Dear Readers, I am pleased to present the 46th issue of the Scientific Journals of the Maritime University of Szczecin. In this issue, the Journal focusses on the latest findings from the fields of transport engineering, marine navigation and marine technology. This issue includes articles related to the problems of transportation safety (chemical cargo carriers, LNG transportation), the latest research in the field of design and operation of marine machinery (including condition assessment of mud pumps for drillships, design of submersible autonomous vehicles and advances in maritime measuring techniques), as well as state-of-the-art solutions for maritime communication, navigation data processing and maritime positioning systems for vessels (Automatic Identification Systems, radar systems, and the Global Navigation Satellite System). We have also included a particularly interesting article entitled “On navigation as a scientific discipline” which summarizes the existing achievements in the field of navigation and describes the potential to classify navigation as an independent scientific discipline. I warmly invite authors to submit articles for consideration by the Journal and readers to send us their comments. In order to access an electronic version of the current issue and archived issues please visit http://scientific-journals.eu/.

The article by Krzysztof Czaplewski, Sławomir Świerczyński and Piotr Zwolan entitled “Using elements of integral calculus in the process of optimizing the configuration of navigation positioning systems”3 published in the previous issue (45/2016) is an English version of the revised article by Krzysztof Czaplewski “Kryterium całkowe jako narzędzie matematyczne wspomagające proces optymalizacji wystawienia stacji systemu nawigacyjnego” 4, published in ZN AMW No. 3/2000. The authors would like to apologize for having forgotten to include this article in the reference section, which mistake was noticed after the article had been published. The authors' intention was not to conceal the previous publication, but to return to the previous studies on navigation processes optimization devised by one of the authors. The authors considered it desirable to get back to the previous results, as the problems of automatization of optimization processes are still valid in navigation and require further work. Furthermore, the subject of the article lies in the area of studies currently performed by the authors. In the context of increasingly frequent information on spoofing and jamming of satellite system signals, ground-based radio navigation systems begin to grow in significance again. For example, the contemporary mutation of the Loran system called eLoran seems to be at the time the best option supporting the operation of GNSS. The erection of new eLoran stations or other systems supporting the operation of GNSS has to be preceded by reliable optimization studies among others, and this is the reason why the authors are interested in this area of studies. We would like to apologize to anyone who felt offended by the situation. The Authors

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.

The paper presents a review of ultrasonic sensors. Attention is focused on the possibility of using such sensors to keep an unmanned aerial vehicle at a constant altitude above the surface. Such a task requires filtered and unfiltered signals, so that the ground level can be distinguished even when obstacles are present. Three selected sensors were tested. The possibility of connecting these sensors to external devices was also studied. The potential of the individual sensors and of a set of sensors is discussed. The study showed that the best solution is to use a set of three ultrasonic sensors. Alternatively, a sensor with both unfiltered and filtered measurement was proved to be an adequate option.

The present paper begins with a presentation of an interdisciplinary research project, the method is then introduced, followed by a brief description of the unmanned autonomous maritime vehicle. The following chapter concerns a combined model describing the motion of the vehicle, including the hydrodynamic and aerodynamic forces. The model takes into account gravity, displacement, resistance, thrust, lift, and other hydrodynamic forces. The primary task of an advanced maritime vehicle is to precisely predict its position. To do so, an integrated model for the acquisition, analysis, and processing of the signals is necessary. The processed signals should then be used for the precise steering of the vehicle. The vehicle should be equipped with a stabilization system. Information on the integrated steering, positioning, and stabilization system of the vehicle is briefly presented in the paper. Such system enables to obtain a fully autonomous vehicle. Some information on the propulsion and underwater energy supply systems is also briefly presented. In the final part of the paper, some of the issues connected with vehicle safety are introduced.

There were a number of circumstances which became the basis for the MarTech liquefied natural gas (LNG) project: the forthcoming regulations reducing permitted sulphur content of a ship’s fuel, and aspirations of Poland and Lithuania to diversify sources of natural gas import by building LNG import terminals. The project was launched in 2012 and lasted more than three years until April 2015. It concerned the uses of LNG in the South Baltic Sea region and was realized by eight partners from five countries surrounding this area. The main aims were promotion of LNG as a fuel and dissemination of knowledge and experiences related to LNG. They were achieved by organizing training courses, seminars and meetings between stakeholders, research institutions and policy makers. This paper is an informal report of activities within the MarTech LNG project.

Computer simulations used for predicting the behavior of oil spills at sea allow optimizing the deployment of oil spill response personnel and resources, and using the backtracking method to identify the polluter in cases where spills are sighted some time after they occurred. Predicting the direction and speed of oil slick spreading is of fundamental importance. An attempt was made to verify the influence of selected simulation parameters, related to hydrometeorological conditions, on the behavior of the resulting oil pollution. Different responses were obtained under the same simulated weather conditions, depending on the type of spilled oil. The experiment was conducted on a PISCES II oil spill simulator.

According to some authors it is estimated that around 80% of accidents at sea are caused by human and organizational errors (HOE). In order to gain knowledge of phenomena that occur during ship operations, a decision was made to design and build a test site for carrying out model-based investigations of ships, including in situations of hazard to buoyancy. The model-based investigations are used as the basic and universal method for forecasting ship dynamic properties. The results of initial research on the dynamic impact of air flow on an 888 project type ship model are presented in the elaboration. The research has been executed at a test stand located in the Polish Naval Academy. The experimental results have been compared with theoretical calculations for angle of dynamic heel. Input parameters for the tests and calculations have been defined in accordance with recommendations of the Polish Register of Shipping (PRS) and International Maritime Organization (IMO) (IMO Instruments).

This article examines the differences in the lifetime of mud pumps, which are part of the equipment on (ultra) deep-water drillships, depending on the strategy of maintenance. The authors conducted research on mud pumps to create an efficient diagnostic tool to help pumps operators on daily maintenance routines. We have created drilling process diagrams, one pertaining to the operation of mud pumps for which maintenance is carried out without technical supervision, the other including diagnostic maintenance. The diagrams show differences pump failure frequency.

One of the factors affecting a ship’s safety during its voyage is the ability to detect encounter situations. Navigators mostly use two parameters: closest point of approach (CPA) and time to CPA (TCPA). Their limit values, considered as safe, depend on the parameters of the vessel, geographic area, and weather conditions. These limits are set by the navigator and are based on his experience; however, in specific situations, there is a need to use other parameters, such as ship domain. It is very important for the automated communication system to determine the critical moment when intership communication should be started. The article presents an algorithm of automatic detection of situations where the communication should be initiated. The influence of data relating to the vessel, geographic area, and weather conditions can be taken into account. The output produced by the program, based on the authors’ algorithm, is presented.

The current systems supporting navigation on board of ships are built on the classic concept for equipment: the system is developed, tested, type approved and installed; and from that time on it is used with no or little modifications. The systems are using data, but the data streams do not influence the system behavior. Looking at other industries, a regime of software and system maintenance has been established which allows more rapid updates. System development in the IT arena is moving towards a more modular approach, encapsulating individual components to ease the implementation and delivery of updates with a limited system-wide impact. This key concept is lately often referred to as the “app-concept”. In addition, more and more systems are using data to adjust system behavior to support a situational centric approach for decision support. The e-Navigation development asks for exactly that: a way to improve innovation, while ensuring system stability for the navigational components used by the navigator on the bridge, and a concept to increase situational awareness. A key aspect of the success of new systems will be the ability to convert data into information as needed in any given situation, creating the necessary knowledge for intelligent decision making and increasing the competence of a navigator. The paper will focus on the following topics: the classic monolithic equipment paradigm; modern system architecture, using components and app-concepts; advantages of using data streams to enable situational driven tool enhancements; and the app-concepts supporting the situational centric information presentation.

The article presents the implementation of an Internet application that graphically depicts the current situation at sea, with the prospect of being used in maritime applications and the possibility to work on multiple hardware platforms. Modern techniques have been applied in order to allow permanent development of the application and ensure that it is maintenance-free and self-reliant, even in case of unexpected situations. This publication covers the procedure followed to build the application as well as its field and method of operation. Possible usages of the application and tests carried out on many platforms have been presented. Ideas for further development have also been introduced.

This article presents a method of obtaining relative and global coordinates using the Global Navigation Satellite System (GNSS). Four GNSS antennas have been compared in this research. The GNSS antennas have been utilized by the Veripos and Septentrio Systems. Global Positioning System (GPS) pseudorange observations are used to obtain relative position of the GPS antennas. Relative positions are based on calculations made by the RTKLIB software. Lever arm range and bearing are used to assess accuracy of the true antenna location relative to the vessel Navigation Reference Point (NRP). The article deals with the problem of assessing the quality of real-time positioning equipment. Comparing results of the raw position calculation with the physical measurements shows the usefulness of the real – time position monitoring.

A number of factors affect the safety of navigation, the collision of two ships being one of them. In ship encounter situations, certain principles of behaviour set forth by regulations are in force. Traditionally, a navigational situation is evaluated by identifying the closest point of approach for the passing ships and by comparing it with the assumed safe distance. Then it is necessary to use technical aids: radar and Arpa (depending on the regulations). In Arpa, navigational situation information is mainly presented in the form of vectors. The other presentation that can be used in an encounter situation is the predicted point of collision (PPC). This is the point or points toward which one’s own ship should steer at her present speed (assuming that the target does not manoeuvre) in order for a collision to occur. This paper presents original results of a study into the assessment of ship encounter situations based on PPC. The methods (analytical and graphical) of PPC as a set of circles are elaborated and an analysis of a ship encounter situation performed.

One consideration required in the resolution concerning radar and automatic radar plotting aid (ARPA) equipment is the possibility of an automatic drift calculation being realized in the base of fixed target tracking. This information is very important to providing safe navigation, especially in restricted areas. This paper presents an analysis of the present regulations contained in IMO resolutions and the results of an experiment conducted in the ARPA simulator. The aim of the simulations was to verify the reliability of the information presented on the ARPA display and to determine the accuracy of the automatic drift calculation implemented in the simulator.

This paper presents initial results from a series of eye-tracking experiments on a Full Mission Bridge simulator. The aim of this research was to develop a stochastic model of a navigator’s attention distribution during their navigational watch. Such model could be used as a tool for workload and usability studies for navigators and navigational equipment interfaces. A structure of the model is discussed together with the evaluation of Markov chains as a main modelling tool. Initial results are presented and discussed. It is suggested that 1st order Markov chains are not fully applicable for this problem. A combination of the 1st and higher-order Markov chains will be applied in the next stage of research.

Automatic identification system (AIS) data are used to analyze vessels’ positions or maritime traffic. Recently, satellites are being adopted for gathering AIS data (satellite AIS). A satellite AIS can gather AIS data from all over the world, including the center of the ocean. However, because a satellite moves around the world every day, there is a very short window of time that the satellite can receive signals from some specific area. Furthermore, because a satellite AIS receives signals simultaneously from a wider area than a terrestrial AIS does, the satellite AIS has lower rate of signal reception, especially near vessel congested areas. This may cause many unrecognized vessels. For this situation, this paper proposes a new method to estimate the number of unrecognized vessels based on a binomial distribution model. With this method, we are able to estimate the number of unrecognized vessels just from satellite AIS data themselves.

The author continues considerations aimed at justifying the establishment of navigation as a scientific discipline, which began in his article included in the collective work titled Admiralski farwater (Walczak, 2015b) (Admiral’s Fairway), and presents the subject and scope of navigation and sets forth other arguments supporting the idea. The author provides further arguments for the draft classification in which navigation would be an independent discipline of technical sciences, indicating the transdisciplinary nature of navigation within a framework of strict relationships with other domains of science in various fields of knowledge.

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.

The ecological protection of the Baltic Sea against extremely noxious pollution by chemical substances is one of the major issues faced by the states that are located on its shore. In this article, the transport of chemicals in bulk has been analysed. An attempt has been made at grouping dangerous chemical substances based on their negative impact on the environment. Databases that were available have been studied with respect to various chemicals transported in the seaports of Szczecin and Świnoujście. Based on the data available, an attempt at analysing the traffic of tankers carrying noxious chemical substances has been taken up.

Many factors that determine the quality and the vulnerability of transportation have changed. During the handling, storage and transport phases of different modes of transport, qualitative changes occur in ground soybean grain. These properties are the subject of changes that determine the quality of cargo and transportability. They constitute the group of quality features. Water content is an important characteristic affecting the quality of soybean meal from its production until after the storage process. In this article, we present the results of research on the hygroscopic characteristics of ground soybean grain and its different fractions, including the effect of temperature, relative humidity, ambient air and grain composition.

The paper presents research performed in order to indicate the threats posed to liquid petroleum gas (LPG) carriers maneuvering in the ports and fairway of Szczecin–Świnoujście. The effects of collision with another vessel, going aground, or striking a stationary object are taken into account. As a safety criterion, the possibility of damage to the cargo tanks is taken. As a result of the research, recommendations for ship movement in the ports and fairway were issued. The research method applied in this study consisted of several stages. In the first stage, experts determined possible scenarios of collision and grounding, taking into consideration local and navigational conditions. In the following steps, the external energy was calculated and an empirical model was used to determine the damage to the LPG carrier. In the last step, the necessary measures to be introduced port regulations are presented as conclusions of the research.

The paper introduces the process of safe ship control in collision situations using a differential game model with m participants. The basic model of process includes non-linear state equations and non-linear, time-varying constraints of the state variables as well as the quality game control index in the forms of game integral payment and final payment. As an approximated model of the manoeuvring process, a model of a multi-step matrix game in the form of a dual linear programming problem has been adopted here. The Game Control (gc) computer program has been designed in Matlab/Simulink software in order to determine the own ship safe trajectory. The considerations have been illustrated with computer simulation examples using the gc program for determining safe own ship trajectory in real navigation situations when passing commonly-encountered ships.

The Eco-Shipping Project has conducted demonstrative experiments since the beginning of this year using about 40 vessels including coastal cement carriers, oil tankers, and ro-ro ships supported by the Ministry of the Environment. The goal of this project is to reduce fuel and CO2 emission by 15%. The authors developed a voyage speed planning system which calculates a vessel optimum speed plan that takes into account weather forecast information and generates minimized fuel consumption for an operation. This paper describes an approach to optimize speed profiles on ship just-in-time voyages to save fuel and reduce CO2 emissions, and introduces some cases of experimental results.

The article presents an analysis of the possibilities of using RIS to assess the probability of collision during the transition of inland vessels under the bridges on the Odra River. Operational and technical analysis of the bridge structures and their restrictions affecting shipping in the area are also presented. The analysis of the traffic streams of the vessels under the bridge in Radziszewo and the bridge in Gryfino was made on the basis of the AIS data. The number of vessels in the selected area was divided into type and length. The probability of an accident, like collision during an overtaking and passing manoeuver, was defined.

This paper presents an overview of ship traffic volume and accidents in the Baltic Sea with a special focus on the Gulf of Finland. The most common accidents are groundings and collisions, usually reported to be caused by human error. The annual number of Baltic Sea accidents reported to HELCOM varied from 34–54 for collisions and 30–60 for groundings. The number of yearly port calls varied from 468–505 thousand with a peak in 2008. Exact port call data could not be found for all ports and hence had to be estimated. The number of line crossingings in HELCOM AIS data was found to be a good, rough surrogate measure for the total number of port calls and could be used if more precise port call data was not available. By analyzing two separate accident databases, an estimate for accident underreporting was calculated. Different statistical methods yielded an underreporting rate in the range of 40–50%. Lastly, the true number of accidents was estimated, based on the estimated underreporting percentage for the Baltic Sea. Based on these results, the true number of true accidents should be first estimated if accident statistics are used in building or validating maritime risk models. When using such models or accidents statistics in decision-making, the underlying uncertainty in the accident statistics should be taken into account as the underreporting frequency estimates are only approximations of the real number of accidents.

Spoofing, anti-spoofing, jamming, and anti-jamming algorithms have become an important research topic within the Global Navigation Satellite System (GNSS) discipline. While many GNSS receivers leave large space for signal dynamics, enough power space is left for the GNSS signals to be spoofed. GNSS signal power on the earth’s surface is around 160 dBW. The goal of spoofing is to provide the receiver with a slightly more powerful misleading signal, stronger than the original GNSS signal, fooling the receiver into using fake signals for positioning calculations. The receiver will generate a misleading position of the navigator. Practical spoofing that provides misleading navigation results of the receiver is difficult to conduct due to the signal infrastructure. Using trivial anti-spoofing algorithms in GNSS receivers, spoofing attacks can be easily detected. The article discusses the vulnerability of unmanned vehicles and provides an approach to anti-spoofing based on measuring distance between two antennas.

Ensuring security in a harbor requires research into its infrastructure using spatial environmental data. This paper presents a methodology that defines the design of a graph for modeling the interactions between surface currents and moving objects. Combining this graph with port charts that integrate electronic navigation charts with coastal orthophotographs allows us to perform a multidimensional analysis. In addition, the complete information about navigation and harbor infrastructure allows us to predict the effects of currents on objects that are moving in the dock. The capabilities of this application were tested in the Gdynia harbor and the defined graph is based on sea currents generated by the numerical hydrodynamic model M3D.

An increasing number of transport vehicles, including vessels, are powered by electric engines supplied by batteries. Warsaw University of Technology, together with the Maritime University of Szczecin and industrial partners, is involved in the “Innovative yacht with hybrid drive, fueled by renewable energy sources” project, focused on the construction of a yacht driven from such a source. The biggest challenge in this field of technology is represented by the batteries. Proper assortment and exploitation can significantly extend their life cycle. For this reason, the interest in forecasting battery life cycle in specific applications has increased. In this article the authors review the types of batteries used in transport and present the design and realization of a laboratory workstation developed to test battery parameters in the context of the project. The process of gathering parameters and the testing conditions are also presented. An original IT system manages the progress of the experiments. Logged cell operating parameters will be presented along with the real, measured data.

Świnoujście is a Polish seaport located on the Pomeranian Bay, on the southern coast of the Baltic Sea island of Usedom and Wolin. The port is situated in the Świna Strait in Świnoujście, Western Pomerania. The harbor consists of a cargo handling quay, passenger terminal and marina. The seaports of Świnoujście and Szczecin are closely linked economically to form a team and are connected by a passage through the Szczecin Lagoon. All big ships directed to Szczecin have to be routed through the port of Świnoujcie. The hydro-meteorological conditions in the Świnoujście Port area and surroundings, affecting safe maneuvering of ships, are analyzed by statistical methods. The conditions studied, with the aid of Port Captain logbook, are: currents, winds, water level, ice conditions and visibility. The statistical distribution of water level was analyzed and proposed as decision-making tool during a ship’s approach to Świnoujście Port.

The lack of proper communication between navigators is one of the many causes of dangerous situations in maritime transport. Automation of communication processes, in particular negotiation processes, can help either avoid such situations or, when they do occur, deal with them more promptly and effectively. We have characterized inference processes in maritime communication and the communication subontology used to describe these processes. The negotiating processes involving two or more parties are considered. An example is given of an encounter by three ships that requires communication (including negotiations) between the three navigators. We also present how the described communication processes can be automated using the developed subontology of communication.

This paper presents the research results on declarative ship domains in restricted areas. The research was conducted for vessels of different sizes and speed relations. In order to determine the declarative ship domain, data were collected in the form of questionnaires. The influence of ship length and speed on the size and shape of its domain were analyzed. The detailed processes of data development and further approximation are shown. Declarative domains for ships of different sizes and speed relations are compared. As a result of the research, a mathematical model of a declarative ship domain showing the elliptical shape of the domain is presented. The intermediate and summary research results are presented and conclusions drawn.