James Li
Centre of Competence for Mass Transit, AME, Bombardier Transportation, Kingston, Canada.

DOI https://dx.doi.org/10.33889/IJMEMS.2017.2.1-003

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Abstract

Sneak Circuit Analysis is intended for critical applications which are essential to mission success and safety. A sneak condition will occur when a designed circuit inhibits a wanted function or results in an unwanted function. Sneak conditions originate from one of the four following scenarios: a sneak path resulting in a flow of electrical current along an unexpected route; a sneak timing that may cause the activation of some desired/designed functionality at an unexpected time; a sneak indication in monitoring functions that may result in an ambiguous or false display of system operating conditions; and lastly, a sneak label which may induce operator error due to inappropriate instruction. This paper introduces a near miss event that occurred in the Sao Paulo monorail which was caused by a sneak time condition. Root cause analysis and design modifications are also discussed in the paper.

Keywords- Sneak circuit analysis (SCA), Sneak timing, Door enable, Door inhibit, Propulsion enable.

Citation

Li, J. (2017). Sneak Circuit Analysis: Lessons Learned from Near Miss Event. International Journal of Mathematical, Engineering and Management Sciences, 2(1), 30-36. https://dx.doi.org/10.33889/IJMEMS.2017.2.1-003.