(Indian Underground Coal Mine – Continuous Miner | DGMS Conditions) 🇮🇳 Understanding the balance between maximum coal recovery and pillar stability is critical in underground mining operations. In this study, I worked on: ✔️ Development Extraction Calculation – 29% ✔️ Depillaring Recovery – Final Extraction ≈ 86% ✔️ Pillar Stress Analysis using Tributary Area Method ✔️ Pillar Strength using Obert-Duvall Formula ✔️ Factor of Safety Evaluation (DGMS requirement ≥ 1.6) 📌 Result: The calculated FOS = 0.52, indicating an unsafe design — highlighting the importance of scientific pillar sizing and geotechnical validation before depillaring. This numerical exercise reinforces how engineering calculations directly impact mine safety, productivity, and regulatory compliance. Safety is not assumed. Safety is calculated.