case study - powerline bushfire safety taskforce
DESCRIPTION
The Powerline Bushfire Safety Taskforce (Taskforce) was 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). The Victorian government, in early 2012, accepted all of the recommendations of the Taskforce with regard to powerline infrastructure and management in Victoria. Richard Robinson from R2A was the expert risk management member of the panel and R2A provided the methodology and modelling approach adopted by the Taskforce.TRANSCRIPT
CASE STUDY.
DUE DILIGENCE ENGINEERS
Powerline Bushfire Safety Taskforce.INFRASTRUCTURE IMPLICATIONS.
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CASE STUDY: Powerline Bushfire Safety Taskforce 2
PREAMBLE
R2A was part of
the expert panel
for the Powerline
Bushfire Safety
Taskforce.
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
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.
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CASE STUDY: Powerline Bushfire Safety Taskforce 3
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.
1 Sappideen, C & RH Stillman, (1995). Liability for Electrical Accidents: Risk, Negligence and Tort. Engineers Australia Pty Ltd. Sydney
How would a reasonable defendant respond to the foreseeable risk?
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CASE STUDY: Powerline Bushfire Safety Taskforce 4
The adoption of
the precautionary
approach is the first
occasion where the
outcome can be
assessed formally.
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
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
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CASE STUDY: Powerline Bushfire Safety Taskforce 5
PRECAUTION v HAZARD
The precautionary
approach differs
significantly from
the hazard based
approach to risk.
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
• Risk assessment (hazard based):
- (Hazard)riskidentification
- (Hazard) risk analysis
- (Hazard) risk evaluation (comparison to criteria)
• Risk treatment.
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CASE STUDY: Powerline Bushfire Safety Taskforce 6
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.
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CASE STUDY: Powerline Bushfire Safety Taskforce 7
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.
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CASE STUDY: Powerline Bushfire Safety Taskforce 8
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.
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CASE STUDY: Powerline Bushfire Safety Taskforce 9
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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CASE STUDY: Powerline Bushfire Safety Taskforce 10
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 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.
The R2A model
tests for
precautions that
provide the best
investment.
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CASE STUDY: Powerline Bushfire Safety Taskforce 11
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 firelossconsequenceareas,witheachprecautionconsideredindependently.
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CASE STUDY: Powerline Bushfire Safety Taskforce 12
CONCLUSION
The Taskforce’s
conclusions and
recommendations
are being adopted
by Government.
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
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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CASE STUDY: Powerline Bushfire Safety Taskforce 13
WHERE TO NEXT
Talk to R2A
about your
next project.
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.
• 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.
DUE DILIGENCE ENGINEERS
Level 1, 55 Hardware LaneMelbourne, VIC, 3000Australia
P +1300 772 333F +61 3 9670 6360E [email protected] www.r2a.com.au