Improved Sprial Geometry for High Speed Rail

摘要

An improved method for the design of spirals for passenger railroads is explained and illustrated. The new method is based on three principles as follows: centre dot The traditional principle that track curvature should correspond to vehicel roll motion and should change as the roll changes so that passengers alwyas experimence zero (or small) lateral acceleration. centre dot A principle proposed here that roll motion should be controlled so that roll velocity, roll acceleration, and rate of change of roll acceleration (roll jerk) all stay within comfortable limits. centre dot Another principle proposed here that roll motion should be about an axis at about chest height for standing or seated passengers so that passengers experience minimum lateral acceleration due to roll per se.