Due to the ongoing climate change, the European Commission is implementing the promotion of inland waterway transport. By creating favourable conditions for the further development of the sector, the Commission hopes to encourage more companies to use this mode of transport. The policy to promote inland waterway transport in Europe is encapsulated in the NAIADES Action Programme. Carriage of goods by inland waterways is climate-friendly and energy-efficient and can significantly contribute to sustainable mobility in Europe. The European Commission believes that transport by inland waterways must be better used in order to relieve heavily congested transport corridors. In inland navigation, we are dealing with water areas of relatively small depths, therefore the units - pushed convoys carrying out the transport task in these areas have a shallow draft. The small draft of the units, as well as the shape of the hull, which is flat-bottomed, makes such a unit very sensitive to hydro-meteorological conditions. At the same time, the shape of the underwater part of the hull greatly influences the maneuverability of the vessel, especially when turning, taking up a large maneuvering space. The number of inland waterway accidents and claims for damages has been increasing year by year since 2014. The value of claims for damages is also growing. According to Paul Goris, President of the IWT Platform, "The inland shipping sector is on the verge of a major transformation in terms of sustainability and digitalisation. This requires further development of standards and certain security requirements".
Growth of demand for containerized cargo shipping has put more ports into pressure to accommodate larger vessels. Considering the limitations on dimensions of navigation channels, this is not feasible unless aiming for significant capital dredging or alternatively creating high precision predictions of vessel motions subjected to environmental forcing and interaction with shallow and restricted waterway. NCOS ONLINE (Nonlinear Channel Optimisation Simulator) is a state of the art navigation support tool which combines DHI’s high level forecast of environmental conditions with mathematical model of ship motions to add an extra level of accuracy in predicting the under-keel clearance and vessel swept path to boost the efficiency of navigation and pilotage within restricted channels. NCOS Manoeuvring Module utilizes an autopilot scheme based on PID (Proportional / Integral / Derivative) controller and Line of Sight Algorithm to FORCE Technology’s SimFlex4 manoeuvring solver for prediction of manoeuvring ship swept path and response, which will effectively bring the accuracy of real time full bridge simulator to fast time operation support tool. In this paper, the result of mathematical model is validated against fullscale measurements of containership transits through Port of Auckland Navigation channel by comparing pilot commands, leeway drift and swept path through output of portable pilotage unit. According to the results the model is found promising to predict the behaviour of human pilots with precision required in operational use. Finally, the swept path and manoeuvring performance of a sample transit is assessed on different environmental conditions and tide stages to evaluate the safe transit windows in operation.
The automatic collision avoidance system introduced in this paper is a system constantly calculating optimal manoeuvring method from the risk and economic preference in the ship manoeuvring space where the course change and the deceleration are performed. The authors also propose a system that quantitatively evaluates the collision avoidance manoeuvring results. Based on the evaluation results of this system, the authors are setting parameters so that ship manoeuvring that does not give anxiety to target ships to be avoided is also realized in automatic collision avoidance manoeuvring. In addition, comparison between the manoeuvring results of the automatic collision avoidance system and the veteran captain's manoeuvring results was quantitatively compared by the proposed evaluation system. Verification experiments were successfully conducted to verify the effectiveness of the proposed automatic collision avoidance system on the actual ship navigating in congested waters.
The following paper presents an original, universal method of formal safety assessment of ship manoeuvring in sea waterways. The method allows evaluation of a ship’s formal safety assessment on various types of waterways. It may be a basis for standardizing the methods of performing the ‘navigational analyses’ which are required in Poland.
In this paper a simple four-point, in terms of time, but eight-value in total, identification method has been developed for the second-order linear Nomoto steering model. The algorithm intrinsically uses the zigzag test data in that it inherited some principles of the well-known procedure for the first-order model, from which it is essentially derived. The performance evaluation was then conducted with both simulated and real data. However, the results of these early, unprecedented efforts are far from satisfactory. Some potential sources of difficulties have been discussed. This calls for further research and improvement in order to provide a practical application of the method.
The problem of considerable difference between the first- and second-order linear Nomoto models is undertaken, not well covered in literature so far. If the former approximates the latter (better one, of a sound hydrodynamic interpretation) for some reasons, its parameters can not be easily derived from the other one, except for some specific rare cases. For such an identification purpose, we can use a simulated zigzag response and the classic procedure proposed by Nomoto in 1960. However, the first-order model thus developed yields somehow redefined constants against the original model, which lose their normal hydrodynamic (or kinematic) sense. In other words, it is very sensitive to the manoeuvre type on input, being therein the zigzag test. Therefore, the model is allowed to be only used for simulating motions essentially similar to the input zigzag. In other words, the identification procedure works like a blind curve-fitting and the first-order model (in contrast to second-order one) is inadequate for reflecting arbitrary manoeuvres, even for mild rudder as to be within 'linear' assumptions. This study examines systematically and in detail such an incompatibility of the first order model in that it presents the conversion charts from the standpoint of 10°/10° zigzag test matching. One can receive higher or lower values for the parameters of first-order model, versus the second-order one, depending on the T3/T2 ratio of the latter model.
PL
Artykuł zawiera systematyczne wyniki identyfikacji liniowego modelu Nomoto pierwszego rzędu na podstawie symulowanej próby wężowej różnych wariantów modelu drugiego rzędu. W toku analizy stwierdzono ogólną nieadekwatność (strukturalną) modelu pierwszego rzędu do symulacji dowolnych manewrów, w przeciwieństwie do modelu drugiego rzędu, nawet w granicach liniowości dynamiki statku. Wyniki identyfikacji silnie bowiem zależą od rozpatrywanego manewru.
This paper is a continuation of papers dedicated to a radar-based CTPA (Collision Threat Parameters Area) display designed to support safe manoeuvre selection. The display visualizes all the ships in an encounter and presents situational overview from the own ship's point of view. It calculates and displays information on unsafe or unrealistic own ship's course & speed allowing a user to select a safe manoeuvre. So far only the manual selection was possible, thus the paper aims at presenting a heuristic approach towards the manoeuvre selection when using the display.
The present paper describes the hydrodynamic modelling solutions, applied in the newly developed shiphandling simulator at SMU (Szczecin Maritime University) for the inland navigation – called InSim. The objective is to provide some guidance on the simulator capability and potential while conducting various research and the crew training projects.
This paper evaluates an ASD tug’s main control parameters in terms of: the propeller thrust, a direction thereof (the thruster angle), and the hull drift angle for given escort speed and required push force. Such a relation is sometimes referred to as the tug performance diagram. A simplified model of tug hydrodynamics is used to arrive at the qualitative and most representative relations of the above variables. This model is rather generic that can also suit any type of tug hydrodynamics, including even that related to a conventional tug.
The ridge regression is presented for identify manoeuvring indices in Nomoto’s model, and the result indicates that the method is robust and does not rely on initial estimation. For selecting appropriate AIS data for manoeuvring indices predicting, a frequency domain identification method is presented.
Short-term prediction is a tool that helps to manoeuvre inland units, allows assessing the effect of the planned manoeuvre and reduces the probability of collision. Model of ships hydrodynamics is required to perform this task. In the paper simple to implement solution based on a Nomoto model is proposed. Method of determi ning the parameters of the model was presented. Researches were carried out with use of INSim Inland Navigation Simulator.
The paper describes a mean of using vessel’s manoeuvring parameters recorded in real conditions for the purpose of analysing the environment influence on ship’s behaviour. This information has also been used to conduct a comparative analysis of a real vessel and its simulation model in the data base of a navigationmanoeuvring simulator. The measurements were taken on an unrestricted sea area so as to eliminate the impact of developed sites on wind field. The research was conducted in the region of the North Sea and Baltic Sea.
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The aim of the present paper is to determine the availability and main features of existing harbour tugs from the viewpoint of type and maximum bollard pull achievable nowadays. Particular interest is also focused on a tug's length as one of main dimensions representing the hull size. This length affects the manoeuvring area occupied by an assisting tug and expresses its basic turning and stopping performance. One can simply state that the involved manoeuvring area is proportional to the length. However, the same hull of a tug within the current shipbuilding practice, unlike in the past (when the higher propulsion power implied a larger hull) can accommodate propulsion units of quite different power. Thus, the higher propulsion power is installed the higher towing forces are achieved, and in addition the turning or stopping ability of a free-sailing tug is essentially improved. The conducted research is based on analysing the world fleet statistical data. The obtained results provide support for making operational and investment decisions by harbour authorities in the aspect of harbour modernisation or its traffic expansion.
PL
Celem niniejszej analizy jest określenie dostępności oraz własności manewrowych holowników portowych w zakresie maksymalnego możliwego uciągu na palu BP (ang. bollard pull). Szczególną uwagę zwrócono na typ napędu holownika i długość całkowitą jednostki LOA (ang. length over all), od której w dużym stopniu zależy przestrzeń manewrowa zajmowana przez holownik i trudnośćw manewrowaniu. Uzyskane wyniki stanowią pomoc w podejmowaniu decyzji operacyjnych i inwestycyjnych władz portowych w aspekcie modernizacji portu lub nowych uwarunkowań eksploatacyjnych, gdzie podstawowym zadaniem jest zapewnienie bezpieczeństwa operacji manewrowych.
The modern simulation software includes an impact of forces acting on the ship hull. One of the most significant forces is sea waves acting. The mathematical model allows simulation of ship motions in irregular sea wave area, both – at deep and shallow waters. The wave surface model enables simulation of the wave elevation in compliance with wave spectrum occurring in various conditions. The paper presents general description of the sea wave model used in maritime simulators. An example of such simulators is used at the laboratory of the Naval University of Gdynia, where it is operated basing on NT-Pro 5000 software by Transas Marine. The latest version of simulation software gives a possibility to select the wave spectrum. Selection of the waving type, depending on sea area location, makes the ship movement more reliable. This is an important element in testing the ships behavior process.
W artykule omówiono wykorzystanie sieci bayesowskiej do tworzenia systemu wspomagania decyzji podczas akcji ratowniczej"człowiek za burtą". Obecnie na statkach stosuje się różne systemy wspomagania decyzji kapitana i oficerów, jednak brakuje narzędzi, które w prosty i szybki sposób pozwolą na ocenę sytuacji podczas akcji ratowniczej, gdzie elementem determinującym jest czas.
EN
The paper presents Decision Support System based on Bayesian Network that can be used during Person Overboard situation on board modern cruise vessels or ferries. Nowadays there are some Intelligent Decision Support Systems assisting navigators to analyse traffic and to take correct decisions to avoid close quarter situations, but there is no automatic tools to support process of making a decisions while emergency situation POB occurs. During that situation time of finding person is the key to determine a successful action and IDSS could help to make action more efficient and in shorter time period.
Safe entrance to the port of LNG carrier (vessel of length abt. 300m) to the terminal requires considering of technical and navigational aspects, as well as fulfilment of series of safety criteria related to manoeuvring, mooring and unloading of LNG carrier (LNGC). Complex manoeuvring, mooring and unloading safety assessment of LNG C in port, might be done as a assessment of particular types of manoeuvres and exploitation operations. Article copes with all this aspects.
The paper presents a concept of elemental manoeuvres that may be used for analysis of ship handling training (including the training with manned model ships) and for simulation of complex manoeuvring scenarios. It shows a set of postulated elemental manoeuvres. A fuzzy clustering method is introduced and applied for the classification of manoeuvring patterns. The fuzzy clustering algorithm is used for the extraction of elemental manoeuvres from the records of ship handling manoeuvres of LCC model ship. The best set of variables for the extraction of elemental manoeuvres consists of normalised ship velocities and controls.
The existing regression models on the bank (wall) effect are compared to one another both dynamically (force level) and kinematically (counteracting helm and hull drift attitude during a steady-state passage along a bank). A small chemical tanker of known hull and rudder hydrodynamics is used as an example of computations. A lot of essential qualitative and quantitative discrepancies have been found, which might claim the regression models of little use in an adequate bank effect simulation. Further research is required in this field.
PL
Przeprowadzono symulację efektu brzegowego w kanale dla małego chemikaliowca, wykorzystując dostępne modele regresyjne tego zjawiska. Główny nacisk położono na wielkość dryfu i wychylenie steru potrzebne do zrównoważenia efektu brzegowego podczas ustalonego ruchu jednostki poza osią kanału. Stwierdzono zasadnicze różnice między poszczególnymi modelami, co uniemożliwia uzyskanie prawdziwego ilościowego obrazu zjawiska. Konieczne są dalsze prace nad modelowaniem efektu brzegowego.
Restricted water effects upon ship manoeuvring are investigated from the full-scale based identification viewpoint. As the resistance increase may be quite accurately correlated with the squat, it is proposed to store in the ship manoeuvring model kernel only data on the ship's squat. The problem of correction factors (multipliers) to be imposed upon ship added masses and hull force coefficients is raised. Different patterns (combinations) of the multipliers are simulated to show the most representative ship behaviour with regard to turning and zigzag manoeuvres.
PL
Przeanalizowano wpływ ograniczeń hydraulicznych akwenu na manewrowanie statkiem w aspekcie identyfikacji hydrodynamicznego modelu ruchu z prób morskich. W odniesieniu do modelowania wzrostu oporów zaleca się ich uzależnienie od aktualnego osiadania. Przeprowadzono symulację różnych konfiguracji współczynników korekcyjnych hydrodynamiki kadłuba na warunki płytkowodzia celem otrzymania charakterystycznych zachowań statku w próbach cyrkulacji i wężowej.
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Identification algorithms of the ship manoeuvring mathematical model require waterrelated sea trial data on input. However, most of contemporary positioning systems estimate the over-ground motion state vector. Because of that, there is a need to correct sea triaIs. Some methods of sea (ocean) current estimation are considered below, and also its effect upon motion data and subsequent force identification. Tuming and zig-zag manoeuvring tests are examined in detail.
PL
Identyfikacja matematycznego modelu manewrowania statkiem wymaga posiadania informacji z morskich prób manewrowych dotyczących ruchu statku po wodzie. Tymczasem większość współczesnych systemów określania pozycji potrafi estymować jedynie stan ruchu względem dna - w rozumieniu zarówno zmiany pozycji, jak i prędkości. To stwarza konieczność dodatkowego szacowania parametrów prądu i tym samym poprawiania danych manewrowych. W artykule szczególny nacisk położono na zniekształcenia w wynikach prób cyrkulacji i prób wężowych spowodowane zjawiskiem prądu oraz ich konsekwencje w ostatecznej identyfikacji modelu manewrowania. Scharakteryzowano również praktyczne metody, które mogą służyć do wyznaczania wektora prądu.
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