Question

The width of the heading in Board and Pillar method of working depends on

• A. Depth of working
• B. Size of pillars
• C. Face machinery used
• D. Ventilation required

Hint:

In modern mining, the system is designed around the equipment.
The mine layout (like gallery width and intersection angles) must accommodate the machinery that will be used.
This operational constraint is often considered first, and then the design is verified for safety and stability based on rock mechanics principles.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
We need to identify a key factor that determines the width of a gallery or heading in a modern Board and Pillar mine.

Step 2: Detailed Explanation:
While several factors influence the final design of a mine layout, the width of the headings is constrained by both geotechnical stability and operational requirements.
-

Depth of working and rock strength determine the maximum safe width that can be excavated without excessive support.
-

Size of pillars is related to the gallery width through the extraction ratio, but doesn't directly determine the width.
-

Ventilation required can be met by adjusting both width and height to achieve a target cross-sectional area.
-

Face machinery used: In modern mechanized Board and Pillar mining, the dimensions of the equipment are a critical and often primary constraint.
The heading must be wide enough to allow the cutting machine (e.g., a Continuous Miner) to operate effectively and to provide sufficient clearance for loading and hauling equipment (e.g., Shuttle Cars) to maneuver.
The size of the machinery often dictates the minimum practical width of the heading, which must then be checked for geotechnical stability.
Therefore, the choice of face machinery is a direct and major determinant of the heading width.

Step 3: Final Answer:
The width of the heading is heavily dependent on the face machinery used.
This corresponds to option (C).