Rockhouse, who oversaw safety systems at the mine, is the father of Ben, who died in the mine, while his other son Daniel Rockhouse survived the first blast.

Rockhouse said he had 40 years experience in the mining industry, but when he commenced working at Pike River in December 2006 it was the first time he had been exposed to a gassy mine.

Yesterday, Rockhouse told a Royal Commission inquiry into the explosion which killed 29 men that his relationship with Whittall deteriorated after his ex-boss refused to back safety projects.

However the major turning point came when Whittall shouted at Rockhouse for trying to help another manager on an operating procedure.

“On one occasion he caught me helping one of the managers do some stuff and he sort of turned around and said, “Keep your bloody nose out of it,” Rockhouse said.

“He’d give me a hard time but he’d also give a lot of the other managers [a] hard time.

“He could be a very intimidating man and a lot of people on site were intimidated by him, I think that's fair to say."

Rockhouse said it had all got too much for him and he resigned twice because he had started falling out with Whittall “big time”

However, Rockhouse decided to stay at the mine after being talked out of resigning by managers, friends and family.

During evidence, Rockhouse admitted to a number of factors which put an immense amount of pressure on workers to increase production.

He said the pressure for workers to lift production at the mine started once it became known that Pike River Coal’s financial situation was deteriorating.

“We found out the money was running out about 14 months before the explosion and that equalled pressure,” Rockhouse said.

Rockhouse said the pressure, combined with “constant machinery breakdowns”, meant the whole project had slipped further and further behind time frame.

“I believe sincerely that when the project first started you know, everyone had the right intent but then over a period of time with the pressures and the challenges and obstacles, it changed,” he added.

At one point in the inquiry, Rockhouse said when he first met PRC chairman John Dow, he came across as knowledgeable and spoke to Rockhouse about his intention to produce “world class systems” at the mine.

However Rockhouse said this intention never translated to reality.

“They’re just words,” Rockhouse said.

“To actually do that in reality you've got to have an incredible paper trail … and unfortunately those were just words.”

Earlier in the day, Rockhouse admitted he was “gobsmacked” about the mine's safety flaws, which he only found out about after the November 19 explosion.

He said his surviving son told him how people were putting plastic bags over gas sensors and using explosives to apply stone dust on the mines walls.

“I was gobsmacked, I was absolutely gutted,” Rockhouse said.

Rockhouse said anyone who ever had anything to do with mining knew these acts were extremely unsafe.

“It’s beyond comprehension … the rules of mining are written in blood,” he said.

Rockhouse admitted hazard reports and risk assessments were never delivered to the health and safety department, so details of high amounts of methane around machinery were never drawn to attention.

“Any time any miner or anyone brought an issue to me I jumped on it,” he said.

“I've never seen this stuff before.”

Under questioning from lawyer James Rapley, Rockhouse admitted that going underground once a month was not enough.

He said work pressures had interfered with his ability to go underground

“In hindsight based on what I know now I would've camped underground,” Rockhouse said.