stank

To stank a mine fire is to isolate the burning area by building or closing barriers, preventing air flow that would feed the combustion. This is a controlled abandonment of a section: you seal off the affected zone with walls, doors, or stoppings (temporary or permanent barriers made of wood, brick, or concrete) and allow the fire to consume its available oxygen and eventually extinguish itself. The goal is to contain the damage, protect workers in adjacent areas, and avoid the catastrophic consequences of an uncontrolled underground fire spreading through the workings.

Stanking requires rapid decision-making because every hour of delay allows the fire to grow hotter and spread further through coal dust, timber supports, or seams of combustible material. Mine managers assess whether a fire can be fought with water and foam or whether stanking is the only safe option. Once the decision is made, crews build stoppings using available materials, working from uncontaminated passages toward the fire zone. The work is dangerous: heat, smoke, and carbon monoxide push back against the stoppings, and visibility is nearly zero.

Standby and monitoring after a stank

After a zone is stanked off, it must be monitored continuously for gas leakage, particularly carbon monoxide and methane. Temperatures at the stoppings can remain elevated for days or weeks as the fire dies down. Teams take readings through boreholes drilled into the sealed zone and adjust ventilation in surrounding areas to prevent dangerous gas accumulation. If pressure builds behind the stoppings, relief vents may be opened carefully to bleed off gas without reigniting the fire.

The term itself is obscure in origin, though some suggest it derives from the action of 'stanching' or stopping a wound. What makes stanking distinct from simple mine closure is the active sealing under emergency conditions, with the sealed zone still burning. It is a last resort, used most often in deep coal mines where underground fires can spread uncontrollably through interconnected passages and coal seams. The decision to stank a section is almost irreversible in the short term: reopening a stanked area to fight the fire directly is justified only if new information suggests the fire can be controlled by other means.