The standard AS/NZS 3584.3:2012 Diesel Engine Systems for Underground Coal Mines Part 3: Maintenance was reviewed, substantially rewritten and republished early in 2012.
Provisions strengthened in the rewrite include the integrity of the explosion protection. This follows an alarming increase in failed inlet and exhaust system joints on diesel engines in Queensland and New South Wales underground coal mines.
Failures have occurred in both “open joints” and “fixed connections” and the failed joints were found to be no longer explosion-protected.
“A diesel engine with a failed joint operating in an underground coal mine risks igniting methane that may be present in the mine atmosphere,” the inspectorate said in the notice.
“Most failed joints are preventable and investigations have highlighted failures caused by insufficient inspections, maintenance personnel lacking competence, and substandard audits-checks, which are all major defects in mine and workshop systems.”
The revised standard uses a three-tiered approach to joint integrity: manufacturing relies on type testing and use of a quality system in manufacture and assembly; specific examination and testing processes are defined and detailed for various maintenance requirements; and using competencies relevant to the tasks undertaken and supervision applied.
“Competence of mine personnel conducting maintenance and joint inspection is sometimes inadequate,” the inspectorate said.
