Luminous flux reduction during operation affects the operating lifetimes of LED lamps. Due to the very long lifetimes of LED sources, i.e. tens of thousands of hours, the lifetime declared by the manufacturer is most often determined by forecasting the luminous flux reduction. Lifetime forecasting is performed based on measuring the operating luminous flux reduction within a time frame of at least 6000 hours, every 1000 hours, followed by extrapolating the obtained results with a relevant exponential curve. This article presents the results of measurements of luminous flux changes taking place between 0 and 10,000 operating hours of several LED light sources. The obtained results were analyzed, and the lifetimes of the examined lamps were evaluated.

For many years, satellite systems have seen widespread use in a variety of technical applications, as well as in operations related to setting-out and the exploitation of track infrastructure. Their main applications include an inventory of the trackage course and detecting changes in its position. In both of these tasks, the most important element that determines the quality of an analyses is the high accuracy of the determinations being carried out. Satellite surveying techniques are not always sufficiently accurate, and in such cases, it is necessary to employ other land surveying methods to process surveying data. This article presents the authors’ considerations with regards to the possibility of applying one of the most common land surveying adjustment methods, the parametric method, to operations related to an inventory of tram infrastructure in Gdańsk. The results are based on surveys carried out during a surveying campaign in the autumn of 2018. The considerations presented in the article concern a small part of the research conducted under project No. POIR.04.01.01-00-0017/17 entitled “Development of an innovative method for determining the precise trajectory of a railborne vehicle” which is being implemented by a consortium of Gdansk University of Technology and Gdynia Maritime University.

The identification of navigational risks of accidents in fairways is a basic principle for the construction or modernization of waterways in restricted waters and when the conditions of safe operation change. The estimation of navigational risk requires the evaluation of the consequences of accidents occurring in fairways: grounding, impact against a vertical shore, port/offshore structure or moored ship. When determining the consequences of these accidents, it is necessary to know the emergency maneuvering area and the speed of the ship at the time of the accident. The method of ship movement simulation in real time was used to determine the parameters of emergency maneuvering areas and the speed of vessels during the maneuvers. The results of the simulation experiment include full form vessels (bulk carriers, tankers) with a capacity ranging from 5,000 DWT to 100,000 DWT. The presented results of simulation tests enabled the evaluation of probability and consequences of ships’ accidents in fairways resulting from technical failures of ships’ steering equipment, allowing to assess the navigational risk for ships sailing through different types of fairways (approach channels, port entrances and inner port fairways).

The main aim of this article is to present a method to process Inland AIS (automatic identification system) data that is part of RIS (river information services), as well as to synthesize and visualize information obtained from it for further analysis. This article presents problems with imaging the position of inland navigation units in the immediate vicinity of the Długi and Kolejowy Bridges in Szczecin. The passing of 80 inland units on this section of the Western Oder River was analyzed. Data were obtained from the AIS message database and industrial cameras of the RIS Monitoring Centre at the Inland Navigation Office in Szczecin. 35 units were equipped with AIS messaging devices. This article analyzed the data after previous processing, which consisted of selecting appropriate research units and decoding AIS messages recorded in the VDM message type (VHF Data Link Message). Then, the acquired positions of inland navigation units on the map were visualized to calculate the number of errors and their location. The obtained data were used to illustrate the locations of interference during the operation of transmitter-receiver equipment that prevented determining the exact position of inland navigation units in the immediate vicinity of the above-mentioned bridges.

This paper addresses the importance of the development of maritime safety culture, in terms of sustainable shipping through continuous improvement of the safety management system (SMS) that enables a shipping company’s personnel to effectively implement the company’s safety and environmental policy. The main aim of the International Management Code for the Safe Operation of Ships and for Pollution Prevention (International Safety Management Code – ISM Code), which was adopted by the International Maritime Organization (IMO) and became mandatory, by virtue of its entry into force on the 1st of July 1998, in SOLAS Chapter IX on the Management for Safe Operation of Ships, is to provide an international standard for the safe management and operation of ships as well as pollution prevention. Thus, compliance with the ISM Code and its effective enforcement is necessary to ensure adequate standards of safety and pollution prevention. The purpose of this paper is to show that the internationally unified legal measures that have been developed under the IMO in the ISM Code are an instrumental consequence of maritime safety values, and allow them to be achieved in practice. The result of this research is the justification of the thesis concerning the need to create a safety culture as a condition for sustainable shipping, including the safe operation of ships in the environment.

The issues discussed in this article concern the basic assumptions for the sustainable development of public transport in cities. We discussed the need and direction of changes that occur in public transport that were referred to both users and transport organizers in cities. To this end, we characterized the activities which encourage urban residents to use forms of urban transport and the limitations of commuting via individual transport. The purpose of this article was to determine the main directions and areas of development of public transport in Szczecin. In addition, we also presented the solutions applied in the city transport system aimed at making it sustainable. In addition, an attempt was made to determine the impact of selected solutions on residents’ transport behaviors. The survey research method was used to examine societal opinions and expectations regarding public transport. We also approximated the basic investments that have been implemented to make transport more sustainable and the activities for the development of electromobility. Future research directions on the sustainability of transport in the city, and especially on limiting vehicular traffic, were also discussed.

The specificity of navigation in the Baltic Sea means that intensive ship traffic occurs on the main shipping routes. Therefore, there is a high risk of a collision that will result in an oil spillage; the Baltic Sea is an area that is very sensitive to this type of accident. In addition, there are sensitive Natura 2000 areas that require special protection. A case study of a potential oil spill in the Słupska Bank area has been carried out in this paper; the results of the oil spill simulations and their analyses are presented in this article. The simulations were carried out in the PISCES II oil spill simulator. The spread of oil pollutants in typical weather conditions, the size of the threatened areas and the oil’s impact time have been analyzed. Based on the results obtained from the simulations, the most adverse weather conditions for the simulated oil pollution accident in the TSS Słupska Bank region have been determined.

The recent rapid improvement of nautical equipment functionality allows one to better observe and predict the dangers related to seamanship. However, these new features come with added complexity, and large amounts of information can overwhelm vessel crews and fleet operation centers, and the current state-of-the-art tools cannot filter out only the most important data for a given time and location. This paper presents the concepts and the algorithms of a software suite that provides a user with problem-oriented advice about a particular risk endangering a vessel and its crew. Based on the calculated navigational dangers and their predicted development, actionable guidance is proposed in an easy-to-understand human language. The quality of good seamanship is improved by a holistic approach to vessel installation, automated fleet operation center priority queuing, and the evaluation of crew performance during simulator training and daily operations. Both the software user interface, as well as the insights provided by the algorithm, are discussed.

The aim of the article is to present the essence of sustainable human resource management and attempt to answer the question of whether enterprises actually use the concept of the sustainable management of human resources in business management to achieve sustainable development. This is why the following research question was chosen for the study: “Is the concept of sustainable human resource management important in achieving sustainable development of an enterprise?” Verification of the research question and the realisation of the stated goal were made on the basis of a critical analysis of the source literature and a case study. In striving to achieve the research goal, the first part of the article presents the essence of sustainable human resource management; the second part presents a case study. This paper concludes with the applications in which the research question was confirmed. Enterprises choose a strategy for human resource management, depending on the following: the situation in the labour market, the economic situation, legal regulations, demographics, changes in technology in a given enterprise, the activities of both the employers’ and employees’ organisations, as well as self-governing bodies, employment agencies or personnel consulting firms and the capital owned by the organisation. The results of this study have shown that enterprises actually use the concept of the sustainable management of human resources in business management to achieve sustainable development.

Seaports are not only transport nodes but they are also important links in the land-sea transport chains and global supply chains. Due to the nature of their activities, seaports have a significant impact on both their internal and external environment. This necessitates the implementation of the concept of Corporate Social Responsibility (CSR). This concept focuses on, to a large extent, considering the positions of all the stakeholders when planning and implementing company strategies. Pursuant to the Act on Seaports and Harbours, the seaports in Szczecin and Świnoujście are ports of primary importance to the national economy. A great challenge for the ports is to simultaneously balance their development with caring for the environment. The aim of this article is to determine whether the seaports in Szczecin and Świnoujście are socially responsible and what the result of their impact on the natural environment and society are. This article uses the case study method, which analyses the activities undertaken by the port management as well as the enterprises that are part of the port service supply centres in Szczecin and Świnoujście, and assesses the effects of these activities. From the results, it can be stated that the Ports Authority, through its business, pro-environmental, pro-social and pro-employee activities, implements the goals of CSR and is a socially responsible entity, although more could be done.

Corporate social responsibility (CSR) is the process of finding out the changing expectations of stakeholders and including them in a business management strategy. CSR is a concept of the optional incorporation of social and environmental aspects into the operations of a business entity. The objective of this article is to: (1) present the historical determinants of CSR and its practical dimension; (2) characterize the activities of fuel companies in the light of the publication of CSR information in reports; (3) indicate the information and contents of the annual reports of oil companies – in particular taking account of the information about corporate social responsibility; (4) provide proposals for the structure of a model annual report including information about corporate social responsibility which could be used for the selected oil companies that were investigated. The methods of inductive and deductive reasoning and descriptive analysis, as well as desk research were used in the writing of this article.

A propeller shaft generally experiences three linear forces and three moments, the most important of which are thrust, torque, and lateral forces (horizontal and vertical). Thus, we consider 4DOFs (degrees of freedom) of propeller shaft vibrations. This paper is presented to obtain the vibration equations of the various coupled vibrations of the propeller shaft at the stern of a ship (including coupled torsional-axial, torsional-lateral, axial- lateral, torsional-axial, and lateral vibrations). We focused on the added hydrodynamic forces (added mass and added damping forces) due to the location of the propeller behind the ship. In this regard, the 4DOFs of the coupled vibration (torsional-longitudinal and lateral vibrations in the horizontal and vertical directions) equations of shaft and propeller systems located behind a ship were extracted with and without added mass and damping forces. Also, the effect of mass eccentricity was considered on vibrations occurring at the rear of the ship.

In this work, the results of tests on castings made from unalloyed cast steel, which was repaired using surface padding, have been presented. The purpose of the work was to present the impact of the application of welding technology on the microstructure of cast steels and the dangers related to it. The appearance of a very adverse microstructure was found in the area where the padding occurred. In the light of the presented research, it seems that it is necessary to apply normalizing annealing after the padding of a cast, which will result in a more uniform and fine microstructure of the material being obtained. As a consequence, this will prevent possible operating damage from occurring in the finished products.

Ethylene is one of the basic raw materials of the petrochemical industry that is used to produce plastics. One of the largest producers of this compound is the USA, and a substantial increase in the demand for ethylene has also been recently observed in the Middle East, the Far East, and China. This requires the transport of this cargo by sea. Ethylene carriers are a type of LPG ships and are equipped with a cascade cycle that uses propylene or refrigerant R404A as a coolant medium. These vessels have been designed to withstand the minimum temperature of ethylene of –104°C for fully-cooled cargo. A mixture of ethylene and air (from concentrations of 2.75–2.6%) becomes explosive during heating under elevated pressures. Hence, it is necessary to form an inert atmosphere in the tanks using mostly nitrogen before the ethylene cargo is loaded. The process of aerating, inerting, gassing-up, and cooling cargo tanks and cargo is constantly repeated during the operation of LPG carriers. Due to the large amounts of ethylene lost during gassing-up, which results in significant financial losses and disruptions in cargo compressors during the cooling of the tanks and cargo, this operation is the most problematic of all. In this article, a solution is proposed for performing the gassing-up procedure which prevents excessive ethylene loss.

Modeling the safety of critical infrastructure free of outside impacts is presented, and basic safety indicators are defined. The safety of the port oil terminal critical infrastructure free of any outside impacts is examined based on critical infrastructure safety statistical data provided by the operators. Its safety function and other safety indicators are identified and predicted. Furthermore, the safety and resilience indicators for the critical infrastructure of the port oil terminal impacted by its operations are determined, and the results are compared to its indicators obtained without considering operation impacts.