The latest and last report from the UK HSE on the events surrounding the Buncefield explosion and subsequent fire was issued earlier this year. Its publication was delayed to accommodate the court case. It contains some very interesting insights into the events leading up to the explosion. Some of these fit firmly within the ‘Human Factors’ framework and are well worth review.
The report is available here.
It’s hard to know where to start, and it’s taken me a while to go through the document. Here’s a few highlights from a Human Factors perspective, there’s a lot more to digest though.
There’s a firm emphasis on safety critical equipment. It’s easy to fall into the trap of considering a Safety Instrumented System or other layer of protection as being independent of human failure or error, but the reality is somewhat different. All safety related equipment requires some level of maintenance and proof testing as well as operation. Human error can render a safety layer inoperative, and indeed at Buncefield that’s one of the main causes of the failures. However, I’ll leave this area for another blog as it’s such a big topic.
Shift handover is criticised on a number of levels, with some justification. The time available (or more accurately the time typically used) was short, with a cultural pressure as the handover wasn’t recognised as working time in the pay structure. We often cover this in some detail in my Human Factors course when there is usually an interesting discussion. If we don’t pay people for the shift handover, then what message are we sending about this vital safety critical activity? Further, the shift log supporting the handover appears to have recorded only the status at the end of the shift, not events that occur during the shift. To be effective, a log (whether hand written or electronic) needs to be a record of the entire shift, preferably maintained throughout the shift as a contemporaneous log. Situational awareness when starting a shift is much more than an instantaneous snapshot of the plant status.
Shift patterns are also addressed in the report. The relationship between shift patterns, overtime and reward is significant. There was resistance to the employment of another supervisor by the existing supervisor team as this would reduce the available overtime and therefore payments. This resulted in significant additional overtime being worked, the report quotes 84 hours in a seven day period sometimes being worked. 12 hour shift patterns were worked, with five days in a row on each shift ‘block’. When we put systems of reward for working patterns in place, the way those rewards will drive behaviours should always be considered.
As is almost always the case, the operating culture played an important part. Maintaining operations became a higher priority than maintaining full control over the inventory and fuel movements. Process safety was compromised in this cultural environment.
One thing the report doesn’t contain is a photograph of the control room after the blast. The HSE website has a number of interesting photos and videos from the incident, but here’s the control room.
I’m sure I’ll come back to some of the other Human Factors lessons from this report in the future, but overall we should be careful with reports like this not to take the obvious ‘Human Factors’ lessons and treat them in isolation. The report paints a picture where many failings, especially those of management and culture, come together to create the circumstances leading to the incident. Technical failures, failures of design and risk management all played their part, not to mention the emergency response and mitigation lessons. All of these elements need to come together under an integrated Process Safety Management framework (including Human Factors) for us be able to manage high hazard processes safely and effectively going forward.
As always, let us know what you think in the comments and feedback section. Are we learning from these events?
The photograph of the control room and others can be viewed on the HSE website at