Improvement of curving performance by expansion of gauge widening and additional measures

Lateral forces between wheels and rails must be reduced in order that rolling stock runs safely and smoothly on curved tracks. The excessive lateral force will cause not only derailment of rolling stock but also destruction of tracks, rail corrugation, track irregularity, squeal noise and wear. It is important to reduce lateral force of wheels in curves, so new wheel-tread profiles and steerable bogie structures have been developed up to now, however, they cannot solve various problems in curving perfectly. In this article, the authors propose three methods for improvement of running performance on curves by using existing types of wheels and rails, and analyse the effects of three methods by numerical simulation. According to analytical results, the authors conclude that ‘expansion of gauge widening’, and ‘larger rail inclination angle of inner rail installation’ or ‘asymmetrically inclined grinding of inner rail head’ can get sufficient rolling radius difference, and are effective for improvement of running performance on curved tracks.