English Polski
Akademia Morska w Szczecinie

DSpace Home

DSpace/Manakin Repository

Advanced Search

  • Kamiński, Włodzimierz; Krause, Paweł; Gumiński, Dariusz; Rajewski, Przemysław (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The quality of marine fuels is standardised by the international standard ISO 8217. As practice shows, even fuels that meet all standard requirements do not completely guarantee avoiding disruptions in smooth and safe operation of the ship. The future is likely to bring more cases of improper operation of vessels, sometimes leading to main propulsion failures. One cause behind main engine breakdowns is the introduction of new products on the fuel market that are intended to meet the ever-increasing requirements of environmental protection (e.g. low sulphur content). As a result, some fuels are chemically different from the previously used residual fuels. Using them in the engine room requires special care on the part of the ship owner and the ship’s crew. The article analyses two cases in which the use of conventional residual fuels resulted in main engine stoppage. The authors, bearing in mind the causes of those failures, focus on technical consequences of using marine fuels produced by currently employed technologies.
  • Łuszczyński, Daniel; Zeńczak, Wojciech (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This article presents an overview of the mathematical models applied for the description of the pneumatic transportation of grain materials. Thus the model that has been selected is best suited for the description of the pressure drop in the pneumatic transport installation of solid fuel for a ship boiler. The research conducted allows for verification of the hypothesis that the ship’s motion is of minor importance and therefore it is possible at the design stage to apply the simplified model to determine the pressure losses in the installation.
  • Miller, Anna (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The procedure of Linear Incremental Model (LIM) identification requires input and output signal deviations as opposed to their actual values. When considering a vessel as a plant, the sequence of input signals determines the traceability of the estimated LIM. The manual input signals selection procedure is a demanding and time consuming empirical procedure. In order to increase the speed of object identification and to eliminate input-output signal sequences which give unreliable data, an incremental linear model identification algorithm was developed and is presented. Moreover, the method of parameter selection for input signal pseudo-random sequences is described in this paper. Emphasis is placed on the practical aspect of astatic objects – ship’s LIM creation and input-output signal deviations selection method.
  • Nozdrzykowski, Krzysztof (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The results of tests presented herein can have practical applications for the adjustment of rotary speed to ensure constant contact between the measuring sensor’s spindle tip and the crankshaft journal of a piston energy converter, whose roundness profile is being measured. Analytical considerations have been supported by the results of simulations as well as experimental tests. The research has also shown that an increase in rotary speed affects the obtained profile shape and the value of determined roundness deviation.
  • Szelangiewicz, Tadeusz; Żelazny, Katarzyna (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    When designing a transport vessel, one of the most important parameters assumed by the owner is the service speed of the ship. Service speed and motor power are calculated as an approximation of the ship’s speed in calm water (i.e., the contract speed) with the addition of the sea margin (SM). In current design practice, the addition of SM is not dependent on weather parameters occurring in liner shipping. This paper proposes a new method for establishing the value of SM depending on the type and size of the vessel and the average statistical weather parameters occurring on various shipping lines. The results presented in this paper clearly demonstrate that further research is needed to determine the precise relationship between the shipping and vessel type and the weather parameters on a shipping line.
  • Ubowska, Agnieszka; Szczepanek, Marcin (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This article discusses requirements for the extinguishing systems in the engine room. The sources of fire hazards in engine rooms were characterized. The causes and consequences of selected engine room fires that occurred within the last five years were presented. The basic requirements for the fire-extinguishing systems installed in engine rooms were scrutinized. The most commonly used fire-extinguishing systems in engine rooms are the ones containing a gaseous extinguishing agent. Their main advantages are short response time after agent release and the ability to supply an extinguishing medium to areas that are hard to access. The agent used in such systems does not cause damage and there is no need to remove its residues after fighting the fire, as in the case of other agents such as foams. As an example, a CO2 system was characterized, as it is the most frequently used in engine rooms.
  • Zalewski, Paweł (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Vessels conducting dynamic positioning (DP) operations are usually equipped with thruster configurations that enable the generation of resultant force and moment in any direction. These configurations are deliberately redundant in order to reduce the consequences of thruster failures and increase the safety. On such vessels a thrust allocation system must be used to distribute the control actions determined by the DP controller among the thrusters. The optimal allocation of thrusters’ settings in DP systems is a problem that can be solved by several convex optimization methods depending on criteria and constraints used. The paper presents linear programming (LP) and quadratic programming (QP) methods adopted in the DP control model which is being developed at the Maritime University of Szczecin for ship simulation purposes.
  • Boć, Renata; Marcjan, Krzysztof; Przywarty, Marcin; Gucma, Lucjan (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This article presents the underlying concepts of a mathematical model optimizing the routes of vessels carrying dangerous goods proceeding in the vicinity of passenger ferries. The method is based on the estimated risk of collision between a chemical tanker and a passenger vessel. Risk assessment was performed using three models. The first model determines the distance of the passing ships on the selected area on the basis of the AIS data. The second one is a stochastic model of navigational safety assessment, which provides statistical data on the probability of collision between the two chosen types of vessels. The third model determines the consequences of collisions between passenger ships and chemical tankers. The study defines the scope of the parameters affecting the objective function of vessel route optimization and their importance in the optimization problem
  • Bugajski, Grzegorz (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    In this article we proposed a probability map that allows for location of the position of survivors. We used a probability model of a survivor drift to create the map. The model is based on the provisions of IAMSAR containing factors like leeway and wind current. Our proposal of utilizing a probability map diff ers from that shown in the IAMSAR by using other probabilistic methods. We performed analysis of a drifting raft using the Monte Carlo method. The map is closer to reality, since it is asymmetrical and generated by the simulation. However, preparing probability maps might be helpful in SAR action planning.
  • Chaładyniak, Dariusz; Jasiński, Janusz; Pietrek, Sławomir; Krawczyk, Karolina (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Wind has huge influence on take-off, landing and cruising of aircraft. Therefore measuring wind direction and speed as well as evaluating its structure are the most important tasks in meteorological support of flights. Wind shear, which is characterized by rapid changes of speed and/or direction, is one of the most hazardous phenomena for aviation. This phenomenon exists mostly in low tropospheric jet streams, areas of active atmospheric fronts, near convective clouds and strong temperature inversions. The paper proves that wind shear is mainly dependent on non-uniform layout of ascending and descending air currents and shows that this phenomenon can be detected by using ground sensors (ultrasonic anemometers), remote sensing methods (sodars, radars, wind profilers) and data from numerical mesoscale models.
  • Pietrek, Sławomir A.; Jasiński, Janusz; Chaładyniak, Dariusz; Krawczyk, Karolina (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The paper presents the results of study of convective cloud development over land and sea. The study was based on data from the Gdańsk-Rębiechowo radar and upper air sounding from the Łeba aerological station. Radar data from the classical channel were analyzed for the atmosphere scanned at 6 elevation angles of the antenna beam. Vertical profiles of the atmosphere along selected paths presenting radiolocation reflectivity in the detected cloud structures were produced using the recorded radiolocation reflectivity. Conclusions concerning the cloud structure, the physical state of water in the clouds and the thermodynamic state of the atmosphere were formulated as the results of comprehensive analysis of the radar and upper air sounding data. The obtained values of selected parameters and indices were used to quantitatively describe selected physical processes and to formulate forecasts concerning weather phenomena that might pose threats to land, air and sea transport as well as for some industrial and agricultural branches. The developed method of radar and aerological data processing will be applied to further studies of convective clouds in other regions. It will also enable to assess the impact of environmental conditions on the development of convective processes.
  • Pietrzykowski, Zbigniew; Magaj, Janusz (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The ship domain is a criterion of safety assessment in ship encounter situations. This criterion allows us to identify dangerous situations in open sea and restricted areas, the latter characterized by natural limitations such as the shore line, or artificial ones e.g., boundaries of Traffic Separation Schemes (TSSs). This article analyzes ship domains in TSSs. These schemes, being established in areas where vessel traffic is intensive, as a rule have virtual traffic lanes that indicate the direction of vessel traffic flow. The influence of the ship size and type on domain shape and size in a TSS has been examined. The domains have been defined on the basis of AIS data and statistical methods. The analyzed ship domains have been approximated by ellipses. The authors have determined intervals of changes in domain parameters.
  • Szymański, Maciej; Wiśniewski, Bernard (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    A ship sailing between the coasts of China, Japan, Korea and the Western coast of North America must cross navigational and geographical barriers of the Kuril Islands Archipelago and Aleutian Chain. Passes between the islands are particularly difficult and hazardous in winter. Most of them are covered by drifting ice for 5 months of the year. A number of allowed passes and offshore routes had been established by the maritime authorities of Alaska on the Bering Sea and in Aleutian Chain. However, use of other passes and routes is limited to exceptional cases only. Similar regulations exist in the Okhotsk Sea and other waters under Russian jurisdiction. The ship must then give grounds for a deviation from recommended or allowed passes and tracks and report other required information. Since January 1, 2015, it is mandatory to use the low sulphur fuel oil (sulphur content no higher than 0.01%) in the main propulsion system and auxiliary machinery when navigating inside the Emission Control Area (ECA) zone. Ships face a constant dilemma whether to remain in the ECA zone for the shortest or longer period of time, if the fuel and cost gain in relation to the entire route justify that. Available decision making support systems, like SPOS and Bon Voyage, do not solve that issue satisfactorily.
  • Wawruch, Ryszard (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    According to the recommendation of the IMO Resolution MSC.252(83), “Adoption of the revised performance standards for integrated navigation system (INS)”, the INS is introduced in order to enhance navigational safety by providing integrated and augmented functions to avoid geographic, traffic and environmental hazards. Its main task is to provide ‘added value’ for the officer of the watch (OOW), ship’s captain and pilot, to plan, monitor or control the navigational safety and progress of the ship. The system should support navigational safety by combining, processing and evaluating inputs from different connected sensors and sources to provide information, giving timely warnings of dangerous situations, system failures and degradation of the integrity of delivered and presented information. An INS is defined as such if workstations provide multifunctional displays integrating at least the following navigational tasks (functions): route monitoring, collision avoidance and alert management. The output data contains a description of the subsystems and devices included in the INS, and the principles of their cooperation and presentation of data, but it does not present recommendations for interfacing the INS with the ship’s radio communications equipment or standardised rules of operation by the user and presentation of information. These restrictions limit the possibilities of using this system in e-navigation. This paper identifies the importance of these limitations with respect to the need for further development of INSs, and presents proposals to solve this problem.
  • Filipek, Wiktor; Broda, Krzysztof (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The depletion of inland deposits of natural resources and the increasing demand for some raw materials have resulted in the growing interest in deep sea exploitation of natural deposits. This gives an impulse to the mounting research and development of methods of exploitation of natural deposits from the sea and ocean floors, which are not limited to petrol and gas. The main area of difficulty in opencast mining methods conducted at considerable depths is the transportation process from the sea floor to the surface. The methods employed so far, such as continuous line bucket (CLB), hydraulic pumping (HP) and air-lift pumping (ALP), have both advantages and disadvantages. The most salient problem is their considerable energy consumption resulting in great costs, hence the need for the development of less expensive methods. The authors have suggested a new method, involving the use of pyrotechnical materials as a source of energy in the transportation from the sea floor and have presented its theoretical grounding. Special emphasis has been placed on determining the depth to which the method can be applied and the energy needed in transportation in relation to the density of the transported substance (output).

Search repository

Advanced Search

Browse

My Account

RSS Feeds