The coal miners in the Illawarra region of New South Wales have co-existed with high levels of the stuff for decades, however, the ever-present threat of a gas explosion has left some of the more nervous blokes working at Appin and Dendrobium with a permanent twitch.
Last week, things came to a head with South32’s Illawarra Metallurgical Coal company making the decision to pull its workers out of Appin as a precautionary measure.
The New South Wales Department of Planning and Environment was notified about the withdrawal, which occurred last Wednesday.
South32 confirmed there was no gas exceedance or breach of gas limits. However, those reassurances were not enough for the DPE, which is taking a hard line on gas exceedances.
The Resources Regulator has issued a prohibition notice and expressed broader concern regarding recent gas exceedance events.
“Safety is a core value and we are working, together with the regulator, to address these issues,” South32 said.
Hogsback tends to agree with the Regulator – which has recently issued several gas related alerts – that it is better to err on the side of caution when it comes to dealing with gas.
There have been several recent incidents in NSW where the Regulator has been very forward in not letting the gas issue escape the notice of mine management.
It warned longwall mine operators to review their windblast management plans to include longwall take-offs after gas levels reached 2.69% in a high potential incident at a NSW underground coal mine.
During the removal of shields on a longwall faceline, the goaf caved behind the buttress supports for a distance of about 30 shields.
This caused gas from the goaf area to be pushed into the return outbye of the longwall face, causing the gas level to rise above 2%.
The level was above 2% for about 26 minutes, reaching a maximum of 2.69%.
“Mines should consider this risk and implement appropriate controls including trigger action response plans that respond to goaf level stand up distances,” the Regulator warned said in an alert.
“Ventilation quantities should be maximised and adequate exclusion no-go zones developed and enforced.”
Then there was the recent case where the gas drainage plant failed to operate during the night shift at a NSW mine after a 66kV feed tripped.
As this was the only plant running at the time, the mine followed its procedures to withdraw people from the mine.
The trip was re-set and the methane level did not exceed 2%.
“Effective gas drainage and main ventilation systems are essential for the control of gas and the safe operation of coal mines,” the Regulator said.
“Where these systems are compromised by electrical power supply faults, the cause must be investigated thoroughly.
“TARPs [trigger action response plans] must be enacted immediately after alarms have been activated.”
Fear of a gas explosion is something that can keep even the most experienced coal miners up at night. Hogsback reckons the Regulator is doing a good job in addressing gas head on and in the process letting the underground workforce sleep more easily.
