The Royal Commission inquiring into the Pike River mine disaster has been told of delays, budget blow-outs and technical difficulties at the coal mine leading up to the explosions last November in which 29 men died.
A lawyer assisting the commission, Simon Mount, questioned the chief executive of the Pike River company - which is now in receivership - about a report detailing problems at the mine.
He asked Peter Whittall to comment on findings that the access tunnel was 100% over budget and two years behind schedule, and that there was a range of technical and operational problems at the mine.
Mr Whittall became chief executive six weeks before the explosions and had been the mine's manager since 2005.
He replied the tunnel did take a lot longer than expected, but he didn't agree it was two years late.
He agreed the budget had blown out, but said money was being spent where it had to be spent.
Earlier Mr Whittall told Commissioners the mine had a low propensity to spontaneously combust.
He said an independent laboratory test showed that the mine's coal was not prone to spontaneous combustion, and that it had a low likelihood of self-heating in normal atmospheric conditions
He said gas monitors were installed at various parts of mine, measuring methane, oxygen and carbon monoxide; and some monitors were programmed to shut down power in the mine when gas was detected at unacceptable levels.
He began his evidence by giving commissioners a detailed description of the mine and its facilities, saying it had the largest-known New Zealand deposit of high-fluidity hard coking coal, with one of the lowest contents of ash in the world.
Mr Whittall described the process of drilling the coal tunnel 2.3 kilometres to the coal seam itself.
He said the original bottom part of the mine's ventilation shaft had to be abandoned and filled in with concrete because it was unstable. Another shaft was constructed around it.
He said most coal was mining using a water cannon machine, which blasted coal with water pressure strong enough to put a hole in a concrete wall at a distance of 40 metres.
Mr Whittall said the mine was quite small and in the early stages of development at the time of the explosions.
The commission chair, Justice Panckhurst, says there is some concern at not meeting the Friday afternoon finish time and flagged an earlier start on Thursday and an extended day on Friday to make up time. He says it may even be necessary to set aside another day next week to complete phase one of the inquiry, which was scheduled to take 10 days.