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Introduction. One of the ways to increase the traffic-carrying capacity of railway lines is increasing the amount of cargo carried in cars, while taking into account the inevitable increase in the axial and linear load of the car. The decision to use cars with increased axial load should be based on an assessment of their technical and economic efficiency in comparison with the innovative and widely used open-box wagons with a load of 25 tonnes per axle. When assessing the economic efficiency of such cars, it is required to consider their impact on changes in the parameters of the organisation of the transportation process.Materials and methods. Based on the presented initial data on the estimated predicted freight flow, the numerical values of the parameters of the transportation process were determined when introducing 8- and 4-axle (27 t/axle) open-box wagons. When determining the increase in the traffic-carrying capacity, its change due to an increase in the net mass of the train and a change in the total number of trains is taken into account. The calculation was made accounting for the increase in traction in proportion to the increase in the gross mass of the 8- and 4-axle (27 t/axle) open-box wagon trains on the existing infrastructure.Results. The authors have developed methodological provisions to determine the numerical values: an increase in the traffic- carrying capacity, the required inventory fleet of cars and the available locomotive fleet in the context of the introduction of new 8- and 4-axle (27 t/axle) open-box wagons.Discussion and conclusion. The article is theoretical and is devoted to calculation mechanisms and methodological issues. The results of the study may be applied to the ranges of the Russian Railways network, in particular, to solve complex issues of increasing the traffic-carrying capacity of the Eastern range.

Mass of a passenger train and, accordingly, number of cars in its composition is selected based on the amount of passenger traffic on the section, determined by the seasonal demand for transportation in each direction. In one direction of the section serviced by an electric locomotive, the mass of a passenger train may differ several times from the opposite direction, which depends on the destination station of the train and the period of its circulation. At present, in addition to 6-axle electric locomotives of the ChS2T and EP2K series, more powerful 8-axle electric locomotives of the ChS7 series operate in the same schedule for traction of passenger trains on railway sections electrified with direct current with a voltage of 3 kV catenary. All three series of the considered electric locomotives are designed for a maximum operating speed of up to 160 km/h. In this regard, there is a situation with the underutilization of the maximum speed and excess power of the ChS7 electric ocomotives, especially when operating with passenger trains of medium and low weight and a limited speed of 120 km/h. The comparative data on the specific power consumption of the EP2K 6-axle electric locomotives and the ChS7 8-axle electric locomotives operating in the same schedule, presented in the article, indicate the need to find additional reserves for saving the specific power consumption when servicing passenger trains of medium and low weight with ChS7 electric locomotives. The electric locomotive power system includes traction and auxiliary electric machines. The article discusses ways to turn off part of traction motors, which can be carried out with a standard electric locomotive circuit. However, when one section of the electric locomotive is turned off, the power of the four traction motors remaining in operation is not always sufficient to drive a passenger train according to the schedule. Therefore, a variant of improving the power circuit of an electric locomotive in the process of carrying out its overhaul is proposed. This option represents the modernization of the power circuit of the ChS7 electric locomotive when operating on a series-parallel connection with a pair of traction motors disconnected. As a result, the power circuit of the 8-axle electric locomotive operates similarly to the circuit of 6-axle DC electric locomotives with a collector traction drive. The expected savings in specific power consumption can reach 15% in comparison with the operation of an 8-axle electric locomotive ChS7 in normal mode. Switching off one section of the electric locomotive and further running the train on four traction electric motors will reduce the specific power consumption by up to 25%.

In accordance with the draft Long-Term Development Program of the JSC “Russian Railways” until 2025, the main driver of growth in freight turnover in this perspective will be a further increase in the transportation of hard coal. It will occur both due to the growth of coal production in Kuzbass and due to the development of new coal deposits. For the period up to 2025, the increase in coal loading by 4 – 5 % per year is predicted on rail transport. Under these conditions, it becomes necessary to increase the capacity of the transport complex, especially the carrying and transport capacities of the Eastern Operation Area.The article presents the methodology for calculating economic effect of increasing the carrying capacity of the site during operation in cars with increased axle load. The scope of this methodology is specific areas (sections), taking into account their technical, operational and economic parameters.Variant calculations were made, the results of which showed that an increase in the carrying capacity of a section with an increase in the mass of a train formed from cars with increased axle loads does not always give a significant positive effect in terms of value for the infrastructure owner. Positive effect of the increase in carrying capacity in the form of additional profits from the additionally used traffic volume in the evaluated variant can be taken into account in the following cases:- operation of large-capacity cars on freight-intensive sections where there is a lack of carrying capacity in the billing period, i. e. the carrying capacity of the section is less than its required value;- exceeding the freight charge for the additional volume of freight carriage incurred transportation costs, i. e. if the tariff compensates for at least the dependent part of the cost of additional volume transportation.Positive economic effect of the increase in carrying capacity in the form of increased money flow is achieved if the profit from the additional traffic volume in the direction exceeds the additional costs associated with changing the technology for servicing the traction arms while promoting high-weight trains formed from cars with increased axle loads. In other words, if there is no increase in the value of the indicator of mileage (in section-km) per unit of transport work, and the unit cost of maintaining one section with a new technology for servicing traction arms.