A risk-reliability comparison of track sections in the passenger railway industry

Mc Naught, M. D. (2015-12)

Thesis (MSc)--Stellenbosch University, 2015.

Thesis

ENGLISH ABSTRACT: In chaotic maintenance environments, executing planned maintenance becomes difficult because the need for immediate corrective action escalates. Reverting back from a poor system state to a stable and well maintained one is a challenge. Railway track environments are prone to system degradation and poor maintenance. They are, therefore, in need of analytical tools to 'get on track' with maintenance. A risk-based method which grades track corridors between train stations according to their level of risk was developed. To achieve this, both the likelihood and the severity components of risk were considered. The likelihood component of risk in the track environment is the reliability of track. Reliability was calculated by quantifying track failure modes first and then analysing the characteristics of failures for each track corridor. Probabilistic models were generated from repairable systems reliability theory from which reliability predictions were made. The severity component of risk is the average delay historically experienced by each track corridor. A risk matrix was developed which brings together likelihood and severity components of risk for each track corridor. Maintenance prioritisation is possible from the risk rankings created by the matrix. The risk rankings for five track corridors were validated when a condition-based track maintenance tool, TQI, was in agreement.

AFRIKAANSE OPSOMMING: In die chaotiese instandhoudingsomgewing is dit moeilik om beplande onderhoud uit te voer, aangesien die nodigheid vir onmiddellike regstellende aksie toeneem. Om terug te keer van 'n swak stelsel na 'n stabiele en goed instandgehoue stelsel is 'n uitdaging. Spoorweg-omgewings is geneig tot stelselagteruitgang en swak instandhouding. Daar is dus 'n behoefte aan analitiese metodes om weer op die regte skedule te begin volg met instandhouding. 'n Risiko-gebaseerde metode wat spoorweë tussen stasies gradeer volgens hulle risiko is ontwikkel. Om dit reg te kry, is beide die waarskynlikheid en die graad van erns van risiko's in ag geneem. Die waarskynlikheid van risiko in die spoor-omgewing is die betroubaarheid van die spoor. Betroubaarheid wordbereken deur eerstens die hoeveelheid spoorfalings te bepaal en dan die kenmerke van die falings vir elke spoorweg te analiseer. Waarskynlikheidsmodelle is opgestel van herstelbare stelsels betroubaarheidsteorie van waar betroubaarheidsvoorspellings gemaak is. Die graad van erns van risiko's is die gemiddelde vertraging wat histories deur elke spoorweg ondervind is. 'n Risiko-matriks wat die waarskynlikheid en graad van erns van risiko's kombineer is vir elke spoorweg ontwikkel. Instandhoudings-prioritisering word moontlik gemaak deur die risiko-graderings volgens die matriks. Die risiko-graderings vir vyf-spoor spoorweë is bevestig toe 'n voorwaarde-gebaseerde instandhoudingsprogram, TQI, eenparigheid bereik het.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/97871
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