The downcast is the primary intake route for a mine ventilation system. Surface fans push clean, oxygenated air down this shaft, or underground exhaust fans pull air through it by creating negative pressure. It ensures miners have breathable air and dilutes hazardous gases before the airflow exits through the upcast shaft.
The main hoist is in the downcast, so you'll feel a strong draft when waiting at the station.
Because it brings in fresh air, the downcast is often used as the main shaft for transporting personnel and equipment.
Do not mix it up with
- Upcast: The downcast brings fresh air in, while the upcast pulls contaminated air out.
Related terms
Upcast
A vertical mine shaft designated for exhausting stale air to the surface.
Airway
Any underground gallery, drift, or shaft designated specifically for routing ventilation air through a mine.
Return
An underground passage that carries exhausted or contaminated air away from the working face.
Fanhouse
The surface building that encloses the main ventilation fans for an underground mine.