Pike River: Miner had questioned safety

The tags of the 29 miners and contractors killed at Pike River mine. Photo / Supplied

One of the miners who died at Pike River told a friend he feared for his safety in the month before last week's explosion.

Conrad Adams, 43, a deputy at the mine, sent his friend text messages revealing a gas build-up at the mine in the lead-up to the explosion that killed him and 28 of his workmates on November 19.

"Are you allowed to cut with a continuous miner updip in four cubic metres per sec from fan? Gassy area? Strong smell of hydrogen sulphide as well as from drillers stub," he wrote in a text message on October 19.

Hydrogen sulphide is a colourless, poisonous and flammable gas.

On October 6 he had written: "Fan on stop 20 hours. Whole mine gassed out to f**k. Off to de-gas. Mining updip has its down sides ay?"

The friend, who also works in the mining industry, said Adams told him he had serious safety concerns about the mine.

Adams grew up in Auckland but moved to South Africa with his father when he was 16. He had 25 years' experience working in gold and coal mines.

He moved back to New Zealand with his two children, who are in their teens.

His text message on October 6 referred to the mine being flooded with methane gas because of a fan not working to clear the dangerous gases from the tunnels.

Methane gas is odourless and is released when coal is mined.

The mining industry friend said a gas outburst could have led to the methane levels reaching explosive concentrations before detection systems could warn the miners.

However, the management could have reduced the risk of outburst by using sufficient gas drainage systems.

The friend claimed the pipes used at Pike River to drain the gas were too narrow.

Usually drainage pipes were 300mm in diameter, but he was told the pipes at Pike River were 100mm creating "back pressure".

"There is absolutely no reason whatsoever, for an explosion like this to be justified in this modern day, with cutting-edge technology, testing facilities to understand coal seam characteristics, educated mining professionals and experts," he said.

The man alleged Pike River Coal believed in "production over safety", an allegation that has been categorically denied by the company all week.

The company has previously acknowledged failing to meet production targets and trying to make up for delays by contracting extra mining equipment and labour.

Adams' sister Megan Adams declined to comment on whether he had spoken to her about safety concerns. "As a family there is so much we don't know," she said. "We are not mining people - all we know is from what Peter Whittall has told us in the family briefings about testing procedures and processes and they all sound very thorough.

"We just have to have faith in the commission of inquiry John Key has promised us."

Prime Minister John Key has announced a commission of inquiry will investigate the deaths of the 29 men. The Department of Labour, the police and the coroner are also investigating.

A Pike River Coal spokesman declined to comment on Adams' text messages but said Whittall, the company's chief executive, had addressed all concerns about methane build-up in press conferences.