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DUE DILIGENCE ENGINEERS

CASE STUDY.

Powerline Bushfire Safety Taskforce. INFRASTRUCTURE IMPLICATIONS.


DUE DILIGENCE ENGINEERS

PREAMBLE The Victorian government in early 2012 accepted all of the recommendations of the Powerline Bushfire Safety Taskforce (Taskforce) with regard to powerline infrastructure and management in Victoria. The Powerline Bushfire Safety Taskforce was

R2A was part of the expert panel for the Powerline Bushfire Safety Taskforce.

formally constituted in August 2010 to consider how the Victorian Government should implement the recommendations of the Victorian Bushfires Royal Commission in relation to the replacement of powerlines (recommendation 27) and changing the operation of the network (recommendation 32). Richard Robinson from R2A was the expert risk management member of the panel and R2A provided the methodology and modeling approach adopted by the Taskforce.

CASE STUDY: Powerline Bushfire Safety Taskforce

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DUE DILIGENCE ENGINEERS

INTRODUCTION As the expert risk management member of the Taskforce, Richard Robinson recommended the Taskforce adopt the precautionary risk management approach,which is consistent with the provisions of the model Work Health and Safety (WHS) legislation. By using this methodology all practical precautions can be discussed and the job is then to determine what cannot be justified on the balance of the significance of the risk vs. the effort required to reduce it (after Sappideen and Stillman1), as shown below.

How would a reasonable defendant respond to the foreseeable risk?

1 Sappideen, C & RH Stillman, (1995). Liability for Electrical Accidents: Risk, Negligence and Tort. Engineers Australia Pty Ltd. Sydney CASE STUDY: Powerline Bushfire Safety Taskforce

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DUE DILIGENCE ENGINEERS

The key aspects of the table above include – • Effort includes expense, which refers to money, • Difficulty and inconvenience, how difficult the precaution is to implement and monitor, and • Utility of conduct refers to what other disbenefits might occur due perhaps to conflicting

The adoption of the precautionary approach is the first occasion where the outcome can be assessed formally.

responsibilities such as that of maintaining an essential service. The precautionary approach is also the analysis method required by the judicial formulation of causation established by the courts. After a serious event, the courts look to see (with the advantage of 20:20 hindsight) what were the precaution/s that should have been in place but were not. Risk is not strictly relevant since, after the event, likelihood is not relevant. The fact of the occurrence of harm at that point is certain. As an Australian judge has been reported as noting to the engineers after a serious train incident: What do you mean you did not think it could happen? There are 7 dead. That is, the notion of risk is really only used to test the value of the precaution it is claimed ought to have been in place. How risky a situation is before the event is not germane except in so far as an aid to determining the reasonableness of possible precautions.1 The adoption of the precautionary approach is perhaps the first formal occasion where the outcomes of this approach in infrastructure terms can be assessed formally.

1 Robinson, Richard M, Gaye E Francis et al 2010. Risk & Reliability – Engineering Due Diligence (8th edition of the R2A Text). R2A Pty Ltd. Melbourne CASE STUDY: Powerline Bushfire Safety Taskforce

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DUE DILIGENCE ENGINEERS

PRECAUTION v HAZARD The precautionary approach focuses on all practical precautions with the subsequent task to determine what cannot be justified on the balance of the significance of the risk vs. the effort required to reduce it. This differs significantly from the hazard based approach to risk which is the one popularly described in the risk management standard AS/NZS ISO 31000, that is: • Establish the context

The precautionary approach differs significantly from the hazard based approach to risk.

• Risk assessment (hazard based): - (Hazard) risk identification - (Hazard) risk analysis - (Hazard) risk evaluation (comparison to criteria)

• Risk treatment.

CASE STUDY: Powerline Bushfire Safety Taskforce

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DUE DILIGENCE ENGINEERS

The diagram below represents the two approaches.

Precaution based risk management Vs. hazard based risk management.

The precautionary approach provides more safety certainty and can be used for defence in the case of judicial scrutiny.

CASE STUDY: Powerline Bushfire Safety Taskforce

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DUE DILIGENCE ENGINEERS

THREAT BARRIER ANALYSIS R2A developed a threat barrier model for the Taskforce, to demonstrate the precautionary approach. The model is shown below. The loss of control point is important legally. It is always better to prevent the problem, either by eliminating the threat or enhancing precautions than by trying to recover the situation after control is lost. This is entirely consistent with the hierarchy of controls described in OHS legislation and risk management literature generally. By correctly identifying the loss of control point, the laws of man and the laws of nature can be made to align.

Fire Season Electrical Fire Start Threat Barrier Diagram.

CASE STUDY: Powerline Bushfire Safety Taskforce

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DUE DILIGENCE ENGINEERS

The loss of control point was defined by the Taskforce as the point at which sufficient ignition energy is present amongst environmental fuel to start a fire, that is, a potential bushfire start. Ignition energy is a combination of fault energy and duration. Defining the loss of control point in this way had the added advantage of representing the scope of the Taskforce’s endeavours, that is to the left hand side of the diagram. Fire starts due to sources other than powerlines are shown by the vertical arrow. Mitigative barriers are after the loss of control point and are outside the Taskforce’s Terms of Reference. Two diagrams were created to graphically show the difference between a fire start during the bushfire season (shown above) and on a Code Red day (shown below).

Code Red Day Electrical Fire Start Threat Barrier Diagram.

CASE STUDY: Powerline Bushfire Safety Taskforce

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DUE DILIGENCE ENGINEERS

The difference between the two diagrams is the fading of many barriers on a Code Red day. For example on a Code Red day the extreme conditions make the likelihood of a fire start if an electrical fault occurs, higher. That is the fault protection barrier is weaker. Further, on Black Saturday the CFA and DSE were overwhelmed with calls and were unable to respond to every request for assistance meaning the escalation control barrier was weaker than usual too.

R2A developed a threat barrier analysis to demonstrate the utility of precautionary effort for the Taskforce.

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DUE DILIGENCE ENGINEERS

PRECAUTIONARY RISK ANALYSIS R2A also developed a precautionary risk analysis model to test the value of potential, practical precautions based on the threat-barrier diagram described above. That is all practicable options are described and

The R2A model tests for precautions that provide the best investment.

the model tests for precautions or combinations of precautions that provide the best investment. Based on the Black Saturday (2009), Ash Wednesday (1983) and Black Friday (1939) fires the model characterises the risk associated with these days as: 100 Victorian deaths every 25 years. This return frequency has been reduced to one in 20 years to take into account predicted weather pattern changes. This is used to normalise the relative risk estimation of the rest of the model. Based on the analysis of consequences produced by Phoenix, the model has three levels of criticality for rural areas: extreme, very high and high presently characterised in the ratio of 1:0.3: 0.1, with extreme consequence areas as the base (worst) case. Relative risk per unit length (km) is presently done for life safety only, for an Ash or Black day. SWER (single wire earth return) and multi-wire powerline options are identified. The precautions that are considered are shown in the table overleaf with the values used for the extreme consequence region assessment.

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DUE DILIGENCE ENGINEERS

Relative effort is estimated on an average unit length (km) basis per option as capital expenditure (dollars),

Results are initially presented as a plot of quantum of risk vs. quantum of effort on a relative risk basis for a unit length of a powerline in the representative bushfire consequence areas. The model presently applies to the three fire loss consequence regions and is then summarised statewide.

Comparison of effectiveness of precautions, for the extreme fire loss consequence areas, with each precaution considered independently.

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DUE DILIGENCE ENGINEERS

CONCLUSION The Taskforce concluded that the most cost-effective solution to reduce the likelihood of bushfires starting by powerlines is the widespread deployment of new protection network technologies (REFCLs and new generation SWER ACRs) assuming a change in the network reclose function, with the targeted replacement of powerlines with underground or insulated cable in the highest fire loss consequence areas. As recommended by the Taskforce, the Government is requiring electricity distribution businesses to install both of these devices across the State over the next

The Taskforce’s conclusions and recommendations are being adopted by Government.

decade. Electricity distribution businesses will be required to specify, through their Bushfire Mitigation Plans, the location and timing of asset rollout. Energy Safe Victoria will then review progress against these Bushfire Mitigation Plans on an annual basis. This is estimated by the Taskforce to cost approximately $500 million over 10 years. Further, the Government will contribute up to $200 million over 10 years for a program of power line conductor replacement. Based on the estimates of the Taskforce, this will replace over 1,000 km, with the final length to be replaced dependent on detailed engineering and geographic assessment. The focus will be on locations with the highest fire loss consequences.

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DUE DILIGENCE ENGINEERS

WHERE TO NEXT If you would like to know more about how to manage due diligence in your business you can: • Contact R2A to organise a briefing for your executive management team.

Talk to R2A about your next project.

• Book an In-House Course or Private Briefing. • Buy a copy of the 9th edition R2A text: Risk & Reliability: Engineering Due Diligence. Order online. • Receive R2A’s email newsletter. • Attend the two day Engineering Due Diligence Workshop presented by Richard Robinson. • Attend the one day Defensible Risk Management Techniques course presented by Richard Robinson on behalf of Engineering Education Australia. • Enrol in the postgraduate unit ‘Introduction to Risk and Due Diligence’ Postgraduate Unit at Swinburne University, also presented by R2A.

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DUE DILIGENCE ENGINEERS Level 1, 55 Hardware Lane Melbourne, VIC, 3000 Australia P +1300 772 333 F +61 3 9670 6360 E reception@r2a.com.au W www.r2a.com.au

Case Study - Powerline Bushfire Safety Taskforce  

The Powerline Bushfire Safety Taskforce (Taskforce) was formally constituted in August 2010 to consider how the Victorian Government should...

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