Despite the company’s best endeavours, it had been unable to reach a level of confidence that any re-entry plan could adequately protect the lives of those who would undertake the work, she said.

Now that Solid Energy has reached its decision about the drift project, the company has decided to surrender the Pike River mining permit.

“We know this decision will be very disappointing to the family members and friends of the men who died in the mine,” she said.

“However any further loss of life in this mine is unacceptable and any possibility of other families having to go through what the Pike families have suffered is not something our board can support.”

Solid Energy was tasked with developing a re-entry plan that was technically feasible, financially credible and safe, according to Dunphy.

It had undertaken a rigorous risk assessment process supported by input from independent technical advisors.

“Safety has been our primary focus throughout. Our analysis shows that, despite every effort to control or eliminate risks to life, there remain a number of potentially fatal risk factors,” Dunphy said.

“These include risks associated with deterioration in the conditions inside the mine. For example it is impossible to rule out some degree of fire-related damage to parts of the roof and the associated potential for collapse.”

There are also risks associated with managing and maintaining gas and ventilation in an environment compromised by difficult terrain, unpredictable weather and unreliable services and infrastructure including electricity supply.

Dunphy said there were further risks associated with the sheer complexity of implementing 600 or more risk control activities, where failure of one or more controls due to human error or events outside of our control could have fatal consequences.

“These are all foreseeable risks, which escalate as the distance from the portal increases because of the distance to safety,” she said.

“Ultimately, we need to be able to rescue people if they became trapped. That would require us to be able to communicate to determine where along the 2.3km drift the entrapment occurred and be able to sustain life while drilling a rescue shaft.

“In recent successful rescues the location of trapped personnel was accurately known. They had to wait while a small diameter hole was bored to enable life to be sustained and then a large diameter bore hole was drilled, through which rescue was achieved. In this instance, there is no guarantee we would be able to do any of these things. The terrain alone is too steep and makes it impossible to site a drill rig of the size needed to facilitate recovery.”

New Zealand Prime Minister John Key met this morning with the families of the 29 miners lost in the Pike River explosion and Solid Energy on plans for the retrievals of the bodies from the mine.

Key, who was accompanied by Energy Minister Simon Bridges and acting Conservation Minister Nick Smith, said he would be having a “final” discussion with Solid Energy.

Last Friday Solid Energy pushed back the decision on re-entering the Pike River mine to this morning after receiving advice from experts.

“Solid Energy’s board decision about whether to continue with the project to re-enter the drift at the Pike River mine will not occur at the October board meeting as first indicated,” the company said.

“The decision has been deferred to ensure the company has sufficient time to consider the feedback from experts advising the Pike River families’ group.

“The company had intended to have this process completed for a board decision by the end of this month. However, the Pike River families’ group has agreed that Solid Energy take a little more time.”

Solid also said it would consider the feedback provided by the families’ advisors before making a decision on re-entry.

The state-owned New Zealand coal producer came under renewed public pressure in September after an Official Information Act request revealed a WorkSafe and Mines Rescue assessment that said re-entering the mine was technically feasible.

“The document goes on to say that there are no technical or safety barriers standing in the way,”3 News reported at the time.

“The worst part of this information is that Solid Energy was given this information almost a year ago.”

Solid has previously outlined the various risks facing any effort to re-enter the mine, with the tunnel re-entry and exploration project based on going up to the rockfall that has blocked off the drift 2.3km in.