Determining the probability of failure for a diesel electric locomotive 060-DA using fault tree analysis

Abstract

The “fault tree” analysis is one of the most commonly used methods for determining reliability, calculating the probability of failure and thereby determining risk. The primary purpose of this analysis is to evaluate, using analytical and statistical methods, the likelihood of an unfavorable event occurring. These calculations involve the knowledge of system reliability data such as probability of failure, failure rate, time to failure, repair rate etc. Building a “fault tree” model can provide insight into how to pinpoint potential deficiencies within a functional system. In this paper, a defective tree structure was made for the main components of the 060-DA electric diesel locomotive. Five types of equipment part of the locomotive were taken into consideration: mechanical, pneumatic, thermal, power and auxiliary electrical. Each of these contains, in turn, other subassemblies and components. For the latter, some parameters needed to draw the fault tree diagrams were calculated on a statistical basis. In this way, the probability of the locomotive exiting operation was determined as a result of the defects that occurred in the component parts.