Dynamic selection and evaluation of alternative milling types for railway points

Abstract

The milled shape of point blades is one of the main factors causing structural problems with railway points (also known as turnouts or switches). Choosing the right type of milling for point blades can improve train running performance. Based on wheel–rail system dynamics, a vehicle–points dynamic model with various milling methods was established, from which a selection and evaluation method for milling was proposed. The service performance of four milling types was compared and combined with point blade robustness to provide a comprehensive evaluation. It was found that a small rate of railhead width change for an oblique tangent point blade resulted in better running performance of trains. The oblique secant point blade caused an abrupt change in the rail layout, which reduced train running steadiness. The railhead widths of longitudinal secant and longitudinal secant–oblique tangent point blades increased quickly, and the corresponding dynamic responses were at an intermediate level. The proposed selection and evaluation method for milling types took into account the dynamic characteristics and structural durability of the points. It will be beneficial in selecting an appropriate milling type for points blades according to their service requirements.