No 1/1999

        The jib and slewing interlocks applicable to the ship deck crane are presented. The interlock were provided to fix the crane jib without supporting it during sea voyage. The paper contains description of design and operation mode of the interlocks, assumptions to and results of their calculations and tests carried out at the manufacturer’s test station.
(POLISH MARITIME RESEARCH, No 1/1999)

        A new universal 40 t deck crane for bulk carries was constructed by the Towimor S.A., Toruń, the main Polish supplier of deck cranes and deck machinery [1]. Strain gauge measurements of the crane were performed during the stand tests at the factory. After the tests a finite element analysis of the crane was carried out to provide additional detail information for checking accuracy of the numerical modelling in view of improving the applied FE model. In this study application of the FE method played a role independent of the experiments. Comparison of the results obtained from the two methods made it possible to improve the FE model and support the experimental results.
(POLISH MARITIME RESEARCH, No 1/1999)

        This paper describes new developments in application of CBT interactive programs intended for familiarization with individual equipment devices such as boilers, fresh water generators, steering gear, anti-pollution plants, fuel separation plant, diesel electric generators etc. Experience gained in CBT applications, benefits and advantages of the use of interactive programs in the education process of ship’s engineers are also presented.
(POLISH MARITIME RESEARCH, No 1/1999)

        The umbilical cord winch for a remotely operated vehicle system is presented. The winch is non-typical as the umbilical cord used to the ROV system is the cable-line comprising, apart from electric cables, a co-axial optical fibre bundle. The optical fibres were assumed not to have any movable connector, which made it necessary to design a special winding mechanism fitted inside the winch drum. The design was elaborated by a team of the Faculty of Ocean Engineering and Ship Technology, Technical University of Gdańsk.
(POLISH MARITIME RESEARCH, No 1/1999)

        The paper is focussed on determination of the trajectory of the free-fall boat and dynamic forces acting upon its occupants to minimalize the risk of an injury. A software package for predicting the behaviour of the boat during launching has been developed on the basis of the mathematical model of the launching motion. The simulation procedure, when used in course of design, makes it possible to improve the hull shape and properly position the seats to ensure minimum load exerted upon the occupants. The described procedure was verified in course of model tests and by measurements taken during tests of prototypes.
(POLISH MARITIME RESEARCH, No 1/1999)

        The paper is devoted to problems connected with pollution of the atmosphere by ship engines. Results of the tests are presented on the influence of charging air pressure and injection advance angle on content of exhaust gas from a high-pressure diesel engine working on heavy fuel oil, carried out at the laboratory of Gdynia Maritime Academy.
(POLISH MARITIME RESEARCH, No 1/1999)

No 2/1999

        The paper deals with stress modelling at static-dynamic random loadings. The material compatible with the Kelvin-Voigt’s model and the stationary loading is assumed. A two-step transformation of the original multiaxial stress into the unixial reduced stress is performed. For this purpose the average-distortion-energy strength hypothesis (a modification of the distortion-energy theory) is utilized. (POLISH MARITIME RESEARCH, No 2/1999)

        Test results of the modified wood (lignomer) are presented with a view to its future application in shipbuilding industry. Influence of modification process of the wood on its strength, water absorbability, impact and fire resistance properties is highlighted.
(POLISH MARITIME RESEARCH, No 2/1999)

        Using the controllable pitch propellers (CPP) on ships introduces, apart from the rotational propeller speed N and an additional degree of freedom: the pitch ratio P/D of the propeller, increasing the setting space of the propulsion system but also imposing the necessity of the optimum setting determination. To realize the aim, as accurate as possible characteristics of the propulsion system must be at disposal. The characteristics can be determined with the use of both the conventional mathematics and artificial intelligence methods such as neural networks or fuzzy logic. The paper presents a method of neutral modelling of the propulsion system and results of the experiments which makes evaluation of the network effectiveness possible.
(POLISH MARITIME RESEARCH, No 2/1999)

        The types of dredgers classified in accordance with their modes of operation are shortly described in the paper. Design solutions of power systems of trailing suction hopper dredgers, the most popular dredger type, are discussed and evaluated. Working conditions of the power systems are described on the basis of investigations of the dredger „Inż. St. Łęgowski” in operation.
(POLISH MARITIME RESEARCH, No 2/1999)

        Preliminary results are presented of fuel consumption measurements in a naval multishaft gas turbine. The main aim of the examination was to evaluate the relationship between fuel mass flow and pressure drop at two-passage fuel injectors. The results are used to verify values of the fuel outflow coefficient applied to an injector mathematical models, as well as to check a method, under development, for diagnosing the fuel supply system of the engine in service conditions.
(POLISH MARITIME RESEARCH, No 2/1999)

        Two variants of waste heat recovery from the exhaust gas emitted by the ship main engines are compared. Input data to calculations of the systems were obtained from sea trials of two containerships.
(POLISH MARITIME RESEARCH, No 2/1999)

No 3/1999

        Design stability were ultimately adopted by IMO quite recently. The designers and operators of ships are, however, aware that the standards do not constitute an ultimate solution. At present much attention is devoted to the operational aspects of stability because it is well known that 70 to 80% of casualties are caused by human unreliability. The author considers operational aspects of stability including human factor and discuses several methods necessary to deal with the situation in order to safeguard safe ship operation in various weather conditions.
(POLISH MARITIME RESEARCH, No 3/1999)

        The paper presents a way of determining the analytical model of axial compressor on the basis of the least squares and polynomial, multidimensional regression methods. The approach was applied to the axial compressors of DR77 engine and proved adequate. A satisfying consistence of the full-scale and model characteristics was obtained, hence usefulness of the method to modelling such objects was confirmed.
(POLISH MARITIME RESEARCH, No 3/1999)

        Notions of the generalised effort and flow rate related to the compressor by using the bond graph theory were introduced in the paper. A model of starting air installation is presented. The complete installation working in steady-state and changeable conditions is described by means of the bond graph method. Relationships between the installation working parameters in selected points of its structure were elaborated with the use of acceptable simplifications. A calculation example of the pressure changes in the tank at changeable air consumption during successive engine start-ups is attached. (POLISH MARITIME RESEARCH, No 3/1999)

        In the paper the ferry and its simulation model are described and identification of its inverse steady-state characteristics is presented. Next results of the open-loop steering of the passenger ferry „Stena Germanica” in longitude and lateral directions and turning in a place are given and compared with results of real-ship trials and model ship experiments.
(POLISH MARITIME RESEARCH, No 3/1999)

        Results of exploitation reliability investigations of the impeller pumps installed on some ships of Polish Steamship Company, Szczecin, are presented. On their basis elements of durability distribution functions of the pumps working in usual exploitation conditions were determined. The obtained results can be useful for both manufacturers and users of the pumps.
(POLISH MARITIME RESEARCH, No 3/1999)

No 4/1999

        A method is presented of determination of reliability function values for elements of the complex engineering system which operates at unserviceability conditions of some of its elements, i.e. in a failure state. The method is based upon information about element’s reliability in the normal state of operation of the system as well as in the system overload state resulting from unserviceability of other elements.
(POLISH MARITIME RESEARCH, No 4/1999)

        The paper presents mathematical model of an aircraft two-shaft gas turbine which operates on the basis of a simple open cycle. The model was used to simulate dynamic characteristics of the gas turbine. The simulation language Simulink, a part of Matlab package, was applied for educational purposes.
(POLISH MARITIME RESEARCH, No 4/1999)

        The principles of both hierarchical and wave algorithms are presented and their possible applications discussed. The aim of both algorithms is to automatically route pipes in 3D space in order to facilitate the process of creation of the virtual 3D model of piping installations. Solutions proposed by the algorithms are based on the P7ID (Piping and Instrumentation Diagram) and known positions of appliances to be connected to the pipes. A brief comparison of the wave and hierarchical algorithms as well as results of experiments made with them are presented. (POLISH MARITIME RESEARCH, No 4/1999)

        The paper describes the problem of aiding the harbour layout design through computer simulation of ship motion. The key aspect of this support relies on treatment of the ship and the commanding pilot as a stochastic sensor testing the given harbour layout under varying environmental conditions. The role and effectiveness of the ship motion simulation in the harbour design are discussed in reference to other existing harbour design support methods. The paper presents an example of the simulation experiment which was used for the selection of the harbour layout during planing of the expansion of Port of Callao, Peru. Such example may be used as a pattern for nautical analysis with the application of ship-handling simulation technology. The paper also evaluates the degree of fulfillment of the simulation objectives and points out the areas for further research.
(POLISH MARITIME RESEARCH, No 4/1999)

        Availability of the transport means, both reparable and unreperable, was presented in the aspect of their preparation for using in accordance with their destination, provided that at random time instant of calling for an arbitrary task they are in the technical state which makes its realization possible with a given probability. In the case of the reparable means the probability is identical with the technical availability factor. The semi-Markov process theory was applied to exemplify determination of the factor.
(POLISH MARITIME RESEARCH, No 4/1999)

        In the paper results of the research on exploitation of the Digital Selective Calling (DSC) system are presented, carried out in real sea conditions during exploitation ships equipped with GMDSS devices. From the acquired data it results that the DSC system has been worldwide accepted although with some reticence and difficulties, and fulfils the presupposed functions in spite of the complicated operational procedures.
(POLISH MARITIME RESEARCH, No 4/1999)