Updating the numerical characteristics of main resistance to wagon movement when rolling down a hump

Abstract

The parameters for humps are designed by the results of the roll-down of wagons with the design running performance. The numerical characteristics of the main specific resistance forces to the movement of wagons currently used in hump design are given in the Rules and Regulations for Marshalling Facilities Design of the 2003 edition. A wagon fleet in operation at the railway network has been significantly renewed, thus requiring a revision of the characteristics of the main specific resistance to wagon movement arising from their roll-down from a hump. The research subject in this paper is the process of rolling individual wagons down the hump. The purpose of the research is to determine the numerical characteristics of the main specific resistance force to the movement of wagons and to compare them with the current values. The findings showed a significant improvement in the running properties of the wagon fleet which is currently in operation and a reduction in values for the main specific resistance force compared to the existing regulations. It was found that the conditions to design humps according to the earlier regulations did not meet the actual operating conditions. The reduced values of the main specific resistance force contribute to an increase in the roll-down speeds of cuts at the designed hump sections, resulting in increased operating costs for braking and an increased risk of abnormal situations at their split-up. In fact, adjustments to the roll-down speeds of cuts are conducted by hump automation systems, including adaptive roll-down speed control systems. Thus, the task to adjust methods for designing hump parameters and their synchronisation with the changed operating conditions is relevant at the present stage of railway transport development.