The physical act of undercutting a working face, typically by removing a narrow band of material near the floor. This provides a free face for the upper mass of coal or rock to break into when blasted or wedged down. Historically done by hand with a pick, it is now performed by mechanized cutting machines to improve the efficiency and yield of the blast.
The undercutter finished holing the longwall face, so we can start drilling the blast holes.
Also heard as
- undercutting
Related terms
Undercutter
A mechanized coal-cutting machine that slices a horizontal slot at the base of a seam.
Underhole
To excavate a deep groove at the bottom of a coal seam to help it fracture.
Coalface
The advancing boundary of a coal seam that is actively being mined.
Longwall
An underground coal mining method that extracts a wide panel in a single continuous slice.