When extracting coal in a room-and-pillar system, miners drive this small cut through an existing support pillar to split it or to prepare it for final extraction. It provides access and ventilation while progressively weakening the pillar before the roof is allowed to collapse.
Heard on the job
We need to drive a jenkin through the main pillar to improve airflow to the return airway.
Related terms
Room and pillar
An underground mining method where material is extracted across a horizontal plane, leaving blocks of ore to support the roof.
Depillar
To extract the supporting columns of ore or coal left behind during initial mining.
Heading
A horizontal tunnel or gallery being driven into an ore body or coal seam.