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

摘要

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.