A culture of denial: Sociological similarities between the Moura and Gretley mine disasters

This 2000 paper from Hopkins compares the underlying sociological and organisation factors behind both the Moura and Gretley mine disasters.

I’ve skipped a lot, so check out the full paper for the details.

First he says that while every disaster has its own unique set of events, “It does not follow that every disaster requires a unique explanation

Research, like that from Barry Turner and far more since this paper was published has shown that some phenomena underlie all disasters. For instance, Turner’s work highlighted that misinformation always plays a critical role, there’s a mixture of both active and latent conditions or factors, and according to some, all disasters “can be traced to management system failure”.

Both accident investigation inquiries remarked that the management in both cases had a belief that this event couldn’t happen at their mine.

This can’t happen here

Hence, it’s argued that a common factor to both disasters was that “mine management mistakenly believed that the mine was protected from the hazard in question and that therefore "it can't happen here”.

In mining, coal exposed to air can heat up slowly (spontaneous combustion) and if the mine isn’t appropriately ventilated, can reach the ignition point of methane. At Moura, there was an operating belief that spontaneous combustion took at least six months to develop – known as the incubation period. Hence, if work was completed prior to the six months period then there was little risk of ignition.

While this incubation period belief was widespread in the industry at the time, “it was without foundation” . The belief spread by mouth and had no substantiating evidence.

Instead, “It was in fact a mistaken belief”, and the Moura explosion occurred within the supposed incubation period. Importantly, management took the mistaken view that the mine was appropriately safe from spontaneous combustion, since they were within that six month incubation period

At Gretley, a known risk was mining in vicinity of an old abandoned mine which had been flooded. Copies of the maps were obtained, and work was planned with a safe distance from where the abandoned mine was believed to be.

However, “because of a drafting error made by the department, the maps were inaccurate”, and, according to the inquiry “management did not verify the accuracy of the maps, as the official inquiry found it had a responsibility to do, but simply accepted the plans at face value”.

Hopkins argues then, that management at both mines were aware of the hazards, and believed they had taken appropriate action to protect themselves; but in his view, they “accepted the validity of information acquired from others without any attempt to verify its accuracy”. And critically, they accepted this info on face value when the safety of their operations “depended critically on this information”.

Warnings ignored

Next, it’s argued that warning signs at both mines preceding the disasters were dismissed or ignored.

He argues that the rationalisations for ignoring or dismissing the warning signs stemmed from some factors like the normalisation of deviance (NOD) and ad hoc criteria to explain unexpected findings.

The rate of CO is a sign of spontaneous combustion, where the greater the rate of CO production, the higher the risk of ignition. At the time, the rule of thumb was that CO >10/L a minute requires investigation, whereas >20L/min indicated considerable danger.

The rate was above 10, but less than 20 for some weeks prior to the accident, but wasn’t responded to. A rationalisation from the mine management was that since a new mining method was being used which left considerable loose coal in the area, then they would expect higher rates of CO production (at least, slow and steady rises).

He then draws on Vaughan’s work on NOD, discussing how performance issues of the o-rings were identified over several launches. But since they hadn’t totally failed, over time their “malfunctioning was reconceptualised as normal and the risk of total failure came to be judged acceptably low” [** I’m heavily simplifying this explanation…]

He suggests a similar effect was at play at Gretley, where signs of accumulation of water were discounted via other rationalisations.

Ad hoc criteria

Another rationalisation for dismissing warnings related to the use of ad hoc criteria, such as to “arbitrarily … raise the threshold of what would count as a danger signal, and then to argue that the observed signs had not crossed this threshold”.

At Moura the prevailing view was that slow and steady rises in CO was normal, whereas a rapid rise was a warning sign. This logic was said to be confused, since an exponential rise in CO “is not a warning of potential danger; it is an indicator that a fire is already raging”.

Gretley had a similar mechanism at play, where ad hoc criteria rationalised the water accumulation in the mine. In that example, the water was explained via the water being a mere trickle, rather than squirting out.

By defining the ad hoc criteria of what is a warning sign – squirting water versus a trickle—the manager “had implicitly defined a new test for danger: water squirting out of the face under high pressure is an indication of danger; a trickle is not”.

Nevertheless, no justification was provided for the ad hoc test.

Dismissing intermittent warnings

Next the role of intermittent warnings is discussed; which many warnings are. An example at Moura was where the CO rate was measured at 19 L/min—just under the 20 L/min threshold for danger. Because the reading was so close, and the warnings intermittent, the reading was challenged as false.

?

The tendency to discount unwanted evidence: the culture of denial

These rationalisations are tied together about the culture of denial. It’s said that:

"new evidence appears reliable and informative if it is consistent with one's initial beliefs; contrary evidence tends to be dismissed as unreliable, erroneous or unrepresentative".

People may face an uneasy cognitive state when beliefs and evidence are inconsistent – called cognitive dissonance. This requires one to either adjust the belief, or the evidence. He notes “Where the belief is strong, it is the evidence which is adjusted”.

He argues that both mines adjusted the evidence to align with their false belief of safety—the apparent culture of denial. This enabled “management to deny that there was any immediate danger, no matter what the evidence”.

Next steps

In exploring how one can challenge these rationalisations and cultures of denial, he suggests:

·?????? For one, there is limited value in trying to change the various beliefs making up the culture of denial, because “Even though some might be corrected or changed, others would very likely develop in their place” and such beliefs are, in any case, “almost inevitable”

·?????? Instead, he says that one method is to limit the discretion exercised by decision-makers, whereby decision-making “must be structured by introducing imperatives to action in certain circumstances which rule out the option of doing nothing”

·?????? After identifying the major hazards and the action plans, these plans must involve the usual HIRAC stuff, but also “how they should deal with the possibility that crucial information on which the safety of the enterprise depends may be incorrect”

·?????? Also, the plans must “identify warning signs which will be treated as triggers to action”, and what actions must be taken and by whom [*** In some later work, Hopkins argues for the use of Trigger Action Response Plans, TARPS, as used in mining]

·?????? In management are to take no action, he suggests for them to record these decisions in writing, along with the reasons

Author: Hopkins, A. (2000). A culture of denial: sociological similarities between the Moura and Gretley mine disasters. Journal of Occupational Health and Safety, Australia and New Zealand, 16(1), 29-36.