What were conditions like on the Gold Mines circa 1940?

I am a writer living in Tuscany, Italy. I am currently writing my grandparents' story circa 1940. My Grandfather worked in Shaft 710 Langlaagte Crown Mines as a skipman. I would like to know if anyone could give me an idea of the conditions of the gold mines at that time?

Thank you in advance

Jacqueline | jacquelinefalcomer@gmail.com