The increasing sizes of ships determine the interest in modifying the already existing solutions. Simulation models allow us to analyse the possible modernisation options. The article presents analysis results for the width of the fairway to Ystad, marked with buoys with respect to navigation safety. After a thorough analysis, taking into account the safety of navigation, further possibilities of development have been determined. Study results are aimed at designing new solutions in case of modernization of the approach channel to Ystad.

In this article an integrated system for dynamic under keel clearance (UKC) assessment is presented. The system was created to improved navigation safety and economic effectiveness in Polish ports. In this paper principle of model operations and utilization with modern, available mobile devices in integration with wireless data transmission technology was introduce

Modeling of ship motions in waves concentrates in most applications on the response amplitude operator (RAO). This mathematically not demanding method of analysis is very attractive, but loses some essential information in certain situations. The objective of present contribution is to establish and investigate preliminary foundations for a seakeeping model as optimal for under keel clearance (UKC) estimation. A special attention was devoted to transients of motions, stationary harmonic motions, coupling between degrees of freedom, and the wave force transfer functions – all in the aspect of shallow water environment

This paper is aimed to clarify the notion of instant pivot point (as being well established in rigid body mechanics) and review its application in practical ship manoeuvring. The extension of the Vasco Costa original results to arbitrary initial ship manoeuvring motions is performed and a transient phase of the pivot point change is studied, especially with regard to ship crash stopping and turning (including inter alia a bow thruster application)

The paper presents basic principles of a ships nondimensional trajectory definition for arbitrary manoeuvres by means of drift angle and nondimensional yaw velocity. This enables faster and better tuning of mathematical model of ship manoeuvring motions against the provided full scale sea maneouvring trials usually in a form of position trajectories – since it is known the governing, basic factors behind the trajectory. A special focus has been applied to the standard turning circle test

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 fundamental fact about manoeuvring of geometrically similar ships, of whatever length (or size) and initial steady approach speed, including scale physical models and the whole series of full-scale ships (if they really exist), is that the nondimensional track (in ship length units), the drift angle and the nondimensional yaw velocity are maintained. The only difference is the allocation of time moments to subsequent ship positions and/or heading. The higher is the speed and the shorter is the hull length, the time 'runs' faster. The present paper deals with a methodical explanation of these phenomena in view of building the manoeuvring model for a virtual ship of arbitrary size. Problems with satisfying the similarity of propeller parameters, the occurrence of scale effect in the resistance coefficient, and the consequences of variation in the ratios of main dimensions are analysed against the increasing ship length.

Restricted water effects upon ship manoeuvring are investigated from the full-scale based identification viewpoint. As the resistance increase may be quite accurately corre-lated 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 (combi-nations) of the multipliers are simulated to show the most representative ship behaviour with regard to turning and zigzag manoeuvres.

The existing regression models on the bank (wall) effect are compared to one an-other 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 re-gression models of little use in an adequate bank effect simulation. Further research is required in this field.

Benefits and limitations of onboard mooring ropes application to improve a ship manoevrability during berthing are discussed. A mathematical model of mooring rope forces is formulated. This has been incorporated in the general ship manoeuvring model for obtainning the real ship moions while a ooring rope is in operation. The simulation output is presented. It appears that the rotational enegry absorption performance is largely governed by the location of ship's instant pivot point in relation to he mooring fix point.

The paper presents the drift angle - nondimensional yaw velocity diagram for various manoeuvres of a single screw ship as the basic element of the hull hydrodynamics identification, optimisation, or validation. Empty ragions in this chart are reported. An attempt is made to provide conditions for the arbitrary manoeuvring moion with an emphasis on filling these gaps by means of fore and aft birtual lateral forces.

The paper presents the development of a new simulation method to optimize bends in marine waterways. This method, using results of empirical research and simulation methods, would allow accurate determination of safe manoeuvring areas. The method was used at the stage of detailed design of parameters of the, which is undergoing modernization, to determine the optimum parameters of horizontal curves of the fairway. The study was conducted on the type of manoeuvring simulator called Polaris Kongsberg and attended by pilots from the Szczecin–Swinoujscie Pilot Station. Based on the studies carried out, the maximum safe ship length was determined for the redesigned waterway and the conditions for their safe operation. The maximum lengths of these ships are as follows: cruise Lc = 260 m, container Lc = 240 m and a bulk carrier Lc = 220 m.

This paper presents a novel step forward in finding the loads of particular mooring ropes that balance the steady environmental excitations for a ship staying at berth. The industrial static equilibrium method for a rough assessment of ship mooring safety is considered to be well-established. The static loads are directly related to the rope’s MBLs (minimum breaking loads) while applying a certain safety margin (usually 50%). The problem is reduced to a set of linear equations that may be solved analytically. The generality in terms of arbitrary horizontal and vertical angles of mooring ropes is preserved. All derivations are provided to enhance trust in the very simple yet absolutely accurate and fast linear solution. The accuracy is studied both analytically, throughout all the development stages, and finally by comparison to the exact numerical solution of the original nonlinear equilibrium equations for an exemplary mooring pattern. A discussion of selected effects in load distribution is also given. Using the approach presented, for instance, we can efficiently test mooring safety when any mooring rope of the set is accidentally broken.

Przedstawiono praktyczny algorytm uwzględnienia 'efektu odbicia' statku od nabrzeża w symulacji manewrowania statkiem. Włączono fizyczne charakterystyki odbojnic jako wykresy siły reakcji w funkcji odkształcenia. Mapa odbojnic zawiera informacje ° dyskretnym (punktowym) rozkładzie ich położenia wzdłuż nabrzeża, wliczając w to rozmiar i typ urządzenia Przeanalizowano konieczność skrócenia kroku całkowania * sytuacji kontaktu z odbojnicą.

Analizowano wpływ falowania morskiego na ustalony dryf zatrzymanego statku, jako prostszego przypadku ogólnych ruchów manewrowych jednostki Uwzględniono oddziaływania od fali drugiego rzędu i szczegółowo rozpatrzono sytuację falowania nieregularnego, jako lepiej oddającego rzeczywistość. Założono również wiatr jako towarzyszący falowaniu. Jednoznacznie wykazano istotny efekt falowania, szczególnie wobec jednostek dłuższych i załadowanych.

W artykule nakreślono stan badań w zakresie oddziaływania wiatru w modelach matematycznych manewrowania statkiem. Konieczne jest zwrócenie większej uwagi na oddziaływanie fał, zwykle silniejsze i towarzyszące wiatrowi. Podniesiono problem korekcji morskich prób manewrowych do warunków zerowych wiatru, co jest istotne przy akwizycji danych do identyfikacji modeli matematycznych ruchu. Przeanalizowano dokładności określenia oddziaływań wiatru.

Podjęło próbę systematycznego przedstawienia problematyki pełnych równań ruchu statku (6 stopni swobody) w aspekcie sposobu ich rozwiązania. Główny nacisk położono na stronę praktyczną zagadnienia, na możliwości bezpośredniego wykorzystania w symulacji komputerowej. Autor wskazał istotne z punktu widzenia doskonalenia modelowania matematycznego ruchu statku obszary badań, na których powinno koncentrować się zainteresowanie naukowców

The presented method for defining the conditions of safe operation of marine ferries in ferry terminals allows verification of shipowner ferry designs. In the first stage of this method, simulations are used to determine the allowable wind speed. The second stage comprises simulations of ferry berthing aimed at defining safe manoeuvring areas, the energy of berthing impact and propeller stream speeds at allowable wind speeds. The method was used in the design of a 228 m long hybrid ferry.

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.