Maintenance, Inspection, Testing, and Asset Management
Maintenance, inspection, testing, and asset management test how you keep railway electrical assets available and safe over their life. Expect condition-based maintenance, diagnostic tests, and asset-register decisions.
Core rules
- RCM asks what failure mode justifies each task; CBM triggers work on condition data. FMECA ranks failure modes by severity and detectability.
- ISO 55000 defines asset management: value, alignment, leadership, and a documented asset management plan.
- Typical tests include insulation resistance, partial discharge, thermography, contact resistance, protection function tests, and visual inspection of creepage and corrosion.
- Trending matters more than a single pass/fail result; records must link asset, test, and limit.
Worked example
A 25 kV cable gives 300 MΩ on a 5 kV insulation test. The acceptance floor is 100 MΩ, so it passes. But the previous three tests were 2 GΩ, 1.2 GΩ, and 600 MΩ. The absolute result passes; the downward trend and partial-discharge rise indicate moisture ingress. The correct action is investigation, not immediate replacement and not “pass, no action.” This is a CBM decision.
Traps
- Accepting a single test result without trend or temperature correction.
- Confusing RCM with a fixed time-based overhaul.
- Treating thermography as a substitute for protection testing.
- Failing to close out defects in the asset register.