Fire danger continues through March
In the aftermath of recent large fires in the Queanbeyan Palerang region, several started by machinery, Captain Sharon Field of the Burra Rural Fire Service, has appealed for extra vigilance from all residents who live and work in our surrounding rural areas.
Given the conditions we have at the moment it takes very little for a fire to take off –one spark is all that is needed, she said.
Living in a rural area brings with it responsibilities that people living in the town do not necessarily have.
Some of things you need to be aware of are:
- don’t mow/slash with metal blades in the long grass – use a whipper snipper and mow early in the morning, not the heat of the day when the grass and bush are very dry,
– long grass can wind around the blade shaft, heat up and ignite
– the blades can hit rocks or metal and send out a shower of sparks into the grass
- if you are mowing, make sure you have water IMMEDIATELY to hand – you will not have time to run to get some if you see flames,
- be careful of hot exhausts from chainsaws, motor bikes, quad bikes and utes in the long grass,
- power tools often throw out sparks that are not visible during daylight hours, but they are there – people use those tools in sheds (near open doors and surrounded by grass) and in the paddocks,
- drilling can cause a metal drill to hit rock and that will generate sparks
- burning household refuse in a drum during the day will send up a shower of sparks which you won’t see in daylight hours
And, if you see smoke, don’t hesitate – ring 000. If it turns out to be a false alarm, it doesn’t matter.
Captain Field provided a couple of frightening scenarios which demonstrate just how quickly grass fires can spread, given the conditions we have been experiencing recently.
Scenario 1: A day early in summer. Temperature is 34 degrees, Humidity is 31%, Grass is 70% cured and the Wind is coming from the NNW at 26 km/hour.
- In these conditions, a fire will take some 7-8 minutes to travel 150 metres
Scenario 2: A day at the height of summer. Temperature is 39 degrees, Humidity is 12%, Grass is 100% cured and the Wind is coming from the NNW at 37 km/hour.
- In these conditions, a fire will take some 40-60 seconds to travel 150 metres
Given the speed at which a fire has the potential to travel, a lot of damage can be done before Brigade vehicles can mobilise and arrive on scene. Even if the Brigade can get to the fire in the first 10-15 minutes, you can do the sums and work out how far the fire will have travelled.
So lets do the sums:
Based on the worst of the scenarios above, it works out that during the height of summer, with temperature at 39 degrees, humidity at 12%, grass curing at a rate of 100%, and wind at 37 kph NNW, a grass fire could potentially rip through over three kilometres of farmland before the flashing lights of a Brigade vehicle arrive on the scene.
That is extremely sobering.
Bottom line for us all? It sounds obvious, but under these conditions, think of the consequences of your activities, and don’t do anything outside (or inside) which is even remotely likely to provide a source of ignition for a grass fire.
Here’s what happened in real life in Burra a day after the Carwoola fire
A fire was started by a mower on a roadside corner.
It was not the type of day we would expect to experience a fire – coolish (relatively) and only a light breeze.
But with the grass is 100% cured, this fire took off very quickly. It jumped a bitumen road, raced through two properties, and was starting to impinge on a third. One property came under threat.
Burra RFS quickly got three choppers in the air dumping water around the property under threat and supporting ground crews. Soon after crews arrived from Jerrabomberra Creek, Queanbeyan, Ridgeway and the ACT.