The Royal Commission investigating the Pike River mine tragedy has been hearing concerns about the training of miners working underground in hydro mining operations.
The commission has been hearing evidence from George Mason, the manager of the underground mining teams at the time of the first explosion in November 2010 and from Stephen Wylie who was in charge of one of the crews carrying out hydro mining.
Mr Mason said he has many years experience in coal mining but had never worked in hydro mining until he was hired at the Pike River mine.
He said he largely learnt abut hydro mining on the job and at times felt overwhelmed.
Mr Mason said there were training modules for the teams doing the hydro mining but about half the workers had not completed the modules, despite carrying out the work for five to six weeks.
He said he was not too concerned about that, as he felt people learn better if they already have an understanding of the job and conditions.
Mr Wylie told the commission he wasn't able to get any training in hydro mining, despite being in charge of a crew carrying out the work.
He said he had had no formal training in hydro mining before he took up the position at Pike River.
He had asked for training for himself and his crew but the requests never came to anything.
Mr Wylie says he was told that the men couldn't be spared from the mining production.
After the first explosion Mr Wylie says Police and the Department of Labour showed him Pike River documents on the operation of the equipment he had been using, but he had not seen these previously.