A blind level is a subterranean gallery driven horizontally between two shafts or workings, lacking any direct adit or portal to the outside world. It often functions as a drainage trap or inverted siphon to manage mine water, or serves as an intermediate haulage route. Because it has no surface access, ventilation and material transport must be handled entirely through the connected vertical shafts.
Heard on the job
The water is backing up in the blind level, so we need to drop a pump down the secondary shaft to clear it.
Do not mix it up with
- Adit: An adit is a horizontal tunnel that opens directly to the surface, whereas a blind level is entirely underground.