Whittall started at Pike as the general manager in 2005, and became CEO in mid September, 2010, roughly two months before the first underground explosion rocked the mine and claimed 29 lives.

At the final day of phase one Royal Commission hearings in Greymouth on Friday, Whittall said Pike River was just a mountainside and a feasibility study when he started – and the project even lacked roads for site access.

“Often after you take these jobs on, you don't know what you've had until you've lost it,” he said.

Whittall said he was with BHP for 24 years and had access to “any system you want and any person you need” during this time.

“I was a member of a number of email forums where I could just send an email, it would go out to 800-900 people and they would give me their views on things around the world.

“When I joined Pike I had literally no one. I had no systems, we didn’t even have a payroll system, New Zealand Oil and Gas paid us but we had nothing.”

Consequently Whittall played a major role in developing the management information systems and he said NZOG even ended up using Pike’s health and safety management plan.

One of the trickier questions he faced on the day was over a New Zealand Mine Service audit of self escape capabilities made in August, 2009.

Lawyer for families of the deceased Richard Raymond raised a paragraph of this report which described that using the mine’s Alimak-driven ventilation bypass shaft as a second means of ingress would be virtually impossible in a fire situation.

The prospect of using the ladder in this 108m shaft to escape the mine was also raised in the previous day.

However, Whittall indicated that this possible escape route was not part of long-term plans.

He said the ladder in this shaft was maintained as an escapeway but the company was working towards the west of the mine to put in a permanent second egress.

The CEO went underground at Pike River about a week before the first explosion, according to his testimony.

He also revealed that a purpose-built changeover station had been decommissioned by the time of this blast, but there was a fresh air base at the bottom of the slimline ventilation shaft.

Later in the day, Queensland Mine Safety and Health Commissioner and Pike Royal Commissioner Stewart Bell expressed surprise that there was only one carbon monoxide sensor in the mine plan submitted by the company.

“I did question yesterday that I thought we were also installing carbon monoxide sensors in association with the substations at pit bottom in stone but they’re either off the plan or they’re not shown on that corner of that plan,” Whittall said.

“I also understand we’ve got a carbon monoxide sensor at the entrance to the tunnel, but I probably don’t wish to comment on your comment about whether that’s appropriate or not. I'm not sure where else they were, whether they are there but not shown on the plan, I just don't know, I can't answer that.”

Whittall said he would try and find out and supply this information to the commission.

Carbon monoxide is generated in coal mine blasts and Pike survivor Daniel Rockhouse reported that the explosion took place when he eventually reached the mine’s telephone underground.

The second phase of hearings, scheduled to start from September 5, will focus on the search and rescue efforts at the mine.