closed shaft

closed shaft

A shaft roofed or enclosed at the top.
References in periodicals archive ?
The bill, the DA says, will stop mining sector growth and probably lead to closed shafts and workers losing their jobs, and will also mean fewer exports and a worse balance of payments position.
Most of the miners are illegal immigrants and break through concrete seals covering closed shafts.
Even though Harmony provided security for closed shafts, some guards are bribed by the illegal miners, Smith said.