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Modern sowing machine-tractor units (MTU) can be divided into single-machine (single-module), two-machine (double-module), and three-machine (triple-module). The firsts, consisting of a tractor and a trailed/mounted seeder, are the most studied and, therefore, the most widespread. Two-module MTUs mainly use trailed or semi-mounted hitch and trailed seeders. The units of this type have been studied less. Three-module sowing complexes are even less common. Most are based on a trailed hitch and trailed seeders placed behind the tractor. There are samples of MTU with side-mounted seeding machines, but their knowledge is extremely insufficient. This paper examines a three-module MTU based on a tractor with reverse motion and a front semi-mounted hitch. One of the problems in using this sowing unit is the choice of design parameters that would ensure safe turning when manoeuvring on the headland. Theoretical and experimental studies have established that by increasing the side seeder's towbar length, MTU's safe turning under analysis with machines of a larger operating width can be performed with a smaller distance between their inner wheels and tractor's wheels (parameter d). If the coincidence condition of side seeders' wheel axes with the tractor wheels axe is met, an increase in the tractor track from 1.7 to 2.5 m allows for a decrease in the value of the distance d. This solution is especially effective when using seeders with an operating width of 3.6 m. In this case, the indicated decrease reaches a fivefold size, from 0.5 to 0.10 m. With the seeders' operating width of 5.4 m, the distance d can only be reduced by 1.4 times. But with this option for sowing MTU, it is possible to use a tractor with dual rear tyres and a parameter d value of 0.98 m. Actual oscillations in the distance d value within 0.28 ±0.01 m in the process of turning the studied sowing machine-tractor unit at a velocity of 2.2 m·s−1 are characterized by low variance (0.64·10−4 m2) and low (no more than 1.75 Hz) frequency. This allows us to consider this MTU's mode movement on the headland quite safe. [ABSTRACT FROM AUTHOR]

Harbour tugs are usually used to moor ships if large ships do not have their own additional propulsion devices (thrusters). Alternatively, during ship loading operations, ships sometimes have to be transferred from one quay to another, and in some cases, port users (shipping companies or other companies) have to pay for port tug services. In such cases, it is very important to guarantee the safety of shipping during mooring operations and to use tugboats optimally and at the same time reduce the cost of tugboat services for ship operators and other companies. For the optimal use of tugboats, it is very important to accurately estimate the required traction force (bollard pull) of tugboats and their quantity, taking into account the parameters of moored ships, the locations of berths, hydro-meteorological and hydrological conditions, and clearance (the gap between the ship's hull and the bottom of the water area), in order to guarantee the safety of navigation and not to order an excess of tugboats in terms of their quantity and powers. This article presents a methodology developed for estimating the required bollard pull and the number of tugs, taking into account the parameters of the ship, hydro-meteorological and hydrological conditions, clearance, and the locations of berths. The developed methodology for estimating the number of tugboats and their traction force (bollard pull) was tested in real conditions (with real ships and tugboats) and using a calibrated simulator, and we found that it can be successfully applied in any port or other complex shipping area by adapting it to specific conditions. The developed methodology for calculating the traction power (bollard pull) of tugboats allows us to determine the required traction force of tugboats in advance with sufficient accuracy, achieved by assessing the specific parameters and environmental conditions of the vessel served by tugboats. In the most difficult areas of the port, in terms of the use of tugboats, this methodology allows us to make reasonable decisions regarding the number of tugboats and the traction force (bollard pull) required and at the same time reduces the risk of emergency situations. [ABSTRACT FROM AUTHOR]

Harbour tugs are usually used to moor ships if large ships do not have their own additional propulsion devices (thrusters). Alternatively, during ship loading operations, ships sometimes have to be transferred from one quay to another, and in some cases, port users (shipping companies or other companies) have to pay for port tug services. In such cases, it is very important to guarantee the safety of shipping during mooring operations and to use tugboats optimally and at the same time reduce the cost of tugboat services for ship operators and other companies. For the optimal use of tugboats, it is very important to accurately estimate the required traction force (bollard pull) of tugboats and their quantity, taking into account the parameters of moored ships, the locations of berths, hydro-meteorological and hydrological conditions, and clearance (the gap between the ship’s hull and the bottom of the water area), in order to guarantee the safety of navigation and not to order an excess of tugboats in terms of their quantity and powers. This article presents a methodology developed for estimating the required bollard pull and the number of tugs, taking into account the parameters of the ship, hydro-meteorological and hydrological conditions, clearance, and the locations of berths. The developed methodology for estimating the number of tugboats and their traction force (bollard pull) was tested in real conditions (with real ships and tugboats) and using a calibrated simulator, and we found that it can be successfully applied in any port or other complex shipping area by adapting it to specific conditions. The developed methodology for calculating the traction power (bollard pull) of tugboats allows us to determine the required traction force of tugboats in advance with sufficient accuracy, achieved by assessing the specific parameters and environmental conditions of the vessel served by tugboats. In the most difficult areas of the port, in terms of the use of tugboats, this methodology allows us to make reasonable decisions regarding the number of tugboats and the traction force (bollard pull) required and at the same time reduces the risk of emergency situations.

Ship stability is one of the most valuable operational situations of ships and provides essential information on the weather conditions, safety and control ability of the ship. To guarantee a ship's sustainability, there is an urgent need to analyze and apply the results of vessel manoeuvring dynamics and establish the controller's design thereby assuring the ship's performance. To address the problem, this study introduces a modified form of the linear quadratic regulator (LQR) controller design to control and influence the random fluctuations in the system state measurements stable results were obtained in the various cases that were tested. The controller was robust enough to deal with measurement noise under varying circumstances. Considering the vessel's turning radius bend of 300 millimeters and the completion of a full turn in 3.5 minutes, the performance of the controller tested in a real situation reveals that increasing the controller gains through the values of the Q and R (quadratic regulator) matrices affected different parts of the response. Furthermore, from the simulation, for every 1 second of simulation time, we have 20.85 seconds of real-time. The real-time plots provided are 0.24 seconds of simulation time. Also, the higher value of the Q matrix coefficients stimulated a faster response since the feedback gain increases commensurately. The result is significant as it enables naval architects to easily manoeuvre vessels in a predictable way which is the effect of this controller design. [ABSTRACT FROM AUTHOR]

An innovative tourist submarine was studied by scale-model tests in a towing tank to determine its steering capabilities and detect motion instabilities during usual manoeuvres and emergency rising. Motion instabilities are caused by the combination of the submarine motions and the fluid flow, leading to excessive roll and pitch that can cause severe endangerment to passenger safety. The submarine model was built on a scale of 1:9. The model had six thrusters to conduct the tested manoeuvres, i.e., two main thrusters at the stern, two side thrusters, and two vertical thrusters. The thrusters were computer-controlled, so each thruster had a speed controller and could run forwards and backwards. Six different steering tests and four rising tests were conducted, with at least two runs per test. During the tests, the roll and pitch were measured. Lifting the submarine by a crane was also a part of the experimental campaign. In general, the steering capabilities of the submarine were satisfactory and rolling instabilities were absent. Just a few deficiencies in the steering capabilities were detected. The rising tests were performed without any major motion instabilities, but in one case, the final position of the model at the surface was unstable. [ABSTRACT FROM AUTHOR]

This paper presents the mathematical model used in MARIN's time domain software to describe the hydrodynamic loads excited by a rudder. The paper provides a detailed description of the mathematical model and its theory, along with highlighting the novel features that have been added to extend the model to four quadrants operations. Furthermore, the paper compares the mathematical model with experiments, showcasing the model's capabilities and shortcomings. For this comparison, a spade rudder behind the KRISO Container Ship with and without a propeller upstream has been used as a case study to illustrate how the model performs in practice. [ABSTRACT FROM AUTHOR]

The paper explores the propulsive power requirements and manoeuvring capabilities of a popular class of inland bulk carriers in Bangladesh. After the initial verification study, model-scale CFD simulations are performed in calm, open waters at different speeds to assess hull resistance. The resistance results are then extrapolated to full scale for calculating propulsion power requirements. Subsequently, manoeuvring simulations are performed using PMM motions to evaluate static drift, pure sway, and pure yaw scenarios to calculate manoeuvring coefficients. Following this, model-scale resistance simulations in restricted waters are performed to estimate the minimum power needed for propulsion in heavy monsoon currents based on common inland waterway dimensions in Bangladesh. Finally, full-scale simulations are performed in open water to investigate the scale effect on resistance (thus power) prediction. The study confirms that the installed power in the vessel is adequate for safe navigation within Bangladesh's inland waters. Although model-scale CFD studies are generally unsuitable for resistance prediction, the study suggests that extrapolated results often offer conservative estimates for power prediction. In cases of resource limitation, these simulations can prove beneficial since conservative estimations somewhat ensure the vessel's propulsion and manoeuvrability in extreme conditions. [ABSTRACT FROM AUTHOR]

To investigate the manoeuvring performance of a body-caudal fin robot fish, a numerical framework combining computational fluid dynamics and multi-body dynamics with a closed-loop control algorithm was established in this study. Within this framework, we modelled a body-caudal fin swimmer as a multi-body system with the shape of a NACA0012 hydrofoil. The manoeuvring performance was investigated by using different curvature magnitudes and distributions along the centre line (the curvature is defined by means of a curvature envelop function as part of the general body undulation equation). To characterize the turning performance, a new parameter named cost of manoeuvring (CoM) is proposed. This parameter provides a combined assessment of the turning radius, linear and angular velocity components, and power. It is found that when the body curvature is introduced, the swimmer switches from straight-line swimming to quasi-steady turning at a constant speed. Further investigations were conducted to study contributions of head and tail deformations on the turning performance by comparing predominantly head and tail curved envelopes. Results reveal that a tail-dominated envelope improves performance, whereas a head-dominated envelope has a negative effect.

An innovative tourist submarine was studied by scale-model tests in a towing tank to determine its steering capabilities and detect motion instabilities during usual manoeuvres and emergency rising. Motion instabilities are caused by the combination of the submarine motions and the fluid flow, leading to excessive roll and pitch that can cause severe endangerment to passenger safety. The submarine model was built on a scale of 1:9. The model had six thrusters to conduct the tested manoeuvres, i.e., two main thrusters at the stern, two side thrusters, and two vertical thrusters. The thrusters were computer-controlled, so each thruster had a speed controller and could run forwards and backwards. Six different steering tests and four rising tests were conducted, with at least two runs per test. During the tests, the roll and pitch were measured. Lifting the submarine by a crane was also a part of the experimental campaign. In general, the steering capabilities of the submarine were satisfactory and rolling instabilities were absent. Just a few deficiencies in the steering capabilities were detected. The rising tests were performed without any major motion instabilities, but in one case, the final position of the model at the surface was unstable.

The paper explores the propulsive power requirements and manoeuvring capabilities of a popular class of inland bulk carriers in Bangladesh. After the initial verification study, model-scale CFD simulations are performed in calm, open waters at different speeds to assess hull resistance. The resistance results are then extrapolated to full scale for calculating propulsion power requirements. Subsequently, manoeuvring simulations are performed using PMM motions to evaluate static drift, pure sway, and pure yaw scenarios to calculate manoeuvring coefficients. Following this, model-scale resistance simulations in restricted waters are performed to estimate the minimum power needed for propulsion in heavy monsoon currents based on common inland waterway dimensions in Bangladesh. Finally, full-scale simulations are performed in open water to investigate the scale effect on resistance (thus power) prediction. The study confirms that the installed power in the vessel is adequate for safe navigation within Bangladesh’s inland waters. Although model-scale CFD studies are generally unsuitable for resistance prediction, the study suggests that extrapolated results often offer conservative estimates for power prediction. In cases of resource limitation, these simulations can prove beneficial since conservative estimations somewhat ensure the vessel’s propulsion and manoeuvrability in extreme conditions.

The manoeuvrability of submarines is one of the important factors from mission and safety points of view. In particular, manoeuvring motions with a large drift angle and/or angle of attack in both the horizontal and the vertical planes have different motion parameters compared to the normal manoeuvring motions. To evaluate the manoeuvrability during these types of particular motions of submarines, especially at the initial design stage, the manoeuvring hydrodynamic derivatives that are related to various manoeuvring motions must be identified. Karasuno model, which is termed a physical based model, has the advantages that it needs only model experiments for drift motion and it can provide greater accuracy under motion with large angles. Despite these advantages, this model has not been applied to other vessels excluding fishing vessels. The applicability of this method to submarines therefore should be examined. The applicability of Karasuno model for submarines is validated through a computational fluid dynamics (CFD) analysis and comparisons with experimental data in this work. The findings contribute to identifying the manoeuvring hydrodynamic forces for submarines and evaluating their manoeuvring performance. Through rigorous validation, the potential of the proposed model as a reliable tool for predicting and analyzing submarine maneuvering motions is demonstrated. • Reliable numerical simulation for the flow around the submarine. • Development of the manoeuvring mathematical motion with new approach, so called physical based mathematical model. • Less amount of analysis procedure compared to the traditional analysis method. • High accuracy of captive numerical calculation based on the various numerical scheme test and the grid convergency test. [ABSTRACT FROM AUTHOR]

This paper deals with the numerical simulation of a ship's manoeuvring performance in regular waves. This is made possible by employing the time-domain code ELIGMOS, which adopts a hybrid formulation to couple seakeeping and manoeuvring contributions. The first and steady second-order wave-induced forces are incorporated, implementing a multidimensional interpolation scheme to account for their dependency on the instantaneous heading and forward speed values. Two methods have been adopted for the calculation of the added resistance regarding the size of the wavelength (short or long wave seas), namely a far and a near-field one, using the hydrodynamic software NEWDRIFT+ and NEWDRIFT v.7. Low-frequency hydrodynamic manoeuvring forces are incorporated by adopting the expressions suggested by the Japanese MMG (Manoeuvring Modelling Group) method. Validation of the suggested methodology is attempted through the comparison of numerical simulations of turning circle tests in calm water and in regular waves with available experimental evidence for the S-175 container ship. [ABSTRACT FROM AUTHOR]

Hydrodynamic loads acting on a ship can nowadays be reliably obtained from Computational Fluid Dynamics (CFD) techniques. In particular for the determination of the hydrodynamic coefficients of a mathematical manoeuvring model, the forces and moments on a ship sailing at a drift angle or with a yaw rate can be computed efficiently with CFD. While computations with a drift angle are relatively straightforward, computations involving a yaw rate present a challenge. This challenge consists in how to deal with the grid, the setup and the ship encountering its own wake when rotating. A solution based on a single grid setup with consistent boundary conditions and utilising a body force wake damping zone to remedy this challenge is proposed in this paper, leading to an effective, fast, and accurate method to compute hydrodynamic loads of a ship in steady yaw manoeuvres. [ABSTRACT FROM AUTHOR]

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.

Accurate determination of hydrodynamic derivatives, appearing in the equations of motion of a marine vehicle, is essential for the correct prediction of its manoeuvring performance. Solution of these equations leads to the simulation of the ship motions in the horizontal plane for a surface ship and thus helps in understanding its course stability, turning ability, rudder effectiveness and ship responsiveness. This paper presents the numerical simulation of the Planar Motion Mechanism test using RANS-based equation to obtain the hydrodynamic derivatives appearing in the equations of motion and to assess the manoeuvrability of a container ship using standard definitive manoeuvers. Experimental validation of the numerical test is carried out by conducting free running model tests in a manoeuvring basin. [ABSTRACT FROM AUTHOR]

The paper presents a methodology to design an electric controller for marine cycloidal propeller. The controller is designed considering the torque and the rotational speed limit of the motor. The influence of manoeuvring dynamics of the ship, rotational speed of the disc, eccentricity ratios and torque, pitching speed and pitch angle of the blades on the controller design are investigated. Feedback signals are used for the controller and combined with multiple PID control logic for controlling the motion of disc and blades. The proposed PID controller helps to stabilize the rotational speed of propeller blades and disc when requirement of torque exceeds the maximum limit of motor torque. The proposed control algorithm enhances the chances of optimizing propulsion efficiency of the blade. This is achieved due to decoupling of the motion of individual blades. Simulation results of different manoeuvring and straight run cruising conditions demonstrate the application of proposed control scheme. Finally, the simulated results are validated with the experimental results of mechanically controlled cycloidal propeller. [ABSTRACT FROM AUTHOR]

The superior manoeuvrability of Z-drive equipped vessels is well known, though the comprehensive manoeuvring characteristics are seldom quantified. This paper presents the results of a sea trial on a 55 m ship equipped with twin Z-drive propulsion. Three manoeuvre types were conducted: turning circles, effective turning tests, and crash stops. Each were done for a range of ship speeds and thruster azimuth angles. For the turning circles, steering modes using both a single thruster and dual thrusters were also examined. The effective turning tests were used to determine the best or best-compromise thruster angles to achieve a high rate-of-turn with the least loss of ship speed. The crash stop tests investigated two different stopping methods: full reverse thrust and stopping by swinging the thrusters to 90°. • Manoeuvring sea trials were performed on a ship with twin Z-drive thrusters. • The data was analysed to quantify the turning and stopping metrics of the ship. • Results show performance changes based on helm configuration and stopping method. [ABSTRACT FROM AUTHOR]

A ship needs to be optimized for cost-effectiveness, operational efficiency, improved safety, comfort of passengers and crew, and for minimum environmental impact. Many of these requirements are contradicting and a decision regarding the optimal ship design needs to be made, based as far as possible on rational criteria and procedures. This is the case for the problem which the SHOPERA project is dealing with. Environmental concern was the reason behind the introduction of the Energy Efficiency Design Index (EEDI) a few years ago. One way of fulfilling the demanding requirements of the EEDI regulation is to reduce speed of future ships. This may result, however, in under-powered designs, raising questions regarding the ability of these designs to operate safely in adverse weather conditions. The present paper focuses on the development of an optimisation procedure for the design of tankers and bulk carriers, to identify designs with adequate powering to ensure safe operation in adverse weather conditions, while keeping the right balance between economy, efficiency and safety of the ship and the environment. [ABSTRACT FROM AUTHOR]

Maneuverability of ships is presently standardized (normed) by rules of classification societies, shipowner requirements, and International Maritime Organization (IMO) standards for ship maneuverability. The latter address turning, initial turning, yaw checking, course keeping, and emergency stopping abilities, evaluated in simple standard maneuvers in calmwater, and have practically become an industry standard. However, these standards do not address ship maneuverability in adverse weather conditions; after the introduction of the energy efficiency design index (EEDI), the importance of this issue increased because of concerns that propulsion and steering abilities of ships may become insufficient if EEDI requirements are achieved by simply reducing the installed power. To provide a rational basis for the standardization of maneuverability of ships in adverse weather conditions, relevant criteria, measures, and standards need to be developed, as well as efficient ways to evaluate the criteria in practical design and approval, keeping in mind that, on the one hand, maneuvering in waves is a difficult hydrodynamic problem, presently tackled in research projects in few centers worldwide, and, on the other hand, simple practical regulations are urgently required to be routinely used in design and approval of all new-built ships as a part of EEDI requirements. Obviously, this contradiction requires significant simplifications. The aim of this studywas to outline possible approaches to practical assessment, based on a sequence of pragmatic simplifications and leading to practical assessment procedures of various complexity (some of which are implemented in the presently acting 2013 Interim Guidelines for determining minimum propulsion power to maintain themaneuverability of ships in adverse conditions, and in other proposals), validate the proposed simplifications, and summarize remaining difficulties. [ABSTRACT FROM AUTHOR]

The project MoVe IT! (www.moveit-fp7.eu), funded by the Seventh Framework Programme of the European Union, was focussed on modernisation of inland waterway vessels by retrofitting. In order to stimulate an implementation of the results by the industry, visualization of the positive impacts was realised by a set of vivid demonstrators. In this paper, the demonstrations by simulators for a single screw motor cargo vessel of the type Johann Welker are described. The motion simulations are carried out by a custom made (for inland vessels developed) computer program, which use common naval architect force calculation algorithms and a new approximation theory for added masses. The simulator demonstrations comprise descriptions and visualisations of ship lengthening, application of different rudder and a new propulsion device. Five different cases are examined, the original vessel and four retrofit options. First retrofit variant is the lengthened vessel with original rudder and propeller. Other two analysis are performed changing only the rudder system. In fourth simulator demonstration the original propeller is changed to a pump propeller (a novel propulsion device). The environment are in the simulator demonstrations: constant draught of the vessel, and calm, infinite deep waterway. As results of simulator demonstrations the effects on fuel consumption and manoeuvrability are discussed in the paper. [ABSTRACT FROM AUTHOR]

Abstract We present an experimental investigation of a free-running manoeuvring inland waterway ship at extreme shallow water conditions. Physical tests of zig-zag manoeuvres at two different water depths were performed in model scale and investigated with regards to the effects of limited under-keel clearance. Experimental data comprise results from repeatability studies and may serve for validation of manoeuvring simulations. [ABSTRACT FROM AUTHOR]

In a two-autonomous underwater vehicle (AUV) system, the hydrodynamic interaction between the two vehicles can have both beneficial and harmful impact on the system. In an aim to investigate the factors that have impact on the hydrodynamic interaction, spacing, appendages effect, drift angle of the smaller vehicle and depth from the water surface were chosen as the simulation variables. Results showed that the tandem configuration in which the larger vehicle led the system can have a combined drag reduction. The appendages can have a favourable effect on the follower and the whole system. The positions where the hydrodynamic interaction had largest and least impact on the system were also discussed. When the system sailed near the water surface, the hydrodynamic interaction was aggravated owing to the water surface impact. This paper can provide a guidance for the design of AUV configuration and manoeuvring strategy of a two-AUV system. [ABSTRACT FROM AUTHOR]

The present paper is a synthesis of the scopes of accounting in understanding the economic processes and transactions from the quantitative and qualitative point of view. The economic life is a continuous set of choices and decisions (of maintaining, developing, correcting) based on the information supplied by the accounting. The input information that are processed can be incorrect, processed with correct models and the outputs can be correct, incorrectly processed and with incorrect results.

The growing number of large container vessels is the reason of port infrastructure modernization necessity and changes of local bylaws in ports. The accessibility studies based on ship motion simulation allow for the assessment of manoeuvring operations safety for the new port designs and reconstructions of the existed infrastructure. Several factors can be used to determine safety of manoeuvring operations. The paper presents an approach to determine the operational reliability which can be included in an accessibility study to determine the best of the possible solutions with respect to the ship entrance into the harbour. The general reliability model has been proposed and an example of reliability of ship entrance into the Port of Gdynia is presented.

The paper presents new results on the inherent properties of ship linear dynamics. The focus is made on the second-order formulation for the uncoupled equations of sway and yaw, and on their unique, unknown performance within the zigzag test. From the standpoint of application to full-mission model tuning, a very important loop in the drift-yaw domain of the zigzag behaviour, as governed by the rudder rate dependent time constants (of T3-type), is brought to the light. This and some other dependent effects, like overshoot angle performance, are likely to be lost, if the well-known, rather ambiguous, first-order approximations are deployed.

The safety of the tankers during the Ship-to-Ship operations carried out in shallow water close to port limit is influenced by many factors. Based on the experience of ship crew involved in STS operation it was found that area for such operation and weather analyses is the most important factors affecting the safety of the tankers. Wind speed and accompanying waves very often determine if such operation could be commenced. For the article simulations were carried out with maximum allowable wind speed and waves for such operation to obtain the drift of both tankers and capacity of area for STS operation. The results obtained from simulations allowed to assess the required space for tankers involved in STS operation.

The concept of the pivot point of a turning ship has been in existence for more than two centuries. It was not, however, properly understood from the beginning, and thus some misconceptions developed. This in turn caused it to be viewed as something mystical, thus preventing ship handling from scientific approach. The concept is expounded in a fresh light, deriving an equation for the definition and others for the calculation of the pivot point location both in general and for specific examples in an idealized condition. The implications of the derived equations are discussed. The results of a verification experiment are presented, which proved centuries’ of teachings and learnings to have been incorrect. A number of exercises for both steady and unsteady cases have been suggested for the training of the practitioners in the light of these new findings.

In article results of researches are presented according to efficiency of application of adaptive algorithm of management by the maneuverable plane realised in a cross-section control path, on the basis of identification of some aerodynamic characteristics of the plane and the indignations caused by formation by an asymmetrical configuration of placing of external suspension. By modelling of movement of the plane during performance S - figurative maneuvers with use of a programmno-modelling complex and the flight stand substantial improvement of characteristics of controllability of the asymmetrical plane and, thus, increase of efficiency of its application is shown.

Manoeuvring characteristics of the vessels at the head-on situation are examined in this study. The meetings between the power-driven vessels are considered based on their propellers. These vessels can either have a single propeller or double propellers. A vessel with a single right-handed propeller alters her course to port side easier than the starboard side. There exists an unnoticed gap, therefore the authors discuss the International Regulations for Preventing Collisions at Sea, 1972 (COLREGs), Rule 14, considering the vessel orientation based on its propeller walk. After presenting all possible cases and their probable consequences, this paper offers authorities to embed the information of propeller characteristics into the Automatic Identification Systems (AIS) in order to prevent misunderstandings during the VHF communications, probable collision risks and discussions on liability issues in case of marine accidents.

Expanding the automation level of the freshly introduced fleet of self-propelled Watertruck+ barges, which house fully-rotatable embedded thrusters, might increase their ability to compete with their less sustainable but dominating road-based alternatives. Hydrodynamic motion models, which reveal the manoeuvring capabilities of these barges, can serve as inputs for many pieces of this automation puzzle. No identified motion models or hydrodynamic data seem to be publicly available for the hull design and the novel actuation system configuration of these barges. Therefore, this study offers: (i) decoupled motion model structures for these barges for surge, sway, and yaw, with a focus on the thruster and damping models; (ii) two identification procedures to determine these motion models; (iii) all the experimental data, generated outdoors with a scale model barge to identify (i) based on (ii). In addition, the identified surge models were compared with both computational and empirical data. These comparisons offer more physical insights into the identified model structures and can aid in the model selection for which the desired complexity and accuracy evidently depend on their envisaged application. Finally, this methodology need not be limited to the vessel and actuation types utilised by us.

Strategically, the Republic of Croatia, with its economy focused on tourism, is directly connected to the sea and coastal area, and integrated management of this area contributes to the sustainable development strategy. Worldwide, the problem of atmospheric pollution from maritime traffic is a poorly researched area, especially when this type of traffic is continuously growing. On the example of Port Split, the paper aims to present the following emission, carbon dioxide (CO2), nitrogen oxides (NOX), carbon monoxide (CO), volatile organic compounds (VOC), sulphur dioxide (SO2), particulate matter (PM) and black carbon, of line vessels during manoeuvring and hotelling phase for 2017, 2018 and 2019. Furthermore, the statistical analysis and appropriate conclusions have been performed on CO2 since all other emissions are linearly dependent. From the analyses in the hotelling and manoeuvring phase of line ships, it can be concluded that during 2019 there was a slight increase in emissions, but overall there was no significant increase in the number of line vessels and increased traffic. The obtained results of case study of port Split provide recommendations leading to further reduction of harmful gas emission, monitoring them, and integrating it into management of urban ports.

The MONALISA 2.0 (ML 2.0) project aims to define the Sea Traffic Management concept (STM), where information is shared amongst all stakeholders in the maritime transport chain, including nautical officers, ports, administrations, etc. Thus, a communication and information centered approach for data exchange by System Wide Information Management principles changing from surface-based- to voyage-based-operations has been proposed. Amongst others, testing and verifying the feasibility and benefits of STM and its solutions shall be done in the European Maritime Simulator Network (EMSN), a macro simulation environment for ship handling simulators. This is an open IEEE 1278 standard network protocol enabling interactive communication between distributed simulation environments. Based on an introduction into ML 2.0, the proposed STM concept is introduced, its expected impacts are listed and Key Performance Objectives are derived. The backgrounds on the EMSN are given and it is shown how it can assist in assessing the impact of STM’s Key Performance Indicators.

The paper presents comparison of the ‘Person over board’ manoeuvres. The article was based on research con-ducted on a group of students of the Faculty of Navigation of Gdynia Maritime University. People involved in studies previously conducted on board training on school training ships: "Dar M?odzie?y" and "Horyzont II", but did not have experience as an officers. Research was carried on the Polaris Ships Bridge Simulator, located at the faculty of Navigation, of Gdynia Maritime University.

A frequency domain-based analysis of a submarine maneuvering model has been completed and used to study the effects of parameter uncertainty. The maneuvering model of the BB1-X submarine has been analyzed for the purpose of understanding the consequences of reduced input fidelity. Inputs were varied individually and ranked based on the resulting deviation from the original model. The model was also reduced to include fewer degrees of freedom or dynamic effects and compared with the original fully detailed model. The intention of this study is to determine which data are most crucial to the accurate maneuvering simulation of a submarine. Depending on the application of such a model, certain accuracies may be sacrificed to reduce resource requirements and save cost. The results of this study give some guidance as to which types of parametric data need to be the most detailed. Although the results will not give exact sensitivities for all submarine maneuvering models, it will give an indication of which areas should be focused on. [ABSTRACT FROM AUTHOR]

Selection of a tugboat to be used in a port according to the operations to be carried out is a difficult problem that requires many criteria to be evaluated at the same time. This selection requires high experience as well as technical knowledge about tugboats and operations. In this study, a numerical analysis was carried out within the framework of design, operational and financial criteria to develop a method to select a tugboat. The propulsion/manoeuvring systems used in the tugboats were investigated and different criteria related to the tugboats with different propulsion systems were evaluated by subject matter experts through a survey including technical and financial data. The responses were interpreted with the fuzzy analytic hierarchy process to select a suitable tugboat alternative based on the type of propulsion system. [ABSTRACT FROM AUTHOR]

A 6 degrees of freedom manoeuvring model of an estuary container vessel was implemented in the inland navigation simulator Lara at Flanders Hydraulics Research (FHR). The container vessel, with dimensions 110 m × 17.5 m × 4.5 m, is equipped with two Z-drives, each one consisting of two contra rotating propellers. Both Z-drives have a 360° azimuth angle of operation during manoeuvring. The mathematical manoeuvring model was built to cover all degrees of operation. This required the execution of a significant number of captive model tests in the shallow water towing tank of FHR (in co-operation with Ghent University). Based on these tests a new mathematical manoeuvring model was built to cover all effects of operation, including the interaction effects between the two Z-drives. The new mathematical model was implemented in the simulator and both fast time and real time manoeuvring simulations have been carried out. A paper discussing the validation of the manoeuvring model has been presented during MARSIM 2015 (Vos, Delefortrie, and Van Hoydonck in Validation of the manoeuvring behaviour on an estuary vessel. MARSIM, Newcastle, 2015). The present paper discusses the details of the manoeuvring model, with emphasis on the interaction effects between the Z-drives and the influence on the hydrodynamic forces. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

One of the basic tasks in the shipping industry is to ensure safe manoeuvring and navigation through channels and confined waterways. This paper has presented a practical and theoretical approach to the assessment of safe manoeuvring in waterways based on knowledge and experience. Experienced mariners had to sail through an approach to Thorn channel in a calm weather using their own knowledge and methods to determine variable angles of rudder deflection. The navigational performance has been determined in terms of deviation from the intended path. The results have indicated the difference in distances of the ship paths between all respondents as compared to the intended path. Besides determining the ship's turn path, it is necessary to consider the factor F which represents the distance between the WOP and the beginning of the actual turn and the width of the swept track. However, the aim of this paper is to present a control methodology for mariners while working at sea. [ABSTRACT FROM AUTHOR]

This study investigated particle and gaseous emission factors from a large cargo vessel for her whole voyage including at berth, manoeuvring and cruising. Quantification of these factors assists in minimising the uncertainty in the current methods of exhaust gas emission factor estimation. Engine performance and emissions from the main marine engine were measured on-board while the ship was manoeuvring and cruising at sea. Emissions of an auxiliary engine working at 55% of maximum continuous rating (MCR) were measured when the ship was at actual harbour stopovers. Gaseous and particle emission factors in this study are presented in g kWh −1 or # kWh −1 , and compared with previous studies. Results showed that the SO 2 emission factor is higher than that of previous studies due to the high sulphur content of the fuel used. The particle number size distributions showed only one mode for different operating conditions of the ship, with a peak at around 40–50 nm, which was dominated by ultrafine particles. Emission factors of CO, HC, PM and PN observed during ship manoeuvring were much higher than that of those recorded at cruising condition. These findings highlight the importance of quantification and monitoring ship emissions in close proximity to port areas, as they can have the highest impact on population exposure. [ABSTRACT FROM AUTHOR]

In the paper a modular manoeuvring model of the passenger ferry “Landegode” is built, validated and studied. Global sensitivity analysis based on the variance decomposition is performed to assess the sensitivity of the individual model coefficients on the simulation outcomes. It is found that uncertainty in both hull hydrodynamic coefficients and the steering and interaction coefficients can result in significant uncertainty in the simulation results. The most influential coefficients are defined for the standard IMO manoeuvres. The possibility of identification of “true” values of the coefficients from full scale trials is studied. Such analysis would allow improving empirical predictions of the coefficients. It is found that different combinations of the model coefficients result in similar time-series. This indicates the presence of correlation between the coefficients. Thus, although the identified coefficients can be used for simulations of the ship manoeuvring, it is impossible to identify the single “true” value for each coefficient from these sea trials. [ABSTRACT FROM AUTHOR]