Application of plate with optical sensors in ship information systems

The article considers application of fiber optic devices in many devices due to their small size and high accuracy. The new fiber optic devices are equipped with a Slab Coupled Fiber (SCF) system. The SCF method uses resonant coupling between an optical fiber and a plate waveguide to create an intra-fiber device. Devices manufactured with this technology consist of polarizers, filters and sensors. Fiber optic systems have been used in torque measurement systems in the oil and gas industry and in aerospace industry. Using this system on ships is more expensive in comparison with the technologies based on strain gauges. There is offered using inexpensive optical measuring system with plate optical sensors. SCF devices use D-shaped fiber as a platform. Plate optical sensor (SCOS) devices are based on the use of an electro-optical sensor. Today, a D-fiber coupled magnetic field sensor has been developed. The device combines a magneto-optical plate waveguide with a D-fiber to measure magnetic fields. The plate coupled magneto-optical sensor (MO-SCOS) measures magnetic fields up to 2 A/m. Due to its short length the sensor can display fields with a spatial resolution of 1 mm.

Ship course control system with compensation of external disturbance on steering gear

The article focuses on developing synthesis methods for automatic heading control systems for the rudder-controlled sea vessel. The solution of the problem of vessel heading control is carried out in the conditions of heavy sea. The disturbing effect of the external water environment causes the vessel yawning, which results in exceeding activity of the steering gear. This leads to its increased wear and loss in the longitudinal speed of the vessel. To reduce the wave effect there has been supposed an approach based on the additionally introduced internal model of the ship dynamics. The given approach is aimed at improving the operation of the steering gear in rough seas. To implement the proposed algorithm, changes are made to the original system by introducing an internal model in parallel to the control object and modifying the feedback channel of the control system. To describe the sea vessel dynamics there is used the 1st order Nomoto model, the steering gear model is implemented in accordance with the imposed speed limits and the rudder shift value. Wave disturbance is close to harmonic disturbance. The identification of the parameters of the internal model can be carried out in advance, both by maneuvering tests and by the process of operation. Numerical simulations carried out in the MATLAB/Simulink system confirmed the advantage of the proposed approach. The synthesis of control in a system with an internal model makes it possible to significantly neutralize the influence of wave disturbance. The modifications introduced to the original control system help to improve functioning of the steering gear, significantly reducing the number of rudder shifts during operation.

Research and development of commercially viable lubricants to intensify working life of marine diesel engines and cylinder piston group in internal combustion engines

The paper presents the results of studying the influence of variable characteristics of lubricating oils for marine diesel engines (concentration of layered friction modifier in lubricating oil, viscosity of lubricating oil, contact pressure in the friction zone) on the tribological parameters of parts of the cylinder-piston group of marine diesel engines. There are considered the aspects of increasing the reliability and wear resistance of the cylinder-piston group of marine diesel engines when a layered friction modifier is added to the base lubricating oil in a concentration of 1.5 vol.%. There have been carried out the comparative tribological studies of M-16G2CS lubricating oil including an additive based on molybdenum diselenide. Dependences of the wear of parts of the cylinder-piston group of a marine engine on different parameters of the studied lubricants are shown. The wear rate of experimental samples in conditions of variable characteristics of lubricants has been studied. According to the tribological studies of lubricants and structural materials, the tribological rating of lubricating compositions containing M16G2CS marine engine oil as a base and a layered friction modifier - molybdenum diselenide as a tribologically active additive was built. The test tool for the antiwear ability of lubricants is a friction machine of an original design with abraded samples according to the “ball-cylinder” contact scheme. Mechanical mixing of the lubricating medium of “oil + additive” type on the RPU-0.8-55A rotary-pulsating unit was one of the variable parameters in the tests. The tribological efficiency of the studied antiwear additive varies depending on the type of mixing of the additive solution before adding to the base lubricating oil and makes 13-54% (the difference in the diameter of the wear spot of the sample) for mechanical mixing, and for rotary-pulsation mixing - 45-56%.

Estimating efficiency of forecasting technical conditions of ship propulsion systems

The article considers an approach to assessing the effectiveness of the most common methods of predicting the technical conditions and failure with reference to the ship shafting. There have been analyzed the main factors in operation of the ship shaft line, which cause the change in its technical state. It has been found that a special feature of some loads acting on the propeller shaft is their stochastic or changing nature over time, which hampers predicting the technical state of the shafting and its units. The features of stochastic and extrapolation forecasting methods have been analyzed. The possibility of using statistical methods in conditions of mass standard production of shafting units with a relatively short regulated service life is estimated. An extrapolation method is proposed for predicting the maximum permissible clearance of stern tube bearings. The case of accumulating samples of measuring results of the propeller shaft sagging in the given time intervals is considered, the approximating functions are constructed. The criteria for the reliability of the results of extrapolation methods for predicting the wear of stern tube bearings are determined. There have been developed the proposals for adapting the causal method as an alternative to the extrapolation method. A schematic diagram of a system for the ship shafting failure predicting has been developed using the registration and analysis of vibration parameters, which serves as the basis for constructing a regression model of damage accumulation. The proposed forecasting system allows studying the actual operating conditions of the shafting, defining the actual external loads and the regularities of their occurrence, measuring deformations and stresses, and determining quantitative indicators of the reliability of the shafting during normal operation and special operating modes, for example, with vibration resonance. The theoretical basis of the algorithm for calculating and registering loads affecting the service life of shafts is proposed.

Solutions to enhance technology in the fabrication process and installation of marine pipelines

The article describes possible solutions of the problem connected with shortening shipbuilding construction time as well as reducing production costs. To reduce the total amount of labour involved in the manufacture and installation of ship piping systems, which is 20% compared to the total labour volume of shipbuilding, authors provide the research on the possibility of manufacturing straight pipe sections with permissible deviations in combination with free flanges, analysis of deviation compensation for pipelines through the use of straight pipe sections manufactured with permissible tolerance and proposing new theoretical solutions to improve manufacturing and installing ship piping systems. Introduction of these technologies contributes to reduction of cycles of building and decrease in labour-intensiveness of pipeline works when carrying out marine orders. The chart of modeling the system of pipelines is presented. A straight pipe manufactured with an allowable deflection on a flat support and a loose flange attached to the end of the welded pipe are shown. The scheme of a permissible deviation α at mounting the connections between pipes is considered. The possibility of assembling curved pipelines using straight pipe sections is described in detail. The compensation zone is illustrated using the rotation of two pairs of deflected straight pipes. A block diagram of the application of research results in manufacturing and mounting a pipeline system has been developed

Evaluating technological feasibility of fruit and vegetable transportation by sea between ports of Caspian Sea

The modern process of fruit and vegetable transportation between countries depends not only on geographical, but also on political and economic factors, which makes for searching more efficient and shorter routes. The availability of such a transport opportunity as sea transportation between the ports of the Caspian Sea makes it possible to analyze new routes for the product transportation from Iran, Azerbaijan and other countries to Russia using dry cargo vessels that are currently used as the general cargo vessels. There have been analyzed the new routes for transportation of perishable products in refrigerated containers and assessed the possibility of their transportation on the “Volga” type bulk carriers. The routes “Astara (Azerbaijan) - Moscow”, “Astara - port Alat - port Kuryk - Moscow” have been illustrated. A general arrangement drawing of a “Volga” type dry cargo vessel (project 19610) is presented, the photographs of transporting timber and containers on the decks of dry cargo vessels are given. Calculating the load of the dry cargo ship’s power plant has shown a technical possibility of transporting 16 refrigerated containers on deck of the “Volga” type vessel without changes in the design of the ship’s power plant. Conclusions are made about the need to develop effective cargo transportation by waterways in modern conditions of the loss of traditional Russian suppliers of fruit and vegetable products, about the possibility of additional use of dry cargo ships, as well as the feasibility of developing a backup diesel generator for emergency power supply of deck refrigerated containers in connection with a possible increase in the capacity of the ship power plant.

Studuing and developing methods of propeller shaft technical diagnostics

The propeller shafts are the structural components that require increased attention. The results of studying the damage of propeller shafts are presented in accordance with the safety requirements (a case of the river vessels). It is shown that residual stresses greatly impact the reliability and operability of the shafts becoming a damaging factor. The residual stresses occur due to surfacing the propeller shaft by ST35 steel with SV-08A welding wire. There is considered the possibility of determining the magnitude of residual stresses by the acoustic method in the surfacing. To estimate stresses the phenomenon of acoustoelasticity was used: the dependence of the elastic waves propagation velocity on the magnitude of the acting stresses. The process of determining the acoustoelasticity coefficients was carried out using standard samples (in accordance with GOST1497). Samples modeling surfacing were manufactured and tested. Metallographic studies were carried out to assess the influence of the material composition of the propeller shaft on the structure and strength properties of the propeller shafts. The influence of the structure on the amount of residual stresses was evaluated. It has been inferred from the tests results that the speed of elastic waves depends on the residual stresses. The results of the work can be used in production conditions for the control of products made of 35 steel with surfacing. In conclusion, the proposed method can be used to determine the residual stresses directly on the propeller shafts in operation conditions during the appropriate maintenance of ships.

Romanenko N. G. Increasing efficiency of ship cables defectation

The ship power supply system is a complex system that supplies electrical energy to various mechanisms and devices using wires and cables. The reliability of power supply largely depends on the technical condition of the cable lines. During operation, cable lines are regularly exposed to mechanical stress, both from external factors and from people. Some of the most common causes of cable damage are: aging insulation, overvoltage, thermal stress, boat vibration, and corrosion and moisture. Leaving the operating state of the cable line can lead to emergencies. A cable with damaged insulation can cause an electric arc with a metal object. If several phases of a cable with damaged insulation, then when they touch, a phase-to-phase short circuit occurs, as a result of which a large amount of heat is released, from which the cable insulation and other nearby combustible materials can ignite. There is considered the principle of operation of DIPCEL (a device for diagnosing ship cables) and shown its main disadvantages in determining the aging and moisture indicators of cable insulation. It is proposed to use the absorption coefficient for increasing the efficiency of measuring the ship’s cable insulation moisture. For insulating materials, in which the absorption current decreases rapidly, resistance measurements should be taken after 15 sec and 60 sec. The absorption coefficient is defined by measuring the ratio of a sixty-second insulation resistance to a fifteen-second resistance. If the value of the obtained coefficient is less than 1.25, then the insulation is unsatisfactory; if the value is within 1.25 - 1.6, than the insulation is normal, if more than 1.6 - the insulation is excellent

Studying reliability of marine pump systems by using technical supervision data

The article describes the analysis of the ship systems’ reliability at the stage of the technical design, which is based on the reliability data of individual system elements and mathematical methods of reliability theory. During the ship operation maintenance deficiencies can lead to the equipment failure, which can be prevented by the methods of instrumental diagnostics of system elements, maintenance repairs regardless of the current technical condition, and classification inspection during the ship operation. Collecting the detailed data on changes in the functional reliability of ship mechanical systems, which could confirm or deny the advantages of each of the existing methods is not enough. There has been carried out collecting, processing and analyzing the actual data on the life cycles of various pumps of ship systems at different stages of service life, as well as beyond the designated service life or operating time. There are examined the general ship systems and auxiliary power units of icebreakers and floating structures. The examined equipment has standard pumps with different capacity and efficiency. Service life, assigned resource (operating time), frequency of repair are taken as the criteria of pump reliability and durability. There have been shown the actual life cycles of pumps in dependence of the service life in years on the operating time in hours; in addition, data on the passage of maintenance repairs, maintenance, inspection of the technical condition, as well as replacement or extension of the service life are plotted on the graphs. It has been inferred that some of the pumps in the ship's systems should be replaced before the full resource was developed, while the performance of the systems as a whole was preserved or restored as a result of repairs; some pumps have exceeded their specified resource, but during the technical inspection their operation was extended, the operability of the systems was also preserved.

Lubricating oils impact crankshaft rotation speed in outboard motors

The most effective assessment of the quality of transmission and motor lubricating oils for marine engines in general and of outboard motors in particular can be given by practical tests on real engines. An important factor for improving the technical characteristics of outboard motors by reducing friction in the movable joints of the internal combustion engine and gearbox is the right choice of a lubricating oil. The stability of the engine crankshaft rotating speed, reducing noise and vibration during the outboard motor operation indicate good lubricating properties of the engine and transmission oil used. There are shown the results of comparative tests of outboard motors SEA-PRO T2.5 (two-stroke) and YAMAHA F4B (four-stroke) using the most common on the market lubricating oil and the oil produced by KUPPER, LLC (Russia). There are presented the illustrations of outboard motors SEA-PRO T2.5 and YAMAHA F4B. The tests were carried out in the laboratory conditions in a small experimental pool by specialists from the Outboard Motors Research and Production Laboratory of Astrakhan State Technical University. The control and measuring devices used were: a tachometer SEA-PRO TSP-02, a gas analyzer “Infrakar-A-02” with a built-in tachometer. It has been inferred that there is a direct dependence of the crankshaft rotation speed during long-term operation of the outboard motor on the quality and characteristics of the lubricating oil. The probability of the research on stationary propulsion systems in water transport is indicated.