Answer:
If there is a shaft with headgear, then mining can take place until that depth of the shaft. If it is accessed horizontal Adits, it can mine until the lowest Adit from upwards. If it is accessed decline, the development and mining can continue so long as economic exploitation is possible.
Explanation:
What are the disadvantages of mining headgear? They totally cut off your vision of anything above your head. They are hot, most of the time
