RELIABILITY DATA AND ANALYSIS FOR TRANSIT VEHICLES

This report provides a data base for the reliability of transit vehicles and their components. This data is essential for the successful implementation of quantitative reliability methods. Failure data on approximately 500 subway cars, 400 streetcars and 1100 buses was obtained from the Toronto Transit Commission for a period of 28 weeks. This results of the analysis of this data are presented in this report. For each category, viz. subway cars, streetcars and buses, the vehicles have been grouned according to the year of acquisition to minimize the differences due to age and design. The available failure data is a combination of complete and censored observations and, therefore, the method of hazard plotting has been used for the analysis. The computed measures of reliability of the vehicles and their components are the Mean Miles Between Defects (MMBD), Miles Per Defect (MPD), and the probability density function (pdf) of the miles between defects. The Miles Per Defect are further calculated for the different levels of severity of the impact on revenue service. It has been found that the more recently acquired subway cars and their components have generally lower reliability than the older stock. For buses the newer ones are more reliable than the older ones and the failure rate tends to stabilize after the fourth year of operation. Exponential and Weibull distributions with a shape parameter less than unity appear to fit the data for the miles between defects of the components. The possible reasons for this phenomenon are discussed. The possible uses of hazard plots for obtaining estimates of the cumulative distribution function, percentiles of the distributions, reliability and conditional probability of failure are also described. The results contained in this report can be usefully applied in planning, operation, design, reliability demonstration and life-cycle costing studies. The relevance of this data analysis to these areas is briefly discussed. The study indicates a need for further investigations and the desirability of collecting more detailed failure data, and also data for the lower level of components. /Author/

  • Corporate Authors:

    Ontario Ministry of Transportation & Communic, Can

    1201 Wilson Avenue
    Downsview, Ontario M3M 1J8,   Canada 
  • Authors:
    • Singh, C
    • Kankam, M D
  • Publication Date: 1977-1

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 73 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00183702
  • Record Type: Publication
  • Source Agency: Transportation Association of Canada
  • Files: ITRD, TRIS
  • Created Date: Dec 3 1981 12:00AM