PhD ThesisWheel/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