Wire fences slow down bushfires

[Little Galaxy]

With the fire season not far off in this corner of the world, someone told me this interesting "old farmer's tale". Wire fences apparently somehow slow down, or even stop, the progress of a fire front.

There was no mention whether they meant straight wire fences, like barbed wire, or chicken-wire. Supposedly there have been cases where properties have burned up to the fence line and no further, but I'd think it's due to different ground conditions or a change in the wind direction. I hardly think a wire fence would stop anything of the sort.

Any ideas?

[A Turtle Named Mack]

The only thing that comes to mind for me is that perhaps greener, moister vegetation than the grasses and such in the fields uses the fence as a support, and the grasses do not support enough of a flame to dry out and set afire the veines and such that use the fence.

Oh, actually the first thing that came to mind was that it was not true, but that never before stopped me from trying to suggest something that might work

[purpleiguana]

I suppose if burning bits of plantlife were flying around, a wire fence might catch them... for a while anyway... and slow their progress from blowing to an as-yet-not-burning patch of vegetation. I can't say as it would actually end up making a different in the long run, tho.

[Singing in the Drizzle]

Most fence lines are cleared when being installed and kept clear to maintain them. Electric fences need to be kept clear of anything touching them or less they will short and not be affective the full length of the fence. Both of these things keep fuel for the fire away from the fence. This can act like a fire brake for small brush fires.

[Sebbenth]

I would think that if it would work, it would probably have something to do with heat redistribution. I think of coal miners' lamp, where the wire mesh surrounds the flame, re-distributing the heat and preventing explosions. I would imagine is a small fire something like that can happen.

[Salamander]

I'd say it would probably be a mix of what Singing in the Drizzle mentioned -- the area along the fence being a firebreak and simply the fact that the fence itself makes a psychological border for anyone fighting the fire.

If I was to attempt to save my property from an approaching fire I probably wouldn't go over a wire fence to fight it on the other side -- after all, if the fire advances quickly I'd be worried about getting stuck on the fence. Instead I'd stand on my side of the fence and do what I could from there.

[Troberg]

Originally Posted by Singing in the Drizzle

Most fence lines are cleared when being installed and kept clear to maintain them. Electric fences need to be kept clear of anything touching them or less they will short and not be affective the full length of the fence. Both of these things keep fuel for the fire away from the fence. This can act like a fire brake for small brush fires.

Possibly, but soon, grass tends to accumulate around the fence, as it's more difficult to cut. At least on my lawn...

Originally Posted by Sebbenth

I would think that if it would work, it would probably have something to do with heat redistribution. I think of coal miners' lamp, where the wire mesh surrounds the flame, re-distributing the heat and preventing explosions. I would imagine is a small fire something like that can happen.

Makes sense. A bush fire has very little energy, I've seen videos of people walking back and forth over the fire front without problem. There is simply not enough combustible material to make a high energy fire.

Such a low energy fire could possibly be sufficiently cooled by a mesh fence to go out.

A simply experiment you can try on that principle is to make a spring-like coil out of copper wire. Hold it with a pair of pliers, then lower it around a candle flame. Do not touch the flame, just hold it around the flame. The flame will go out, as the copper absorbs too much heat from the flame for the combustion to go on.

[R.Swanson]

It's also possible that the people living within the fences have been watering their landscaping more than the surrounding land, and that it isn't as flammable.