Two earthquakes preceded the deaths of seven mineworkers at Sibanye Stillwater’s mine in Westonaria, the company said this week. The mineral resources department has launched a full investigation amid renewed calls for better working conditions underground.
The National Union of Mineworkers (NUM) and union federation Cosatu led a march to the Chamber of Mines on Thursday against companies that allegedly cut corners on safety to maximise profits.
The 2.1 magnitude earthquake that caused the collapse at Stillwater mine followed another larger earthquake, eight kilometres away.
“We were in the process of mobilising all the rescue teams when the second seismic event happened,” said Sibanye spokesperson James Wellsted. “But it still wasn’t in the [company’s operations area] so we have to work out why it caused more damage.”
But NUM health and safety chairperson Peter Bailey said tremors before the seismic events should have triggered Sibanye’s early warning systems, and the support system for the roof should have prevented the collapse.
“The support system is what keeps the roof intact … If it is adequate, and warning signs adhered to, it would have been a different ball game,” Bailey said.
The NUM questioned whether adequate support was in place at Stillwater before the second earthquake hit.
But Wellsted said Sibanye had adequate support in place. “Obviously our deep-level mining layouts are designed to withstand this sort of seismic activity. So we’ve had to design systems that can cater for that,” he said.
The government has not yet completed its assessment of Sibanye’s support system and it is not clear when the investigation will be completed. Sibanye said it would co-operate fully with the investigation.
Three years ago South Africa had one of the best mine safety records worldwide. In 2007, there were 220 fatalities and the number had steadily declined. But last year, the number of fatalities increased from 77 in 2016 to 86. This is partly because of increased seismic activity, mining companies said this week.
Falls of ground are common in deep mining and can be triggered by seismic events, the Chamber of Mines said. Fall of ground is a term for accidents that relate to the unexpected movement of rock and the uncontrolled release of debris and rock, according to the Mine Health and Safety Council.
In 2003, when the highest number, of seismic events was last recorded by the chamber, 48 of the 270 miners who died were killed in falls of ground accidents. Last year the industry experienced an increase in seismic activity, said the chamber’s head of safety, Sizwe Phakati.
“A particular concern has been the increase in the number of rockbursts related to seismic activity while the number of rockfalls … decreased.” The chamber has spent R250-million on research on seismic activity to reduce the safety risk since then, Phakati said. It has also established a fall of ground task team.
This is not the first time the NUM and Sibanye have been at loggerheads. The union has previously accused the company of ignoring safety officers, whose job it is to raise red flags when they observe a risk.
Bailey said the NUM has found companies ignoring officers and threatening them with disciplinary action. Mining companies had “the attitude that, when workers want to withdraw from a dangerous workplace, they want to first agree that it is dangerous. [Yet] the Mine Health Safety Act says ‘if it is deemed unsafe in the opinion of the worker’.”
He said there had been an exodus of competent safety inspectors when Mosebenzi Zwane was mining minister. “We now want to call on the new minister [Gwede Mantashe] to employ highly competent people to enforce the Mine Health and Safety Act.”