Railway illumination covers yard lighting (for shunting and safety at night), platform and station lighting, and town/colony supply for railway residential areas. AEE-level questions focus on lighting design fundamentals rather than architectural detail.
Core Terms & Units
- Luminous flux (lumen, lm) — total light emitted by a source.
- Illuminance (lux, lx) — luminous flux per unit area falling on a surface.
- Luminous intensity (candela, cd) — flux per unit solid angle in a given direction.
- Utilization factor and depreciation factor — used when calculating the number of luminaires needed for a target lux level.
Lumen Method (Number of Luminaires)
N = (E × A) / (F × UF × MF)
N = number of luminaires, E = required illuminance (lux), A = area (m²), F = lumen output per luminaire, UF = utilization factor, MF = maintenance (depreciation) factor.
Yard Lighting Considerations
- High-mast towers are preferred over individual poles in large yards to reduce glare and shadow zones during shunting.
- LED fixtures are now standard replacement for older sodium-vapour/mercury-vapour yard lamps — better efficacy and lower maintenance.
Content Status
Draft note, self-authored for the platform skeleton. Not yet cross-verified against the official RBE 14/2014 syllabus PDF — treat as study-aid only until verified.