Ship Types Research Articles

Investigation on the effect of bow configuration on motion and green water for tumblehome vessels based on cartesian grid finite difference method

The special bow design of the tumblehome vessel makes it easy to produce green water, resulting in serious damage to the superstructure. However, the harsh environment numerical studies supported by experimental data on the bow configuration of tumblehome vessels are few. Based on the Cartesian Grid Finite Difference Method (CGFDM), this paper studied the motion response of the ship and the green water characteristics in regular waves under different bow configurations. The Finite Difference Method (FDM) based on a fixed regular staggered Cartesian grid system is used to solve the flow field, and the Tangent of Hyperbola for Interface Capturing with Slope Weighting (THINC/SW) scheme is used to capture the severe free surface flow. At the same time, the immersed boundary method is used to effectively solve the problem of the large motion of the object. The numerical simulation results were compared with the experimental values, showing good consistency. The calculation results show that the bow configuration has little effect on the motion response of the tumblehome vessel in regular waves and only shows some local differences in some wave conditions. Macroscopically, the change of stem angle has little effect on the green water degree of the ship. However, under high wave conditions, the change of stem angle greatly influences the height of green water and the slamming pressure characteristics of the ship. Compared with the bow configuration schemes with stem angles of 30° and 60°, the ship with the stem angle of 45° has a better comprehensive load performance when green water occurs. This study can provide a suitable reference for selecting ship types and structural designs of tumblehome vessels.

Ship Type Recognition using Deep Learning with FFT Spectrums of Audio Signals

Ship type recognition has gained serious interest in applications required in the maritime sector. A large amount of the studies in literature focused on the use of images taken by shore cameras, radar images, and audio features. In the case of image-based recognition, a very large number and variety of ship images must be collected. In the case of audio-based recognition, systems may suffer from the background noise. In this study, we present a method, which uses the frequency domain characteristics with an image-based deep learning network. The method computes the fast Fourier transform of sound records of ships and generates the frequency vs magnitude graphs as images. Next, the images are given into the ResNet50 network for classification. A public dataset with nine different ship types is used to test the performance of the proposed method. According to the results, we obtained a 99% accuracy rate.

A study on treatment efficacy of ballast water treatment system applying filtration + membrane separation + deoxygenation technology during shipboard testing

The efficacy of a BWMS with filtration + membrane separation + deoxygenation technology in treating ballast water was investigated under marine operational circumstances in five shipboard tests. The shipboard tests were carried out between August 2020 and March 2021 onboard a bulk carrier JIN HAI HUA, which sailed between Mawei, Qinhuangdao and Caofeidian in China throughout spring, summer, and fall season. The discharge results in all five tests met the D-2 standard in IMO BWMS Code, with the shortest holding time of less than three days. The BWMS does not involve application of chemicals or generation of by-products, and is considered to be an appropriate choice for certain types of ships.

Identification and analysis of ship carbon emission hotspots based on data field theory: A case study in Wuhan Port

Carbon peaking and carbon neutrality in the shipping industry are hot topics but now facing serious challenges. One of them is the current lack of scientific guidance on ship carbon reduction. Precise identification of carbon emission hotspot areas and ship types in ports is the key to controlling carbon emissions from ships. In this paper, a method of identifying and extracting ship carbon emission hotspots based on data field theory is proposed. Based on the theory of field in physics, the spatiotemporal aggregation pattern of ship carbon emissions in the port region is analyzed with regard to the characteristics of ship emission trajectory data. Taking Wuhan Port as an example, we successfully extracted the ship's carbon emission hotspot area based on the proposed method and analyzed the spatial and temporal dynamics of the ship's carbon emission hotspot in the area from several perspectives. The method proposed in this paper can be further applied to coastal ports, which is conducive to exploring the distribution of carbon emission hotspots and the spatial and temporal variation patterns of ships in China's ports. It provides scientific guidance for relevant departments to formulate and implement policies to reduce carbon emissions from ports, and promotes the early realization of the dual carbon goal of China's shipping industry.

Analysis of factors affecting the severity of marine accidents using a data-driven Bayesian network

A data-driven Bayesian network model (BN) is used to analyse the relationship between the severity of marine accidents and relevant Accident Influential Factors (AIFs). Firstly, based on the marine accident investigation reports involving 1,294 ships from 2000 to 2019, the severity grades of marine accidents are classified, and a database of factors affecting the severity of marine accidents is established. Secondly, a Tree Augmented Naive Bayesian algorithm (TAN) is used to establish a data-driven BN model, and the established database of AIFs is analysed by data training and machine learning to reveal the influence of related factors on the severity of the accident and the mechanism of action. Finally, the sensitivity analysis and verification of the model are conducted. Through the analysis of the Most Probable Explanation (MPE), it explains the possible configurations in different scenarios and identifies the related potential risks. This study finds that “accident type”, “engine power”, “gross tonnage”, “ship type” and “location” are the five most important AIFs of three accident severity grades. “Capsizing/sinking”, “hull/machinery damage” and “collision” that are most likely to lead to “very serious accidents”. Further, the possibility of fishing boats or other small ships leading to “very serious accidents” is also higher than that of other types of ships. The results of this study can help to analyse and predict marine accidents and ensure the safe navigation of ships and hence benefit such maritime stakeholders as safety authorities and ship owners.

VERDA: A Multisampler Tool for Mesopelagic Nets

Different types and systems to discriminate plankton samples at different strata in the water column have been developed in recent decades. For sampling at sufficient depth, opening and closing zooplankton multinets are ideal because there is no contamination of one sample with organisms of the previous one. However, for bigger nets, such as those used to collect micronektonic organism, it is difficult to use multiple net units, and multiple cod ends are preferred because of their simplicity, but with the problem of sample contamination from having a common net passageway. We present here a cod-end Multisampler design, VERDA, that uses a carrousel-like system. Similar to some sediment traps, the system works like a revolver with six or eight compartments whose turning mechanism is triggered when the net arrives to a programmed depth level. This prototype was built with inexpensive and recycled components and electronics similar to Arduino® and Teensy PCB to carry out electronic control. The net we used for testing the equipment was a mid-size midwater trawl of ca. 30 m2 and total length of 58 m that works with a single towing cable and no doors. The overall system is useful for all type of ships, due to the relatively easy deployment operations and because the Multisampler does not need electrical cable or acoustics. In our case, we used a Marport® (Reykjavik Iceland) and Scanmar (Åsgårdstrand, Norway) sensors for real-time depth monitoring and opening distance.

An investigation of the maritime accident in the Aegean Sea Turkish search and rescue region

The Aegean Sea is risky for marine accidents due to its geography and dense vessel traffic. Revealing the patterns of marine accidents in the region is essential for preventing such accidents in the future. With this motivation, this study analyzes the data on maritime accidents in the Aegean Sea Turkish Search and Rescue Region. For this purpose, the descriptive analysis of the 576 marine accidents in the region between 2001 and 2020 was accomplished. Moreover, by applying hypothesis tests, the relationships between the factors that affect the occurrence of marine accidents were investigated. As a result, the most common contributing factors to the event of accidents were revealed. The relationships between the variables of the data set were determined. Accordingly, the type of ship with the most accident are yacht/recreational boat. Hull/machinery failure is the most common type of accident, and summer is the most frequent season for maritime accidents. It was revealed that there are significant relationships between the variables such as the type of accident, the sub-region where the accident occurred, the time of the accident, and the ship type. Finally, deficiencies were evaluated, and suggestions were made for more effective investigation and prevention of accidents.

Roman Thalassocracy during the Gothic Wars in the Mid-Sixth Century: The End of Hegemony?

This article considers the question of whether the Roman state was thalassocratic during the period of the Gothic-Byzantine wars of 535–554. Based on the narrative sources from the fifth and sixth centuries, primarily, the information from the writings of Procopius of Caesarea, the author of the article studies data on the time of appearance, the size of the fleet, the types of ships that the Gothic tribes had in the mid-sixth century, as well as the methods of conducting naval battles the Goths used in the Mediterranean in the face of a lack of relevant experience and skills. The author concludes that even though before the start of the wars, the Goths had warships at their disposal, they were clearly not enough to compete with the Romans, therefore, during the reign of Vitiges, the war was predominantly waged on land. The maritime hegemony of the Romans was undeniable. According to Procopius of Caesarea, the fleet was most actively used in the conflict during the reign of the Gothic ruler Totila. For some time, he managed to compensate for the lack of experience in naval battles with thoughtful tactics. The Goths pursued a policy of establishing control over the most important ports and straits of the Mediterranean. Trying to avoid full-fledged clashes with the Romans, the barbarians successfully blocked the supply of food and additional contingents to Italy. However, the information provided by Procopius should be treated with caution, since his writings are full of elements of anti-Justinian propaganda and attempts to discredit the ruler. In fact, the Goths dominated the seas as much as the Romans allowed them to. In connection with the above, it is impossible to speak of the completion of the Roman thalassocracy in the Mediterranean in the mid-sixth century. The Romans retained control of the maritime and coastal regions of the Mediterranean.

The method of navigation performance optimization analysis for high speed monohull ships

This paper is based on the drag resistance test data of the high-speed monohull model, a mathematical model for comprehensive optimization of the navigation performance of a high-speed monohull taking into account the rapidity, maneuverability, seakeeping and static performance of the ship is constructed. The optimization calculation software based on particle swarm, standard genetic algorithm and growth mechanism genetic algorithm is designed and written. Taking a high-speed monolithic sea-going ship with a displacement of 1500 tons and a large inclination-measuring single propeller as the object of discussion, the comparison of optimization methods, the comprehensive navigation performance of different ship types and the sensitivity analysis of design variables are carried out respectively. It provides a practical approach and an effective and practical scientific method for analysis and evaluation of how to maintain the comprehensive optimal navigation performance of high-speed monohull ships. At the same time, it provides a way to quickly evaluate the comprehensive performance of similar high-speed monolithic ships in the preliminary design stage, and can also obtain the model diagram with the best comprehensive performance through this software or method, which is useful for shortening the preliminary design cycle of the ship and improving the design quality of the ship. It has important reference value.

Shipping Communities in a Mediaeval Thalassopolis (Caffa from the Thirteenth to Fifteenth Century)

This article explores the phenomenon of shipping communities and the development of various forms of micro-spatial group identification among the sailors in the Pre-Modern world. The key research method is the heterotopia. From the late thirteenth century on, the port of Caffa possessed more than 100 large and medium vessels, each forming separate movable space which circulated between Caffa and the ports in the Black, Azov, Marmora, and Mediterranean Seas, and housing 12 to 200 sailors. The initial principle in the universal identity was the type of the ship. Her image was sometimes a marker of micro-group and individual identity. When the ship type was shown, there was need in clarifying descriptors. The most common form of identification covering two thirds of the vessels was attribution by the name of patron or owner who possessed the decisive share of the ship’s property. The patron’s naval jack and coat of arms were the identification markers of himself and the entire ship’s crew. The second of importance identification form that spread on one-third of the ships was vessel’s name by her patron saint. Here the identity marker was the saint’s icon on the ship altar, sometimes its duplicate on a foremast sail, and personal icons of the sailors. Finally, the third form was the naming of ship by moral and ethical values as a kind of motto.

Uporedna analiza pokazatelja transportne efektivnosti rečno-morskih brodova na sektoru donjeg Dunava

An important place in the process of increasing the effectiveness of the transportation of cargo by water transport is occupied by direct river-sea transportation between ports located on inland waterways and sea ports. Such transportation can be realized in two ways: 1) without transshipment of cargo in ports at the mouths of rivers into the sea and, 2) with transhipment of cargo from sea vessels to river vessels and vice versa. Increasing the effectiveness of transportation should be based on the introduction of new resources and energy savings, as well as the introduction of advanced technologies in the field of transportation. In order to consider the possible introduction of direct transport technology on the river-sea route for the needs of the Serbian economy, it is necessary to determine the technical, technological and economic parameters by means of which the justification for the application of such a method of transport is determined. This paper approaches, applying the methods of known indicators of exploitation, the determination of the transport properties of several characteristic types of river-sea ships that carry out transport on the waterways of the Russian Federation and which, at the same time, to a certain extent, participate in the transport of cargo on the Danube.

Krążownik ciężki – problemy klasyfikacyjne. Część 3. Krążowniki ciężkie w służbie Stanów Zjednoczonych, Japonii i Wielkiej Brytanii

This article is the third in a series of six texts devoted to classification problems in the group of artillery ships, such as heavy cruisers. In the first text, we dealt with the genesis of the heavy cruiser and formulated its definition, necessary for making reliable scientific analyses. In the second text, we confronted this definition with ships with a disputed classification. This section presents the heavy cruiser fleets of the three largest owners. The following will discuss the fleets of these types of ships under the other flags and their global characteristics. The three most numerous owners of heavy cruisers: the United States, Japan, and Great Britain, had 70% of their total number. These values clearly reflect for whom they were the most desirable weapons. This is confirmed by the hostilities of 1937-1945, especially the Pacific War. The U.S.A. had the largest fleet of 38 ships, followed by Japan with 18 ships, and the third with Great Britain with 13 ships of this type. As a result of World War II, the Japanese Navy’s heavy cruiser fleet was completely wiped out, the Americans lost 7, the British 4, and they also handed over 1 to Australia. The Anglo-Saxon powers’ remaining heavy cruisers were gradually decommissioned during the Cold War. At the same time, the Royal Navy completed this process by the end of the 1940s, for reasons of economy. U.S. Navy also used them, among others in the Korean Wars 1950-1953 and Vietnam Wars 1964-1973. The last American heavy cruiser, Newport News, was decommissioned in 1975. On the other hand, the last deletion from the records of the U.S. Navy was made in 1991 when it happened to reserve Salem.

ДИНАМІЧНИЙ МЕТОД ІМІТАЦІЙНОГО МОДЕЛЮВАННЯ ВИКОРИСТАННЯ БОЙОВИХ РЕСУРСІВ ДЛЯ ПРОТИДІЇ ВИСАДЦІ МОРСЬКОГО ДЕСАНТУ НА ОСНОВІ МАРКІВСЬКИХ ЛАНЦЮГІВ

A method and a simulation model for calculating the volume of shells and used artillery pieces during the time necessary to stop the landing of amphibious assault forces is proposed. The simulation model contains. The law of distribution of projectiles. Model of hitting a rectangle of a given shape. The model of the probability of projectiles hitting the target is not less than a given number. Model of movement of types of ships without changing the course. The dynamic method for modelling the use of combat resources to counter an amphibious assault is based on discrete Markov chains. The operational-tactical formulation of the problem contains information that allows using the Markov chain. The definition of the considered system is formulated. The possible states of the system are determined. The step of the process and the time points of the steps are found. Possible transitions of the system from state to state in one step are developed. The conditions for the initial state of the system are accepted. In the problem that has been solved, the system is a ship of the same type with its own properties, which has the goal of reaching the coastline. Conditions accepted. A ship that receives a certain number of hits in the future is not considered. Artillery guns with their own properties that fire at enemy ships in order to prevent ships from reaching the coastline have no restrictions on the number of shells. The conditions for using the model and method are determined, the amount of combat resources to stop the landing is obtained. To increase the likelihood of stopping the landing operation, it is assumed. On the one hand, it is necessary to increase the rate of fire of artillery pieces, significantly improve the quality of firing, which will increase the probability of hitting in conditions of a limited number of shells. On the other hand, an increase in the number of artillery pieces allows you to start destroying enemy ships at shorter distances, which will increase the chance of hitting and reduce the amount of shells used.

The Bay of Fraschia. Characteristics and Function in the Maritime and Shipping Activities of Venetian Crete (15th–16th Centuries)

While the role, architecture, and use of the port of Candia on Crete have been extensively studied, little is known about the island’s other ports and bays. This article considers key questions to evaluate the role of Fraschia Bay in Venetian Crete’s port system and, by extension, in Venetian shipping activities in the late fifteenth century and mainly during the sixteenth. What kind of shipping activities were carried out in Fraschia Bay - commercial (legitimate and illegitimate) or/and military? What types of ships docked there? And under what circumstances was the bay used, especially compared to the port of Candia? The analysis, based on unpublished archival documents of the Archivio di Stato di Venezia, aims to determine whether the activities carried out in the bay of Fraschia were part of the integrated port system of Candia, or whether Fraschia Bay served only as an occasional substitute. The analysis concludes that Fraschia served a complex purpose in Candia’s port system and as a substitute port at times when Candia was unsuitable, due to weather conditions or construction operations. Moreover, Fraschia Bay’s role went well beyond official mercantile shipping, since it also supported military activities and the movement of contraband.

Evaluation of maritime industry compliance with existing environmental regulations – A benchmarking assessment from energy efficiency perspective

The present study provides an initial mapping process for the maritime industry from an energy and environmental perspective. The methodology follows a three-step evaluation process for assessing energy efficiency. At first, an initial categorization of all existing ship type and volume categories based the applied taxonomy within maritime transport sector is made. Secondly, two key energy performance indicators (EEXI & CII) are described and estimated for each individual vessel category. Lastly, an assessment between the examined KPIs values is performed in order to depict the compliance level of each vessel category with the existing environmental regulations set by the International Maritime Organization (IMO). The results of this paper aim to highlight the alignment of the existing vessel categories with the established environmental regulations and offer a starting point for decision-makers in maritime industry to adopt green shipping energy transition strategies, such as the usage of energy efficiency measures or green alternative fuels.

PENGARUH BESAR PENGETAHUAN METEOROLOGI MARITIM DALAM KEMENANGAN PERTEMPURAN NORMANDIA 1944

The Battle and Landing of Normandy 1944 was four years in the making. General Dwight D. Eisenhower as the Allied Commander wanted the invasion of Normandy, D-Day to be carried out immediately, but the operation plan almost failed due to bad weather. The Battle of Normandy 1944 began with the German conquest of France and the Allies wanted to free France from German occupation. The writing methodology uses a descriptive method by analyzing the facts that occurred at the Battle of Normandy 1944 supported by literature studies, literature, and scientific journals. Meanwhile, Maritime Meteorological information at the time of the Normandy 1944 landing was obtained from the analysis of weather reports and literature studies. From this incident, it can be concluded that the TNI, especially the Navy, must take maritime weather into account in supporting operations at sea and needs to collaborate with BMKG to obtain Maritime Meteorological information. BMKG provides impact-based maritime weather that issues weather impact map information to sailing ships. The Impact-Based Weather Map provided will provide a color that indicates the risk status of maritime weather based on the type of ship, which can help TNI-AL's equipment in navigation at sea. Maritime Meteorological information and data are obtained using BMKG's ocean prediction model - Ocean Forecasting System (BMKG - OFS) and BMKG's InaWIS (Indonesia Weather Information for Shipping). The InaWIS system is integrated with the Automatic Identification System (AIS) shipping navigation data that will be able to identify ship risks to maritime weather such as wind, currents, and waves. InaWIS is also equipped with real-time weather observation data that is able to model sea predictions for the next 10 (ten) days which makes it easier for TNI AL's equipment to navigate at sea to avoid areas that have the potential for extreme weather and also to support landing operations.

Offshore ship recognition based on center frequency projection of improved EMD and KNN algorithm

Ship-radiated underwater noises are essential in marine target identification. However, it is very difficult to extract valuable target information from ocean ambient noises. Here, a combined classification method is proposed based on the improved empirical mode decomposition to process the underwater signals of offshore ships. The signals are separated into a series of samples with a signal duration of 100 ms and a set of intrinsic mode functions (IMFs) is generated for each sample. The feature extraction of each IMF is realized by defining and calculating its central frequency and energy intensity. Then, the central frequency of each IMF is projected into a three-dimensional space according to the three top-ranked IMFs based on energy intensity, and the K nearest neighbor (KNN) algorithm is employed to identify the different offshore ships. It was observed that the proposed method can efficiently distinguish the three ships when 80 % of the samples are randomly selected as the training set and the remaining 20 % are used as the test set. The overall recognition rate after 1000 random tests was greater than 95 % for the short-time signals of approximately 100 ms and completely unknown types of ships, which indicates that the proposed method is applicable to offshore ship classification and identification.

Watertight Compartment Fujian Ancient Ship Art Value and Extended Development Take the "Hei Bo Wu Qing An" ship type as an example

As the "Cultural Capital of East Asia" and one of the starting points of the Maritime Silk Road, Quanzhou has nurtured a long-standing maritime culture, and the prosperity of maritime trade cannot be achieved without exquisite shipbuilding techniques.In July 2021, "Quanzhou: China's World Maritime Trade Center in the Song and Yuan Dynasties" was successfully declared a World Heritage Site. More and more local intangible cultural heritage in Quanzhou is being paid attention to and protected, and the watertight, compartmentalized Fujian ancient ship is one of them. The Fujian ancient boat is the Quanzhou people's contribution to maritime culture, with deep cultural heritage, a major invention of China's ancient shipbuilding technology, high artistic and aesthetic value, and a unique connotation; we must excavate and protect it as part of our intangible cultural heritage. In order to better understand the connotation of watertight compartment Fujian ancient ships, the author conducted several field studies in Fengwei Town and Quanzhou City, the birthplace of watertight compartment Fujian ancient ships. This paper explores the artistic value of Fujian's ancient boats in Quanzhou, Fujian, and their extended development from the perspective of art design.

Fuel Cell Systems for Maritime: A Review of Research Development, Commercial Products, Applications, and Perspectives

The ambitious targets set by the International Maritime Organization for reducing greenhouse gas emissions from shipping require radical actions by all relevant stakeholders. In this context, the interest in high efficiency and low emissions (even zero in the case of hydrogen) fuel cell technology for maritime applications has been rising during the last decade, pushing the research developed by academia and industries. This paper aims to present a comparative review of the fuel cell systems suitable for the maritime field, focusing on PEMFC and SOFC technologies. This choice is due to the spread of these fuel cell types concerning the other ones in the maritime field. The following issues are analyzed in detail: (i) the main characteristics of fuel cell systems; (ii) the available technology suppliers; (iii) international policies for fuel cells onboard ships; (iv) past and ongoing projects at the international level that aim to assess fuel cell applications in the maritime industry; (v) the possibility to apply fuel cell systems on different ship types. This review aims to be a reference and a guide to state both the limitations and the developing potential of fuel cell systems for different maritime applications.

ФЛОТ У ЛОГІСТИЦІ ДАВНЬОГО ЄГИПТУ ЧАСІВ НОВОГО ЦАРСТА

The article devoted to comprehensive study of the role of the fl eet in the development of the logistics network of Аncient Egypt. The research is based on the principles of historicism, objectivity, systematicity and comprehensiveness, as well as on the use of methods – analysis and synthesis, historical-comparative, historical-typological. It consists in the fact that for the fi rst time in domestic his-toriography an attempt was made to comprehensively analyze the role and place of the fl eet in the development of the logistics of the Egyptian Empire. In the period of the New Kingdom, due to the needs of logistics, old and new types of ships designed for use in the open sea were modernized. New ships could freely transport manpower and necessary cargo. As a result of the conquering cam-paigns of the pharaohs of the 18th ‒ 19th dynasties, a powerful logistics network was established, in which the fl eet played an important role. The ships delivered soldiers with weapons, provisions and forage to any Egyptian base from Semna and Mirgissa in Nubia to Bybles, Ullaza or Simira in Phoenicia in a fairly short time with much less expenditure of productive forces