Mining consultant David Stewart yesterday kicked off the second week of the phase three inquiry of the New Zealand Royal Commission into the tragedy.

Stewart conducted a prefeasibility study on Pike River in 1977 and administered compliance audits at the mine on a contract basis throughout February, March and April of 2010.

While giving evidence, Stewart told the inquiry he felt the culture of the mine was filled with an immense amount of pressure.

“At the time of the audits and particularly when I was underground there was a sense of pressure to achieve targets,” he said.

“This was evident because everybody was aware of the cost of the operation to date, the missed targets for development and production and the financial crunch relating to the company as a whole.”

Stewart said although the drive to achieve targets drove most of the workers, he noticed there was an underlying suspicion and “mistrust” of management among workers.

He said this was a universal feeling throughout the industry, but it seemed more prevalent at Pike River.

“There appeared to me at PRC mine to be a greater level of dysfunction and mistrust than at other mines I had worked at,” Stewart said.

“I was not surprised about this, because the mine and the company were under a lot of public, financial and internal pressure and the turnover of senior and middle management and technical staff aggravated this.

“I do believe this may have contributed to some of the problems the mine had experienced.”

Stewart also revealed to the inquiry that there was an imbalance between the experienced people at the mine compared to inexperienced miners.

“The ratio in my opinion was not favourable in that the experienced miners were far less in number than desired given the nature of the operation and conditions,” Stewart said.

Stewart said this made it difficult for PRC to maintain consistency and development as much of the skills were left to the experienced few.

Under cross-examination from lawyer James Wilding, Stewart said the desirable ratio for underground miners would be to have six experienced miners at all times.

On top of the high percentage of inexperienced miners, Stewart told the commission the workers at Pike River were a mix of nationalities which seemed to create more problems for the mine.

“The workforce was further complicated by the mix of New Zealanders, Australians and South Africans scattered through all levels,” Stewart said.

“In many operations this can be an advantage, but at PRC mine it appeared to add to the apparent dysfunctional nature of the organisation and communication within the mine and between underground and surface.”

During his time auditing Stewart held numerous concerns over compliance at the mine, which included an absence of a mine ventilation manager and methane management.

Stewart said it was unusual that Pike River had no ventilation engineer or manager given the mines high methane levels and the introduction of a high pressure high producing hydro-monitor unit.

“There is no statutory obligation in New Zealand for this position as there is in Queensland I believe, but there is normally a person, usually either the mine manager or a mining engineer who is given the ventilation engineer duties,” he said.

Stewart also held reservations over the main fan because it was located at the shaft collar and did not meet compliance with instrumentation as specified in the regulations.

He was particularly concerned over the fact Pike River had no remote gas monitoring sensor or any display in the surface control room, “which meant they had no idea what methane concentrations were in the main returns and shaft, and therefore no idea of what was passing through the main fan or was in the general body of the mine.”

“I suggested that they needed to get a real time sensor in the main shaft as a minimum.”

On top of this, Stewart was concerned about the mine’s second egress.

“I inspected the alternate egress via the access to the Alimak rise and commented that this route was impracticable for a large number of personnel at any one time and only the fittest would escape through this route,” Stewart said.

Under questioning from Pike River Coal lawyer Stacey Shortall, Stewart agreed he was unaware whether or not his concerns had been addressed before the November 19 explosion.

Later in the day, Solid Energy general manager Craig Smith took the stand to explain the mechanics of hydraulic mining, also known as hydromining, which was employed at Pike River in September 2010 on a trial basis.

Although Solid Energy adopted hydraulic mining technology from Japan, Smith said he understood that hydraulic mining had now ceased in Japan and Canada but was still continuing in Russia and China.

At the beginning of the hearings last week, Royal Commission chairman Justice Graham Panckhurst said hydromining warranted examination because it could have been a factor in the first explosion at the mine.

Smith will continue to give evidence today.