Pike River mine disaster

On 19 November 2010, following an explosion in the Pike River mine on the South Island of New Zealand, 29 men lost their lives. I’ve read the Royal Commission reports (about 450 pages) and pulled out some of the key lessons from a human and organisational factors perspective. As with other incidents described on this website, there are of course lessons for many other industries. This was a mining tragedy, but when we strip back the lessons from the Royal Commission, what we find is an organisational accident.

A failure to learn

I’ve used this phrase several times in my analysis of major accidents and disasters, but it is very appropriate here. This is also the title of Chapter 20 in the Commission report (volume 2).

In the Preface to the Royal Commission, we learn that this is the 12th commission of inquiry into coal mining disasters in New Zealand. Since the industry began, hundreds of men have died in the New Zealand coal mining industry (including 172 deaths from just five previous tragedies). At the time of the Commission, the country had a poor health and safety record more generally, when compared with other advanced countries including the United Kingdom, Australia and Canada.

“This suggests that as a country we fail to learn from the past”

Royal Commission on the Pike River Coal Mine Tragedy, 2012 (Preface, p.3)

What happened at Pike River mine?

On 19 November 2010, at 3.45 pm, at the Pike River coal mine, near Greymouth, a major explosion occurred whilst 31 men were working underground. Only two men escaped from the mine. Five days later, before search and rescue operations could commence, a further explosion occurred, from which no-one underground could have survived. Further explosions occurred on 26 and 28 November. When the Commission was published, the bodies of the 29 men had not been recovered, and they still remain entombed in the mine.

The immediate cause of the first explosion was ignition of a substantial volume of methane gas. This was therefore a ‘process safety’ accident. The ignition source is unclear, given the inability of the investigation to re-enter the mine, but there was no shortage of potential ignition sources.

The Commission concluded that there was a failure to manage methane at the mine. Several precursors of a major accident were present in the months leading up to the disaster. In the sections below, I outline some of the human and organisational factors gleaned from the Commission reports. Although I have structured these findings into discrete headings, it’s important to note that many of these factors are inter-related, and so this is a somewhat artificial structure.

A tag board shows the identification cards of the 29 miners who lost their lives in the Pike River Mine Disaster on 19 November 2010.

The Pike River company

Pike River Coal Ltd was a new company with no underground coal mining experience. And yet it obtained permits to develop the mine with little oversight of its health and safety plans. It operated a single mine, which was its only source of revenue. This was a ‘gassy’ mine, located in a region with a history of methane tragedies.

The company faced many challenges in the development of this new mine in a mountainous area. Development costs escalated, and the company faced many technical and financial challenges. It had aims of developing a productive and safe mine, but “Unfortunately, Pike lost sight of that aim as its drive for production intensified” (2012, Vol.1, p.17). The CEO resigned two months before the disaster.

The important role of safety leadership

The Board of Directors had governance responsibilities, but does not appear to have been well-placed to discharge these responsibilities. For example, four days before the explosion, they were told by the mine manager that methane gas management was more of a daily nuisance than a significant problem.

“Ultimately, all explosions are a manifestation of the failure of an organisation’s health and safety management system”.

Royal Commission on the Pike River Coal Mine Tragedy, 2012 (Vol.2, p.190)

The Board was reactive in its approach, assuming that they would be informed of any major health and safety concerns; rather than verifying that effective risk management systems were in place. Even so, they were not informed of an insurance survey in July 2010 that identified serious concerns – including potential for a gas explosion. Nor did the decision to place a main ventilation fan underground (a world first) receive adequate consideration by the Board.

Ventilation is a significant issue for an underground mine, and yet no-one at the mine had responsibility for ventilation management. Unfortunately, the main fan was not protected and failed in the explosion; shutting down the ventilation system.

As with several other major incidents, the company experienced significant organisational change – for example, there were six mine managers in the 26 months leading up to the explosion.

The Commission concludes that the Board was distracted by financial and production pressures, and that the disaster happened during a drive to achieve coal production in a mine with leadership, operational and cultural problems. Cash-flow pressures meant that the company had to reduce costs and increase income – and so it reduced investment in non-productive infrastructure.

The push towards production increased the release of methane. It also meant that additional people were working in the mine to achieve the production rate, leading to more lives lost in the tragedy. As with other major disasters (for example, see Nimrod), senior management decisions played a significant role. Management decisions made an explosion more likely, and increased the consequences should one occur.

The safety manager received little support from other departments, and key concerns that they raised were not addressed. It appears that although well-intentioned, their department was marginalised within the company.

“The board did not provide effective health and safety leadership and protect the workforce from harm”.

Royal Commission on the Pike River Coal Mine Tragedy, 2012 (Vol.1, p.18)

Unsafe by design

A key aspect of the design of an underground mine (especially one with the presence of significant methane gas) is the ventilation system, which both provides fresh air for workers and removes methane-rich foul air. The decision to place main fans underground, (rather than on the mountainside as originally planned), was not adequately risk assessed. The concerns of a ventilation consultant and Pike River staff were not addressed.

The ventilation system would be more likely to be impacted by an underground event (as was the case in this disaster). The design of the ventilation system was such that when it failed, it did so abruptly and completely. The system was not designed to degrade gracefully.

Following the initial explosion, it was not possible to gain access to the mine to repair this main ventilation fan; and so the methane continued to build up, resulting in further explosions. The secondary fan was located outside, at the top of the ventilation shaft, but was also damaged in the initial explosion and then destroyed in subsequent explosions. This secondary fan, as well as being under-specified to perform if the main fan failed, was only accessible by helicopter.

The catastrophic damage to the ventilation system not only allowed methane to build up, it made the atmosphere in the mine inhospitable, and so any survivors had little chance of self-rescue. Without knowing the methane levels inside the mine (there were no remote sampling instruments), a rescue attempt could not be initiated.

The location of electrical services and equipment was determined by engineering simplicity, rather than following a suitable risk assessment. The design and maintenance of these systems was described by the Commission as ad-hoc.

The lack of an effective secondary means of escape made it impossible to ventilate the mine after the explosion, and also prevented a rescue attempt. The design of the mine and key infrastructure increased the consequences of methane gas events.

Health and safety considerations should be built into the design. They are not ‘add-ons’.

Royal Commission on the Pike River Coal Mine Tragedy, 2012 (Vol.1, p.29)

Methane monitoring

In addition to ventilation, monitoring of methane gas levels is a critical activity in a mine such as Pike River. Fixed sensors provided continuous monitoring of methane levels, but there were too few of these sensors and they were not well positioned. In addition, some of these sensors were out of service for several weeks, or were known to be unreliable.

Sensors attached to machinery are designed to trip power to the equipment at certain methane levels, but these led to the constant tripping of machines and were therefore bypassed by some workers.

Complicating the ventilation management was the fact that the mine was simultaneously in both exploratory and production phases. It was considered to still be in start-up mode.

“The drive for coal production before the mine was ready created the circumstances within which the tragedy occurred”.

Royal Commission on the Pike River Coal Mine Tragedy, 2012 (Vol.1, p.12)

The company increased production before all necessary safety infrastructure was in place. This move towards seeing the mine as operational whilst still in a developmental phase reminds me of the Space Shuttle incidents, where the shuttle was seen as fully operational when in fact it was still in development. The acceleration of the NASA shuttle towards operations was also due to ‘production’ pressures, in this case the need to launch satellites into space.

Failure to heed warnings

The mine workforce reported many incidents and accidents – the Commission analysed a total of 1083 reports. However, investigation of previous events has been described as haphazard, and a month before the disaster, the large backlog of outstanding investigations was simply written off.

Despite the shortcomings of the methane monitoring system, it was still able to highlight that the mine had a serious methane problem. High readings (many of them dangerously high) were recorded on most days, but this information was not assessed or addressed.

Pike River used an uncommon and specialised mining technique called hydro mining, where a high-pressure water jet is used to cut the coal face. This method is known to cause roof falls. As the width of the extraction area increased in October 2010, the risk of a major roof collapse was highlighted by a geotechnical engineer – and a significant roof fall did occur later that month. However, the risk of further roof falls was not assessed. And at the same time, high methane levels continued to be recorded.

A likely scenario is that on 19 November 2010, a large volume of methane gas in the roof void above the production area was released suddenly as the roof collapsed.

“At the executive manager level there was a culture of production before safety at Pike River and as a result signs of the risk of an explosion were either not noticed or not responded to”

Royal Commission on the Pike River Coal Mine Tragedy, 2012 (Vol.1, p.19)

In the same way that insulation foam impacting on the space shuttles was seen by NASA as an operational issue and not a safety concern; the high readings of methane gas was seen by Pike River as an operational issue to be managed. Just as the space shuttles continued to come home safely, even with foam damage; the Pike River Mine frequently operated with high levels of methane gas without incident. But as with many safety incidents, complacency sets in, until it is too late. The company rolled the dice too many times and the inevitable happened.

This quote from the Commission outlines the reports made by underground deputies and workers:

“There were numerous warnings of a potential catastrophe at Pike River. In the last 48 days before the explosion there were 21 reports of methane levels reaching explosive volumes, and 27 reports of lesser, but potentially dangerous, volumes. The reports of excess methane continued up to the very morning of the tragedy. The warnings were not heeded”.

Royal Commission on the Pike River Coal Mine Tragedy, 2012 (Vol.1, p.12)

Senior management should have stopped production, and re-assessed the situation. Risks were simply not assessed, and management may have failed to realise how little safety margin was left.

The Pike River Recovery Agency was established to undertake the task of re-entering and recovering the Pike River Mine to support the Police investigation, to promote accountability for this tragedy, and to help prevent future mining tragedies.

A note on safety culture

The Commission documents refer to several aspects of culture. In particular, the approach to hydro mining indicates a culture that put production before safety. This technique was introduced in September 2010 without a comprehensive risk assessment, with little understanding of the roof strata, no reassessment after the collapse on 30 October 2010, and widening the extraction area despite a geotechnical deficit. The company had no previous experience in hydro mining, and used a largely inexperienced workforce.

James Reason (1998) has stated that key to developing a safe culture is “a safety information system that collects, analyses and disseminates the knowledge gained from incidents, near misses and other free lessons“. This system was clearly lacking at Pike River. Key safety information was either missed completely or not assessed. I note that a section in the Commission report is titled ‘An indifference to methane spikes’. Many notifiable incidents were not reported to the Department of Labour, including high methane readings of about 5% in October 2010.

“The commission considers that as at November 2010, the emphasis placed on short-term coal production so seriously weakened Pike’s safety culture that signs of the risk of an explosion either went unnoticed or were not heeded”.

Royal Commission on the Pike River Coal Mine Tragedy, 2012 (Vol.2, p.177)

There are references to an attitude of recklessness in some of the workers, but this may be largely attributed to an inexperienced underground workforce.

Emergency planning and response

A lack of advance planning for mine emergencies hampered an effective search and rescue response. The Pike River company had very little planning for response or recovery. They were almost totally reliant on external help.

Police assumed the lead role in the response, but lacked context and mining expertise. Many decisions were not made at the Pike River mine site, but were made by non-experts at Police National Headquarters in Wellington. This incident management structure was considered by the Commission to be unsuited to the rapidly changing conditions at the mine.

The atmospheric conditions did not permit rescuers to enter the mine; and further explosions would have been unpredictable. Some families felt that they were given false hope of survival and a rescue. Uncertainly around the recovery of bodies hindered the grieving process for family members.

Competence and supervision

The need for training was recognised but not effectively actioned; with training deferred given the push for production. Even though this type of mining was new to the company, the hydro project manager and the hydro co-ordinator had no previous hydro-mining experience. There was a shortage of qualified and experienced supervisors; and a high ratio of inexperienced to experienced miners. Shortly after hydro mining commenced, Pike moved to a 24-hour production, introducing more inexperienced workers.

A number of the underground workers were contractors, many of whom had never worked underground before and were not miners by trade. The Commission states that “The management of contractors got away from Pike in 2010 and these workers were often left to their own devices” (2012, Vol.2, p.67).

Levels of absenteeism were high, and compounded the lack of experienced miners.

Underground, workers bypassed safety devices so that machinery could continue to operate in the presence of methane. For example, on the morning of the disaster, at least one worker admits to taping a plastic bag over a methane monitor to render it inoperable. The Commission describes these behaviours as “reckless”. However, the focus on financial issues by company leadership may have influenced the behaviours of front-line workers to put production before safety (although inexperience and competence would likely have contributed).

As an example of the production pressures faced by workers, they were offered an incentive bonus of $13,000 if they met production targets by late September. After this date, the bonus payment would decrease from week to week. This production incentive was implemented when there were known issues with equipment, ventilation, inexperience and gas monitoring.

The bonus was also reduced by $200 for each absence from work, in an attempt to reduce the high levels of absenteeism.

Regulatory failures

The Commission had wide-reaching terms of reference, including to consider the regulatory framework in New Zealand. It concluded that there was a lack of oversight by the health and safety regulator and that the legal framework for health and safety in underground mining was deficient.

The Department of Labour (DOL) undertook quarterly mine inspections, but as the company was assumed to be a ‘best practice’ employer, they adopted a low-level compliance approach, which proved to be ineffective. In this compliance strategy, Inspectors did not review safety or operational information from the mine.

The ineffective approach to regulation was most evident in relation to the lack of a suitable secondary means of escape from the mine. The main ventilation shaft was deemed to be an emergency escapeway, but this required climbing a 110m ladder – something not considered physically possible by the Commission. In the tragedy, it acted as a chimney of fire, making this secondary escape route impassable.

The Commission found that more robust action should have been taken by the Department, specifically the prohibition of hydro mining until a suitable second means of escape was in place.

The Commission concluded that the Department failed to resource, manage and support the mining Inspectorate. At the time of the tragedy, the inspectorate had just two mining inspectors covering many workplaces. The Department relied heavily on personal safety statistics, and the need to focus on other process safety data for high-hazard industries is stressed by the Commission.

The Department of Labour produced high-level documents, such as annual reports to Parliament, but the Commission concluded that “The gap between the high-level statements in those documents and the reality on the ground was remarkable” (2012, Vol.1, p.30). The regulator required a major change in its strategy and structure, and the New Zealand Government has since taken positive steps.


The Commission made a total of 16 primary recommendations. These include high-level regulatory and legislative reform (to address the poor health and safety record more generally, not just in relation to mining). This includes ensuring that health and safety is integral to mining permits.

Given the importance of safety leadership, recommendations target the roles, responsibilities and competence of company directors and mine managers.

There are also several recommendations relating to emergency management and incident response.

Final thoughts

This disaster was a complex combination of factors at various levels: financial and production pressures, engineering challenges, priorities, culture, and ineffective regulatory oversight. There are multiple layers of contributory factors, and these are not independent.

But the Pike River tragedy was preventable.

There are lessons here for all high-hazard industries where the frequency of major accidents is low, but the consequences severe.

The disaster did have a significant impact – leading to a total review of New Zealand’s health and safety legislation, and with that, a potential for change in attitudes and priorities. If we can learn the lessons and prevent future tragedies, we will honour those 29 men who did not return home to their families on 19 November 2010.

Further reading

Royal Commission on the Pike River Coal Mine Tragedy (Te Komihana a te Karauna mō te Parekura Ana Waro o te Awa o Pike), Volume 1 and Overview, October 2012.

Royal Commission on the Pike River Coal Mine Tragedy (Te Komihana a te Karauna mō te Parekura Ana Waro o te Awa o Pike), Volume 2, October 2012.

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