: Definition Shaft is a mode of vertical approach to mineral lying at depth beyond approachable by other means technically and economically. : Technology/methodology Sinking of a vertical shaft is confronted with maximum risk, requiring maximum skilled and expertise and is the largest capital item in working a mine. Sinking is performed by conventional method of drilling, blasting and mucking either by manually or mechanically. Shaft sinking jobs are mainly subdivided in 3 stages - (i) Sinking & lining in alluvium/soft rock upto rock head (ii) Drilling, blasting & mucking and (iii) Side supported by PCC or RCC lining of various thickness from 300mm to 600mm along with Excavation in strata along with. Drivage of No. of insets at various depth to approaches and extract coal and metal as the case may be.