It follows from the legislation requirements that strata control issues should be addressed on a risk-management basis within an overall WHS legislative and management framework, incorporating a PMHMP for strata failure.

“The risk assessment is the basis for developing an effective PMHMP,” the draft legislation states.

“Strata control practice in underground coal mining has significant implications for safety and the mine operator.

“Risk management should be applied at a number of levels within an organisation, including strategic planning and operational roles.”

The code of practice is issued as part of public comment on the draft NSW Work Health and Safety (Mines) Regulations 2014 under the Work Health and Safety (Mines) Act 2013.

There were 67 fatalities due to falls of roof and sides at Australian underground coal mines between 1980 and 2008.

These strata-related incidents included nine fatalities associated with rib falls; 23 fatalities in 18 pillar extraction incidents; 13 fatalities in 11 incidents that occurred while mining was taking place; and 13 fatalities while supporting the roof.

Several actions have followed these incidents, including the widespread introduction of breaker line supports for pillar extraction, the use of temporary roof supports during support activities and increased use of rib support.

In the same period, there has been a major change to longwall extraction and the use of full-face gate road development machines with multiple rib and roof bolters.

After 2001 there was a resurgence in pillar extraction. These changes led to differing hazards and controls for the strata management systems to cater for and control.