Design of Lighting System for Surface Mine Projects

Abstract

Indian mining illumination standard is based on incident light without mentioning about uniformity ratio. But CIE (International Commission on Illumination, Austria) stresses upon uniformity ratio as well. In a mine because of low surface reflectance, the surrounding illumination level is much lower than the minimum lighting standard, as specified by various regulatory bodies. The surface brightness further reduces in wet surface condition, resulting in poor visibility. In the present study, design has been made both in mineral and overburden benches based on minimum acceptable reflected light and reflected uniformity ratio. For the sake of comparison of various types of lighting systems, a stretch of 1.0 km long haul road was considered and design was attempted with five different types of luminaries. Lamp mounting heights have been varied at five steps, namely 8, 10, 12, 14 and 16 m. Design under wet condition would incur an excess cost of about 9.4 % for mineral bench and about 50 % for overburden bench haul roads under study. Thus designing under wet surface condition would ensure minimum light level even under worst condition of surface reflectivity, with marginal increase in cost.