Preventing Disaster in High Risk Organisations

Preventing disaster learning from Longford Esso Gas Plant explosion

Until September 1998 Melbourne, the second largest city in Australia, had all of its gas supplied by one plant, the Esso gas plant at  Longford  in South Eastern Victoria.  It consisted of three gas plants which process gas from wells in Bass Strait, as well as a plant which processes crude oil from other Bass Strait wells. On the 25th of September 1998 Gas Plant One at Longford exploded, causing the death of two operators and injuries to eight others. For two weeks after the blast, Victorians were without gas causing financial hardship for small and large businesses alike, and disrupting the lives of all of Melbourne’s residents – The cost of the crisis was estimated to be $A1.3 billion.

The Government of Victoria held a Royal Commission into this accident- This is the most powerful form of legal inquiry possible in Australia. In July 2001 Esso was fined a record $A2 million in the Victorian Supreme Court after being found guilty of 11 charges under the Victorian Occupational Health and Safety Act. 

What we discover when we look at the causes of accidents is that they are very similar across a wide range of industries. The things that go wrong in the petroleum industry are also the things that go wrong in the coal mining industry, in the construction industry...and so on.

It means we can transfer lessons from one industry to another. While we are looking at what happened at Longford- and the Lessons that emerge - we need to constantly keep in mind how these lessons can also apply to other industries - and other organisations, such as yours.

Like most accidents, there was not a single cause that made the Longford disaster happen. The diagram that illustrates this may seem complex at first glance, but Professor Andrew Hopkins goes step by step through the diagram to uncover the causes of the accident.

The accident occurred just after midday on a Friday. The accident sequence began about 16 hours earlier. About 8 o’clock the previous night plant operators made a mistake when they incorrectly operated a bypass valve.

The result of that mistake was that condensate began to overflow into parts of the gas processing system where it shouldn’t have been. This was essentially a process upset which the operators were not aware of and didn’t manage. It developed over the next several hours until the next morning about 8 o’clock. Then some warm oil pumps closed down automatically, basically as a process safety precaution. These pumps tripped out because the process upset had got to the point where the system was now in some danger

The plant used processes of heating and cooling, and with the warm oil heating pumps having closed down, the cooling processes were now out of control and the parts of the plant began to cool down, and down, and down to the point where a couple of large metal heat exchangers, 14 tonne heat exchangers were down to minus 48 degrees Celsius, which was way below their design temperature. Frost was forming on the exterior of these vessels, leaks were occurring, and they were now brittle with cold.  Then four hours after the pumps had closed down they tripped out and they got them going again. So here was the second crucial mistake by the operators. They re-introduced warm oil into a brittle cold vessel.

The Royal Commission was deeply disturbed by the fact that the workers were quite unaware of the danger they were in, unaware that they were standing around a bomb that would go off at any moment. The Commission took the view that there was a systematic training failure here.  It concluded that lack of training was, in their words “the real cause”

But we shouldn’t stop there. We need to ask: Why weren’t these workers properly trained? Why was there no training and in particular why was there no training about what to do when warm oil pumps fail?

Preventing Disaster: Learning from Longford
An interactive training workshop with Professor Andrew Hopkins