By allocating each occurrence a severity rating it makes it much easier for users of the occurrence system to get accurate data (provided the ratings are consistent). This is a key aspect of being able to monitor trends and take action when appropriate to improve the safety of the rail industry.
The table below provides the definition of each rating, with severity 1 being an ‘accident’.
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Severity ratings and descriptions
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1
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- Any accident that caused a death (to people)
- Any accident that caused serious harm to people (requires hospital treatment)
- Any accident that caused significant damage to property (estimated more than $200,000)
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2
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- Any incident that placed people at risk of death or serious harm
- Any incident that placed property at risk of significant damage
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3
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- Any incident that could have placed people at risk of death or serious harm
- Any incident that could have placed property at risk of significant damage
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4
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This rating is used for when you are not sure whether you are required to notify us or not.
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Severity rating principles
The idea of an incident placing people or property at risk (or one that could have) should be measured against the following principles:
Risk
- Occurrence severity is about the risk to people or railway property. A collision with an animal for instance is only relevant to severity in relation to how it put people or property at risk
- Occurrence descriptions need to focus on the risk (eg whether a rail was broken) not the event (eg how someone noticed it may have been broken)
- Carrying passengers increases risk - they are untrained, they don’t have PPE, and there are more of them
- An occurrence can lead to consequential risks that increase its severity (eg a derailment in a tunnel or a train hitting a broken barrier arm).
Consequence
- An accident will always be rated severity 1 (as per the table above)
- An occurrence that causes more than minor damage will be rated severity 2 if the property was placed at risk of significant damage. If the worst possible outcome would still not have seen significant damage caused, then the severity will be 3.
- All persons are of equal value – passengers, workers, public, trespassers.
Safety system failures
- Severity 2 ratings are typically where there has been a failure of all applicable safety controls and it was lucky that noone was hurt
- Severity 3 ratings are typically where there has been a failure of safety controls, but at least one critical control remained in place (aka failed safe)
- When routine inspections and maintenance pick up faults before they are serious, this is the safety system working and are not notifiable occurrences.
Ambiguity
- Use precise keywords in the occurrence descriptions to avoid the need for subjective decisions (eg near collision, rail corridor, safety critical, significant damage, serious harm)
- We use a precautionary approach. This means in the absence of evidence that people weren’t exposed to the risk, we err on the side of caution and assume that they were
- An ‘alleged incident’ is not an incident. Delay the notification up to 72hrs until it is confirmed or otherwise.
