Join us for latest updates from the Pike River inquiry throughout the day. Former chief executive of the Pike River Coal company Peter Whittall is giving evidence for a second day:
4:44: Royal Commission counsel Simon Mount has completed his questioning. The commissioners are now retiring to discuss how proceedings will continue.
4:34: Mr Whittall says he does not draw a link between New Zealand's depleted mine inspectorate and the November 19 explosion at the Pike River mine. He says a new and improved mines inspectorate would not necessarily have changed how the tragedy unfolded. The cause of the explosion at the mine is still unknown, he says.
4:28: New Zealand mine safety standards are inadequate and need wide-ranging review and revision, the Pike River Coal submission said. Mr Whittall says he still agrees with that view. He says 'Minex' mining standards referenced regularly throughout the Royal Commission proceedings were irrelevant to Pike River Coal. "This is the first time I've heard of them."
4:24: Mr Mount is quoting a Pike River Coal submission to a Department of Labour mining review.
It asked for a more comprehensive approach to risk and hazard reviews in New Zealand mining. It said more mine inspectors were needed. But it said a 'safety case' regime was not needed. Mr Whittall says the submission was a company document and he cannot take ownership of all the views contained in it.
4:18: Stone-dusting at Pike River mine fell below statutory levels at one point in 2010, Mr Whittall says. He says Mr White was "embarassed" about the dip in standards.
4:12: Mr Whittall says there were concerns about whether the ventilation system in place at Pike River could support hydro-mining. Operations manager Doug White was investing a lot of his time making sure the ventilation was adequate and Mr Whittall understood it was "tight".
3:55: A type of mining used briefly at Pike River can pose significant gas risks, Mr Whittall says. The high pressure water gun used in hydro-mining can displace gas at the coal face, he says. He then explains the phenomenon of 'wind blast'. It involves a large section of roof falling in at once and forcing high pressure air up a mine tunnel, he says.
3:50: Mr Whittall says he has no idea what gas sensors were working at the time of the first explosion on November 19 and that detail was no usually provided to him. "I have absolutely no knowledge of what gas sensors were working or in place." He is then asked whether it is important to measure barometric pressure in a mine. It was not important at Pike River because the mine is so small, he says.
3:45: Methane sensors were placed near the top of the mine's ventilation shaft, Mr Whittall says. Ideally, those sensors should be recording less than one per cent methane in the atmosphere, he says.
3:44: The inquiry has resumed. Mr Whittall says data from gas sensors was immediately available at the Pike River mine. Gas data from the mine was able to be mapped at its control room, he says.
3:24: The inquiry has adjourned for a 15 minute break.
3:20: Mr Whittall says tube bundling monitoring can give more detailed analysis and predict potential gas outbursts. However, the Pike River mine did not have a system in place at the time of the November explosion. "We just weren't there yet." There was a plan to buy a tube-bundling system for Pike River in April 2011, Mr Whittall says. The purchase had been set back by cash problems afflicting Pike River Coal, he says.
3:14: Mr Whittall is discussing the 'tube-bundling' system for monitoring gas levels. It involves gas being transported through plastic tubes and sampled outside a mine. Mr Whittall says the advantage of the system is it can cheaply extract samples from all over the mine - but those take time to be tested. That is contrasted with 'real time' monitoring' using electronic equipment, which is expensive but can immediately measure gas levels.
3:04: Mr Mount asks again whether Mr Whittall would have expected staff to raise Mr Brown's concerns over gas drainage at Pike River with him. Mr Whittall says he wouldn't expect operations manager Doug White to raise the report with him unless he thought he could not continue operating the mine safely.
2:58: Gas outburst management was of 'great concern' at the Pike River mine, Mr Brown's report said. It said no outburst threshold had been set for the mine. Mr Whittall says there had been no history of gas outbursts at the Brunner coal seam, and it was considered a "mild" threat. He says Mr Brown did not see outbursts as a significant enough risk to raise the issue with him directly.
2:54: A later report from Mr Brown - this time from September 2010 - is tabled. Mr Mount asks whether the mine's gas drainage pipeline had been upgraded from four inches to 10 or 12 inches, as was recommended in previous reports. Mr Whittall says there had been no change to the pipeline, or gas riser.
2:38: The report said it would be "difficult" for Pike River to maintain its expected production levels with existing gas drainage equipment. It would create too much gas in the mine shaft, it said.
2:27: Mr Brown's report also said water management of the gas drainage pipeline was not consistently maintained. Mr Whittall says he knew the pipeline was "at or near" its capacity and acknowledges it had not been upgraded by July 2010. However, he says the failure of Pike River mine to meet its production targets meant the upgrade was not needed as urgently as Mr Brown's report suggested.
2:22: Pike River Coal (in receivership) counsel Stacey Shortall queries Mr Mount's line of questioning, saying Mr Whittall has made it clear he did not see the report. Justice Graham Panckhurst says the report is relevant to the inquiry and rules its contents can be put to Mr Whittall as he is the only witness for Pike River Coal and held a senior position in the company.
2:18: The report said the gas drainage pipeline at the Pike River mine was inadequate. It said the four inch pipeline at the mine needed to be upgraded to 10 inches. "The last outcome Pike River Coal needs is a safety failure." Mr Mount asks whether Mr Whittall would have expected to be made aware of a statement like that. He says he was "well aware" of the need for a new pipeline and is not surprised the report was not brought to his attention by staff.
2:15: More data was needed on gas drainage at the mine, the report said. It recommended three months of data collection to provide enough information for a gas drainage model.
2:12: The report recommended installing a new 'gas riser' within three months. Mr Whittall says his managers were working on identifying a place where a riser could be installed. He was not aware of the report from Mr Brown and is seeing it for the first time.
2:11: Royal Commission counsel Simon Mount has presented a report by gas drainage specialist Miles Brown on the Pike River mine. It says inadequate gas drainage pipeline diameter and inadequate workforce knowledge of the risks of gas holes in pipelines were safety problems. Mr Whittall says the inadequate pipeline diameter was a problem and was being addressed.
2:00: The inquiry has resumed, with Mr Whittall being questioned on gas drainage.
12:56: The inquiry has adjourned for lunch and will resume around 2pm.
12:50: Mr Whittall is now discussing methane gas drainage in the Pike River mine. He says gas is intentionally collected in pipelines. That can be a risk water builds up in the the pipeline or gas is expelled into the mine roadway through a leak, he says.
12:42: A new underground fan was turned on at the Pike River mine in November last year after a series of difficulties in installation, Mr Whittall says. He says to his knowledge, it was delivering the planned amount of air to the mine and continued to do so until the November explosion.
12:28: Mr Whittall is discussing the complications and requirements involved in installing an underground fan system in the Pike River mine.
12:12: Mr Whittall confirms the 'Alimak' rise repairing the collapsed lower section of the Pike River mine's ventilation shaft was originally meant to be 4m wide. It was later narrowed to 2.5m due to construction complications. Mr Mount asks whether the smaller size would restrain the ability of the ventilation system to provide the right amount of air to the mine. Mr Whittall says no, the fan at the top of the shaft was powerful enough that it was not an issue.
12:06: Mr Mount is asking about the suitability of the Pike River mine ventilation shaft site. He points to evidence the shaft was planned for the east side of the mine, but cost and feasibility issues saw it moved back west. Mr Whittall says putting the ventilation shaft to the east would have meant excavating "half the hillside". It would have cost up to $15 million, rather than about $5 million, he says.
12:01: It is revealed Pike River Coal had plans for a another fan to boost ventilation at the mine. Mr Whittall confirms that fan had not been constructed by November last year. He also confirms the mine's ventilation shaft was not 4.1m wide from roadway to surface because of the narrower 'Alimak' raise to its lower section.
11:57: Mr Whittall says there was no role at Pike River for a 'ventilation engineer'. "It's actually very difficult to recruit people with specific ventilation qualifications... unless you're a very large mine." He says the company instead had access to an on-call ventilation consultant.
11:55: Mr Whittall is being shown the Pike River mine's ventilation management plan from November 2008. That plan was still in place when the mine was hit by an explosion in November last year. Mr Whittall says he understands a new plan was in the process of being drafted before the explosion.
11:50: Mr Mount points to a report saying pre-drainage of coal is necessary to avoid dangerous gas build up in mines. Mr Whittall says that is opinion presented as fact and ventilation should mitigate gas risks. He says pre-drainage was started once the Pike River mine development reached pit bottom.
11:30: Mine ventilation is now being discussed. Mr Whittall says Pike River was a "gassy mine" according to New Zealand regulations. Mr Mount points to a 2010 recommendation that Pike River Coal employ a ventilation officer. That was never done, Mr Whittall says. But he says the ventilation officer role is not defined in New Zealand legislation and Queensland is the only state to officially establish the role.
11:24: Mr Mount points to a Pike River Coal report to the Conservation Department saying the mine's ventilation shaft was inappropriate as a second exit point. Mr Whittall says those words were "poorly chosen" and later amended to say the shaft was not appropriate as a permanent second means of egress.
11:17: The inquiry has resumed, with Mr Whittall continuing his evidence.
10.53: The inquiry has adjourned for a 15 minute break.
For a full account of yesterday's proceedings at the inquiry, read the Listener report from Rebecca Macfie. It reveals the high turnover and financial pressure that beset the Pike River mine.
10.50: Mr Mount asks whether there was ever a test to see whether a miner wearing self-rescuer breathing apparatus could climb out of the mine using the ventilation shaft. Mr Whittall says he is not aware of any test. It would have been more difficult to climb out of the mine with a self rescuer on if the atmosphere was not breathable, he says.
10.45: Mr Whittall says the ventilation shaft was not the second means of egress at the mine. That would have compelled staff to go there in case of an emergency when it was safer for staff to go to the fresh air base, he says. Mr Mount asks whether that means there was no second exit from the mine. Mr Whittall says the mine had a primary entrance, a fresh air base and an 'escapeway' - which could be deemed a second egress.
10.30: Mr Mount points to an assessment from Mines Rescue claiming the it would be "virtually impossible" to get out of the Pike River mine by its ventilation shaft if there was a fire. Mr Whittall says the company discussed its rescue plans with the Department of Labour mines inspectorate after seeing those comments. Harnesses were installed at the bottom of the ventilation shaft, he says.
10.25: When the lower section of the Pike River ventilation shaft collapsed during construction, it was replaced by a narrower 'Alimak' raise connecting the shaft to the mine. That narrow shaft was fitted with a ladder and was marked as an escapeway from the mine, rather than as a 'second egress', Mr Whittall says. He admits the company never conducted a trial evacuation of all mine staff up that shaft. However, the exit was used by staff, he says.
10.20: Mr Whittall is shown a May 2005 design drawing showing a ladder up the Pike River mine's ventilation shaft. He is asked whether the mine's leadership assessed the risks of putting a ladder up the shaft and whether they considered replacing it with a winch. A winch was never considered, Mr Whittall says.
10.11: Mr Whittall says it is his understanding that New Zealand mines are required to have two exits. A second exit was planned in the west of the Pike River mine on plans in 2005, he says. That was still not constructed at the time of the first explosion at the mine on November 19.
09.57: Mr Mount says employees of a company responsible for a 2005 report on the prospects for the Pike River mine received shares in the company in return for their work. Mr Whittall says he understands workers in consultants Minarco were shareholders in the mine. He relied "substantially" on the company's report when he recommended work should begin on the mine in 2005. However, he qualifies that statement by saying he had 24 years mining experience and didn't blindly accept the company's recommendations.
09.45: Pike River managers were consistently optimistic about the mine development, Mr Whittall says. He says there was an expectation every access agreement would be granted on the day it was due and every contract would be delivered on budget.
09.42: The report proposes two stone drives into the Pike River mine, Mr Mount says. Mr Whittall says he had not seen that report until two weeks ago and was not aware of any proposal for two stone drives. West Coast miner Harry Bell earlier criticised the use of a single drive to drill through the Hawera Fault.
09.40: Mr Mount discusses a 1995 report which puts the cost of the Pike River mine development at $30 million. The report says the rate of return on the mine would be "just sufficient" to justify it. Mr Whittall's only comment is "it was going to be cheap wasn't it".
09.33: Mr Whittall is asked about Solid Energy chief executive Don Elder's claim the Pike River mine would only produce a low value semi-hard coking coal. Royal Commission counsel Simon Mount says that type of coal is discounted below the value of hard coking coal on the international market. It is unclear what Mr Elder knows about coal at Pike River, Mr Whittall says. "I've no idea what he's based that on or his motive for making those comments"
09.25: The Pike River mine was still about a year away from consistently running at full capacity when it was hit by an explosion on November 19, Mr Whittall says.
09.20: Mr Whittall admits the Pike River mine was running below its production targets.
09.15: The Royal Commission of Inquiry has resumed for the day, with former Pike River Coal chief executive Peter Whittall giving evidence.