The PURPOSE of the study is development of an optimal functional diagram for the electrical equipment of micro hydroelectric power plant (HPP), as well as the development and study of a stand alone source of electric power based on micro HPP and an induction generator with capacitor excitation. METHODS. The set purpose is achieved through the use of the methods of mathematical and computer modeling. Experimental studies are conducted on computer models. RESULTS. An optimum functional diagram of micro HPP electrical equipment, a mathematical model and a computer model of micro HPP in Matlab/Simulink program are proposed. The research of the developed model has allowed to draw a number of important conclusions on its practical application as a stand alone source of electric energy. CONCLUSIONS. We have developed an optimal functional diagram of micro HPP electrical equipment, a mathematical and computer models of a stand alone electric power source based on a micro HPP and an induction generator with capacitor excitation. The conducted studies of the developed model have shown its correct operation that provides the opportunity to be used in design for specific areas and loads.

PURPOSE. The operation reliability of electric power systems is strongly dependent on the correct operation of relay protection devices. The modern technological stage of these devices is characterized by the application of various algorithms of digital signal filtering including Fourier filters for information parameter calculation. Therefore, the study of filtration errors arising under the effect of various factors including the sampling frequency, the presence of aperiodic, harmonic and non-harmonic components in the signal and variation of the input signal frequency is relevant it terms of ensuring the required reliability of microprocessor protective relays, especially given the need to improve the sampling frequency with the introduction of the IEC data transfer Protocol-61850-9-2. METHODS. The research employs the methods of digital signal processing and mathematical modeling of filter operation. RESULTS AND THEIR DISCUSSION. The conducted analysis of amplitude-frequency characteristics of filters has allowed to identify an extremely minimal sampling frequency of the signal. The received numerical estimation of filtration error at various influencing factors demonstrates the necessity of preliminary filtration. CONCLUSIONS. Reliable operation of relay protection devices using Fourier filters can be ensured through the use of special measures enabling the elimination of the revealed errors.

The PURPOSE of the study is an analytical solution of the flow distribution problem of a multi-circuit heating network and the use of this solution in the optimization of heating network parameters. METHOD. The study uses the method of splittance of graph, the mathematical modeling of a hydraulic circuit, the analytical method for solving biquadratic equation. RESULTS. The problem of flow distribution is reduced to an algebraic equation of the fourth degree, which is solved by Ferrari method. The error of the approximate analytical solution of the problem is estimated. The dependences of the economic value function on the parameters of the heating network circuit are found. CONCLUSIONS. The proposed method of graph splittance allowed to reduce the problem of flow distribution to the algebraic equation and obtain its analytical solution. This significantly reduced the amount of computational work when hydraulic circuit modeling and optimization. The linear approximation of the function containing the square root gives the result, the accuracy of which is acceptable for engineering calculations.

The PURPOSE of the paper is to consider and analyze the past decade publications on the study of flexible mesh-plate soundproofing panels (MPSPP). METHODS. The purpose is achieved through the analysis of literary sources and research works. RESULTS AND THEIR DISCUSSION. The current trends in the technical development of flexible mesh-plate soundproofing panels and their research are identified. An important trend is related to the search for a rational basis for the methodology of design calculation of MPSPP sound insulation efficiency. The relevance of further theoretical and experimental study of flexible mesh-plate soundproofing panels and their modernization is substantiated. CONCLUSIONS. The insufficiently studied issues of flexible mesh-plate soundproofing panels have been revealed in the scientific literature. The interaction problem of MPSPP and an external field of elastic waves as well as the problem of MPSPP characteristics control under conditions of development, production, commissioning, operation and repair are of greatest interest.

PURPOSE. Modern machine-building industry tends to decrease the output of batch production and increase the use of universal equipment. The purpose of this article is development of an automated sorting algorithm of microelement changeover between the inner and outer changeover in order to reduce the Single-Minute Exchange of Die (SMED) implementation time. METHODS. The authors suggest the use of MES systems and quick changeover methods with the use of the automated SMED implementation technique for optimal workshop scheduling. RESULTS AND THEIR DISCUSSION. An algorithm of automated change proposal on quick changeover introduction has been developed. It is based on the lists of objects and techniques and allows to speed up the process of SMED method implementation. CONCLUSIONS. The flexibility of piece-work production with a wide range of product and enterprise competitiveness can be improved through the use of the following optimization methods of product start-up: optimal master production scheduling by the use of MES systems and automated implementation of the quick changeover procedure.

PURPOSE. As a rule the parts of aircraft primary structures made of aluminum alloys have longitudinal-transverse ribs in order to increase rigidity. As a result, the cross-section of such parts has a complex shape in the form of a T, a channel, double T, etc. with straight and tilted shelves. The manufacture of these parts involving the processes of milling and subsequent hardening by impact methods is accompanied by the unwanted deformation (buckling) which is represented by the deviation from flatness and blade shape. The buckling can be eliminated after milling by the methods of local plastic deformation including roller burnishing, or pressing. Mechanical processing after hardening including the straightening by the magnetic particle method is not regimented by the industry normative technical documentation due to the possibility of introduction of an undetermined stress-strain state in the hardened surface layer and occurrence of weakened zones in the surface layer of the part. Enhancement of technological capabilities for low rigid part production with the use of the preventive deformation technology implies the introduction of part shape distortion in order to compensate the buckling that arises in subsequent hardening operations performed by the methods of surface plastic deformation. METHODS. The study employs the modeling using nonlinear finite element analysis to determine the general bending strain of a part resulting from surface hardening of small fractions by shot peening, study of the sample curvature with the help of indicating devices to determine the force factors of the hardening process on the basis of the known laws of the theory of elasticity. RESULTS AND THEIR DISCUSSION. The results of an experimental study on machining of simulators of structural elements reinforced by ribbed parts are obtained. The need for using modeling to determine the deformations of parts subjected to hardening by impact methods is substantiated.

PURPOSE. The paper studies the effect of the special modification of epoxy matrices and epoxy matrix-based polymer composites on thermophysical parameters of machining processes under hole formation. A goal is set to produce experimental samples from matrices and experimental panels from carbon fiber plastics based on modified matrices. It is necessary to reveal whether there is any dependence of machining process thermal effects on the modification degree of matrices and carbon fiber plastics. METHODS. Experimental methods are used to achieve the purposes of this work. The experiment includes: production of experimental panels (binder preparation, liquid-phase combination with a dry filler, impregnation and vacuum-pressure oxidation molding); checking of their quality and mechanical properties (non-destructive testing of experimental panels by acoustic methods and standard mechanical tests); measurement of the cutting temperature under hole drilling in the sample made of experimental panels (infrared thermography of the hole formation zone). RESULTS AND THEIR DISCUSSION. It has been determined that the matrix samples feature the lowest heat release in the intervals from 0.1 to 0.3% wt depending on the type of the tool used. The peaks of the lowest heat release of the matrix-based carbon plastic samples are shifted to the range from 0.2 to 0.5%. The decrease in the maximum temperature in these ranges is due to the antifriction properties of the zinc stearate modifier: the coefficient and friction forces are reduced. Further increase in the modifier concentration leads to the recovery or even excess of the thermal effects relative to the initial unmodified matrices and carbon fiber plastics (0 % zinc stearate). This fact can presumably be explained by the decrease in cutting efficiency at reduced friction coefficients. The shifts of the peaks to the right and their “widening” for carbon fiber plastic samples is probably related to the thermophysical properties of the filler, which change the conditions of heat removal from the contact zone of friction bodies (a part and a processing tool). It is the carbon fiber plastic that is of some practical interest being a composite combination of a matrix and a carbon filler, which demonstrates more advantageous values of the thermal parameters of machining processes according to the study results. CONCLUSIONS. It has been shown that modification does not have any negative effect on the mechanical properties of modified composition-based carbon plastic. The dependences of the thermal effects of the machining processes under the hole formation in the samples on zinc stearate modifier concentration have been revealed. This fact proves the effectiveness of modification.

PURPOSE. The paper studies the material composition of the ore from the Jamgyr deposit located in the Chatkal region of the Jalal-Abad district of the Kyrgyz Republic and determines the expediency of its gravity concentration. The ore belongs to the quartz low sulfide type. Its main valuable component is gold, the content of which averages 8.5 g/t. METHODS. Complex mineralogical analysis was performed using X-ray phase, optical and microscopic analyzes. Sulphide minerals and gold were studied using the method of selective dissolution of natural minerals. X-ray phase analysis was carried out on a portable X-ray diffractometer D2 PHASER (CuKa) of Bruker AXS design in the range of 20 angles from 5 to 80°. The obtained diffractograms were processed in the DIFFRAC.EVA program. A qualitative X-ray phase analysis was performed via comparison of standards (ICDD PDF-2) and diffractograms. A semiquantitative analysis of the sample was carried out using the DIFFRAC.TOPAS program according to Rietveld method. The content of gold was determined on the atomic absorption multielement spectrometer AGEP-0,1 by the assay atomic absorption analysis. RESULTS AND THEIR DISCUSSION. Having studied the morphology of particles of free gold, we have found that the shape of coarse gold is mainly dendritic, small-size gold has the shape of a drop in pyrite. The data on the granulometric distribution of gold show that the percentage of coarse gold is about 70%. The phase analysis data show that the percentage of free gold is 64.37%. The ore study has allowed to substantiate the use of gravity concentration through the GRG test at a hydraulic pressure of 25-12 kPa, ore feed rates from 1000 g/min to 400 g/min, stage-by-stage reduction in size from 100% of 85 μm to 80% of 75 μm. The technique of performing the stage-by-stage gravity concentration conducted in three stages on Knelson concentrator is given and the GRG test determination diagram is presented. The results of each stage and the total result of the GRG test are provided. According to the GRG test result 19.86% of free gold is extracted at the first stage, 35.83% - at the second stage, and 17.65% - at the third stage. The total recovery is 73.34%. CONCLUSIONS. The morphology and release of gold on the concentrates obtained by gravitation on a centrifugal separator are studied. The degree of gold release is determined as well as the gold grain size in I, II, III stage concentrates and relative amounts of free gold grains. The final determination is given to the main shape of gold grains: it is either dendritic or flake. It is also noted that stage-by-stage decrease in the grind size causes changes in the gold grain shape: the particles of isometric forms are expanded into flat grains.

The PURPOSE of this article is determination of the construction principles of the system for storing and processing of information on engineering product electronic structure as well as the implementation of the storage system based on the formulated principles. METHODS. When building the system the electronic structure of an engineering product is considered as a directed acyclic graph where the tree elements are graph nodes and facts of one component inclusion into another are graph edges. It is proposed to implement the system using the mechanism of contexts considering the time of introduction of changes. The relational data model with immutable table values is used for information storage. The article provides the practical RESULTS of building such a storage system in the Experimental Design Bureau “Novator” JSC (Ekaterinburg). CONCLUSIONS are derived on the potential of the operation scheme under discussion to withstand big loads; therefore, it can be used to solve similar problems.

PURPOSE. The article deals with transport supported agricultural harvesting processes under simultaneous parallel execution of technological operations. The agricultural harvesting and transport system is presented in the form of a two-component technical system consisting of a harvesting unit and a vehicle. Failures of the system under consideration arise due to technical, technological, operational and organizational causes of its element failure. The time between the failures of the agricultural transport system is a continuous random variable and follows a certain distribution law. The conducted analysis of the distribution laws used in the theory of technical system reliability has allowed to justify the use of their compositions for estimating the time between the failures of the agricultural harvesting and transport system. Composite formulas for the new distribution law describing the time parameter under investigation are obtained. METHOD. The time between the failures of a technical system consisting of a harvesting unit and a vehicle is estimated on the basis of a composition method that determines the probability density function of the sum of two continuous random variables described by different distribution laws. RESULTS. We have derived more than 10 compositional formulas of probability density of time between the failures of the agricultural harvesting and transport system allowing to determine the numerical characteristics and parameters of new distributions. CONCLUSION. By combining the laws of time distribution between the failures of the harvesting unit and the vehicle in pairs the expressions of the probability density of the composition of the laws of time distribution between the failures of the agricultural harvesting and transport system as a whole are obtained. The results of the performed theoretical studies can be used in experimental work and its systematization on studying the efficiency of agricultural harvesting and transport systems, determination of output parameters and identification of regularities between them when improving various technological processes in agriculture, and also in calculating the reliability of two-component technical systems.

The PURPOSE of the study is evaluation of the role and significance of simulation models in digital twin construction and operation. METHODS. The main research methods are system analysis and methodology, techniques and construction methods of simulation models. RESULTS. Having analyzed the technologies for digital twin creation and use, the author shows that simulation models form the basis for their existence. The information technology used in this case is a tool providing digital twin operation but it is not a determining factor. The quality of the constructed simulation model determines the efficiency of digital twin technology creation, use and development. CONCLUSION. To improve the quality of a digital twin simulation core a list of problems that need to be solved is formulated. They include automation of statistical analysis of time series, which is completed with an intuitive explanation of analysis results and generation of the sets of random numbers with certain probabilistic properties; development of quality assessment methods of the selected tools of simulation modeling; creation of quality assessment methods for digital twin core transformation in the process of its modernization based on the results of field operation and formation of methodology, methods, algorithmic tools and software; creation of digital twins of poorly formalized systems.

PURPOSE. Filtration of anomalous measurements (outliers) of frequency values of hydrogen standards which form a part of the group standards of time and frequency will allow to reduce an algorithmic estimation error of the state vector of group standards. METHODS. The study employs the methods of noise-immunity estimation in the mode of static and dynamic data processing. RESULTS. It is proposed to use α-trimmed estimates with an unknown percentage of outliers to filter the outliers in the static mode. In the case of dynamic data processing, the outliers are rejected if the estimates obtained at this stage go beyond the confidence intervals. The latter are calculated on the basis of the predictive models of frequency variation constructed at the stage of static processing of data. The proposed algorithms are implemented in Mathcad 15.0. The efficiency of the proposed methods has been verified by statistical modeling and confirmed by the processing of real data obtained as a result of VET 1-5 secondary standard operation. CONCLUSIONS. The received results form an important development stage of a formalized estimation procedure of the state vector of the time and frequency group standard in static and dynamic modes based on the use of predictive models.

The concept of ranking and choice are closely related. The selection process is the final phase of the ranking procedure, the result of which is the preferred subset of alternatives. The ranking procedure is the process of establishing a strict order relation between a given number of alternatives. The PURPOSE of work is the experimental confirmation of the hypothesis advancing the idea that the problem of providing a strict order relation for complex ranking/selection problems can be overcome on the basis of mechanization (computerization) of the mental activity of the subject of choice via decomposition of original intuition manifestations on the set of presented alternatives into a set of particular, simpler problems. METHODS. The set purpose is achieved through the use of mathematical and statistical methods. RESULTS AND THEIR DISCUSSION. The procedure for establishing a strict order relations is presented by two aspects in two stages. In the first case, the number of alternatives is increased stage-by-stage under the fixed number of essential characteristics. In the second case, there is a step-by-step increase in the number of essential characteristics under the fixed number of alternatives. The process of establishing a strict order relationship involved the respondents with different choice strategies, who were offered to initiate the alternative ranking procedure first intuitively, and then by constructing a model of preferences in Decon Jobs software product. CONCLUSIONS. The specific examples of establishing the strict order relations between the alternatives obtained intuitively and using the averaged preference model allowed to conclude that the growth in the number of alternatives complicates a person to establish a strict order between them. The software product Decon Jobs allows to reduce the level of uncertainty between individual alternatives and to increase the percentage of establishing a strict order relation.

The PURPOSE of this article is to study the operability of KAMAZ truck systems in severe natural and climatic conditions of the permafrost region. The METHODS of mathematical statistics are used to process database information on KAMAZ operability in the temperature-load conditions of the North. RESULTS. The conducted study of failures of the main groups of assembly components and parts of KAMAZ trucks operated in the North allowed to classify these systems into the types by sensitivity to low climatic temperatures. We have distinguished the groups of parts and assembly components of KAMAZ truck for which low ambient temperature is the dominant factor influencing their operability; the groups whose operability is affected by low temperatures along with other operational factors; and the groups whose operability is slightly affected by low ambient temperatures. CONCLUSION. The systems and parts limiting the performance of KAMAZ trucks in permafrost region have been identified. The study is given to the monthly distributions of failures of KAMAZ part groups and assembly units by months. These groups are classified according to the degree of sensitivity to low climatic temperatures.

PURPOSE. The paper presents experimental studies on the determination of the compressibility coefficients of diesel fuel and its mixtures with palm oil, as well as pure palm oil in order to estimate the effect of compression pressures and mixed fuel compositions on sound velocity and compressibility coefficients of the fuels under analysis. METHODS. Having reviewed and analyzed the existing methods, the authors chose the method for measuring sound velocity in the fuel located in the discharge pipe. The sound velocity is determined by the moments of initial pressure rise in the inlet and outlet sections of the pipeline. RESULTS AND THEIR DISCUSSION. When the compression pressure and fuel density, which depends on the volume content of palm oil in the mixture with diesel fuel, grow the sound velocity in the fuel increases, while the true compressibility coefficient decreases. In this case the lower the density, the greater the limit variations of the true compressibility coefficient. Therefore, the proof is given to the data of previous studies where it was found out that the dependence of hydrocarbon fuel compressibility approaches the Hooke’s law as fuel density grows. CONCLUSIONS. The results of the study can be used for the simulation of fuel supply in diesel engines operating on the mixtures of diesel fuel and palm oil.

PURPOSE. The paper deals with the analysis of the development possibilities of transport systems in large cities and urban agglomerations. The work focuses on the problem of formation and effective use of the modern city transport space in the context of lack of free land for extensive expansion of road network based on the interaction of high-speed urban highways, rail and traditional public transport. The purpose of this work is to develop the theoretical foundations of increasing efficiency of using the city and urban agglomeration areas and forming an optimal development strategy for the urban transportation system and traffic management operating on the basis of rail and wheeled vehicles interaction. METHODS. The work uses the following methods of scientific analysis: dialectical, comparative-economic and statistical, system, system-functional and historical-genetic, economic-mathematical modeling, theories of organizational and economic system management and the method of scientific abstraction. Their complex use allow to ensure the reliability of the conducted research. RESULTS AND THEIR DISCUSSION. Based on the tendency of growing motorization of the large city population the work substantiates the need for the cardinal change of the approach to urban transport system formation and operation. The proposals are developed to improve the efficiency of using the transport space of cities and urban agglomerations. Criteria for determining the efficiency of city transport space use are given. The author has formulated, justified and described the measures aimed at increasing the efficiency of the use of the transport space of the city. CONCLUSIONS. The need to develop an optimal strategy is objective since on one hand, there is a significant increase in the motorization of large city population and on the other hand, the possibilities for transport network extensive development have come to the end of their resources. The main advantages of the strategy, the number of which will increase in the process of restructuring, development and modernization of the urban transport system, primarily are reduction in the total amount of transport costs in the cost of production manufactured by enterprises located in the area of implementation or influence of the project of city transport system restructuring. Another advantage is growth of the level of the industrial and production potential of the area where the project on transport infrastructure development or restructuring is implemented. The final result of the taken measures should be an increase in the level of transport accessibility of the areas, agglomeration settlements and facilities engaged in economic, socially significant or other activity, which are located on the territory of a large city or agglomeration as well as improving the safety of freight and first of all passenger transportation.

PURPOSE. The paper studies the influence of urbanization on the social and economic aspects of regional transport and tourism industries. METHODS. The tourism transport infrastructure is characterized by non-linear processes. Nonlinearity allows to create and test the models of the system with realistic dynamic characteristics and develop the models of various processes. Simulation modeling is the most promising method for building simplified descriptions of real processes in order to study their behavior in different possible situations. RESULTS AND THEIR DISCUSSION. Simulation modeling is a theory that describes the structure and internal interactions in the system. The structure of the model can be based on the principles of dynamic behavior of a system with a feedback. Alternatively, the model can present a description of some observed fragments of the system. Describing process dynamics, the model can change the rates and levels for system’s behavior transformation in time, and according to the tasks for which it was developed. CONCLUSIONS. It is found that modeling of regional tourism transport infrastructure aims at finding its optimum states which would correspond to the growing transport and tourist flows. It would also offer the alternatives of transport system development and redistribution of transport flows in the region in order to reduce the load on the territory and environment, propose the ways to increase customer satisfaction with the complex of tourist and transport services as well as present the methods to transform transit passengers and visitors into the tourists of the region.

The PURPOSE of the paper is to determine experimentally the influence of the damping device and various combinations of variable and constant air volumes in the diaphragm pneumatic suspension on damping efficiency of free decay oscillations of the sprung weight at a pulsed kinematic disturbance. METHODS. The excitation of free damped oscillations of the sprung weight on the air suspension was carried out on a dynamic test bench by means of a hydropulsator by the method of piston push of the air spring upwards or downwards by 50 and 100 mm. Magnetostrictive displacement transducer GEFRAN MK 4 registered the oscillations of the sprung weight in time and sent the data to the control panel. The test method provided for the recording of the oscillograms of the free damped oscillations of 500 kg sprung weight mounted on the air spring with a sleeve-type rubber-cord shell, the structure of which depended on different combinations of the values of the constant and variable volumes of the air spring and installation of damping devices between them. The tests were carried out at the following displacement volumes of the air spring piston: 11; 18.6; 31 and 38.6 litres, where 11 litres is a variable volume above the piston; 18.6 litres - the total volume of the rubber-cord shell (11 litres) and the hollow piston (7.6 litres); 31 litres - the total volume of the rubber-cord shell (11 litres) and the receiver (20 litres); 38.6 litres - the total volume of the rubber-cord shell (11 litres), the hollow piston (7.6 litres) and the receiver (20 litres). When the volumes equaled 11 and 31 litres connection with the piston cavity was blocked by a plug. When the volumes were 18.6 and 38.6 litres the connection of the rubber-cord shell with the piston cavity was either free, or through a damping unit represented by a 6 mm diameter throttle and a reverse pressure valve opened during the compression strike of the air spring piston. When the volumes equaled 31 and 38.6 litres the receiver was connected to the top cover of the air spring by piston by a 1 m-long hose with the section of 20 mm. RESULTS AND THEIR DISCUSSION. The analysis is given to the effect of air damping and various combinations of variable and constant volumes of the air spring on its damping properties. The results are presented in the form of oscillograms of free damped oscillations. CONCLUSIONS. As compared with the air spring without a constant additional volume, increase in the displacement volume from 11 to 18.6 litres due to connecting the piston cavity with the throttle and reverse pressure valve installed on the piston decreases the natural frequency of oscillations on average from 1.75 to 1.25 Hz and reduces the amplitude of the first oscillation by 23%. A receiver with the volume of 20 litres connected to a variable volume of the air spring decreases the amplitude of the first oscillation of free damped oscillations of the sprung weight by 50% and reduces the oscillation damping time on average from 1.7 to 1s.

PURPOSE. The purpose of the paper is to justify the need for a scientific selection of a series of tire profiles when replacing tires in order to ensure vehicle safety. METHODS. The study uses the methods of mathematical statistics, mathematical modeling and provides a detailed analysis of the scientific and technical documentation on the topic of the research. RESULTS AND THEIR DISCUSSION. The article presents the statistical data on the wear of tire protector and shock absorbers and provides the criteria for the critical threshold of their life. Description is given to the selection features of lower series tire replacement. The results and analysis of comparative tests on the evaluation of shock absorber wear effect on the braking length of vehicles equipped and not equipped with ABS and ESP systems are presented. A formula is given for determining the conditional probability of the coincidence between the road accident and vehicle movement with wheel breakaways from the road. The results of calculations by the formula are presented as well. It is concluded that this probability can be more than 20% for road conditions in the territory of the Russian Federation. The amplitude-frequency characteristics of the relative accelerations of the vehicle body and wheel movements are constructed and analyzed. It is noted that the replacement of worn tires with the tires of a lower profile even if shock absorbers are serviceable significantly raises wheel vibrations (2 times), which increases the likelihood of wheel breakaway from the road and reduces the safety of motor vehicles. CONCLUSIONS. It is necessary to develop a methodology for scientifically based selection of a tire profile series when replacing tires taking into account the condition of shock absorbers in order to improve the safety of motor vehicles.

The PURPOSE of the work is to obtain experimental data for the development of mathematical models of vehicle suspension silent blocks operation to develop a method for their diagnosis. The object of the study is the operation process of a vehicle suspension silent block. METHODS. The tests were performed in the research laboratory of the Motor Car Department of the East Siberian State University of Technology and Management. A test bench implementing the mode of static and dynamic loading was used. The frequency range of the lever with the tested silent blocks was set in the range from 0 to 1.67 Hz. The silent blocks of different technical conditions, both new and those from the failure flow of vehicles in operation were subjected to the tests. RESULTS. Power characteristics of silent blocks of a vehicle in a dynamic mode have been received. CONCLUSION. The developed diagnosis method based on the obtained experimental data will allow an objective determination of the technical condition of vehicle suspension silent blocks. Also, the application of the method in practice will significantly reduce the complexity of diagnostic work.

PURPOSE. The work assesses the influence degree of various factors causing significant difficulties in planning the technical and production operation of machines and the actual technical state of machinery. METHODS. To compensate the shortage of information in the control process of transport and technological complex operation and decision- making for achieving the planned level of machinery technical readiness an expert method was used that allowed to build the a priori ranking of the factors having the most significant effect when controlling complex technical systems. RESULTS AND THEIR DISCUSSION. The Pareto and Ishikawa diagrams were constructed based on the data of West Siberian railway on the failures of nodes and systems of track machinery of a snowplough-class (SP-class). The analysis was given to the causes of failures by the “5 why” method. Based on the opinions of experts eight factors, which could be the root cause of failures, were ranked. The deviations of the sum of ranks from their average sum were determined as well as the specific weights and the place occupied by the factors according to their importance. The variance was calculated and the a priori diagram of ranks was constructed. The value of the concordance coefficient W = 0.876 indicates a high degree of consistency in experts’ opinions that confirms the statistical reliability of the materials used in the study. CONCLUSIONS. A number of measures aimed at improving the organization of snowplough machinery technical operation has been determined in order to prevent the failure of individual nodes and systems of the track machines of the SP class.