The use of linear motor technology to increase capacity in conventional railway systems

Abstract

Wheel/rail adhesion is an important constraint on the design and operation of conventional railways. The research question considered for this thesis is whether linear motor technology can improve the performance of railway systems by reducing the dependence of tractive and braking effort on the available wheel/rail adhesion. The two principal contributions of the research are an analysis of the influence of several different linear motor technologies on the capacity of conventional railways, and the development of a new design concept for train braking (named LEMUR – Linear Electromagnetic Machine Using Rails). Multi-train simulation of three different railway networks was used to investigate the capacity benefits and energy consumption of the LEMUR concept, along with four other existing or proposed implementations of linear induction motor technology with the running rail used as the secondary component of the motor. A model of each network was built using OpenTrack software, and Monte Carlo simulation with pseudorandom distributions of initial delays to train services was carried out to compare train movements under the influence of the delays typically encountered during day-to-day operation. An indication of the improvements in railway capacity possible with different linear motor technology options was then derived from these simulations. The results of the experiments indicate that the LEMUR concept provided the greatest increase in capacity and the lowest energy consumption of the five linear motor technology options tested. Although the limitations of the study do introduce some uncertainty into the precise values of capacity and energy consumption obtained, the experimental methods were considered sufficiently robust for this conclusion to remain valid. The most promising application in the study was suburban passenger services that are part of busy mixed-traffic networks. Here, the capacity benefits of the LEMUR concept appear to show sufficient promise to justify further development and application.