Former mines inspector prepared to re-enter Pike River mine

Solid Energy is about a week away from completing a permanent seal on the Pike River mine entrance. Photo / Mark Mitchell

Former New Zealand chief mines inspector Tony Forster said in an e-mail tabled in Parliament yesterday the Pike River Mine drift re-entry was feasible and he was personally prepared to go in.

Writing to the Pike River families, Mr Forster said re-entering the tunnel before entering the mine "could be done quickly, safely and within the budget originally allocated".

Prime Minister John Key and Environment Minister Nick Smith have ruled out the re-entry, and say the methane gas levels deep inside the drift are dangerous and risk another explosion.

Solid Energy is about a week away from completing a permanent seal on the mine entrance, including a concrete plug, sparking anger and a blockade from some mine family members and supporters on the Pike River access road, pleading for one last look inside the drift in case bodies could be recovered. The around-the-clock sit-in was abandoned after the earthquake, and a threat from Smith that they would be arrested for disrupting Solid Energy's work.

Forster wrote that recent de-gassing trials carried out in the drift during the commencement of work on the reversible seal at 170m had been "very effective".

"Ultimately, the complete re-entry to 'pit bottom in stone' would be conditional on the integrity of the drift rock tunnel.

"That could only become apparent by systematic inspection and geotechnical assessment during staged entry."

Forster said he would be honoured to take part in or lead the drift recovery: "I would never ask anyone to do what I would not be prepared to do myself".

Sonya Rockhouse, whose son Ben died in the 2010 explosion, said the e-mail showed that re-entry was possible and the permanent sealing must be stopped.

"The Government needs to work with us to put a re-entry plan in place so that we can recover any remains that are down there and find any evidence of what caused this disaster."

West Coast-Tasman MP Damien O'Connor, who tabled Forster's e-mail in Parliament, said an independent perspective was required as the Government was "making excuses and hiding behind Solid Energy".

"The letter ... explains the facts and provides no justification for sealing off the mine," Mr O'Connor said.

Smith told Parliament the seal would be 600mm thick and made of Stopcrete. There was an additional wall 30m further away at the portal. That was then in-filled with softer material.

Justifying the decision not to look at the drift, he said the mine was 98% methane, and had within it over 100,000 cubic metres of explosive gas.

Secondly, the experts advised that there were still likely to be residual heat sources capable of triggering an explosion if oxygen was ever present.

Thirdly, the 2010 explosions in the mine would have fractured the strata in the mine, and there was a high risk of further rockfalls.

Finally, there was just one means of egress.

"If there is any lesson to learn from Pike, it is that politicians should not be making decisions on safety," Smith said.

- Greymouth Star