Focus Live earlier: Pike River re-entry delayed due to safety concerns
Animals nibbling through tubes is one of the possible causes mining experts are looking into after plans to re-enter the Pike River Mine had to be postponed.
The Pike River Recovery Agency confirmed a wild animal chewing through a gas monitoring tube was a possibility they were looking into but said other possible reasons were more plausible.
Today, Pike River Recovery Minister Andrew Little announced an eleventh-hour delay to tomorrow's re-entry operation after the Agency got an "unknown reading of oxygen" from a borehole 2.3km into the mine's drift, where the roof collapsed in the 2010 explosions.
The oxygen had the potential for a "spontaneous combustion event".
Pike River Recovery Agency chief operating officer Dinghy Pattinson denied it was a tough call to delay the re-entry, because they have also stressed a safety-first attitude.
Dinghy Pattinson, the chief operating officer of the Pike River Recovery Agency, stands outside the entrance to the Pike River Mine near Greymouth. Photo / File
"It was an easy decision to make," said Pattinson, who was due to lead a three-man team of miners back into the mine tomorrow.
The cause could be as simple as a damaged tube in a borehole, Pattinson said, but they needed to go through a process of elimination which would last "however long it takes".
"We've got the readings. We have an issue. We're going to sort through that issue," he said.
"At the moment, the mine is full of nitrogen, so nothing can happen. As it is now, the mine is stable."
While a wild animal like a goat or a possum chewing through the tube was possible, other causes could be inaccurate monitoring equipment or oxygen coming through the strata.
Little said the delay "could be days, could be weeks", but a safety priority meant that further action could not take place until more is known about the elevated oxygen levels.
Twenty nine miners' helmets sit on crosses erected on the roadside leading up to the Pike River mine near Greymouth. Photo / Alan Gibson
The elevated readings meant that the atmosphere in the drift had changed and the air is not breathable.
He said he was disappointed at the delay and for the families, but safety had to come first.
He said the families knew the technical challenge of the project, and while the families were disappointed with the delay, they were also realistic.
"Safety must come first. No more lives can be put at risk," Little said.
Families had been readying themselves for an emotional moment when the 30m-seal at the mine's entrance was to be breached.
It has been more than eight years since the heartache from the loss of 29 men's lives, outrage over attempts to permanently seal the mine - which the families successfully fought - and frustration at the lack of accountability.
They've also wanted it to be treated as a crime scene, and any clues which may lead to a future prosecution, gathered and explored.
After the methane gas explosion, fears of further explosions prevented any search-and-rescue attempts.
Toxic gas levels and safety concerns meant the first attempt back into the mine – four days after the initial explosion – came with a New Zealand Defence Force robot sent underground. It broke down just 550m in after reaching water.
Four more robots would go in, with mixed results, including video footage on November 25, 2010 from 1600m into the mine, which showed extensive damage from the second blast and ended hope of recovering the 29 trapped miners.
