Ground support and modelling through railway switches & crossings and transitions

Switches and crossings (S&C) and other transitions in railway tracks experience a large number of degradation modes which can be interrelated and in which state and evolution are not currently easy to predict. This results in a high cost for infrastructure managers in inspection, maintenance, delay minutes and renewal. The Track to the Future (T2F) programme aims to investigate innovative measures to prevent some of the most significant degradation modes of S&C, potentially leading to substantial cost savings. A key factor affecting S&C performance is the non-uniform nature of the structure support stiffness along the S&C panels. The complexity of the system, i.e. the number of components and the variability in their properties, leads to increased dynamic loadings which subsequently generate differential settlement of the ballast support and lead to geometrical degradation of the switch and crossing components.

This project will focus on using field and laboratory test data to develop improved ways of specifying and representing support stiffnesses for S&C and other problematic transitions. It will work closely with an associated project located at Huddersfield, where the aim is to analyse the dynamic behaviour of a complete turnout taking into account the train-track interaction. The Southampton results will be incorporated into models run at Huddersfield, where a numerical model of the track system will be developed and integrated with commercial railway vehicle dynamics simulation software (e.g. Simpack and VI-Rail).

The Ground support and modelling through railway switches & crossings and transitions research project is part TRACK TO THE FUTURE (T2F) a major five-year, £8M research programme, funded by EPSRC, industry and the Universities of Southampton, Birmingham, Huddersfield and Nottingham. Its aim and vision is to support the development of railway track systems that are efficient in terms of embodied carbon, materials use and cost; robust in requiring little maintenance; and unintrusive in producing little noise. It will address this aim through three interlinked Research Challenges (RCs).

TRACK4LIFE (RC1): low-maintenance, long-life track systems with optimised material use, through
• developing, and demonstrating the effectiveness of, new track forms or components and promising interventions e.g. under-sleeper pads and random fibre ballast reinforcement (1A)
• developing an understanding of the relationships between the key measurable parameters of track stiffness and track settlement, and the key performance parameter of geometrical standard deviation, taking into account the interactions with rail geometry and vehicle dynamics (1B), and
• extending the life of ballast by reducing or eliminating the factors leading to its degradation, assessing the feasibility of design for the degraded state and facilitating re-use rather than downcycling or disposal (1C).

DESIGNER CROSSINGS AND TRANSITIONS (RC2): crossings and transitions that optimise the behaviour of the vehicles traversing them, thereby minimising damage. This will be achieved by developing new understandings of the highly complex interactions between switch and crossing geometry, sub-base support, wheel profile and vehicle dynamics, including the effects of varying the support stiffness through the crossing or transition; and combining them with the potential of modern manufacturing methods to provide a tuned variation in geometry and materials properties.

NOISE-LESS TRACK (RC3): an integrated approach to designing a low-noise, low-vibration track consistent with reduced whole life costs and maintenance needs. Track is the main source of railway rolling noise and has a key role in vibration transmission into the ground. Noise is increasingly cited as the main objection to the expansion, reopening or construction of railways. However, design changes are usually driven by other concerns with the implications for noise and vibration considered as secondary effects.

Applications for this PhD research project are accepted on a rolling basis and we therefore advise you to apply early if you are interested. To make your application please go to: http://www.southampton.ac.uk/engineering/postgraduate/research_degrees/apply.page

If you wish to discuss any details of the project informally, please contact Professor William Powrie, Infrastructure research group, Email: [Email Address Removed], Tel: +44 (0) 2380 59 3214.