Which of the following is a type of equipment that must be protected by methane detectors?

• A. Longwall shearer
• B. Tunnel boring machine
• C. Coal feeder
• D. Diesel locomotive

Answer: (A)

Methane detectors are used where there is a real risk of ignition from or around equipment operating in methane-prone areas. At the coal face, the longwall shearer is the piece of equipment most closely associated with ignition risk because it operates with high-energy electrical and mechanical systems right in the zone where methane can be released from the coal seam. If methane levels rise, detection systems can trigger ventilation changes or shut down the equipment to prevent an explosion, making this equipment the one that must be protected by methane detectors.

The other options are not the primary targets for methane protection in the same way. Tunnel boring machines are used in development headings and aren’t the standard focus for methane detectors at the face. A coal feeder and a diesel locomotive have safety controls and methane considerations, but the requirement to shield equipment with methane detectors is most directly tied to the high-risk, methane-prone face area where the longwall shearer operates.