Use of k-spiral, bend, jog, and wiggle shapes in design of railroad track turnouts and crossovers

摘要

Railroad track transition curves having shapes referred to as K_spirals, Bends, Jogs, and Wiggles are suitable for use in various situations where railroad track transition curves are needed and have good dynamic characteristics. Such shapes can be used for design of railroad track turnouts and crossovers. In order for such shapes to be incorporated into turnouts and crossovers, rail switch arrangements are provided that can accommodate the superelevation profiles on which the favorable dynamic characteristics of those shapes depend. Such shapes can be used for turnout and crossover design in conjunction with two mechanical switch arrangements that are themselves well known, namely the transfer table and stub switch arrangements, and with two switch arrangements that are variants of the commonly used movable point arrangement, namely an arrangement in which the through point rail is wide over its whole length and an arrangement using a through point rail of relatively conventional taper and width but one that is bowed downward between its point and the frog.