Empty Wagons Research Articles

Правовая характеристика договора на оказание услуг оперативного управления перевозками порожних вагонов

In this article, the authors provide an analysis of the contractual relationship between the operator under the contract for the management of transportation of empty wagons and operators of rolling stock. The provisions of the current legislation and scientific views on the legal nature of contractual relations for the management of empty wagons are revealed. The conclusion is made about the mixed nature of the relationship: rental relations prevail in combination with service relations. The analysis was carried out on the basis of regulatory documents of JSC "Russian Railways". It is established that the management agreement is an affiliation agreement. It is determined that the relations for managing the transportation of empty wagons represent two groups of interrelated relations: lease — with the managing operator and mutual lease — between the operators of rolling stock. The conclusion is made about the need for the normative establishment of a new legal structure of the contract for the management of empty wagons at the legislative level in the form of a new type of lease agreement complicated by the provision of services.

Two-stage stochastic programming approach for fleet sizing and allocating rail wagon under uncertain demand

In this paper, a scenario-based two-stage stochastic programming model has been developed to determine the optimal number of wagons and allocation of full and empty wagons during different time periods to optimize profit. In allocating wagons, when the wagon arrives at a station, it is not possible to reallocate the wagon at the moment of arrival, this issue has not been addressed before. In addition, the possibility of renting wagons to/from other companies is concerned in the railway planning. These two actions have not been addressed before. In this paper, firstly, the research problem is formulated in the form of an integer programming model with deterministic data. Due to the inherent uncertainty in the transportation demands of the real case study, the deterministic model has been transformed into a scenario-based two-stage stochastic programming model with recourse. Then the L-shaped method was proposed to solve the stochastic model and by using it for 34 instances, its better efficiency than CPLEX software was shown. The stochastic model was solved using the L-shaped method and the results show that the studied company should rent 749 wagons to meet the demands, and on average, the stochastic model is expected to have about 1.1% added value in the company's profit compared to the deterministic model.

Разработка методики перераспределения вагонопотоков (на примере Северо-Западного полигона)

Purpose: To increase economic efficiency of the process of finding and moving loaded and empty cars on the basis of improving the dynamic model of loading the infrastructure of JSC “Russian Railways” during the implementation of the process of approving applications for cargo transportation and notification requests for the transportation of empty wagons. Methods: Systematic approach and the theory of algorithms have been used to find out the reasons for the accumulation of cars on railways, an analysis has been made of the current distribution of car traffic in the North-Western Polygon to identify systemic patterns that encourage an increase in economic costs. Results: A method of stage-by-stage progress of car traffic has been developed, which allows to synchronize the capabilities and needs of participants of the transport services market in order to obtain a positive economic effect; the conditions for the uniform loading of infrastructure elements are determined, which make it possible to exclude overloading of critically important sections. Practical significance: The method allows us to balance the capacity of the infrastructure and the processing capacity of the consignee, which increases the economic efficiency of the transportation process. Consignees will have access to a tool that allows them to influence the progress of goods to their address, and the carrier will reduce operating costs by eliminating the occupation of infrastructure at the approaches to destination stations.

Методологические аспекты организации грузоперевозок железнодорожным транспортом в проектах развития Восточного полигона с учетом рисков инфраструктурных ограничений

Purpose: To develop a methodology for the organization of freight transportation in the project of comprehensive modernization of the Baikal-Amur Mainline (BAM) and Trans-Siberian Railway (Transsib) (Eastern polygon). Methods: The study is based on operational data of freight traffic on the railway infrastructure of the Eastern polygon of JSC "Russian Railways", their systematization and analysis. The method of in-depth analysis of structured data on the dependence of the performance indicators of the projected railway infrastructure and the passage of projected freight volumes, taking into account empty wagons, is used. Results: The methodology of regulation of the organization of freight rail transportation has been updated. The key problems, risks and restrictions of freight transportation in the Eastern polygon development project are classified. The results of statistical processing and data mining are presented, specifying the parameters of the forecast model for the growth of freight volumes and the increase in the capacity of the Eastern polygon. An algorithm has been developed for analyzing freight rail transportation in the projects of the development of the Eastern polygon, taking into account the risks of infrastructure restrictions. Practical significance: An assessment of the degree to which risks of infrastructure restrictions impact the effectiveness of the organizing freight traffic in the railway infrastructure development project is given.

Neuro-fuzzy-based mathematical model of dispatching of an industrial railway junction

In any transport system, especially at industrial railway junctions, it is fundamentally important to build an effective timetable (traffic schedule) to regulate traffic flows. The task is complicated by the high dimensionality of the railway network of the node, the large number of variable parameters associated with scheduling the use of a traction resource (locomotives) during operation for sorting wagons and transporting payloads (ore, fuel, finished products and empty wagons). The problem is that most plotting problems are NP-hard, i.e. the algorithms for solving them, used to automate the process, may require an unacceptably long execution time by traditional methods of solving this problem (sequential, using reference information; method of thread laying). The article deals with the issues of building a mathematical model for dispatching an industrial railway junction to minimize the time of using locomotives in order to increase the efficiency of its operation. The mathematical model uses the technique of neuro-fuzzy computing to determine the parameters for identifying fuzzy systems and calculating the priorities of operations in the framework of creating a flexible schedule for the decision support system of the dispatching service. The results of modeling and recommendations on the use of the developed methodology are presented.

Effects of mixed marshalling modes on longitudinal freight train dynamics

Mixed freight trains have more diversified vehicle characteristics and train combination modes than unified freight trains, so it is more difficult for mixed freight trains to predict the accident caused by longitudinal impulse. At present, train dynamics theories and numerical simulation methods have been increasingly used to reduce longitudinal train impulse and decrease freight wagon instability. According to these research experiences, this paper focuses on the marshalling modes of mixed freight trains and their effects on the longitudinal in-rain forces. For this purpose, an advanced simulation model for mixed freight trains was developed and several typical mixed marshalling modes were designed and simulated. The results indicate that, for the mixed train including empty and loaded wagons, empty wagons should be arranged at the tail of the train and should avoid being marshalled together. For the mixed train including marshalled wagons with various actual live loads or nominal axle loads, heavier wagons should be centrally arranged in the front part of the train, and meanwhile marshalled wagons should avoid being sorted by weight in the concave and ascending distribution mode. For the mixed train including marshalled wagons with various body types, container flat wagons and oil tank wagons should be arranged as much as possible in the front of the other wagons.

Valuation of the influence of the basic specific resistance to the movement of freight cars on the energy costs of driving a train

The primary specific resistance to the movement of freight wagons is a key parameter for normalizing the time and energy consumption of trains. Although the “Rules of Traction Calculations” calls for dividing wagons into six groups when calculating this resistance, in practice (using the traditional method), appropriate regulations are developed based on the separation of train wagons into two groups (4th and 8th lips). One of the main reasons for this is the inability to account for the unique features of each wagon in a given train. To address this issue, a program was developed for determining the necessary parameters of wagons for traction calculations based on their identification numbers. This software can be accessed through the website https://trainlocomotive.netlife.app/. Using this program, a method for calculating the primary specific resistance to the movement of freight wagons has been developed. Field sheets of freight trains moving through the Uzbekistan Temir Yullari railway station were analyzed. As a result, it was discovered that nearly half of the freight train composition consists of empty wagons, while the proportion of loaded gondola cars and tanks is 23%. The primary specific resistance to the movement of wagons in such a mixed composition is calculated using both traditional and developed methods. The impact of the primary specific resistance on the energy costs of maintaining the train is evaluated. As a result, the feasibility of utilizing the developed method for normalizing electricity consumption based on traction calculations is demonstrated.

Effect of lateral misalignment defects of rail joints on dynamic derailment behaviour in railway turnouts

This study aims to investigate the mechanism of wheel jumping derailment in the railway switch panel after a freight wagon passes over a rail joint defect (RJD) situated before the switch. For this purpose, a 3D vehicle-track (turnout) coupled dynamic model that considers the elastic deformation of the rails and wheelsets has been established. Several extreme running conditions, including sharp curves, low-speed railway turnouts, lateral misalignment defects of RJs, and empty wagons are all considered in the simulation model. The vertical wheel rise limit for the railway switch panel is presented for the evaluation of a quasi-static derailment risk. The wheel-rail impact behaviour and the evolution of the derailment processes in the switch panel are revealed, and the effects of wagon load and misalignment width of RJ sections on the vehicle’s dynamic response and running safety are investigated. The results show that the root cause of the high derailment risk in the railway switch is a lower wheel rise limit at the front region of the switch rail when compared with the mainline. This dynamic derailment limit is sensitive to the car-body load and the misalignment width. Severe lateral defects of the RJ before the switch toe should therefore be avoided.

Evaluating the efficiency of investment in a project for railway transport companies

This study aims to provide a methodology for selecting an appropriate railway track location for carrying out technical inspection of empty wagons involved in dual-run handling. The object of study is railway goods sidings. The subject of study is the criterion for selecting optimum location of railway goods sidings such as minimum costs. Operating costs per halfruns at different values of factors on layout parameters and a number of local wagons are calculated based on shunting simulation modelling. Statistical research methods were used to reveal mathematical dependencies and determine the impact of changing parameters on the values under study. As a result, the dependence of operating costs on a number of wagons in a shunting train and the length of a halfrun when travelling along a conditioned runway were obtained. The methodology developed to select a site for technical exchange of wagons involved in dual-run handling is tested at an actual runway. The practical significance of selecting the optimum technical wagon exchange site within the "connecting railway station - non-public tracks" system applying the methodology developed is reducing demurrage of local wagons at stations and improving service conditions for consignors and consignees by accelerating cargo delivery.

Running safety analysis of a freight train passing through a single crossover during braking

In addition to the discontinuity of the rail profile of a normal turnout, the unique S-shaped curve of a crossover significantly affects the negotiation performance of a train. For heavy-haul freight trains, the in-train forces generated during the braking process may further deteriorate the running safety. Investigating the dynamic behaviour of the train passing through the crossover under braking forces, therefore, can provide a reasonable basis for ensuring train safety. This paper analyses the dynamic response and wheel wear of a three-vehicle train negotiating a single crossover under variable conditions, including variable braking forces, wheel-rail friction coefficient, and crossover layout forms. The results show that the three factors have considerable influences on train safety. If one of the three factors keeps an ideal level, the safe probability of empty wagons can be significantly improved. Considering that there are still some crossovers with tight curves in the existing railway system, avoiding large braking or lubricating the wheel flange in the crossover is still an effective solution to improve the vehicle's performance. In addition, for a new single crossover, a 600-m-radius curve is a good option for balancing permissible train speeds and construction costs of the crossover.

Implications of Lateral Coupler Forces for Rail Vehicle Curving Resistance

Abstract Curving resistance is an important topic that requires a lot more research. This paper studied the implications of lateral coupler forces for curving resistance. More than 1800 simulations were conducted using a three-piece bogie wagon model developed in the simpack software package. The results show that lateral coupler forces have significant implications for curving resistance and that empty wagons are more sensitive to lateral forces than loaded wagons. With 20 kN lateral forces, curving resistance can be increased by 52% and 225% for loaded and empty wagons, respectively. The implications are significantly greater when the lateral forces are acting on the front and rear ends of a carbody have opposite directions. The differences caused by lateral forces that have opposite directions are more than two times greater than those caused by lateral forces that have the same direction. The results also show that, when front and rear lateral forces have the same direction, forces pushing toward the high rail are generally helpful in reducing curving resistance. However, curving resistance can be increased when these push forces are too high, or track curves already have high cant deficiency. When two lateral forces have opposite directions, curving resistance can be decreased when front lateral forces are pull forces toward low rail.

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.

Dynamic derailment simulation of an empty wagon passing a turnout in the through route

Turnouts are among the weakest links of railway lines, but the derailment risk of vehicles passing the through route of a turnout is seldom considered. The potential factors affecting derailment are screened according to field investigations of a train derailment case at the through route of a turnout. A detailed wagon-turnout interaction model considering the non-uniform cross-sections of turnout rails and the interaction between adjacent wagons is developed and validated. Through numerical simulation, the dynamic performance of an empty wagon passing the through route of turnout at a low speed is studied. When the wagon passes the turnout under the continuous lateral force condition, the wheels climb onto the rail head at the switch area in the facing direction, while the derailment occurs at the frog area in the trailing direction. Moreover, the possibility of derailment of the empty wagon increases with increasing coupler force and wheel-rail friction coefficient, and with decreasing speed. To improve the safety of empty wagons in the turnout area, rail lubrication should be implemented to reduce the wheel-rail friction coefficient, and large braking forces should be avoided. Furthermore, the wheel surface condition after re-profiling requires continuous attention.

Modeling and optimization of plans for railway freight transport performed by a transport operator

This paper offers one approach for solving a problem that arises for railway transport operators. The task is to manage the fleet of freight railcars optimally in terms of profit maximization. The source data for the transport operator is a list of requests received from customers, as well as the location of railcars at the beginning of the planning period. The request formed by each customer consists of departure station, destination station, name and volume of cargo that the customer would like to transport. The request also contains the rate that the customer has to pay to the transport operator for each loaded wagon transported. Planning is carried out for a month in advance and consists, on the one hand, in selecting the most profitable requests for execution, on the other hand - in building a sequence of cargo and empty runs that will fulfill the selected requests with the greatest efficiency. Direct transportation of loaded and empty railway cars is carried out by Russian Railways with pre-known tariffs and time standards for each of the routes. At the same time, tariffs for driving loaded wagons are additional costs for the customer of the route specified in the request (customers pay both the transport operator for the use of wagons and Russian Railways); transportation of empty wagons is paid by transport operators. To solve this problem, one of the possible ways to reduce it to a large-dimensional linear programming problem is proposed. An algorithm is proposed, the result of which is a problem written in the format of a linear programming problem. To demonstrate the approach clearly, a simplified problem statement is considered that takes into account only the main factors of the modeled process. The paper also shows an example of a numerical solution of the problem based on simple model data.

Estratégia de utilização da folga de tração de trens para planejamento da distribuição de vagões vazios

No transporte ferroviário, o planejamento da distribuição de vagões vazios é importante porque a maioria dos vagões nas ferrovias brasileiras retornam vazios do pátio de descarga para o pátio de carregamento não gerando receita para a ferrovia e gerando mais custos com maquinista e combustível. Assim, este artigo propõe um modelo matemático de Programação Inteira que se baseia numa estratégia para distribuição de vagões vazios, onde esses são transportados utilizando a folga na capacidade de tração dos trens que circularão com vagões carregados já programados para atendimento às demandas dos pátios. Para avaliar o modelo proposto, foram criadas instâncias baseadas em dados reais da Ferrovia Centro-Atlântica (FCA) que foram resolvidas de forma ótima utilizando o solver CPLEX 12.6. O modelo matemático utilizando a estratégia proposta apresentou redução na formação de trens exclusivos de vagões vazios quando comparada com o planejamento manual da ferrovia.

Experimental study on ground vibration attenuation induced by heavy freight wagons on a railway viaduct

Studies on ground vibration induced by railway operation usually focused on wagons running on ground or abutments, while vibration from a railway viaduct is often assumed to be much lower. Based on field test in the vicinity of a heavy freight railway viaduct above Shenshan Village, China, the attenuation of ground vibration induced by heavy freight wagons for coal transportation is studied. And evaluation is conducted on an adjacent house to access vibration disturbance to residents near a viaduct. Propagation and attenuation of vibration induced from viaduct are studied by analyzing peak particle velocity and spectra of ground and house vibration in the vicinity of the viaduct. Vibration signals were collected for 34 trains with different train speed and wagon weight. In all monitored situations, vertical vibration is generally larger than horizontal vibration. The relationship between distance to pier and PPV is revealed by a power function modified from Sadovskii formula with high correlation factor. Analysis also indicates a much lower dominant frequency induced by low-speed trains with or without acceleration than normal speed trains. A dramatic amplitude reduction is shown within frequency between 25 Hz and 35 Hz when train speed is reduced. Empty wagons also show smaller amplitude in most frequency bands, with significant difference in 15–25 Hz. Analysis on the house also shows larger vibration in vertical than horizontal, and vibration amplitude in some frequency bands has exceeded relative criteria. Analysis result shows significant ground and house vibration effect form a viaduct, and piers should be considered as vibration sources for ground and houses in future studies.

Study on Longitudinal Forces of a Freight Train for Different Types of Wagon Connectors

Most of the freight revenue of Indian Railway come from open wagon rakes carrying bulk goods such as coal, iron ore, etc. A typical full rake load consists of 40 wagons and 2200 t weight. The pneumatic brake system is used for braking in Indian Railway. When braking is applied, brakes of all wagons do not act simultaneously. This variable braking action is the cause of a relative motion between the wagons and this motion creates huge longitudinal forces. Longitudinal forces have a considerable impact on the safety parameters like derailment coefficient, ride quality. These forces are transmitted from wagon to wagon through wagon connectors. For this reason, wagon connectors have an enormous importance on the longitudinal dynamics. The longitudinal forces are also different for different types of wagon connectors.In this paper, longitudinal forces by using Sh-1-T, Sh-2-T, and Sh-2-V wagon connectors are investigated for various loading conditions of wagons. The software Universal Mechanism UM8.1 is used for simulation. The train is modelled with a locomotive and thirty open wagons and it runs on an S curved, 1520 mm gauged track having 300 m radius. Nine train configurations are made by these three types of wagon connectors which are placed at different positions of the train. Three different types of wagon, namely fully loaded, partially loaded, and empty wagons are considered. The best type of wagon connectors along with their positions which generate the least longitudinal forces in a freight train irrespective of loading patterns of wagons is the aim of this analysis. After analysing the simulation results, it is found that Sh-2-T wagon connector gives the least longitudinal forces when it is used throughout the train, irrespective of loading conditions of the wagons.

Investigation on Derailment of Empty Wagons of Long Freight Train during Dynamic Braking

The derailments of empty wagons of long freight trains frequently occurred around the world, which caused tremendous losses every year. Aiming at an actual derailment of empty wagons on straight line during dynamic braking, the field investigation was conducted to find the reasons of the accident. According to the investigation results, the large coupler yaw angle and coupler force, the special connection mode by drawbars, as well as the poor conditions of wheel treads and flanges were supposed to be responsible for the accident. The simulaiton model composed of 3 C80‐type gondolas, and two RFC‐type drawbars is established, the accuracy of which is validated by the field experimental test. When the wheel‐rail friction coefficient is set to be 0.7 and the coupler forces are set to be 350 kN with a coupler yaw angle of 7 degrees, the simulation results are consistent with the field investigation results. Simulation results indicate that the coupler yaw angle, coupler force, and wheel‐rail friction coefficient have significant influences on the derailment. The increasing coupler yaw angle and coupler force will increase the risk of derailment. For the wagon units adopting the drawbars, the riskiest wagon changes from the middle wagon to the front one as the lateral components of the coupler forces increase. A large wheel‐rail friction coefficient can raise the risk of derailment. However, an overlarge friction coefficient will decrease the derailment risk. According to the field investigation and simulation results, the wheel‐rail friction coefficients should be limited below 0.5 to ensure the running safety of empty wagons. Besides, the operations of the train should be optimized to avoid large coupler yaw angle and coupler force.

Creep Forces Effect on the Ride of Empty Indian Freight Wagon

Indian Freight system is facing huge competition. The average speed of wagons at 40-50 kmph for empty wagons faces huge hunting problem. In these paper Indian parameters are studied using a numerical model The numerical model is consist of a whole wagon with two conventional three-piece bogie running on wheelsets. The wheel-rail contact is considered with heuristic nonlinear creep model for both single point and two point contact. Coulomb friction model is considered for contact between the truck and bolster. The present study concentrates on the critical hunting which is mainly depending on primary and secondary suspension parameters. A numerical study is run in Matlab to obtain the optimum parameters for increasing critical speed to stabilize wagon for both increased speed and at loaded vehicle.

A mixed integer programming approach for freight railcar distribution

Abstract The attendance of the demand for freight transport is related to the process of allocation of the wagons that in turn is associated with the way in which the decision is taken. The distribution of wagons to the shipment terminals depends on the planning as well as on movement of the empty wagons. In addition, the trips of the empty wagons have the major financial impact on the railroad system. In such a way, an efficient mechanism of wagon distribution is vital to the railroads, because it provides important operational profits and of costs. Therefore, the purpose of this study is to analyze the problem related to the distribution of the load wagons and to develop a mathematical model that can propose an optimal scheduling of the wagons.