A manager in charge of hydraulic mining at Pike River received no formal training and was left searching the internet for advice on handling the risky extraction process.
George Mason was hydraulic mining coordinator at Pike River mine before it was hit by a deadly explosion on November 19 last year.
In evidence to a Royal Commission of Inquiry this morning, he said he never received formal training in the mining method described as a "prime suspect'' in the fatal explosion.
His on-the-job training left him feeling overwhelmed at how to handle the "very high tech" machinery involved hydraulic coal extraction.
He was left searching the internet, without any success, for more training information.
"At that point in time Pike River was a very busy place, there were a lot of people and a lot of things going on. There were many systems that were in place or being put into place.
A lot of events that made me feel I guess overwhelmed to some extent," Mr Mason said.
Mr Mason's lack of experience in hydraulic mining was highlighted by a Solid Energy team that toured the Pike River mine on November 3.
Their notes said: "George Mason appeared out of his depth".
He was asked to accompany the team by his supervisor in the hope he would learn from them.
Mr Mason acknowledged the Solid Energy team had more knowledge of hydraulic mining.
However, he said he had a long history of experience in coal mining and knew about extraction.
Engineering, Printing and Manufacturing union counsel Nigel Hampton also questioned Mr Mason's ability to get methane readings from the Pike River mine.
He did not print out graphs showing methane records as he had difficulty with the computer process.
"I was aware of what was happening in the mine without referring to a graph," Mr Mason said.
Earlier, Minserv mining consultant David Stewart, who performed a series of audits on the Pike River between February and April last year, said Mr Mason had not received enough training for supervising hydraulic mining.
"It's inadequate training and experience to take on a role such as that.
"I would not be recommending such a person."