The Hernes Oak fire
At approximately 1.15 pm on 9 February 2014, the Hernes Oak–McDonald’s Track fire was reported as having escaped its containment lines. The bigger fire that ensued after the Hernes Oak–McDonald’s Track fire escaped is known as the Hernes Oak fire.23
The CFA Fire Investigation Report records that the Hernes Oak fire broke its containment lines in the north-east area of the fire footprint. From there the fire ran parallel on the north and south sides of the Princes Freeway in a south-easterly direction towards Morwell and the Hazelwood mine24 under the influence of a generally north-westerly wind.
The Board was provided with photographs taken from the air, which identify the spread of the Hernes–Oak fire and the effect of the wind change during the course of the morning and early afternoon of 9 February 2014 (see Figures 2.5 and 2.6).
Figure 2.5 The Hernes Oak fire travelling on a generally north-westerly wind on 9 February 201425
This photograph was taken facing east from an aircraft hovering above the Princes Freeway at 1.27 pm on 9 February 2014. The Morwell township is in view in the top left-hand corner and the Hazelwood mine is in the top-middle of the photograph.
Shortly before 2 pm, from a vantage point near the north-western boundary of the mine, GDF Suez personnel observed the flames from the Hernes Oak fire spreading in the general direction of the Hazelwood mine and saw embers inside the mine’s perimeter.26
Prior to the fire reaching the mine’s north-western perimeter, the wind changed from a more north-westerly wind to a more south-westerly wind.27 The Bureau of Meteorology provided an analysis to the Board of the wind change by reference to the location of Morwell and the timing of the wind change recorded at the Latrobe Valley Airport automatic weather station, situated seven kilometres north-east of Morwell. The Bureau estimated that the likely time of the wind change at Morwell was 1.40 pm, to within plus or minus five minutes.28 The effect of the wind change can be seen in Figure 2.6.
Independent expert, Mr Roderic Incoll, Bushfire Risk Consultant, also provided evidence to the Board about the prevailing winds on 9 February 2014. Appendix 3 to Mr Incoll’s report describes changes throughout the day to the wind speeds and gusts, and temperatures (amongst other weather features), from information at the Latrobe Automatic Weather Station based at the Latrobe Airport. Between 12.30 pm and 1.56 pm, the wind directions are shown as:
- 1.30 pm: north-westerly wind with wind gusts of 57 kilometres an hour
- 1.47 pm: west-south-westerly wind with wind gusts of 63 kilometres an hour
- 1.52 pm: south-south-westerly wind with wind gusts of 63 kilometres an hour
- 1.56 pm: south-westerly wind with wind gusts of 74 kilometres an hour.29
Appendix 3 to Mr Incoll’s report also describes the drop in temperature from 40 degrees at 1.30 pm to 28.2 degrees at 1.56 pm after the wind had changed direction.30
Figure 2.6 The Hernes Oak fire moving generally north-easterly with the wind change on
9 February 201431
This photograph was taken from an aircraft facing north-west at 1.41 pm on 9 February 2014. The Morwell township is not visible because it is covered by smoke. The Hazelwood mine is not in the photograph but is located to the right of the photo edge.32
At approximately 2.10 pm on 9 February 2014, Mr David Shanahan, GDF Suez Services Superintendent, observed the Hernes Oak fire near the northern boundary of the Hazelwood mine. He took two photographs showing fire in the plantations to the immediate north of the mine boundary, neighbouring the Strzelecki Highway. (as shown in Figure 2.7).33
Figure 2.7 The Hernes Oak fire near the Strzelecki Highway on 9 February 201434
These two photographs were taken at 2.10 pm (left) and 2.17 pm (right) by Mr Shanahan. Both photographs show fire in the plantations to the immediate north of the mine boundary, neighbouring the Strzelecki Highway.35
As a consequence of the wind change, the general direction of the fire changed. It started burning in a generally north-easterly direction towards and into the western edge of the Morwell residential area.36 The Hernes Oak fire spotted into the Yallourn mine37 and the west of Latrobe Street, and then burned into the plantations north of Morwell.38
The cause of the Hernes Oak–McDonald’s Track fire was investigated by the CFA. Although a CFA investigator concluded that the fire was caused by the inadequate control of a camp fire,39 Victoria Police regard the fire as suspicious and it is the subject of an ongoing police investigation.40 Victoria Police have excluded lightning strike and power asset failure as causes of the Hernes Oak–McDonald’s Track fire.41 There is no suggestion in the evidence before the Board that the break out of the Hernes Oak fire was itself suspicious, although this is also under police investigation.