The Hard Hat is an intergrial part of the safety of mining
Australian regulations demand that safety hard hats be worn on sites when there is a risk of being hit on the head, whether by falling objects or from a collision with a fixed object.
The risk of free falling objects increases in different situations. It could happen where workers are using tools at heights. Maybe poorly secured or unstable loads are being lifted. Moreover, roof scaffolding, bricks, rocks and soil could be dislodged by humans or the weather. Lastly, fixtures such as ceiling panels and pictures might not be properly secured.
Unstable structures also pose a risk, as do objects or materials which could become falling hazards when ejected from hand tools or machinery.
So as miners finish teir time in the area this has become a location to mark your leaving