The GAG crew and New Zealand rescue teams spent their Christmas running the jet and maintaining the status quo at the Pike River mine in preparation for sealing of a cracked shaft this week, Hanrahan told ILN from outside the minesite where the bodies of 29 miners are trapped.
The crew has been working in the difficult terrain and severe weather conditions in the region around Pike River, which can only be accessed by helicopter and which have made it a slow and extremely difficult operation, he said.
“I would like to express my sincere thanks to the members of the Queensland Mines Rescue Service jet crew, their families and employers for their support and dedication to this operation, which has a way to go yet before it’s completed,” Hanrahan said.
“The GAG is still running and holding the mine inert.”
The GAG unit, which is pumping water vapour into the mine, was flown in from Queensland in an attempt to make the mine safe for re-entry by recovery teams.
Hanrahan also sought to clarify some inaccuracies in reports by the NZ Police about the progress of the GAG operation.
“In brief, the GAG began operation on December 1, 2010, after the GAG crew and NZ Rescue built an airlock that was inserted into the portal. This was a point to inertise and for re-entry at a later date,” said Hanarahan, who is also operations manager at the inertisation unit at the Queensland Mines Rescue Service in Dysart.
“On December 8, the GAG had inerted the mine and extinguished the visible fire, it continued to inert and cool the mine until a cap was built and put in place on the vent shaft and on Sunday [December 12], the GAG was shut down. The GAG had successfully extinguished the fire and inerted the mine.”
On December 13, the oxygen levels had increased to a level of concern. As it appeared oxygen was entering from an unknown location, the GAG was started again, Hanrahan said.
“With the mine now sealed and the GAG able to insert a pressure on the mine atmosphere, it became evident the oxygen was entering through cracks in the strata around a 600-millimetre shaft named the ‘Slimline’ as the GAG’s helium tracer product was now exiting through these same cracks.
“The GAG has continued to run since this was discovered to maintain an inert atmosphere in the mine until a solution is found on how to seal these oxygen paths.”