Penstock failures on gold tailings dams in South Africa

Penstock failures occur at fairly regular intervals on South African gold tailings dams. This results in disruptions of the tailings deposition programme on the mine and sometimes in overloading of other tailings dams while the failed penstock is being repaired or replaced. The failed penstock is normally replaced by the installation of a “floating” penstock at considerable cost to the mine. The name implies that the penstock is floating in tailings. This paper investigates the mechanism of penstock failures, reasons for failure and possible mitigating measures.