This article indicates the development trends in the construction of offshore wind turbines worldwide, and the characteristics of existing and planned ships for wind turbine installation and maintenance; it presents an approach to design ports with their future operations in mind. Problem: The safety of navigation in port waterways is the basic restrictions for the construction of harbors (terminals) to handle ships used for the construction of OWT and for increasing their size. Navigational risk is a criterion of navigational safety assessment that allows its accurate estimation in port waterways. Method: The article presents the method for dimensioning port waterways for ships serving offshore sea wind turbine transport and construction. Furthermore, a method for determining the navigational risk of jack-up vessels navigating in port waterway areas is presented. Results: The authors have determined conditions for safe operation of these ships in restricted areas and defined the basic condition of navigational safety. The presented method of navigational risk analysis refers to the departure of a loaded ship carrying offshore wind turbine components in the presently designed port terminal in Świnoujście for handling offshore wind farm projects. Conclusion: These are universal methods that can be applied to the design of ports serving vessels that install offshore wind turbines in various types of waters.

New systems are produced and developed to meet specific needs, and their reliability is the most important issue. In the maritime industry, evaluating failures in a ship’s propulsion system results in high costs and the loss of prestige for the company. Land/sea fleet employees need to detect and minimize the failures that may occur in ship propulsion systems in advance to ensure the continuity of the ships’ operations. In this study, the recorded failure data of four different ships belonging to a fleet in the last 10 years are used. Failures were examined as a whole since the ships have similar propulsion systems. The obtained failure data were grouped, and the average time to fix the failures was determined by the chief engineer and made suitable for reliability, availability, and maintainability (RAM) analysis. A suitable model was created for grouped failures by Isograph’s RWB software. As a result of the analysis of the propulsion system and its subsystems, the main engine of the ship was shown to have the best reliability. Furthermore, the most important components were the cylinders of the main engine as subsystems. This study highlights the components that are important to the reliability of a propulsion system. Thanks to the RAM analysis, improvements can be pinpointed on a ship’s propulsion system, which will increase the operations of the maritime industry. Reducing failures will further increase the confidence in maritime transport and strengthen its place among the modes of transportation. This study provides a valuable resource for academicians, experts, as well as companies working on reliability, availability, and maintainability in the future.

This study examines the volatility of the forward freight agreement (FFA) time series in the dry bulk shipping market. Series pattern analysis is first performed to determine the volatility and the characteristics of the unique FFA price time series. It then applies the ARIMA-GJRGARCH model to the Capesize FFA time charter (C5TC) and specific voyage charter one-month contracts (C3, C5 and C7), creating long or short signals, which helps market participants with FFA trading or hedging. In this study, these signals are collected and used to calculate the profit and loss for a specific period. Finally, the model-based return results are compared with the common buy-and-hold strategy. The empirical result suggests that this methodology is effective in generating trading signals, especially in the volatile periods, providing traders with prompt warnings about imminent market shocks. The purpose of the study is to examine whether this volatility-focused method is efficient in modelling FFA time series, and it also provides a handy method that may help market players make more accurate predictions when volatile days arrive.

Recently, technological advancements, globalization, ongoing mergers and acquisitions, and intense competition have dominated the container shipping industry. This situation has led to the formation of major container shipping lines with similar technologies, offering the same service. In such an environment, a strategic competitive advantage is no longer entirely dependent on the basic features of the service provided and customer relationships, which is more difficult to replicate, has gained importance. Container shipping lines must develop customer-centric relationship marketing strategies that cover the whole organization and marketing activities to survive, and maintain their profitability, in the current competitive environment of the industry. However, these strategies and their implementation are not precisely defined in the container shipping industry. Therefore, this study explores the relationship marketing strategies that are practiced in the container shipping industry. Data is collected via 22 semi-structured interviews with container shipping partners (i.e. container shipping lines and freight forwarders). Loyalty programs and relationship pricing are the most often mentioned relationship marketing strategies that foster customer loyalty in these interviews.

In this paper, to improve the mechanical behavior of DeepCwind semi-submersible floating offshore wind turbine (FOWT) platform mooring lines, the nonlinear catenary cables of the platform were divided into multi-segment and intermediate buoys. Mathematical formulations of the boundary element method (BEM) governing the dynamics of mooring line systems with buoy devices were described. This study was applied to the OC4-DeepCwind semi-submersible FOWT platform, which is designed for a 200-meter water depth with mooring lines consisting of three catenary steel chain cables at 120° angles to each other. The dynamic response of the multi-segment catenary mooring lines with different buoy radiuses and different positions along the cables was investigated. The full-scale platform was modeled in ANSYS-AQWA software, and the simulations were performed under harsh offshore conditions. The mooring line’s general arrangement, tension, strain and uplift force for different buoy radiuses and their position along the cable are presented and discussed. Moreover, platform motions in three directions (surge, heave, and pitch) were also analyzed. It was concluded that by correctly selecting the buoy volume and position along the cable, the tension of the cable may be reduced by up to 45%. By incorrectly selecting the buoy, the results caused adverse effects.

The purpose of this article is to determine the main conditions for the profitable production of motorboats in Poland by taking into account the implementation of an R&D project. Theoretical considerations were made for the analysis of the main considerations based on the VT Sport case study. A descriptive analysis was carried out, indicating the market conditions for the functioning of enterprises producing motorboats, including electric boats. The effects of the implementation of the R&D project for the production of electric motorboats were indicated. Results were obtained for defining changes in the business model through the use of the R&D project, and a critical discourse on the effectiveness of electric propulsion of motorboats was carried out.

Deterioration in the performance of gas turbines is a well-known phenomenon occurring during their operation. The most important form is a decrease in the internal efficiency of the compressor and turbine due to fouling, which is the most significant deterioration problem for an operator. This article presents the effect of gas turbine fouling as a drop in airflow, pressure ratio, and compressor efficiency resulting in a reduction in power output and thermal efficiency. This resulted in a decrease in the nominal power of a gas turbine and an increase in the fuel consumption (heat rate). The fouling effects were described using the example of the MT30 marine gas turbine with a nominal power of 36 MW. The estimated profit loss during the operation of the gas turbine was within the range of 1–10% of the total fuel consumption cost. A 2% deterioration in the output of a gas turbine accounted for US$ 10,000–20,000 per year and 1 MW of gas turbine nominal power (according to marine fuel prices in 2019–2020) – this means at least US$ 300,000 annually for an MT30. Due to the low accuracy of fuel consumption measurements, another possibility was provided. The correlation between the gas turbine power deterioration and thermal efficiency was presented, which made it possible to estimate the increase in the specific and total fuel consumption when the nominal power deterioration is known. Two linear approximations were proposed to calculate increases in the annual operating costs for an MT30 due to fouling.

This article explores the use of ontology for semi-automatic marine vessel navigation and ship-to-ship communication to mitigate collision risk. Semi-automatic vessel communication is a step towards automatic communication for autonomous ships. Examples of how such communication can be used is discussed, based on a comprehensive analysis of selected marine collisions, with particular attention to the communication conducted on ships. The effectiveness of such communication was assessed and compared. The suggested solutions are based on the review of official reports from accident investigations. The novelties of this work include original ontologies and interfaces. Through this work, it could be possible to fully automate communication processes between ships. In future work, the research results in this work will be used to create a system of automatic communications for manned and autonomous vessels.

In this study, a functional diagram for an automatic sliding mode control system for a three-phase bridge buck current converter was developed. To achieve this, a simulation program was created in MATLAB/Simulink which analyzed the dynamic performance of the developed automatic control system, operating in the active rectifier and network current inverter modes. The results present the mathematical modeling outputs, along with the analyzed control algorithm and the automatic control system of the buck current converter evaluated.

The aim of this article is to present the results of research on solutions that can be implemented by the Gdynia Sea Port to allow it to obtain the title of a Green Port. The conducted research concerned a broad area, i.e., the identification of initiatives taken by seaports distinguished as Green Ports and other possible solutions consistent with the ideas of sustainable development. The article focuses on solutions for the Gdynia Sea Port, which, despite the implementation of many pro-ecological initiatives, does not have the official title of a Green Port. Seaports serve many modes of transport, but they are currently dominated by road transport. The activities of seaports located in urban agglomerations significantly contribute to the emission of air pollutants, noise, congestion, and other factors, which directly affect the health and quality of life of its inhabitants. The research process involved a critical literature analysis, the method of deduction, and a structured interview with representatives of the seaport in Gdynia. Based on the conducted research, areas important for obtaining the title of Green Port were identified, including increased investments in renewable and alternative energy sources, as well as a focus on the implementation of intelligent solutions.

Dear Readers, This is the last and fourth issue (No. 68) of our journal in 2021. This issue includes twelve articles by authors from research centers in Poland and abroad. The articles deal with diverse problems in the following branches of science: Civil Engineering and Transport, Environmental Engineering, Mining and Energy, Material and Mechanical Engineering, Economics, Management and Quality Science and Information and Communication Technology. The Civil Engineering and Transport section consists of five articles. The authors of the first paper found that the vessel stability criterion is not valid due to a turning maneuver and it needs a new approach. Further in the article, they claim that there are no accurate procedures and formulas to calculate the heeling moment due to the centrifugal forces as a function of time. This provided the reason for the authors to develop such a procedure, taking into account appropriate formulas to separate the heeling moment due to centrifugal force from the other heeling moments acting on the vessel during the turn. The second article elaborates on the effects of the international maritime safety requirements implemented over recent years. The authors studied the impact of these regulations on improving vessel safety in European maritime waters by analyzing accidents between 2014 and 2020. The analysis was based on the classification of accidents by their severity, type of vessel and the identified causes or contributing factors. The next study presents the new, fourstep approach to selecting the location of an LNG terminal, where the area concerned was the Adriatic Sea. The expert authors carried out a multi-criteria analysis of six locations for three different scenarios using the PROMETHEE method. The author of the fourth study notes that, in the development of vessel safety assessment methods, it is necessary to reach a balance between the accuracy of the results and their availability. This article describes the calculation of the theoretical hull in relation to the damage stability provisions set out in SOLAS 2020, ICLL 66/88 as amended in 2003 and MARPOL 78. The correlation between the required GZ properties and the actual vessel’s circle on a wave is presented. The study demonstrated the influence of GZ curve parameters on the ship’s circular motion. The last article in this section presents best practices for reducing private transport in selected European cities. Methods of source analysis, descriptive analysis and the method of inference made the analysis possible. As the analysis shows, for city administrators, it is a challenge to continuously search for new solutions to reduce traffic problems. In addition, it is noted that transport policy is a key tool for changing the public’s awareness of the ecological approach in the use of private vehicles in the city. There is one article in the Environmental Engineering, Mining and Energy section which is aimed at determining the impact of changes in the global economy on the evolution of the fishing fleet. An attempt is made to identify the most common type of vessels currently operating in the world fleet. The authors intended to determine the size and structure of the existing fishing fleet and, moreover, to find whether it is changing because of environmental transformation. The Material and Mechanical Engineering section consists of two articles. The first study discusses the existing and future regulations on the energy efficiency of vessels and methods for improving it. The authors compared the design and operating characteristics of slow-speed gas-fired main engines, conditions for liquefied natural gas regasification and the amount of waste cold. The second article deals with the problem of the long-term operation of hydromechanical fittings exposed to aggressive water. The author aimed to find the importance of water quality during the operation of wind power plants and geothermal power plants, especially hydromechanical fittings during long-term operation at the base of the Baltic Sea and geothermal power plants. In the Economics, Management and Quality Science section, we present a study that addresses an important and topical issue in supply chain management. The subject of the study centers on the uncertainty in supply chain operations. The authors’ objective was to create a catalogue of typological disruptions as an inherent component of supply chain management under the conditions of uncertainty. The overview leads to the conclusion that contemporary supply chain management requires at least an attempt to forecast the effects of uncertainty conditions, including the risk of disruptions. Three studies are presented in the Information and Communication Technology section. The aim of the first article was to evaluate the potential of using modern virtual reality (VR) and augmented reality (AR) to investigate passenger evacuation from vessels. The results of the study showed that there is excellent potential in the implementation of VR and AR technologies in navigation. The subject of the next two articles is unmanned aerial vehicles. It should be noted that the development of unmanned vehicles in transportation is gaining momentum, so it can be believed that the use of such vehicles will become commonplace in the near future. In the first study, the author notes that unmanned aerial vehicles allow relatively cheap and fast acquisition of high-resolution data for small areas, making it possible to produce not only an orthophotomap, a two-dimensional set of data, but also a three-dimensional cloud of points, which is the basis for obtaining a numerical terrain model. The study evaluated the effectiveness of algorithms used for the classification of terrain in photogrammetric point clouds and obtaining a correct NMT. Three algorithms were tested: Adaptive Triangulated Irregular Network, Progressive Triangulated Irregular Network and Multi-Scale Curvature Classification. The research included two test areas on natural coastlines. The author of the second article on unmanned aerial vehicles notes that low-altitude imaging enables rapid acquisition of high-resolution data for various objectives, especially for mapping. This article presents the mapping of a bridge and its warning signs, lighting and spans to create electronic navigation maps for inland navigation. The object of study was the Cłowy Bridge on the Regalica River in Szczecin. We hope that the presented studies will receive much interest, and it will inspire discussion and drive new research.

Dear Readers, We are pleased to announce the third 2021 issue (No. 67) of the Scientific Journals of the Maritime University of Szczecin. This issue features novel findings and perspectives in the following areas: Civil Engineering and Transport, Environmental Engineering, Mining and Energy, Material and Mechanical Engineering, Economics, Management and Quality Science, and Information and Communication Technology. The Civil Engineering and Transport section features two articles. The main research objective in the first study was to identify and propose new risk assessment tools. A maritime accident involving a Cosco Busan container ship that struck the base of the Delta Tower of the San Francisco-Oakland Bay Bridge in November 2007 was chosen as an example. An analysis of the factors that led to the accident was conducted, and the effects of the accident were outlined. On that basis, a risk analysis using mathematical and tabular values related to navigational risk in a specific navigation region was performed. Drones and their potential uses in the maritime sector by various entities, including ship classification societies, shipyards, and search and rescue (SAR) missions, was the subject of the second study. The benefits and limitations of drone implementation were highlighted, and a plan for the use of drones in shipping was presented. Projections of drone applications in the maritime sector in Poland, in the West Pomeranian Voivodeship and Pomeranian Voivodeship, were also made. The Environmental Engineering, Mining, and Energy section contains an article discussing waste treatment methods to identify the best method to reprocess (recycle) polyurethane (PUR). Glycolysis was concluded to be the most promising process for polyurethane waste management. The research material was produced by the glycolysis of scrap polyurethane foam. Based on the research, analysis, and testing, it was concluded that the most suitable reaction conditions for the recovery of polyols from scrap were: a temperature range of 170–190°C, alkaline pH, and an air atmosphere, which were the same for all samples. The Material and Mechanical Engineering section contains two articles. In the first study, the influence of the stern wedge length and height on hull drag and trim to glide in calm water was examined. For this purpose, liquid flow was simulated with Star-CCM+ software using a shifted mesh model and a turbulent k-ε model. The stern wedge sat below and near the stern perpendicular to the hull to facilitate moderate spread. To evaluate the hydrodynamic properties of the hull at different speeds, different wedge lengths of 0.2 B, 0.5 B, and B were investigated at two different heights of 5 mm and 10 mm. The trim angle, resistance, water surface elevation, porpoising, roster tail, and the stern and bow were computed and analyzed. The results showed that as the length of the wedge increased, the drag and trim decreased. It was also found that the best wedge for a vessel with the desired wake generation was one with a length of 0.2 B and a height of 5 mm. The author of the second study argued that the good quality of composite castings can be mainly attested by their user. In his research, he presented the casting defect porosity, with particular emphasis on the porosity in suspensions and saturated metal composites. The purpose of the study was to detect and analyze the porosity in composites using microscopic and sub-microscopic methods. Three articles are featured in the Economics, Management, and Quality Science section. The author of the first study shows that the increasing unpredictability of socioeconomic or biological changes (e.g., the SARSCoV-2/COVID 19 pandemic), the multidirectional nature of their impact, the variability of their intensity, and the uncertainty in estimating their potential impacts, made it difficult for supply chains to stably operate. This reality demonstrates the great unreliability of the classical economic measuring instruments and methodologies used in management and quality sciences. This observation sparked an attempt to produce a sample set of expectations for contemporary supply chains that are particularly appropriate for emerging market challenges in the form of threat and condition megatrends, including those illuminated during the SARS-CoV-2/ COVID-19 pandemic. The author suggests a holistic perspective on the nature of the supply chain system and its processes. The proposed approach, based on an interpretive (qualitative) research method enhanced by an idiographic nomothetic approach, is treated as a creative alternative that does not exclude other ways of perceiving the supply chain. The research subject of the second study was the relationship between the characteristics of consumer product demand and the profitability of the purchasing strategy, considering both the supply source and the transportation technology. A model was developed for two demand distributions (Gaussian and gamma), varying sales fluctuations, and changes in demand during delivery. Then, Monte Carlo simulations were performed by considering transportation costs, warehousing costs, capital costs associated with maintaining inventory, and lost sales costs. The simulation results showed that the higher the fluctuation and the lower the demand predictability, the more profitable the air freight and local deliveries. The calculated results further indicated that the strategy of outsourcing production in low-cost countries will, in many cases, become unprofitable if the production costs in such countries grow even marginally. Team coaching was the research problem in the third study. The goal was to present a team development process using the High Performance Team Coaching Model. The first part of the article characterized the theoretical essence of team coaching and the specifics of the team coaching process, along with the specific tools at each stage. In the second section of the article, the author explains the process for implementing the High Performance Team Coaching Model in business practice. The Information and Communication Technology section features a study on the use of artificial neural networks (ANNs) to solve image classification problems. SHREC (Automatic Ship Recognition and Identification) projects were used to classify and identify ships based on images obtained from CCTV cameras. The authors collected an image dataset of ships during the 2018, 2019, and 2020 video survey campaigns and utilized three pre-trained neural networks, GoogLeNet, AlexNet, and SqeezeNet, to explore the classification feasibility and then assess their quality. About 8,000 ship images were used, which were divided into seven categories: barges, special-purpose service vessels, motor yachts with motorboats, passenger ships, sailing yachts, canoes, and others. The authors compared the results obtained using neural networks to classify floating inland vessels. The articles in this issue show the continuous theoretical and practical inspiration of the authors, contributing to important and current scientific investigations. I encourage you to read these articles in the hopes that they will be of interest to you and that they will stimulate debate and inspire you to undertake research, not only in the discussed areas but also on an interdisciplinary level.

This article concerns the issue of the long-term operation of hydromechanical fittings during their contact with aggressive water. The aim of this analysis was to investigate the significance of the quality of water during the operation of wind power farms and geothermal power stations, especially hydromechanical fittings during long-term operation at the base of the Baltic Sea and geothermal power stations. This article presents the properties of water and their impact on hydromechanical equipment during long-term operation in marine and geothermal waters. The paper includes the analysis and evaluation of their impact. Additionally, the article describes important problems with the operation of wind power farms and geothermal power stations. The results of periodical analyses of southern Baltic marine water and thermal groundwater from “Geotermia Podhalańska” were evaluated and used as the basis for future research. Every negative parameter of water, known as its aggressiveness, adversely affects the basic materials of wind masts and pipelines, as well as the hydromechanical equipment in contact with marine and thermal water. The presented results show the necessity of controlling the water quality prior to the operation of geothermal water and building wind power masts in coastal marine water. Attention was paid to corrosion during contact with aggressive water with unprotected materials. This issue is rarely seen in the literature but is very important.

The shoreline is an important geographical zone, and knowledge of its accurate location can be crucial for coastal management and mapping. The ever-increasing number of aerial and satellite sensors is leading to research related to the development of new methods for the automatic extraction of the shoreline. Currently, there is a lot of research in this area with different research methodologies. In this paper, an analysis of shoreline extraction methods was carried out. Based on the analysis undertaken, current research processes in this field can be verified. This enabled the further evaluation of the research methodologies studied, including the identification of basic assessment elements for shoreline extraction accuracy. Practical aspects of this work include the ability to establish the correct methods to assess the accuracy of extracted shorelines for both research and production processes related to data extracted from remotely sensed images.

The aim of the article is to designate catalogues of typological disruption as an inherent element of supply chain management in the light of uncertainty conditions. By means of deduction, the typological characteristics of the disruption and the catalogue of management decisions were determined. In this way, the scope of theoretical knowledge based on the theory of risk and supply chain management was expanded by leading the discourse towards the location of the so-called the required uncertainty in the canon of obligatory components of management strategies. The article presents an overview discourse leading to the conclusion that contemporary supply chain management requires at least an attempt to forecast the effects of uncertainty conditions, including the risk of disruption.