Scaling is the act of knocking loose rock off the walls and backs (the roof of an underground mine is known as the backs). Ensuring safety during this process requires strict adherence to best practices and constant vigilance. In this article we explore safety considerations in manual scaling.
Key safety considerations
Ground assessment
- Always visually examine the area before starting work.
- Never assume an area is safe; check for fresh cracks, loose rock, or signs of instability.
- Sound the rock using a scaling bar to detect hollow or unstable areas; good ground gives a ringing sound, while loose ground sounds dull or hollow.
Personal protective equipment (PPE)
- Wear gloves, safety glasses, helmet, cap lamp, protective clothing, safety boots, and hearing protection.
- Use a safety rope and harness if there is a risk of slipping or falling.
Work position and technique
- Always stand under stable ground, never directly under areas being scaled.
- Maintain secure footing and keep a clear retreat path in case of unexpected rock falls.
- Pry up, not down, with the scaling bar to avoid dislodging rocks onto yourself.
- Start scaling from the crown (top), then move to the haunches (shoulders) and side walls.
Equipment
- Use a scaling bar of sufficient length for the heading.
- Never use loader buckets or inappropriate tools for manual scaling.
Environmental controls
- Ensure adequate ventilation to disperse dust and fumes, especially after blasting.
- Water down the area to minimize airborne dust.
Procedural controls
- Scale from good ground toward bad ground.
- Frequently check the area during the shift for new hazards.
- If a hazard cannot be immediately corrected, post warnings and install barriers to prevent entry.
Training and communication
- Only trained personnel should perform manual scaling.
- Communicate any hazards or concerns to supervisors and coworkers.
- Ongoing training and adherence to structured safety protocols are essential.
