Turkish coal mines Soma, Zonguldak and Elbistan move coal by conveyor belt. Friction ignites the belt and fire spreads along the tunnel; Soma 2014 with 301 dead was Turkey's worst mine disaster. NFPA 122 requires belt-slip alarm, CO detector at 50 ppm and methane LEL 1 percent.
Tunnel Hazards
- Methane: Coal gas, LEL 5 percent
- CO: Early fire indicator
- Coal dust: Pneumatic explosion
- Belt friction: Idler stuck
- Hydraulic oil: High-pressure hose
NFPA 122 Detectors
- CO alarm: 50 ppm
- Methane: 1 percent alarm, 2 percent trip
- Belt slip: 10 percent alarm
- Thermal cable: 68 C linear
- Dust detector: 250 g/m3
Tunnel Sprinkler
- Overhead: 12.2 L/min/m2 deluge
- Water spray: NFPA 15 envelope
- Duration: 60 min
- Foam: Hydraulic oil
- Dry pipe: Cold tunnel
Emergency Escape
- Refuge chamber: 96 h O2
- SCSR: Self-contained 1 h
- Walkway: 600 mm min
- Lifeline: Cable guide
- Escape van: Personnel transport
Soma and Lessons
- Soma 13 May 2014: 301 dead
- Ermenek 2014: 18 dead
- Amasra 14 Oct 2022: 42 dead
- Cause: Methane + CO buildup
- MSHA Upper Big Branch 2010: US 29 dead
Conveyor with MEP Calc
MEP Calc sizes tunnel ventilation 1,200 m3/s, CO detector 50 ppm, methane LEL 1 percent and NFPA 122 belt-slip monitoring.
Download MEP Calc on the App Store
Sources & Further Reading
NFPA 122, NFPA 120, MSHA 30 CFR 75, ISO 5924, TKI Soma Report. NFPA 122 Prevention and Control of Fires in Mines.