case study - powerline bushfire safety taskforce

CASE STUDY.

DUE DILIGENCE ENGINEERS

Powerline Bushfire Safety Taskforce.INFRASTRUCTURE IMPLICATIONS.

http://www.r2a.com.au/


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.




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?




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




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.




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.




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.




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.




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.




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.




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.




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.




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.


http://www.r2a.com.au/contact.html

http://www.r2a.com.au/education/r2a-short-courses.html

http://www.r2a.com.au/publications/r2a-text.html




http://www.r2a.com.au/education/eea-short-courses.html

http://www.r2a.com.au/education/eea-short-courses.html

http://www.eeaust.com.au/

http://www.r2a.com.au/education/swinburne-post-grad.html

http://www.r2a.com.au/education/swinburne-post-grad.html


Level 1, 55 Hardware LaneMelbourne, VIC, 3000Australia

P +1300 772 333F +61 3 9670 6360E [email protected] www.r2a.com.au



case study - powerline bushfire safety taskforce

Documents

powerline infrastructure

foreseeable risk

precautionary approach

notion of risk

expert risk management

diligence engineerscase

safety whs legislation

modeling approach