In a drift being driven from the surface in material other than coal, what triggers alarms to everyone in the drift?

• A. Detection of products of combustion
• B. Any alarm level
• C. When methane exceeds a threshold
• D. At scheduled times only

Answer: (A)

The key idea is fire detection. In a drift being driven from the surface through material other than coal, alarms are wired to go to everyone in the drift when combustion products are detected. Smoke, carbon monoxide, and other combustion gases are reliable early indicators of a fire, so triggering the alarm on their presence ensures all personnel are alerted immediately to evacuate and respond. Other triggers don’t fit the scenario as well: methane thresholds aren’t the primary fire signal in non-coal material, alarms at arbitrary levels could miss a developing fire, and scheduled-only alerts won’t reflect real-time hazards. Detecting combustion products provides the best, fastest warning of a fire in the drift.