A reliability analysis of railway switches

Abstract

Switches and crossings (S&C) are critical elements on railway networks. Any failure of S&C usually leads to train delays and cancelations having a negative impact on the quality of service delivered, railway safety and also operating costs. S&C is a multi-component system and to enable proactive prevention of S&C unit faults, with their undesirable consequences, the ability to predict problems at component level is needed. This paper describes the derivation of lifetime distributions of individual S&C components based on field data collected. Maintenance was identified as a potential contributor towards increased frequency of reported S&C faults. The outcomes of the analysis and lifetime distributions for the elements of the switch units provide a means of predicting the expected number of maintenance activities, and associated costs for these units over any specified period of time. They provide an essential input to the optimisation of maintenance in developing an asset management strategy.

Identifying the Input Uncertainties to Quantify When Prioritizing Railway Assets for Risk-Reducing Interventions

“…Monte Carlo sampling from skewed normal distributions was used as part of the methodology to identify the input uncertainties that affect which assets are prioritized for risk-reducing interventions. Although other distributions could be used for the input variables, the use of skewed normal distributions as shown in [57,[61][62][63][64][65][66], is a reasonable simplification in this analysis. This is because its scope was not to quantify the uncertainty in the ranking but to obtain an initial impression of the effect on the ranking when distribution functions of the inputs are used instead of best estimates.…”

“…The necessity of a systematic consideration of input uncertainties has been widely acknowledged in railway management. Many scholars have investigated the effect of input uncertainties in the estimation of risks due to failures of railway assets (e.g., [32,[58][59][60][61][62][63][64][65]), as well as of costs and effects on rail service due to interventions (e.g., [57,[66][67][68][69][70][71][72][73]). As there are uncertainties in the estimations of risks, costs, and effects on service, the ranking of assets for interventions, which is based on these estimates, might not be reliable.…”

A Petri-Net-based modelling approach to railway bridge asset management

“…One way to format the historic data is to use a timebased approach (Agrawal et al, 2010;Niroshan et al, 2014;Rama and Andrews, 2013a), which is typically used with PNs. Each structure is routinely inspected and so a record can be built up of the health of each element that the structure comprises of.…”

A new approach to railway track switch actuation: Dynamic simulation and control of a self-adjusting switch

“…Its aim is to reduce and/or prevent any unexpected failure in the switches through condition based maintenance and studying the reliability of the switches. 6,7,8,9 Other researchers are tackling the problem by seeking to develop new actuation techniques or alternative switch layouts. 10,11 Across the range of switch machines in the UK, closed-loop feedback control is not employed; nor has it been addressed in the literature.…”