Four of the five burns were on the classic high intensity slash removal theory, where the centre of the block was ignited, then after a period of time, when a convection column started to form, the edges were ignited as rapidly as possible.
In years gone by, following logging, this type of burn was standard practice. For various ecological reasons, this is no longer the normal practice, which is in a way a pity as it exposes crews to very high intensity fires, and gives them a good understanding of radiant heat, discomfort from smoke, and the noise which most people cannot comprehend.
The fifth fire could not be ignited in the same pattern because of the steep slopes that dictated a different ignition pattern.
All fires went extremely well, and the result was outstanding, as all objectives for slash removal were achieved. The estimates of fuel quantity before burning were 100 to 120 tonnes per hectare, and the burns removed 80% to 90% of the slash.
Geoff Carey, lecturer in Fire Science at the ANU, was in attendance with 60 odd forestry students on the first day, and gained valuable experienced for their Course.
Geoff calculated that the fire intensity on the second fire was up to 40,000 kilowatts per metre.
This is an intensity equal to the worst of the Sydney fires of January 1994. Overall, the intensities were at least 20,000 kilowatts per metre, which is equivalent to an uncontrollable crown fire.
There were many departmental and volunteer units in attendance, who all did a great job.
However, special thanks must go to:They all carried out instructions to perfection which allowed the safe operation of the burns.
The crews used on the central ignition also deserve credit for the job they did. Graham Todkill, Steve Welch, Margot Sharp, Anne Connolly and Odile Armin were used in this role, and it cannot be emphasised enough that this could have been potentially very dangerous.
There was only one near miss, when the crew of Rivers 20 were in a very hot spot during the second burn, which melted a few plastic bits and pieces on the Light Unit.
Poor Arthur, as Operations Officer, copped all the associated paperwork. However, it must be emphasised, that due to prior planning and the low intensity hazard reduction burn in the adjoining eucalypt block, the crew were in no real danger, just very uncomfortable for a while.
Everyone was fascinated by the number of whirlwinds associated with the fires, and the ferocity of some of these whirlwinds. Hopefully, some good shots have been captured on film and videos.
The Emergency Service catering crew did a great job with lunch and a hot dinner at the end of each day. Their services were much appreciated by all.
A post fire field day with the Revegetation Working Group were very impressed with the result, and the ashbed that was left. This means that there is now an excellent seed bed for ongoing re-vegetation work.
All in all, everything ran smoothly, and a lot of fire fighters, both departmental and volunteer, gained a lot of valuable experience, and the burns could not have been successfully completed without everyone's co-operation.
Ian McArthur
DCFCO