Friday, 29 September 2006

Fire Risk posed by Electric Fencing

It was recently suggested to me that the use of electronic fencing in areas such as Grenfell creates an unacceptable fire risk, especially during the summer months. With this as a backdrop I set about conducting some research on the subject. Below are the organisations and people I contacted or gathered information and views from, together with what I found out.

Wesfarmers Federation Insurance (WFI)
I contacted one of the WFI Regional Managers who in turn spoke with a couple of his peers. In short WFI does not consider electric fencing to constitute a material fire risk and thus does not charge a premium over conventional fencing where these types of fences are used.

Gallagher Australia Pty Limited (GAP)
Gallagher is one of the leading global designers and manufacturers of “Power Fence Systems”. I contacted GAP and received an email response which in part reads:
“Re starting fires - the voltage is sent through at a very low ampere which makes it very difficult for a fire to start. On extremely hot days you can turn your fence off for greater piece of mind as the animals won't be moving around anyway on the really hot days.”

Australian Government Department of Environment & Heritage
A web search brought to light the following on the Federal Government Department of Environment & Heritage website (see link to full article if required):

“7.3.3 Fire risk posed by electrical fences
Electric fences have been suspected of causing several fires (McCutchan 1980, Sexton 1984), however McCutchan (1980) concluded that the combination of conditions necessary to ignite surrounding vegetation make electric fences a possible but improbable cause of bushfires. He found that an arc can pass through the air between an electric wire and another electrical conductor if these components are separated by several millimetres or less. Alternatively, an electrical 'flashover' can occur across a suitable green leaf that contacts an electric wire and a conductor separated by 20 mm or less. These events will only be capable of starting a fire if very dry, finely divided tinder, such as thistle down, is present between the conductors, and there is also sufficient dry vegetation within the immediate vicinity to be ignited. High temperatures, low humidity and the presence of wind are conditions that will cause the tinder to become suitably dry (McCutchan 1980).
To reduce any potential fire risk in areas where bushfires are a hazard it has been recommended that fences be well maintained, porcelain insulators be used (Sexton 1984), vegetation be cleared in the immediate vicinity of the fence line (Australia Standards and Standards New Zealand 2003) and, in high fire risk seasons, the output voltage be reduced or current-limiting resistors installed (Australia Standards and Standards New Zealand 2003, Sexton 1984). However, Coman and McCutchan (1994) point out that reducing the voltage is unlikely to greatly reduce the fire risk and, because higher voltages are likely to be necessary in the drier months to counteract the poor conductivity of animal fur, this may reduce the effectiveness of the fence."

NSW Rural Fire Service - Forbes
I spoke to the Forbes office of the NSW Fire Service. In the 20 years the person I spoke to has been employed by the NSW Rural Fire Service he is aware of 1 or 2 instances where fires started on farms that had electric fencing, but it was not clear what the cause of the fire was i.e. electric fencing was suspected but not proven. Electric fencing is not considered to be a material fire risk. The major ‘man-made’ causes of fires on farms include angle grinders, welders, headers, slashers and power poles (cross-arm breaks).

NSW Rural Fire Service – Volunteer – Orange
A family member who lives on a farm at Orange and is a volunteer member of the local bushfire brigade advised that he went to a fire a few years ago that burnt down the local gun club. The fire was allegedly started by an electric fence but is at present subject to a Coronial inquiry (as the damage caused was over $50,000) and cause cannot be confirmed.
“Farm fire causes are many and range from machinery sparks, stubble burns (& burn off in general) that have got away, hot mufflers and cigarette butts in stubble/grass, lightning strikes etc. and of course arson. The inquiry into a fire at Alectown a few years ago found that the fire started by a tree touching power lines.”

NSW Rural Fire Service - Sydney
The Customer Support office advised that the RFS does not have statistics regarding research into the fire risk associated with electric fencing. They referred me to Section 7.3.3 of the 'Cost effective feral animal exclusion fencing for areas of high conservation value in Australia' document produced by the Australian Department of the Environment and Heritage - which I'd already located (and have included above).
For information in relation to Asset Protection Zones or other Bush Fire Protection Methods for building in a bush fire prone I was referred to the link below;

Tuesday, 26 September 2006

Ochre in the context of Aboriginal culture

Local Grenfell resident and historian, Ian Pitt, recently gave me a copy of a brochure titled “Ochre Dreaming – Victoria’s Aboriginal Tourism experience” produced by the Aboriginal Tourism Marketing Association. Ian sent me the document in light of his personal interest in Ochre Arch (having lived on the property from 1981 to 1987) and our recent discovery that Aborigines had mined red-orange ochre from underneath the natural arch on the property. What follows is a verbatim copy of the information about ochre in the context of Aboriginal culture, set out on the inside front cover of the brochure:

“Ochre is a natural earth pigment which has been used by Aboriginal people for thousands of years. Aboriginal people believe that ochre has spiritual power which is released through ceremonial ritual. Red ochre is considered sacred. In tradfitional Aboriginal life, ochre was a highly prized commodity used as currency in the Aboriginal trade system when clan groups traveled great distances for ceremony and Trade. Particular worth was placed on ochre from certain areas with mythological significance. Archaeological evidence shows that ochre was used in ceremonial rituals and almost every excavation older than 10,000 years uncovers quantities of ochre. Modern Aboriginals employ ochre for painted designs used in ceremonial body decoration and for paintings on bark or canvas. The ochre is ground to a fine powder and water is added to achieve the desired colour and consistency. Ochre is applied in a variety of ways according to the purpose and design. It is often applied through blowing from the mouth to achieve a splatter effect. For fine art work brushes made of hair or a chewed twig are used.”

Thanks Ian! For those wanting further Aboriginal tourism information check out

Sunday, 24 September 2006

Email newsletter issuing tips

In the past 6 months or so I've created a couple of blog sites and send out quarterly Ochre Archives newsletters from distribution lists. A friend of mine, David, who lives near Cradle Mountain in Tasmania also sends out newsletters, was having difficulties with file sizes and asked me for some tips. Both of us like to include photographs in what we send out. Below is pretty much a word-for-word copy of the ‘suggestions email’ I sent him.

“Optus restricts the size of the files it will allow a non-commercial 'user' (horrible term) to 7.0 MB, and a commercial user to 10 MB ... not much difference. Some other Internet Service Providers (ISPs) will only permit 5 MB files to enter their customers email mailboxes.

The following are the ways I know of that will allow you to potentially address the newsletter file size problem:

1. Reduce the size (and in the process the quality ... but not significantly) of your digital photo files.
The easiest way I know to do this is as follows:
a. Open the file in "Paint". To do this:
i) Open Explorer
ii) “Left click” on the photo file name once (in effect you are simply highlighting the file name)
iii) "Right click" on the file name and choose 'Open with' and then "Paint"
b. When the file is open in "Paint" select Image > Stretch/skew > and under "Stretch" reduce the 100 % horizontal and vertical numbers to, say, 25 % (both).
c. Then save the file with a different file name. In this respect I have adopted the practice of simply including the letter 'r' just before the '.' i.e. if the original name was photo.jpg then the name of the reduced file is photor.jpg. This allows me to retain the original file intact as well and distinguish the 2 going forward.

2. Set up a blog site, create the newsletters on it, and send a link to those you want to give access to.
My blogsites were set up via By putting my newsletters on the blogsite it means that I only email out a link to the site rather than an email with attachments (which the PC in fact sends individually). This means that it is much faster to send the email and the recipient can choose to download. Taking this path is a bit trickier to begin with but is fine once you get the hang of it.
If you do set up the blog site you are still best to only post small image/picture files to it. restricts its customers to a total of 300 MB of stored photos. I have adopted the practice of reducing my digital photos (using 'Paint') from around 3 MB to less that 50 KB ... and the quality is still pretty good I reckon.

3. Send the whole newsletter as a single document via
This web site allows you to give people access to files of up to 100 MB.
There are some downsides:
a. Because this web site is free for small time users it allows various companies to advertise on the site VERY AGGRESSIVELY. The main 'advertisers' are virus protection companies who install 'cookies' on the users PC and have flashing advertisements telling the users (falsely) that they have viruses on their PC and need to purchase the advertiser's software in order to be safe. When I first went on this site I nearly fell for the advertising myself ... the flashing ads 'just about frightened the wits out of me'!
b. If the person you send the link to (to do the download) does not do so within 7 days they will not be able to access the newsletter. manages its data storage by deleting posted files at intervals as short as 7 days … and longer for those who pay money.
Having said the above, this web site is extremely useful. I've used it in recent weeks with files of around 14 MB ... connected with my desire to have some proper 3D digital maps of my farm that I can use to create my farm water scheme/plan.

4. Only include 1 or 2 photos in you newsletters to make sure the total document is less than 7 MB.

5. Create relatively small distribution lists
At the beginning I used to have just one distribution list but found it too cumbersome and frustrating when something went wrong. I’ve now divided all of the names on my list into surname groups, which are currently: A-B, C, D, E-G, H, I-L, M, N-O, P, Q-S & T-Z. Did you know that the most common letter in the alphabet that European origin surnames start with is the letter H!?
When sending the newsletters within the different alphabet ranges I include the applicable alphabet range at the end of email heading.”

No doubt there are other ways of sending email newsletters with photos. Readers should please feel free to let me know other ideas that might help.