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Search results for: corvette-type ship
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Numerical assessment of maneuvering properties of ship with a conventional type of propulsion
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Influence of redundancy and ship machinery crew manning on reliability of lubricating oil system for the MC-Type diesel engine
PublicationW referacie przedstawiono wyniki rozważań na temat wpływu zastosowania redundancji i prewencyjnych działań załogi na niezawodność instalacji oleju smarowego dla silników spalinowych, wysokoprężnych typu MC. Uwzględniono przy tym trzy poziomy wyszkolenia załogi: wysoki, przeciętny oraz niski.
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Assessment of safety of ships after the collision and during the ship salvage using the matrix type risk model and uncertainties
PublicationW pracy omówiono metody oceny bezpieczeństwa statków w stanie uszkodzonym w warunkach operacyjnych. Przedstawiono proponowana metodę oceny bezpieczeństwa statku w stanie uszkodzonym opartą na ocenie zachowania się statku i ocenie ryzyka. Opisano całościowy, macierzowy model ryzyka wypadku. Podano informacje na temat zastosowania proponowanej metody do oceny bezpieczeństwa uszkodzonego statku w czasie katastrofy na morzu.
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Magnetic signature reproduction of ferromagnetic ships at arbitrary geographical position, direction and depth using a multi-dipole model
PublicationThe reproduction of magnetic signatures is an important issue concerning the safety of ship traffic, as well as the identification and classification of vessels. Moreover, military applications of magnetic signatures and their reproduction refer to the activation or protection against activation of magnetic naval mines. Previous works on this subject focused on recording and replicating the signatures under the same conditions...
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PODEJŚCIE WARIANTOWE WE WSTĘPNYM PROJEKTOWANIU STATKÓW Variant methods approach to the preliminary ship design.
PublicationKlasyczna metoda projektowania okrętów jest metodą iteracyjną, bazującą na zgromadzonym doświadczeniu ze statków już zbu-dowanych. Natomiast w przypadku statku całkowicie nowego typu, bez „posagu wcześniejszych doświadczeń”, projektowanie polega na opracowaniu szeregu równoległych, wariantowych rozwiązań z wykorzystaniem optymalizacji. Artykuł wskazuje wybrane metody projektowe wykorzystujące optymalizacje, używane we wstępnym...
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Architektura statków pasażerskich XX wieku.
PublicationArchitektura okrętów jako dyscyplina naukowa zajmuje się projektowaniem wnętrz oraz sylwet, jak również systematyką przestrzenną statków. Referat przedstawia rozwój architektury statków pasażerskich, które powstały w XX w. od momentu pojawienia się nowej dyscypliny naukowej – architektury okrętów, której prekursorami byli pracownicy Wydziału Architektury PG, aż do przełomu wieków XX i XXI. Statki pasażerskie ulegały przemianom,...
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Approach Manoeuvre During Emergency Ship-to-Ship Transfer Operation with Oil Spill
PublicationOne of the major activities during Ship to Ship (STS) transfer operation at sea is to safe approach the Ship to be Lightered (SBL) which moves on a constant heading with slow speed or drifting. In the paper described the manoeuvring problem for approaching during emergency STS transfer operation with oil spill. The approach manoeuvre is considered as a sequence of navigation manoeuvres in specific navigational environment with...
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Towards Improving Optimised Ship Weather Routing
PublicationThe aim of the paper is to outline a project focusing on the development of a new type of ship weather routing solution with improved uncertainty handling, through better estimation of ship performance and responses to sea conditions. Ensemble forecasting is considered to take into account the uncertainty levels that are typical of operations in a stochastic environment. Increased accuracy of weather prediction is achieved through...
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A simplified method to assess the impact of ship-to-ship collision on the risk of tanker ship hull girder breaking accounting for the effect of ageing
PublicationOne of the most critical structural failures is the exceedance of the ship hull girder’s ultimate strength, which may result in hull breaking, and subsequent severe consequences, including loss of life and property as well as environmental damage in case of an oil spill. A cause for such loss of structural continuity can be triggered by a collision with another vessel. In addition, the ageing mechanisms of the hull structure could...
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New Concept of Numerical Ship Motion Modelling for Total Ship Operability Analysis by Integrating Ship and Environment Under One Overall System
PublicationThe paper presents a new concept of overall ship motion modelling for application to total ship operability. The delivered model is a multi-phase and includes both submerged part of ship’s hull and the surrounding water as a unique body. The Discrete Finite Element Method is applied. The model is successfully examined and illustrated for a selected AHTS.
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Automation of ship and control
PublicationSummaryThe article presents the problem of automation of ship and control. This paper will discuss the basic tasks of the track ship control, collision avoidance and automatic dynamic positioning. The following subjects will be presented: the general structure of the ship's control, methods and control algorithms for the above mentioned tasks..StreszczenieArtykuł przedstawia zagadnienia automatyzacji i sterowania statkiem. W pracy...
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VARIANT DESIGNING IN the PRELIMINARY SMALL SHIP DESIGN PROCESS
PublicationShip designing is a complex process, as the ship itself is a complex, technical multi-level object which operates in the air/water boundary environment and is exposed to the action of many different external and internal factors resulting from the adopted technical solutions, type of operation, and environmental conditions. A traditional ship design process consists of a series of subsequent multistage iterations, which gradually...
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ANALYSIS OF IMPACT of SHIP model parameters on changes of control quality index in ship dynamic positioning system
PublicationIn this work there is presented an analysis of impact of ship model parameters on changes of control quality index in a ship dynamic positioning system designed with the use of a backstepping adaptive controller. Assessment of the impact of ship model parameters was performed on the basis of Pareto-Lorentz curves and ABC method in order to determine sets of the parameters which have either crucial, moderate or low impact on objective...
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TOTAL SHIP OPERABILITY – REVIEW, CONCEPT AND CRITERIA
PublicationThe ship operability can be understood and analysed in different manners, and its quality is described using different indexes by different authors. Practically, there is no general and widely accepted description of total ship operability in the literature, nor in the rules of classification societies, which would include both seakeeping and manoeuvrability characteristics of a ship, and simultaneously take into account all ship...
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Multisource model of ship electric field
PublicationA steel-hulled ship in sea water produces an electric field around itself. The source of this field are electrochemical processes and ship's cathodic protection. The analysis of the electric field around the ship is important by the reason of the ship's identification and counter-mine protection. The paper presents a simplified model of the ship's multisource electric field, which allows to calculate the electric field distribution...
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Supporting development of the smart ship technology by CFD simulation of ship behavior in close to real operational conditions
PublicationThe shipping industry is at the milestone of technological development – autonomous ships. Involving smart technologies accelerates development of green and safe shipping. Also IMO regulations, especially EEDI en-hanced application of new technologies. Meeting economic and ecological requirements future ships need to be designed with respect to increased reliability and operational performance. Design process of ships may be improved...
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INDICES FOR ASSESSING POTENTIAL ENVIRONMENTAL HAZARD FROM FUTURE SHIP SCRAPPING PROCESS, DETERMINABLE IN SHIP DESIGN STAGE
PublicationThis paper shortly presents the issue of utilization of ships after their withdrawal from service. Information on number of floating units liquidated in previous years was presented. Hazards to the environment , health and life of workers employed in the Far East ship scrapping yards operating on the beaches, were indicated. Then, the most important rules which have to make the ship recycling process safe were referred to. This...
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Identification of hydroacoustic wave sources of ship in motion
PublicationThis paper deals with results of identification tests of acoustic field spectrum of underwater noise generated by ship in motion. The field is connected with acoustic activity of ship mechanisms and devices in operation. Vibration energy generated by the mechanisms and devices is transferred through ship structural elements to surrounding water where it propagates in the form of acoustic waves of a broad band of frequencies. In...
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Review of ship safety domains: Models and applications
PublicationShip safety domain is a term which is widely used in research on collision avoidance and traffic engineering among others. Classic ship domains have been compared in multiple reports. However, up till now there has been no work summing up contemporary research in this field. The paper offers a systematic and critical review of the newer ship domain models and related research. It discusses multiple differences in approach to ship...
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The structure of the control system for a dynamically positioned ship
PublicationThe article discusses functions and tasks of dynamic positioning (DP) systems for ships. The analysed issues include ship steering, in particular stabilisation of ship position and direction of motion (real course) at low manoeuvring speeds, and commonly used DP ship models. Requirements imposed by classification societies on DP ships are quoted. A multi-layer structure of the DP control system is presented, with special attention...
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Parametric method for evaluating optimal ship deadweight
PublicationThe paper presents a method of choosing the optimal value of the cargo ships deadweight. The method may be useful at the stage of establishing the main owners requirements concerning the ship design parameters as well as for choosing a proper ship for a given transportation task. The deadweight is determined on the basis of a selected economic measure of the transport effectiveness of ship – the Required Freight Rate (RFR). The...
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REDUNDANCY AS A WAY INCREASING RELIABILITY OF SHIP POWER PLANTS
PublicationOne of key ways of assuring a high level of reliability of a ship power plant is to design redundancy of its structural elements, for example redundancy of prime drivers, drivelines etc. This paper deals with issues related to the redundancy as a way increasing dependability of the ship power and propulsion systems. Especially, fundamental characteristics of dependability, major design strategies influencing the reliability, and...
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A Simulative Comparison of Ship Domains and Their Polygonal Approximations
PublicationThe paper investigates the impact of a precise ship domain shape on the size of collision avoidance manoeuvres. The considered collision avoidance manoeuvres include both course and speed alterations. Various ship domains are compared with their polygonal approximations, which vary in the number of points of a domain contour and placement of these points. The best of all considered approximations is determined in the course of...
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A Framework of a Ship Domain-based Collision Alert System
PublicationThe paper presents a framework of a planned ship collision alert system. The envisaged system is compliant with IMO Resolution MSC.252 (83) “Adoption of the revised performance standards for Integrated Navigation Systems (INS)”. It is based on a ship domain-oriented approach to collision risk and introduces a policy of alerts on dangerous situations. The alerts will include cautions, warnings and alarms, which will be triggered...
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Hydrodynamic Pressure Field of a Ship on Shallow Water
PublicationResults of calculations of the hydrodynamic pressure field around the ship were obtained by application of the boundary element method. Hydrodynamic field was calculated for a Polish Navy’s tugboat and transport ship using a program called SHiPP and compared with measurements of the field taken on river near Swinoujscie for two identical tugs H-4 and H-10. Next, a series of HPF calculations was carried out on planes situated at...
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Mathematical Models in Design Process of Ship Bow Thrusters
PublicationThe paper describes an application of simulation models for computer-aided design of ship bow thrusters. Generation of simulation models of ship bow thruster requires development and verifying of mathematical models of system component elements. Using the results of simulation the expert system is able to determine, that the rules of classification societies are met. Design procedures and mathematical models are part of an expert...
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Mathematical Models in Design Process of Ship Bow Thrusters
PublicationThe presentation is about an application of simulation models for computer-aided design of ship bow thrusters. Generation of simulation models of ship bow thruster requires development and verifying of mathematical models of system component elements. Using the results of simulation the expert system is able to determine, that the rules of classification societies are met. Design procedures and mathematical models are part of an...
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Methods of determination of C coefficient for period of rolling vessel in calm water for example of pax cargo ship
PublicationThis article presents a different approach to calculate the C coefficient needed to determine the period of own rolling vessel in calm water. The C coefficient is usually adopted as the approximate value from the available literature, usually depending on the type of vessel, and less dependent on the loading condition. In experimental studies of marine properties (seakeeping) often have a problem with the selection of the correct...
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An analysis of domain-based ship collision risk parameters
PublicationAccording to a lot of contemporary research on ship collision avoidance the classic approach parameters – distance at closest point of approach (DCPA) and time to the closest point of approach (TCPA) – are not sufficient for estimating ship collision risk and for planning evasive manoeuvres. Consequently new measures are introduced, often utilizing the concept of a ship domain. Their drawback, up to this point, was the lack of...
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Strength analysis of container ship subjected to torsional loading
PublicationThe objective of this work is to investigate the torsional response of a container ship, with particular consideration of the warping effect. Two different models are investigated. In the first case, the full length model of a ship is analyzed and a distributed load is applied with the use of a novel approach. The model is supported in the torsional centre of the cross-section, which is derived analytically. In the second case,...
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Advanced Ship Control Methods
PublicationThe chapter presents two main streams of research in vessel control at sea: dynamic positioning (DP) of the vessel and decision support in case of collision at sea. The control structure and basic requirements for the DP system are defined. Selected issues of automatic control of a dynamically positioned vessel are discussed. A review of advanced methods of controlling a DP ship is carried out, taking into account the tasks of...
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Dynamically positioned ship steering making use of backstepping method and artificial neural networks
PublicationThe article discusses the issue of designing a dynamic ship positioning system making use of the adaptive vectorial backstepping method and RBF type arti cial neural networks. In the article, the backstepping controller is used to determine control laws and neural network weight adaptation laws. e arti cial neural network is applied at each time instant to approximate nonlinear functions containing parametric uncertainties....
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Hybrid System for Ship-Aided Design Automation
PublicationA hybrid support system for ship design based on the methodology of CBR with some artificial intelligence tools such as expert system Exsys Developer along with fuzzy logic, relational Access database and artificial neural network with backward propagation of errors.
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Predicting Thrust Loss of Ship Propellers Due to Ventilation and Out-of-Water Effect
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USING ARTIFICIAL NEURAL NETWORKS FOR PREDICTING SHIP FUEL CONSUMPTION
PublicationIn marine vessel operations, fuel costs are major operating costs which affect the overall profitability of the maritime transport industry. The effective enhancement of using ship fuel will increase ship operation efficiency. Since ship fuel consumption depends on different factors, such as weather, cruising condition, cargo load, and engine condition, it is difficult to assess the fuel consumption pattern for various types...
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Strategie wzrostowe dla Neptun Ship Service Ltd.
PublicationW ekspertyzie przeprowadzono ewaluację strategii wzrostowych dla firmy Neptun Ship Service Ltd.
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APPLICATION OF REDUNDANCY IN SHIP POWER PLANTS OF OFFSHORE VESSEL
PublicationPower and propulsion systems of offshore units must be of a very high level of reliability. The loss of ability to perform functions of their components causes generally to very high economic losses, which may be increased by unused the weather window resulting to postponing the planned offshore operations. To ensure carrying out so expensive offshore operations in the most reliable way, various types of redundancies are built-in...
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COLREGS compliance in Evolutionary Sets of Cooperating Ship Trajectories
PublicationIn general, Evolutionary Sets of Cooperating Ship Trajectories combine some of the assumptions of game theory with evolutionary programming and aim to find optimal set of cooperating trajectoriesof all ships involved in an encounter situation. In a two-ship encounter situation the method enables the operator of an on-board collision-avoidance system to predict the most probable behaviour of atarget and to plan the own manoeuvres...
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Modelling of some stealth features for a small navy ship at the concept design stage.
PublicationIn this paper the basic research problems associated with modelling the basic stealth features for a small navy ship at the concept design stage are introduced. Amongst the major stealth features considered are: the modification of the immersed ship hull form by a rapid change of the ship loading condition, and modification of the ship boundary layer by the hull skin cover. The other stealth features of the ship are not presented...
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Influence of pitting corrosion on fatigue and corrosion fatigue of ship structures. Part I: pitting corrosion of ship structures.
PublicationThe paper is a literature survey focused on pitting corrosion and its influence on fatigue of ship and offshore steels. Mechanisms of short- and long-term pitting corrosion in marine environment have been described including pit nucleation and growth phases. Some models of pit growth versus time of exposure have been presented. Some factors which influence the pit growth have been discussed briefly.
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In Search of Naval Beauty. Historical Study of Ship Architecture
PublicationDesigning ships is no mean achievement. In the old days, constructors focused on making their ships visually appealing, while paying scant regard to the living conditions of the crew. Such an approach reflected the state of the art in ship building at the time as well as the social order prevalent in those days. A breakthrough came no earlier than at the turn of the 19th / 20th centuries. The industrial revolution brought along...
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Simulation Environment in Python for Ship Encounter Situations
PublicationTo assess the risk of collision in radar navigation distance-based safety measures such as Distance at the Closest Point of Approach and Time to the Closest Point of Approach are most commonly used. Also Bow Crossing Range and Bow Crossing Time measures are good complement to the picture of the meeting situation. When ship safety domain is considered then Degree of Domain Violation and Time to Domain Violation can be applied. This...
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Accident susceptibility index for a passenger ship-a framework and case study
PublicationThe continuous monitoring and assessment of operational vulnerability and accident susceptibility of passenger ships is crucial from the perspective of ship and passenger safety. Despite the existing solutions for vulnerability monitoring, stemming mainly from watertight door operations, a comprehensive framework for accident susceptibility assessment and monitoring is missing in the literature. Therefore, this paper offers a...
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Advances in Modelling and Analysis of Strength of Corroded Ship Structures
PublicationThe present study reviews the recent advances in modelling and analyses the strength of corroded ship structures. Firstly, the time-variant methodologies that consider only the mean structural element thickness loss due to corrosion degradation are identified. Corrosion degradation is regarded as the phenomenon that causes uneven thinning of specimens. This has been captured by various researchers as the loss of mechanical properties...
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Testing the impact of simplifications adopted in models describing wave loads on ship
PublicationThe wave-ship system in naval architecture is generally assumed to be a linear one. This allows for the computation of a transfer function of ship response to waves including wave loads on ship. The transfer function and the wave spectral density function enable the development of the stochastic process of wave loads on ship, corresponding to the irregular wave generating that loads. If the mathematical models of wave load transfer...
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Testing the impact of simplifications adopted in models describing wave loads on ship
PublicationThe wave-ship system in naval architecture is generally assumed to be a linear one. This allows for the computation of a transfer function of ship response to waves including wave loads on ship. The transfer function and the wave spectral density function enable the development of the stochastic process of wave loads on ship, corresponding to the irregular wave generating that loads. If the mathematical models of wave load transfer...
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THREE-LEVEL F-TYPE INVERTER
PublicationGiven the recent available IGBT switch modules up to 6.5 kV, 1200 A rating, the prospect of the diode-free variant topology of the three-level neutral-point-clamped (3-level, T-type) inverter in certain medium voltage applications is bright; due to its small part count and low conduction losses compared to the diode-clamped NPC inverter. However, within this voltage range, the input dc voltage rating of 50% of the switches per...
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On ship roll resonance frequency
PublicationThe paper deals with the problem of modeling of rolling motion under a variety of excitation parameters. Special emphasis is put on the analysis and prediction of the frequency of the resonant mode of rolling, since it is often an essential issue in terms of motion of a ship related to her safety against capsizing or excessive amplitudes of roll. The research is performed for both free rolling and excited rolling and it is based...
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Evolutionary Sets of Safe Ship Trajectories: Evaluation of Individuals
PublicationThe paper presents a description of the evaluation phase of the Evolutionary Sets of Safe Ship Trajectories method. In general, the Evolutionary Sets of Safe Ship Trajectories method combines some of the assumptions of game theory with evolutionary programming and finds an optimal set of cooperating trajectories of all ships involved in an encounter situation. While developing a new version of this method, the authors decided to...
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UNDERWATER NOISE GENERATED BY A SMALL SHIP IN THE SHALLOW SEA
PublicationStudy of the sea noise has been a subject of interest for years. The first work of this scope were published at the turn of the twentieth century by Knudsen (KNUDSEN et al., 1948) and G. Wenz (WENZ, 1962). Disturbances called "shipping noise" are one of the important components of the sea noise. In this work the results of an experimental research of underwater noise produced by a small ship of a classic propulsion are...