of shipping. The results of extensive numerical experiments further demonstrate the ability of the proposed policies to reduce social costs, providing important insights for voyage-dependent ECA policy design. Funding: This work was supported by the National Natural Science Foundation of China [Grants 72025103, 72201163, 71831008, 72071173, 72371221, 72394360, 72394362, and 72361137001]. Supplemental Material: The e-companion is available at https://doi.org/10.1287/opre.2022.0361. [ABSTRACT FROM AUTHOR]

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This paper argues that the Nordic boatbuilding tradition and the use of sail in Scandinavia can be traced back to the Early Bronze Age when it developed in response to emerging chiefdoms and an associated need for long-distance trade in bronze metals. The southern Scandinavian boat imagery dated to the Bronze Age (BA) depicts different types of boats and means of propulsion, including large vessels and the use of sail. This paper focuses on crew-lines on such imagery as indicative of boat length in relation to both the 350 BC Hjortspring boat, a BA type boat and the width-to-length ratio of BA ship-settings. This comparison suggests the BA boat imagery and ship-settings depict the same type of plank-built vessels and that the BA ship-settings are likely to represent 'real' vessels. Centrally positioned post holes in four of these ship-settings are therefore likely to represent masts, providing a direct link with mast-like features also present in the rock art boat imagery. Available BA boatbuilding technologies, based on analysis of the Hjortspring boat, and other indirect evidence of BA boatbuilding technologies, suggests that large, sailed vessels most likely existed, propelled in combination with mainly paddling. [ABSTRACT FROM AUTHOR]

Stern flaps and interceptors are prevalent stern appendages on medium- to high-speed ships, designed to modify the sailing posture of ships and diminish resistance. Using the Reynolds-averaged Navier–Stokes (RANS) method combined with overset mesh technology, this study evaluates the performance of a ship in regular waves before and after interceptor and stern flap installation. The findings indicate that the interceptor and stern flap resistance reduction rates initially declined and then rose with wavelength, typically 1–3% higher than in calm water. For a constant wavelength of 1.5 LPP and when wave steepness ak ≥ 0.05, the interceptor and stern flap resistance reduction rates in regular waves decline as wave steepness increases. The stern appendages have a more prominent impact on ship posture owing to heightened ship motion amplitude in wave conditions compared to calm water. Moreover, after fitting the interceptor and stern flap, the heave and pitch transfer functions of the ship lessen after fitting the interceptor and stern flap, particularly when λ/LPP = 1–2; average reduction rates for TF3 and TF5 are 7.2% and 3.9%, respectively, with a stern flap, and 4.4% and 2.1% after fitting the interceptor. This study offers invaluable insights and practical guidance for designing and applying stern appendages. [ABSTRACT FROM AUTHOR]

Introduction: This study focused on a Chinese Antarctic krill vessel utilising continuous pumping fishing technology. The resistance characteristics of Antarctic krill ships trawling in floating ice areas is of great significance for the navigation and fishing of krill ships in ice areas. Methods: Firstly, MATLAB programming using discrete elements combined with genetic algorithms was used to construct a normal distribution ice flow model. Secondly, a fluid-structure coupling interface is created through the contact between the fluid and the trawl grid, and the displacement and resistance of the trawl grid are evaluated on the shared interface. Finally, the effects of ice density and ship sailing speed on ice resistance were studied. Results and discussion: The results of the calculations results show that ice resistance is positively related to the concentration and speed of floating ice, moreover, there is a special speed point where ice resistance increases rapidly. As the speed increases, the proportion of trawl resistance to the total resistance continues to increase, while the proportion of ice resistance continues to decrease. This paper provides a reference for the navigation and fishing resistance assessment of Antarctic krill ships in floating ice areas. [ABSTRACT FROM AUTHOR]

A first-person account of a missionary's return transatlantic voyage linking the Scottish Highlands and Upper Canada in the 1850s offers a valuable insight into church operations and migrant networks as well as the realities of travel at a time of profound societal change. By considering the journal in its local contemporary situations, and by drawing on modern scholarship, this article considers the motivations for keeping the journal, push and pull factors related to religious and socioeconomic influences and observes that previous scholars have been correct in identifying an ongoing trend of episodic or temporary emigration for Highlanders and Scots in the mid-nineteenth century. [ABSTRACT FROM AUTHOR]

For more than a century and a half, apprenticeship was of fundamental importance to the recruitment and training of British seafarers. From the introduction of compulsory apprenticeship in 1703, through the removal of compulsion in 1850 and up to the outbreak of the First World War, tens of thousands of boys and young men served apprenticeships on British ships, making up a substantial proportion of the maritime labour force. Apprenticeship in the merchant shipping industry has received little attention and the whole question of maritime training remains under-researched. This article opens by revisiting the debates of the 1840s over the Navigation Laws and argues that shipowners' attitudes to apprenticeship were ambivalent. It provides a survey of the decline and evolution of apprenticeship in the six decades following the repeal of the Navigation Laws, highlighting the unevenness of its decline and the existence of countervailing factors in some sectors. Finally, it examines the widespread concerns over the quality and skill of British seafarers and the impact of apprenticeship on recruitment to the Royal Navy. [ABSTRACT FROM AUTHOR]

This paper presents research results on CO2 emissions originating from maritime vessels with various main engine settings. The impact (i.e., the volume and amount) of gas emissions into the environment is shown, along with the characteristics of the marine fuel used. This research was carried out on a container vessel sailing on a fixed route between Rotterdam and St. Petersburg. It covered mainly two different engine operations, at 124 RPM and 100 RPM settings, in the Kiel Canal area. The purpose of this study is to demonstrate that the engine setting of 100 RPM compared to the same voyage through the Kiel Canal, with an engine setting of 124 RPM, leads to a significant reduction of CO2 emissions. Though proving such a thesis seems to be evident, the analysis in the paper shows that, in practice, mainly due to time constraints and engineers' assumptions of engine technical status, the higher speeds are still preferred over lower ones. In studies not related to passive use or active methods, only specific and simplest methods of obtaining CO2 emissions are presented. [ABSTRACT FROM AUTHOR]

This paper delves into the multi-port berth allocation problem (MBAP), enriching the traditional berth allocation problem (BAP) with vessel speed optimization (VSO). In the MBAP, it is assumed that there is cooperation between the port and the shipping companies, and the operation of the vessels and the ports is planned to maximize the overall benefits. Exploring this potential collaboration between ports and shipping entities has the potential to mitigate, or even resolve, the challenges plaguing maritime transportation, e.g., port congestion and suboptimal vessel schedules, to ultimately enhance the efficiency of maritime trade. In this paper, a new mixed-integer linear programming (MILP) model for the MBAP is formulated, which attempts to minimize the total cost incurred during operations, with various constraints such as vessel sailing, the vessel space–time relationship in ports, and the planning period. Meanwhile, an innovative variable neighborhood search (VNS) algorithm is presented, in which the initial solution generation method and neighborhood structures are proposed according to the MBAP characteristics. Furthermore, two sets of MBAP instances are generated to test the proposed MILP and VNS, of which the first set is based on real-world port data and the second on existing studies. The numerical experiments verify that the VNS can efficiently and reliably solve instances of all scales, with each neighborhood structure contributing uniquely to the iterative process. In addition, by analyzing the impact of varying oil prices on the MBAP, the study offers valuable management insights. Finally, a case study based on real data from a port group in the Yangtze River Basin is presented to further demonstrate the necessity of considering vessel service time window and planning period in the MBAP as well as the important role of the VSO in scheduling. [ABSTRACT FROM AUTHOR]

Underwater noise pollution is a significant environmental issue that can have detrimental effects on marine ecosystems. One of the main sources of underwater noise pollution is ship traffic, which has been shown to negatively impact marine animals by masking communication signals and altering their behaviors. This study represents the first comprehensive analysis of underwater ship noise in the Red Sea, wherein noise maps of ships sailing through the main shipping lane in the Red Sea were simulated by integrating both anthropogenic and environmental variables. These maps offer valuable insights for policymakers, enabling them to make informed decisions and implement targeted mitigation efforts. [ABSTRACT FROM AUTHOR]

This paper explores volunteers' sense of (dis)connection and belonging at a major peripatetic sport event. Utilizing qualitative in-depth interviews with 31 volunteers at the Tall Ships race held in Sunderland in 2018, we sought to understand their lived experiences of this event 18 months after it was held. We argue that the Turnerian concepts of liminality and communitas, can be used to comprehend these lived experiences but require more critical problematization in their application. Our contention is that volunteers demonstrate intricate (dis)connections with a range of people, with place, and with the event itself and thus communitas should be conceptualized as more complex and paradoxical when applied within the context of liminal event spaces. We further suggest that volunteers' sense of belonging to place influences how they experience liminal event spaces at least in the medium term. Space and place are therefore intimately connected in the lived experiences of volunteers. [ABSTRACT FROM AUTHOR]

Trim optimization is an available approach for the energy saving and emission reduction of a ship. As a ship sails on the water, the draft and trim undergo constant changes due to the consumption of fuel oil and other consumables. As a result, the selection of the initial trim is important if ballasting or shifting liquid among the tanks is not considered during a voyage. According to the characteristics of ship navigation and maneuvering, a practical trim optimization method is proposed to identify the Optimal Trim over a Whole Voyage (OTWV) which makes the fuel consumption of the voyage minimum. The calculations of speed vs. draft and trim surfaces are created according to hull resistance data generated by CFD, model tests, or real ship measurements, and these surfaces are used to calculate the OTWV. Ultimately, a trim and Main Engine (ME) power joint optimization method is developed based on the OTWV to make the total fuel consumption minimum for a voyage with a fixed length and travel time. A 307000 DWT VLCC is taken as an example to validate the practicality and effect of the two proposed optimization methods. The trim optimization example indicates that the OTWV could save up to 1.2% of the total fuel consumption compared to the Optimal Trim at Initial Draft (OTID). The trim and ME power joint optimization results show that the proposed method could steadily find the optimal trim and ME power combination, and the OTWV could save up to 1.0% fuel consumption compared to the OTID in this case. [ABSTRACT FROM AUTHOR]

The strengthening of regulations such as EEXI, EEDI, and CII on ship emissions is underway. Despite their application, objective comparisons of ships are hindered by diverse navigation patterns and varying velocity regulations in different seas and ports. Additionally, a lack of basic data impedes comparisons of the optimal design and objective energy efficiency for ships. To address these issues, representative sailing modes, similar to those in the automobile industry, are needed. However, there is no reference for marine applications. This study introduces a methodology for representative sailing modes using the Markov chain. A hundred candidate sailing modes were created, and representative modes were identified through an evaluation equation. All chi-square values for representative sailing modes are within 1%, indicating significant results. This study's findings can aid in designing optimized systems for new vessels and computing authorized fuel efficiency for vessels with diverse sailing patterns. [ABSTRACT FROM AUTHOR]

This paper develops a methodology to estimate ship emissions using Automatic Identification System data (AIS). The methodology includes methods for AIS message decoding and ship emission estimation based on the ship's technical and operational characteristics. A novel approach for ship type identification based on the visited port terminal is described. The methodology is implemented in a computational tool, SEA (Ship Emission Assessment). First, the accuracy of the method for ship type identification is assessed and then the methodology is validated by comparing its predictions with those of two other methodologies. The tool is applied to three case studies using AIS data of maritime traffic along the Portuguese coast and in the port of Lisbon for one month. The first case study compares the estimated emissions of a ferry and a cruise ship, with the ferry emitting much less than the cruise ship. The second case study estimates the geographical distribution of emissions in the port of Lisbon, with terminals corresponding to areas with a heavier concentration of exhaust emissions. The third case study focuses on the emissions from a container ship sailing along the continental coast of Portugal, differing considerably from port traffic since it operates exclusively in cruising mode. [ABSTRACT FROM AUTHOR]

In the present study, the added resistance, heave, and pitch of the KRISO Container Ship (KCS) in waves, at both model scale and full scale, are predicted numerically in regular head waves, for four wavelengths and three wave heights. The ISIS-CFD viscous flow solver, implemented in the Fidelity Fine Marine software provided by CADENCE, was employed for the numerical simulations. The spatial discretization was based on the finite volume method using an unstructured grid. The unsteady Reynolds-averaged Navier–Stokes (RANS) equations were solved numerically, with the turbulence modeled by shear stress transport (k-ω) (SST). The free-surface capturing was based on the volume-of-fluid method. The computed solutions were validated through comparisons with towing test data available in the public domain. To predict the uncertainties in the numerical solution, a systematic grid convergence study based on the Richardson extrapolation method was performed for a single wave case on three different grid resolutions. Specific attention was given to the free-surface and wake flow in the propeller plane. The purpose was to compare the numerical results from the model- and full-scale tests to examine the scale's effect on the ship's performance in regular head waves. The comparison between the model scale and full scale showed obvious differences, less accentuated for the free-surface topology and clearly observed in terms of boundary layer formation in the propeller's vicinity. [ABSTRACT FROM AUTHOR]