Hopper Cars Research Articles

Evaluation of the Efficiency of the Use of Hopper Cars with Aluminum Alloy Bodies

The use of aluminium and its alloys in the world history of car building began in the 30s of the last century.The paper considers various types of cars made using aluminium alloys produced in different countries, as well as an assessment of the effect of the use of cars with bodies made of aluminium alloys in the Russian Federation. The effect was determined for three parties of the transportation process: car owners, the carrier and the consignor. The paper calculated the effect of using a hopper car made of aluminium alloys model 19-1299 with an axle load of 25 tf in comparison with hopper cars with steel bodies with an axial load of 25 and 23.5 tf. It is shown that for the consignor and the carrier, the use of a car with an aluminium body by reducing the tare weight and increasing the carrying capacity brings a significant economic effect, at the same time, as for the owner of the car, there is a reasonable increase in the price of the car by 25–30 %. The purchase of cars with aluminum bodies is more expensive for the owner, and therefore it is necessary to increase the rental rate to compensate for the costs or take measures for state support.

INVESTIGATION OF LOADING STRUCTURE OF HYPER-HOPPER TWO-SECTION CARRIER DURING CARRIAGE BY RAILWAY

To increase the efficiency of operation of the hopper car, it is proposed to improve it by dividing the body into two separate sections, which facilitates the possibility of transporting different types of cargo. In order to adapt the hopper car for transportation on railway ferries in international traffic, it is proposed to install on its pivot beams knots for fastening chain ties. Determination of the dynamic load of the load-bearing structure of the hopper car was performed by mathematical modeling. The case of the on-board rocking of the railway ferry is taken into account. The solution of the mathematical model is implemented in the MathCad software package. The total amount of acceleration acting on the supporting structure of the hopper car was 2.4 m/s2 (0.24 g). The obtained value of acceleration is taken into account when calculating the strength of the load-bearing structure of the hopper car. The calculation was performed by the finite element method in the SolidWorks Simulation software package. The results of the calculations established that the maximum equivalent stresses are 312.3 MPa and occur in the node for fixing. However, they do not exceed the allowable values. The conducted researches will promote increase of efficiency of operation of hopper cars, and also creation of developments concerning designing of their perspective designs.

ИНФРАСТРУКТУРА ХРАНЕНИЯ И ТРАНСПОРТНО-ЛОГИСТИЧЕСКОЕ ОБЕСПЕЧЕНИЕ РЫНКА ЗЕРНА И ПРОДУКТОВ ЕГО ПЕРЕРАБОТКИ В СИБИРСКОМ ФЕДЕРАЛЬНОМ ОКРУГЕ

The article is devoted to the research of the storage infrastructure and transport and logistics support of the grain market and its processed products in the Siberian Federal District. The study made it possible to determine the state and importance of the storage infrastructure and transport and logistics support in the development of the grain market of the regions of the district. The article provides information about the grain storage infrastructure in the regions of the Siberian Federal District, the gross harvest of grain and leguminous crops in 2021 and the availability of elevators. The main problems in the field of grain storage have been identified. The characteristics of the main hopper cars transporting Siberian grain from the district by rail are presented. The volumes of export and domestic rail transportation from the Siberian Federal District are determined in dynamics. The discrepancy between the state of the storage infrastructure and transport and logistics support in the Siberian Federal District with the growing needs of the grain market and its processed products has been determined. The main directions in which the storage infrastructure and transport and logistics support of the grain market in the district should be developed are presented. The conclusion is made about the need for state support of the storage infrastructure and transport and logistics support of the grain market in the Siberian Federal District.

Modernization of hopper car for transportation of agglomerate and other materials

The paper considers results of the analysis of operability of the transporting equipment at agglomeration shops of the Ural metallurgical enterprises. It was established that during long-term operation of the hopper car for transportation of hot agglomerate, dust settles on its walls, growths of accumulated dust are formed, and the effect of vaulting occurs. Due to compaction and increase in dust layer, useful volume of the hopper car decreases which in turn leads to the need to carry out dangerous work to clean the dust directly inside the hopper car. Manual labor is used for this purpose. Such works are very dangerous for human health due to high dust content and high injury risk. In order to eliminate the problem of vaulting and accumulation of dust on the car walls, it is proposed to use the installation of two vibrating devices of the “False wall” type together with a vibrating neck (vibrating beam). The vibrating element of the device is a plate that is mounted on the inner wall on flexible suspensions (round link chain). Rubber shock absorbers are installed between the plate and the hopper wall, which are used as rubber-fabric conveyor belt. A vibrator is mounted to the plate through the support post, and the transmission of vibrations to the agglomerate is carried out using a vibrating hump, which is welded to the plate (false wall). Introduction of the designed device ensures reduction of unplanned downtime of the hopper cars team and rejection of hazardous to human health work related to the bunkers cleaning. The economic calculation confirms feasibility of the ongoing measures for reengineering of hopper cars in the conditions of agglomerate production at metallurgical enterprises.

Upgrading Hopper Cars for Transportation of Sinter and Other Materials

Upgrading Hopper Cars for Transportation of Sinter and Other Materials

Loading Research of Load-Bearing Structure of Hopper Car with Composite Roof

Purpose. The work is aimed to investigate the loading of load-bearing structure with composite material roof. This will allow reducing the dead weight of the hopper car and will contribute to the possibility of increasing its carrying capacity. Methodology. Investigations were performed using the example of hoper car for grain transporting, model 19-6869, manufactured by Karpaty Experimental Mechanical Plant. It is important to say that the use of composite material reduces the roof weight by up to 40% in comparison with the metal design. That is why mathematical modeling of dynamic loading of the hopper car with composite roof was carried out. Differential equations were solved by Runge-Kutta method in MathCad software package. Initial conditions were assumed to be zero. During the calculations, the spring suspension parameters of the 18-100 bogie models were taken into account. The obtained results of calculations were used when determining the main indicators of the roof strength. The spatial model of the hopper car roof was created in SolidWorks software complex. Calculation was performed by the finite element method, which is implemented in the SolidWorks Simulation (CosmosWorks) software complex. When constructing the finite element model of the hopper car, the isoparametric tetrahedra were used. The optimum number of the model elements was determined by the grapho-analytical method. Findings. The basic indices of load-bearing structure dynamics of hopper car with composite roof were obtained. Acceleration of the body in the mass center was 5,0 m/s2. Coefficient of vertical dynamics is equal to 0.67. It was found that the maximum equivalent stresses in the roof for all the considered loading schemes do not exceed the admissible values, that is, the roof strength is ensured. Originality. The mathematical modeling of dynamic loading of the load-bearing structure of the hopper car with composite roof was carried out. The acceleration values as the components of dynamic loading acting on it during operation as well as vertical dynamics coefficient were determined. The strength indicators of the composite roof under the main operational loading modes have been found out. Practical value. The conducted research will contribute to the creation of guidelines for the design of innovative structures of the rolling stock, as well as increase the efficiency of its operation.

Analysis of the strength of the frame of a two-section hopper car with a closed center beam design

Background. Ensuring the profitability of rail transportation and maintaining their leadership positions necessitates the commissioning of promising rolling stock designs. Such rolling stock should not only have improved technical and economic indicators, but also ensure the minimization of empty runs. Therefore, the creation of promising designs of rolling stock, designed for the simultaneous transportation of different types of cargo, is a very topical issue.
 Objective. Illumination of the results of determining the strength of the frame of a two-section hopper car with a closed center beam design under the main operating modes of loading.
 Methods. In order to reduce the material consumption of the frame of the hopper car, the optimization method for safety reserves was used. For this purpose, the strength of a typical frame of a hopper car was calculated using the finite element method implemented in the SolidWorks Simulation software package. To reduce the material consumption of the hopper car frame, it is proposed to use a rectangular profile for the center sill.
 Results. The use of a rectangular profile for the center beam of the hopper car frame is substantiated. At the same time, it becomes possible to reduce its weight by 2.3% compared to the standard version. The results of calculations for the strength of the hopper car frame showed that the maximum equivalent stresses in it are 341.5 MPa and do not exceed the permissible values.
 Conclusions. The conducted research will contribute to the creation of developments in the design of advanced rolling stock structures, as well as to increase the efficiency of railway transport operation.

Determining the features of temperature influence on the load-bearing structure of a hopper car with a composite cladding when transporting pellets to metallurgical enterprises

This paper reports the improved load-bearing structure of a hopper car for transporting pellets and hot sinter. In order to increase the strength of the load-bearing structure of a hopper car under the influence of high temperatures from the transported cargo, the use of cladding made of composite material has been proposed. This solution also contributes to a 5 % reduction in the wagon's tare compared to the prototype car. The dynamic load on the load-bearing structure of a hopper car was determined. This study was carried out for the case where an empty wagon was moving over an irregularity between the rail joints. The calculations showed that the studied dynamics indicators did not exceed the permissible values. At the same time, the ride of a hopper car is rated as "excellent". The main indicators of the strength of the carrying structure of a hopper car were determined taking into consideration the proposed improvement. That took into account the temperature effect exerted on the load-bearing structure of a hopper car by hot sinter. It was established that the maximum equivalent stresses occur in the zone of interaction of the girder beam with the pivot beam and are about 290 MPa. At the same time, stresses in the cladding of a hopper car are about 200 MPa, which is 12 % lower than those in a regular structure. Modal analysis was carried out to determine the frequencies and shapes of the natural oscillations of the bearing structure of a hopper car with a composite cladding. The calculation results demonstrated that the first natural frequency exceeds 8 Hz. Therefore, the safety of the wagon is provided. The coefficient of fatigue resistance of the load-bearing structure of a hopper car was calculated. It was established that its value is almost twice as high as the permissible one. That is, the resistance to fatigue of the supporting structure is provided. The research reported here could contribute to ensuring the strength of the load-bearing structures of hopper cars, reducing the cost of maintenance, and increasing the efficiency of their operation.

Computer modeling of the temperature resistance of the load-bearing structure of the hopper car

This article describes the results of computer modeling of temperature resistance of the hopper car load-bearing structure. For this purpose, a spacious model of load-bearing structure of an opera-car in SolidWorks program complex was created. As a prototype the hopper car model 20-9749 was used, which was built by "Ukrspetsvagon" and is intended for transportation of pellets and hot sinter. Calculation of the strength of the load-bearing structure of the operating car was carried out by the method of concatenated elements, which is implemented in the program complex CosmosWorks. When creating the design scheme, the temperature impact of the transported cargo on the inner surface of the hopper body was taken into account. The results of the calculation showed that the maximum equivalent loads in the load-bearing structure of the hopper car is about 340 MPa and is located in the area of interaction between the backbone beam with the kingpin. The maximum load in the load-bearing structure of the opera-car, which is caused by temperature pressure, occurs in the vertical struts and hump and amounts to 335 MPa, which is 3% lower than the load of the plinth of the material of the structure. The influence of temperature load on the indicators of load-bearing capacity of opera-car structure has been determined. It was found that this dependence is linear. The maximum equivalent loads at a temperature of transported cargo at 700°C are more or less equal to the plinth of the material of the structure. With a slight increase in the temperature impact on the supporting structure of its strength indicators will not be ensured. Therefore, there is a need to improve the load-bearing structure of the opera car to ensure its durability in operation. The conducted research will contribute to the creation of guidelines for the design of modern designs of freight cars with improved technical and economical indicators

Determination of loading of a hopper car with an improved design of the spine beam

The substantiation of use of a closed structure of the spine beam of a hopper car filled with a filler possessing viscoelastic properties is carried out. The dynamic loading of the load-bearing structure of a hopper car is determined taking into account the proposed solutions. It is established that the value of acceleration of the improved load-bearing structure of a hopper car during shunting collision is 3.7% lower than that obtained for the load-bearing structure without a filler. The main indicators of strength of the load-bearing structure of a hopper car were determined by the finite element method, which was implemented in the SolidWorks Simulation software package. The maximum equivalent stresses in this case were recorded in the area of interaction of the spine beam with the pivot one. The obtained value of the maximum equivalent stresses is 6% lower than that obtained for the structure without a filler. Modal analysis of the load-bearing structure of a hopper car was performed. The conducted research will help to ensure the strength of the load-bearing structures of hopper cars in operation, reduce maintenance costs, as well as create recommendations for the design of their modern structures.

Design optimization of hopper cars employing functionally graded honeycomb sandwich panels

In this paper, a novel multiscale and multi-stage structural design optimization procedure is developed for the weight minimization of hopper cars. The procedure is tested under various loading conditions according to guidelines established by regulatory bodies, as well as a novel load case that considers fluid-structure interaction by means of explicit finite elements employing Smoothed Particle Hydrodynamics. The first stage in the design procedure involves topology optimization whereby optimal beam locations are determined within the design space of the hopper car wall structure. This is followed by cross-sectional sizing of the frame to concentrate mass in critical regions of the hopper car. In the second stage, hexagonal honeycomb sandwich panels are considered in lower load regions, and are optimized by means of Multiscale Design Optimization (MSDO). The MSDO drew upon the Kreisselmeier–Steinhausser equations to calculate a penalized cost function for the mass and compliance of a hopper car Finite Element Model (FEM) at the mesoscale. For each iteration in the MSDO, the FEM was updated with homogenized sandwich composite properties according to four design variables of interest at the microscale. A cost penalty is summed with the base cost by comparing results of the FEM with the imposed constraints. Efficacy of the novel design methodology is compared according to a baseline design employing conventional materials. By invoking the proposed methodology in a case study, it is demonstrated that a mass savings as high as 16.36% can be yielded for a single hopper car, which translates into a reduction in greenhouse gas emissions of 13.09% per car based on available literature.

INTERACTION DYNAMICS OF SOME TYPES OF FREIGHT CARS WITH A RAILWAY TRACK

Purpose. An integral and essential feature of the modern wagon fleet is its large scale. For the entire fleet of rolling stock, even the smallest structural changes take on enormous proportions. The aim of the work is a theoretical study of the influence of the inertial characteristics of bodies of various types of freight rolling stock, taking into account the loading mode and the movement speed, on their main dynamic and interaction indicators with the track structure. Methodology. Theoretical studies were carried out by the method of mathematical and computer modeling of the dynamic load during the movement of some types of freight cars: gondola cars model 12-532, hopper cars for transporting coal model 12-4034 and flat wagons model 13-401 on standard bogies 18-100 at speeds in the range from 50 to 90 km/h on curves of small and medium radii. Findings. The analysis of theoretical studies of the dynamic qualities and interaction indicators of freight rolling stock and the railway track is presented. In the course of theoretical studies and after modeling taking into account the oscillation processes of freight cars at different loading modes the dependences of the main dynamic indicators on the movement speed were obtained. Originality. The influence of inertial characteristics of bodies of various types of freight rolling stock and loading modes on the dynamic load of a car was first explored in order to solve the problem of predicting the rolling stock dynamics and indicators of its interaction with the track. The results of theoretical studies taking into account the movement speed along curved track sections of small and medium radius were obtained. Practical value. The presented calculation results make it possible to determine the optimal values of such parameters as dead weight, height of the mass center and car base length when solving the problems of modernizing the operated car fleet and determining the reserves for increasing their carrying capacity. They make it possible to solve the problems of finding the optimal directions for modernizing the rail vehicle; contribute to the creation of technical conditions for the manufacture of new and modernization of the operated freight cars and are aimed at increasing the level of reliability and safety of the transportation process in modern conditions on the railway transport.

Research of the Vertical Dynamics of the Supporting Structures of Freight Cars Made of Round Pipes

Purpose. This study is aimed at determining the vertical dynamics of supporting structures of freight cars made of round pipes. Methodology. Mathematical modeling of the dynamic loading of the supporting structures of the main types of freight cars made of round pipes (gondola car, covered car, flat car, hopper car) was carried out. The studies were carried out in a plane coordinate system – the XZ plane. At the same time, it was taken into account that the car is moving in an elastic-viscous track so that the reactions of the track are proportional to both its deformation and the rate of this deformation. The studies were carried out for the case of empty cars. The joint inequality is described by a periodic function. The calculation was performed at a speed of 80 km/h. Differential equations of motion were solved in the MathCad software package using the Runge-Kutta method. Findings. Based on the mathematical modeling of the dynamic loading of the supporting structures of cars made of round pipes, the main indicators of their dynamics were obtained: accelerations acting on the supporting structures in the mass center, forces acting in the spring suspension of bogies, dynamics coefficients. For gondola car, covered car, and hopper car, the acceleration at the mass center of the supporting structure is within 0.4 g, and for a flat car – 0.5 g. It was found that the obtained indicators of the dynamics of cars made of round pipes are within the permissible limits. The accelerations acting on the supporting structures of cars made of round pipes are almost the same as those obtained for prototype cars. At the same time, the motion of cars is assessed as "excellent" for gondola car, covered car, and hopper car and "good" for flat car. Originality. Mathematical modeling of the dynamic loading of the supporting structures of cars from round pipes was carried out and the main indicators of their dynamics were obtained. Practical value. The research carried out will contribute to the creation of recommendations for the design of supporting structures of freight cars of round pipes, and can also be useful developments in the creation of innovative car designs.

EVALUATION OF DYNAMIC QUALITIES OF MOVEMENT OF RE-EQUIPPED HOPPER CARS OF PILS OF LONG-TERM OPERATION

As part of the work, a theoretical and experimental study (based on running dynamic tests) of the running qualities of empty hopper cars, converted from cement trucks and mineral trucks, was conducted. Computer simulation of the dynamics of empty hopper wagons converted from cement and mineral wagons depending on the condition of the track, the technical condition of the wagons and the weight of the container, the repeated presence of maximum vertical deviations and horizontal deviations of the track. A significant disadvantage of the railway transport of Ukraine is the limitation of the speed of trains with individual freight cars in an empty state, which are equipped with carts model 18-100. Among the reasons for the descent of the wheels of cars from the rails are: malfunctions of the running gear of the cars (fracture of the side frames and spring beams of the carts, malfunctions of the roller bearings of the axle box), wear of friction damper elements, unacceptable deviations and upgrades. As part of the work, a theoretical and experimental study (based on running dynamic tests) of the running qualities of empty hopper cars, converted from cement trucks and mineral trucks, was conducted. Computer modeling of the dynamics of empty hopper wagons, converted from cement and mineral wagons depending on the condition of the track, the technical condition of the wagons and the weight of the container and studies of the dependence of the wheel stability on the east.

ProBot – A Procedure Chatbot for Digital Procedural Adherence

One of the major implications of Industry 4.0 will be the application of digital procedures in process industries. Digital procedures are procedures that are accessed through a smart gadget such as a tablet or a phone. However, like paper-based procedures their usability is limited by their access. The issue of accessibility is magnified in tasks such as loading a hopper car with plastic pellets wherein the operators typically place the procedure at a safe distance from the worksite. This drawback can be tackled in the case of digital procedures using artificial intelligence-based voice enabled conversational agent (chatbot). As a part of this study, we have developed a chatbot for assisting digital procedure adherence. The chatbot is trained using the possible set of queries from the operator and text from the digital procedures through deep learning and provides responses using natural language generation. The testing of the chatbot is performed using a simulated conversation with an operator performing the task of loading a hopper car.

Research of dynamic indicators and influence of different types of rolling stock on railway track

The technical level of rolling stock of railway transport directly affects the economic indicators of the transport industry and the economy of the country as a whole, which leads to the need for improvement of the control, quantitative assessment of the dynamic loading o f rolling stock to ensure safe and reliable communication at the railways. Therefore, in the process of designing and operating the rolling stock the quantitative assessment of dynamic loadings is a relevant scientific and technical problem. The purpose of this work is to study the influence of different types of rolling stock, taking into account the speed of movement on their main dynamic indicators and indicators of interaction of track and rolling stock. The basis of the research is the method of mathematical and computer simulation of the dynamic loading of a freight car using the model of spatial variations of the coupling of five cars and a software complex developed in the branch research laboratory of dynamics and strength of rolling stock (BRL DSRS). Theoretical studies have been carried out under condition of movement of several types of freight cars: a gondola car of the model 12-532, a hopper car for coal transportation of the model 12-4034 and a flat car with a long cargo of the model 13-401 and typical bogies 18-100 with the speeds from 50 to 90 km/h in the curves with radii 350 and 600 m, with superelevation 130 and 120 mm, correspondingly.

INVESTIGATION OF CHARACTERISTICS OF THE GRAIN RECEIVING FROM RAILWAY TO THE GRAIN TRANSSHIPMENT TERMINAL

In the future, in Ukraine it is planned to increase the sown area for cereals, legumes and oilseeds, to increase the gross grain harvest to 80 million tons, and its export abroad was increased twice. Intensive construction in the southern ports of Ukraine of grain transshipment terminals with large metal silos will solve the problem of increasing grain export in the future. At these powerful terminals, the bulk of the grain comes mainly by rail, and is shipped to water. The aim of the work was to study the characteristics of the grain receiving from railway transport to the grain transshipment terminal of LLC “Ukrelevatorprom” in order to improve its works efficiency. The object of the study was the development of technology of grain receiving at the grain transshipment terminal; the subject of research is cereals, legume sand oil crops, as well as data from daily volumes of receiving and dispensing operations at the grain transshipment terminal of LLC “Ukrelevatorprom” for 2015-2016. The studies were carried out on the basis of processing data from the consignment notes for 2015-2016, according to which there was a summed amount of grain (net) daily transported by the railway. Further processing of the obtained data was carried out by a combined graphoanalytical method, for which, on the basis of tabular values for each studied year, the corresponding histograms and graphs were built and the necessary indicators were determined. Analysis of the structure of grain crops supplied by railway to LLC “Ukrelevatorprom” in 2015 and 2016 and their ratio showed that the main share was occupied by cereal crops (78.0 % and 73.1 % respectively), which were mainly represented by corn, share which was significantly dominated by other crops (wheat of various classes and barley) and amounted to 45.8 % and 44.5 %, respectively, which can be explained by its high demand in the international grain market, in which Ukraine occupies a leading position. Oilseeds (rapeseed) were taken in accordance with 19.1 % and 14.9 %, and legumes (soybeans) — 2.9 % and 12.0 %. An analysis of the timing of the unloading of grain wagons (hopper cars) showed that the total duration of this process, depending on the crops, averages 37...59 minutes. The longest steps for unloading wagons are to determine the grain quality indicators, especially rapeseed, and to spill grain from the wagons, therefore, to reduce their duration, it is necessary to form feeds of wagons with grain batches of the same quality and use more modern express analyzers to determine grain quality indicators, which will increase the productivity of the grain receiving line from the railway. According to the research results, the enterprise has the potential to increase by about 30 % the volume of grain intake. It was established that the periods of the grain receipt at the enterprise in 2015-2016 amounted to 349 and 353 days, respectively, the actual coefficients of the daily irregularity Kdaily for the grain receipt from the railway in these years are equal to 1.47 and 1.52, and the monthly irregularity Kmonth, respectively 1.33 and 1.21, does not exceed the standard values Kdaily = 2.5 and Kmonth= 2.0. This made it possible to clarify the database from the actual characteristics of the process of grain receiving by railway and can be used in design and verification calculations of equipment in technological lines for receiving grain from railway transport, and will contribute to increasing the efficiency of grain transshipment terminals.

Экспериментальные исследования и расчет условий теплового самовозгорания отработанного активного угля марки СКД

По предшествующей (1989 г.) и новой (2018 г.) методикам определены условия теплового самовозгорания отработанного активного угля марки СКД. Новая методика, в отличие от предшествующей, учитывает кинетику процесса, позволяет рассчитывать условия самовозгорания для различных реальных геометрических форм и размеров горючих материалов при их хранении и транспортировании. Результаты расчетов могут быть использованы при прогнозировании и для предотвращения пожаров при хранении и транспортировании твердых дисперсных горючих веществ и материалов. Например, выполненные расчеты условий теплового самовозгорания отработанного активного угля марки СКД при транспортировании в вагонах-хопперах размерами 2,64  2,112  13,37 м, смонтированных на железнодорожных платформах, по территории России (с учетом максимальной летней температуры 40 °С), показали, что самовозгорания произойти не может. Исследование условий теплового самовозгорания отработанного активного угля марки СКД проводилось в соответствии с методикой, представленной в ГОСТ 12.1.044-2018.Analysis of fire properties of active coal of various grades shows that only for two of 11 grades of active coal (AP-14 and B) there was experimentally obtained the ignition temperature and there were defined the conditions for thermal self ignition. For other 9 grades no information is available. These data are not available for active waste coal of SKD grade. The self-heating arising in coal stacks initially can be General, i.e. over the whole stack volume including the surface layer of 0,3-0,5 m thick, but in process of temperature increase the centre moves insight the embankment where heat accumulates. The temperature growth in the centre is very slow and can be preserved or even reduced, for example, when pulling coal from the stack or when it is ventilated. At the temperature values above 50-60 °C the rate of coal self-heating in the stack can increase. This temperature is called a critical temperature. The main cause of spontaneous combustion of coals in piles or stacks is their ability to oxidize and adsorb vapours and gases even at low temperatures. In this case, oxidation process is slow and little heat is released. The formation of source of coal self-ignition in piles and stacks is associated primarily with the possible contact of the combustion source with air flows as well as with favourable conditions of heat accumulation inside coal deposits. For example, as for coal there are given observations on the combustion source origin on the stack slopes mainly at the height of 0,5-1 m from the base and at the depth of 0,5 m from the surface. If the stack is heterogeneous in density and size of the pieces, the self-ignition sources can arise in other places where smaller coal fractions with the lowest density are concentrated. Heat removal from the sources of spontaneous combustion is mainly due to the size of the stack (embankment) and heat removal by air flows. In large accumulations of coal, where heat transfer to the environment is difficult, spontaneous combustion occurs. Air flows can form as a result of temperature and material density gradients, as well as of air mass movement. The tendency of coals to spontaneous combustion in stacks and embankments is different. The greater the yield of combustible gases and vapours formed during the thermal-oxidative destruction of coal, the higher the dispersion (specific surface area), the lower the density inside the material mass and the greater the moisture content and pyrite in it, the higher is this tendency. The study of the conditions of thermal spontaneous combustion of waste active coal of SKD grade was carried out in accordance with the methodology, presented in GOST 12.1.044-2018, which takes into account the kinetics of the oxidation process of the investigated substance (material). It allows to calculate the conditions of spontaneous combustion for various real geometric shapes and sizes of combustible materials during their storage and transportation. The results of experimental studies as well as calculations of kinetic parameters such as the critical temperature of self-ignition, the critical size and time of induction for waste active SKD brand carbon showed that in real conditions of storage and transportation of this substance, taking into account the upper range limit of climatic air temperature drop of 40 °C, spontaneous combustion will not occur. For example, transportation in hopper cars of railway platforms, provided that the product fills the specified in the calculations shape and size of the hopper car, is fireproof and cannot lead to spontaneous combustion in transit.

Railway-Associated Attractants as Potential Contaminants for Wildlife.

Grizzly bears (Ursus arctos) appear to be attracted to natural and anthropogenic forage along railways, which may increase collision vulnerability, but also potentially causes exposure to contaminants associated with railway infrastructure. We assessed contaminant exposure for a vulnerable population of grizzly bears in the Canadian Rocky Mountains by determining if (1) dandelions (Taraxacum officinale) growing adjacent to a railway and grain spilled from hopper cars contain heavy metals, polycyclic aromatic hydrocarbons (PAHs), and mycotoxins and (2) metal concentrations from hair samples of individual bears correlates with use of the railway or other anthropogenic features. We used principle components analysis to represent 10 heavy metals and 16 PAHs and then compared their concentrations in railway-associated sources of grain and dandelions to reference samples that we purchased (grain) or sampled from nearby sites (dandelions). We also measured metal concentrations in the hair of bears that were captured and fitted with GPS collars. We found significantly higher concentrations in railway-associated samples of dandelion and grain for both metals (particularly lead, iron, and chromium), and the sum of 16 PAHs. Several metals and PAHs in railway-associated samples exceeded regulatory standards for soil or animal feed. Mycotoxins were detectable in grain samples, but occurred well below permissible standards. Metal concentrations in bear hair were not predicted by railway use, but higher metal concentrations occurred in male bears and two individuals that used ski hills during fall. As mitigation to reduce wildlife exposure to contaminants, particularly in protected areas, we encourage removal of railway grain deposits, regular maintenance of railway infrastructure, such as lubricating stations, and investigation of contaminants associated with other human infrastructures, such as ski hills.

Substantiating the optimization of the load-bearing structure of a hopper car for transporting pellets and hot agglomerate

The strength parameters have been determined for the bearing structure of a hopper car used to transport pellets and hot agglomerate. The calculation was based on a finite element method, implemented in the software COSMOSWorks. Strength reserves of load-bearing elements in a carbody have been determined. In order to reduce material consumption for a carbody, it has been proposed to use pipes with a circular cross-section as the bearing elements. Mathematical modeling was applied to determine the accelerations that act on the optimized bearing structure of a wagon when it is struck at shunting. It has been established that the accelerations that act on the bearing structure of a wagon amount to 42.4 m/s2 (4.3 g). The derived acceleration magnitude was accounted for when calculating the strength of a hopper car's bearing structure. The maximum equivalent stresses in this case reached about 270 MPa and were concentrated in the region where a girder beam interacts with a pivot beam while not exceeding the permissible ones for the grade of steel used in the metallic structure.We have simulated the vertical dynamics of the optimized bearing structure of a hopper car used to transport pellets and hot agglomerate. During calculations, the parameters for a spring suspension of the 18-100 model's undercarriage were taken into consideration. The results of our calculations make it possible to conclude that the accelerations of a hopper car body, as well as undercarriages, are within the allowable limits. In this case, in terms of compliance with the requirements of normative documents, the car ride quality can be described as «excellent».The proposed technical solutions justify the use of round pipes as the load-bearing elements of a hopper car body for transporting pellets and hot agglomerate. In this case, it becomes possible to reduce the hopper car tare by almost 5 % compared to a prototype car. In addition, the introduction of round pipes in the bearing structure of a hopper car could bring down manufacturing costs for railroad car building enterprises.Our study would contribute to the construction of modern structures of hopper cars, as well as to the improved efficiency of railroad transportation