Walking safely in bushfire prone times.

[wildwanderer]

With bushfires becoming increasingly common over the last few years I started thinking about how to manage the risk when planning for or undertaking a walk.

Currently I do the following.

• Review the fire authority and parks website to see if any fires are in the area.
  
• Check the fire danger rating. (for nsw) https://www.rfs.nsw.gov.au/fire-informa ... and-tobans If danger is extreme or catastrophic I won’t go. With severe danger rating I will strongly consider not going.
  
• Review the Bureau of meteorology site for the weather forecast. Generally, if its going to be windy (above 30km/h) and a hot day (above 30C) I’ll seriously consider not going on the walk.
  
• I definitely wont go if there is fire/s in the general vicinity and high winds/ temps or if its a calm day but there is a fire in the immediate area

However now fires are regularly occurring in the cooler months. The risk is increasing that I will find myself in a situation where my conditions for a relatively low risk fire day have been meet and I elect to go on the walk but still encounter a fire regardless.

I found myself with a decision to make a few weeks ago while walking federal pass in the blue mountains.

It was a cool day 10-14 degrees with 15-25km winds and the occasional stronger gust. I was taking a friend on their first bushwalk and we were walking from Leura to Katoomba. After descending Leura cascades and about to embark on a further decent I saw the following small fire across the valley at the base of mount solitary.

Small fire at base of Mount Solitary

The wind was blowing in my face and from the direction of the fire. My first thought was to abandon the walk as it was an easy 15 min climb back to Leura. I tried to check the fire service active fire map however was too low in valley to pick up a data signal. I recalled seeing a 4wd fire service command vehicle at the Leura cascades car park but It was parked and unoccupied.

As the track ascended again a bit further, I pressed on and was able to get data and check the fire map. Sure, enough there was an indicator for Mt solitary hazard reduction and a further marker for out of control bushfire immediately next to it. Both were marked as 0 hectares in size. So I concluded that the fire service had decided to undertake a minor haz reduction in the already burnt area and it had sparked up or perhaps a dormant heat spot from the major solitary haz reduction 2 months ago had flared up.

I then reviewed the weather bureau site and it said the winds were southerly. Which ment the winds were blowing the fire in the opposite direction of our walking track location. It also occurred to me that the northerly wind I was feeling blowing towards me was likely just the updrafts that occur when close to a cliffline. EDIT. Im wrong here.. southerly winds mean the wind was actually blowing north towards me.. fairly big mistake! The smoke I could see was drifting up (eg not being blow by a strong wind) and not getting larger or moving. The fire service was already observing the fire and hadn’t closed off the walking tracks nor could I see any active fire fighting going on. There was a escape route up the giant stairway or at the walk exit point had we seen the fire approach down the valley. Probably always within a 30 min fast jog of most locations on the walk. And the previous large hazard reduction had reduced the fuel in the area around the fire significantly.

So based on these observations I decided to continue on.

Still undecided if I pushed it from a risk management perspective. Even though the fire was small, didn’t move or get any bigger and we concluded the walk safely.

Interested in forum members experiences and thoughts on what to do if this situation occurs?

If you see a fire/smoke do you immediately abandon the walk?
Or do you consider the temp/wind direction/fire size etc?
Do you only decide to continue on if there are easy evacuation routes available?
Other criteria?

Thought it might be interesting to discuss as seems the rule book is being thrown out a bit with fires occuring in the cooler months.

EDIT. Obviously im talking about a situation where you see a small amount of smoke. If there is significant fire/smoke then Im heading to safer ground immediately. That will be a river/lake or other low lying area clear of fuel. Not uphill unless im very very close to a evac point eg carpark. Fire travels much faster uphill and heat goes upward. Sad tale but valuable lesson of schoolboys who encountered bushfire in the Grose Valley many years ago. The ones who ran down to the river survived, the others who ran uphill for the 'safety' of the Perrys Lookdown carpark/road perished. https://www.rfs.nsw.gov.au/about-us/our ... r-50-years

I do wonder if a canyon would be a safe shelter? would a fire roar up into a canyon like a funnel?

Last edited by wildwanderer on Mon 20 Aug, 2018 7:17 pm, edited 1 time in total.

[GPSGuided]

Fortunately have not walked in the presence of fire/s. I take the general view that if it's hot enough to have spontaneous fires, then it's probably too hot for an enjoyable walk (did walk in the RNP in near 40 deg heat once when I was at silly and still at uni). However, with the recent 60 fires in NSW in late winter and what seemed to be quite moderate temperatures, my guiding logic no longer works. Then I'd say, walking is for health and enjoyment, it's not worth it if there's a risk to one's life or health detriments from breathing smoke filled air.

[wildwanderer]

Some tips provided by the NSW Rural fire service on what to do if caught in a fire.

https://www.rfs.nsw.gov.au/__data/asset ... ochure.pdf

[north-north-west]

Some tips provided by the NSW Rural fire service on what to do if caught in a fire.

https://www.rfs.nsw.gov.au/__data/asset ... ochure.pdf

I'm surprised they don't mention trying to keep upwind of the fire front.

[jdeks]

Some tips provided by the NSW Rural fire service on what to do if caught in a fire.

https://www.rfs.nsw.gov.au/__data/asset ... ochure.pdf

I'm surprised they don't mention trying to keep upwind of the fire front.

More than likely because an alarming number of people would stuff up figuring out where 'upwind' is, let alone were it might change to be, and consequently get themselves into more harm based on a false sense of confidence.

[GPSGuided]

Some tips provided by the NSW Rural fire service on what to do if caught in a fire.

https://www.rfs.nsw.gov.au/__data/asset ... ochure.pdf

‘Wear clothing that will protect you from radiant heat’ and warning on melting synthetic clothing. Whilst it makes sense but would any one do it? Long sleeve thick cotton shirt in summer?

[Warin]

Some tips provided by the NSW Rural fire service on what to do if caught in a fire.

https://www.rfs.nsw.gov.au/__data/asset ... ochure.pdf

‘Wear clothing that will protect you from radiant heat’ and warning on melting synthetic clothing. Whilst it makes sense but would any one do it? Long sleeve thick cotton shirt in summer?

Cotton overalls work well. Of your trying to protect your home from a fire10 meters away ... yes you'll do it because it makes sense. If your more than 1 km away then no - it does not make sense.

[Xplora]

From the photo posted, I would not have any problem completing the Federal Pass walk regardless of the wind on the day. The area between you and the fire has already burnt and it would take a lot more than 15 minutes for it to reach the other side of the valley. If you have no experience with fires then it is better to err on the safe side. I have walked in two fires (one being 2003 down Diamantina spur when the storm hit and started the fire) and been around a number of other big bushfires. Certainly wetter areas will have a better impact on survival as the fire will not be as fierce on the ground. In 2003 I made the decision to keep walking down to the river as there may have been fires behind us. We managed to complete the walk to Hotham safely but you would not have been able to do that a few days later. The other we made a hasty retreat for the car only to find a note from a ranger who was a personal friend.

Having some understanding of fire and what to do is helpful. Fire travels downhill slower than uphill as also. Going uphill to safely could be counterproductive.

[wildwanderer]

From the photo posted, I would not have any problem completing the Federal Pass walk regardless of the wind on the day. The area between you and the fire has already burnt and it would take a lot more than 15 minutes for it to reach the other side of the valley. If you have no experience with fires then it is better to err on the safe side. I have walked in two fires (one being 2003 down Diamantina spur when the storm hit and started the fire) and been around a number of other big bushfires. Certainly wetter areas will have a better impact on survival as the fire will not be as fierce on the ground. In 2003 I made the decision to keep walking down to the river as there may have been fires behind us. We managed to complete the walk to Hotham safely but you would not have been able to do that a few days later. The other we made a hasty retreat for the car only to find a note from a ranger who was a personal friend.

Having some understanding of fire and what to do is helpful. Fire travels downhill slower than uphill as also. Going uphill to safely could be counterproductive.

Thanks for the info Xplora, it was my first encounter with a fire in the same valley as I was walking in.

‘Wear clothing that will protect you from radiant heat’ and warning on melting synthetic clothing. Whilst it makes sense but would any one do it? Long sleeve thick cotton shirt in summer?

Alot of offtrack walkers wear long sleeved cotton business shirts to protect from scrub. Light coloured and breathable they work fairly well in summer. Stink a bit by Day 3 though!

Some more information Ive picked up reading through websites on fire behaviour.

Fire Speed and movement.

• Fire can move at 10 km/h or more
• Its slowest but more intense in forests with thick trees.
• Fastest over grasslands
• Will move uphill faster and be more intense. Can double in speed for each 10 degree increase in slope.
• In the case of very strong winds and dry ample fuel, fire can move much faster than 10km/h. Embers will create spot fires ahead of the main front.

Some sources.
https://www.cfa.vic.gov.au/plan-prepare ... re-behaves

[GPSGuided]

• Fire can move at 10 km/h or more

A lot more would be the take home message if wind picks up.

[FatCanyoner]

Wildwanderer, in your specific situation, I would have continued walking. Knowing that the valley had been burnt in a major hazard reduction just a couple months earlier (you can see the extensive burnt area in your photo) I would have been confident that fuel loads are low. The wind you describe was also not strong enough to drive a fast-moving fire. Finally, as has been pointed out by others, fires burn more intensely uphill. This one would need to burn down a deep valley before it could be expected to speed up in any way. Another thing to consider is that this is a very visible area, as the fire would have been identified almost immediately and firefighting commenced. So the likelihood of it growing is greatly reduced. You are also on well marked tracks with multiple routes available to you, so if you saw the fire was growing (increasing smoke, sound of water-bombing choppers getting closer, etc), there would be many options available to safely exit the valley.

There's a lot of good points above, but if you're interested in reading further, I pulled together some detailed advice on bushfire safety from a bushwalking perspective last year (https://fatcanyoners.org/2017/12/05/bushfire-safety/). It basically brings together my own training in the RFS around bushfire behaviour with the advice that is provided by a range of fire services, parks agencies, and others. It goes into detail about the factors that influence how a fire behaves, how you should prepare for fires before going into the bush, what to do generally to reduce your risk if you do encounter a fire, and what to do if you are faced by a fire. It's fairly long, but it's good to have thought through this stuff in detail before dealing with a bushfire in real life.

[ribuck]

In most of the Blue Mountains, there are deep valleys with streams or damp areas, and lots of large boulders to shelter from radiant heat. Fires advance slowly down steep hills, and often jump the valley without reaching the stream at the bottom. Furthermore, on steep complex ground the fire front is often irregular and if you're caught there may be opportunities to find a way through.

I would be much more concerned in level or undulating forest than in steep intricate country.

[wildwanderer]

• Fire can move at 10 km/h or more

A lot more would be the take home message if wind picks up.

Some interesting stats from the The Ash wednesday and Black Saturday fires.
- moved at an average of 12km/h
- The black saturday fires created spot fires up to 35km ahead of the main fire front. and intense spotting 1-2km before the main front.
- One of the fires on black saturady spread at 26km/h for aprox an hour.
- Prevailing winds were 60km/h.
Source - https://wikis.utas.edu.au/download/atta ... lhurst.pdf

IMO Those are fires were created in catastrophic conditions, which no bushwalker should be out in. Fires created in less than catastrophic conditions may have slower spread due to lower wind speeds and provide some ability to evacuate or find shelter before the fire arrives.

One scary fact. Un-survivable (except for very short periods) radiant heat is generated for a distance 3-4 times the height of the flames. Which makes finding a safe zone with shelter much more challenging. As a general rule, flame height is between three (3) to five (5) times the height of the fuel that is burning. So, if one (1) metre grass is burning then the height of the flame could possibly be between 3 to 5 metres high, but if you had a 10 metre tall tree burning the height of the flames could be 30 metres or greater. So in the case of 10m tall tree you would need to be sheltering atleast 90 metres away to escape the radiant heat. (or be behind a rock etc). For reference a catastrophic fire such as Black Saturday had a flame height of 100 metres. (so 300m away to escape the radiant heat, next to impossible to shelter from IMO)

Wildwanderer, in your specific situation, I would have continued walking..... SNIP

There's a lot of good points above, but if you're interested in reading further, I pulled together some detailed advice on bushfire safety from a bushwalking perspective last year (https://fatcanyoners.org/2017/12/05/bushfire-safety/). ...SNIP.

Thanks for the considered opinion. I read your article. Lots of good information in there and would encourage others to read. Unfortunately I think fire danger is something all bushwalkers will need to be increasingly mindful of in the future especially now fires are occuring in the cooler months. I know im now going to consider potential fire shelter locations in my future walk planning.

[ribuck]

One thing which hasn't been mentioned yet is back-burning.

Here's how it works. Suppose the fire is distant and the wind is light, but it is blowing the fire towards you. As the fire approaches, there comes a point where the updraft from the fire's heat is so strong and so close that it's drawing air in from both sides (upwind and your side). At this time, if you light your own fire front it will be drawn towards the main fire front by the backdraft. When the main fire front arrives, you will have an already-burnt-out area to provide a refuge.

That's the theory anyway. Backburning is a desperate measure, because you need to get a large enough burnt area that you can keep far enough away from the radiant heat (which is the main killer). But it's better than nothing. And as the main fire front passes either side of the backburnt area, you can run through the already-burnt area to get to the upwind side of the fire.

In decades gone by, back-burning was always described as a valid but desperate technique for bushwalkers.

[wildwanderer]

One thing which hasn't been mentioned yet is back-burning.

Here's how it works. Suppose the fire is distant and the wind is light, but it is blowing the fire towards you. As the fire approaches, there comes a point where the updraft from the fire's heat is so strong and so close that it's drawing air in from both sides (upwind and your side). At this time, if you light your own fire front it will be drawn towards the main fire front by the backdraft. When the main fire front arrives, you will have an already-burnt-out area to provide a refuge.

That's the theory anyway. Backburning is a desperate measure, because you need to get a large enough burnt area that you can keep far enough away from the radiant heat (which is the main killer). But it's better than nothing. And as the main fire front passes either side of the backburnt area, you can run through the already-burnt area to get to the upwind side of the fire.

In decades gone by, back-burning was always described as a valid but desperate technique for bushwalkers.

Very interesting, I’ve not heard of this before.

Do you know how close to the main front of the fire a backburn needs to be for the backdraft effect to be useful?

As you said this would need to be an absolute last resort measure to save life. The authorities could easily charge a person with arson (with severe prison terms) and it would be up their discretion whether they did or not... (even in the circumstances that a person lit a backburn to provide a safe zone against an approaching bushfire.)

Another risk is that the backburn could itself generate a significant amount of radiant heat. As unlike the fire service, a desperate bushwalker is not going to have any means to control how intense the backburn becomes.

[potato]

As unlike the fire service, a desperate bushwalker is not going to have any means to control how intense the backburn becomes.

Timing is key to controlling the intensity of a burn. Even the best intentioned fire service can get this wrong.

[GPSGuided]

One thing which hasn't been mentioned yet is back-burning.

For a regular bushwalker with a 25-50L pack, how much resources and time would this individual have in starting and managing a back burn that would be effective? Given the likely adverse condition at the time, what's the risk the supposed back burn would become a main fire and consume the individual? Nice concept I'd say.

[FatCanyoner]

I don't think you'd find any modern fire service that recommends lighting a fire to protect yourself.
Serious bushfires are driven by the wind. To be close enough to a fire for the convection to counteract the wind, you simply wouldn't have time to get a fire big enough to protect yourself. Better to spend that time looking for a clear area, something to hide behind, or a natural hollow. Also note that is generally the smoke and radiant heat that will kill you, not the flames, so most advice is actually about avoiding those elements of a bushfire.

[GPSGuided]

One question I have is, is there enough oxygen in or near a bushfire for an individual's survival? I understand that in really serious fires, oxygen gets sucked up big time and there's a risk of asphyxiation. Do these asphyxiation scenarios happen in bushfires? That is, no point in hiding in a ditch when all the oxygen gets consumed by the fire.

[ribuck]

...what's the risk the supposed back burn would become a main fire and consume the individual?

The chance is pretty low. You don't back-burn until the updraft is close enough that it's pulling air from where you are towards the main fire, so the backburn is going to burn towards the main fire until they meet.

If someone has an old bushwalking book, it will probably have a detailed description of backburning for survival. All I could find in modern sources is a statement from the Darwin Bushwalking Club Handbook for Leaders saying "As a last resort, consider back burning (but be very aware of wind direction first)."

...is there enough oxygen in or near a bushfire for an individual's survival?

Shouldn't be a problem. The fire only removes the oxygen at the point of combustion, and most of that deoxygenated air goes upwards. Close to the ground is mostly free of smoke and fumes.

[highercountry]

One question I have is, is there enough oxygen in or near a bushfire for an individual's survival? I understand that in really serious fires, oxygen gets sucked up big time and there's a risk of asphyxiation. Do these asphyxiation scenarios happen in bushfires? That is, no point in hiding in a ditch when all the oxygen gets consumed by the fire.

I suspect this is a bit of a myth.
Oxygenated air is drawn into the fire and is constantly recharged from the surroundings. If there is no oxygen in the air the fire will stop. It can't burn without oxygen.
In 2003 myself, a dozer driver and his offsider sheltered in a Hilux. Each of us wrapped in woolen blankets. All the Dept. (DSE at the time) vehicles had been supplied with numerous blankets.
We experienced a serious "burn over" in the Upper Livingstone area west of Omeo. Hot enough to melt plastic exterior fittings on the vehicle and set alight a tyre.
The most frightening aspect was the darkness immediately prior to the front arriving, and the noise.
We got very very hot but were still able to breath. Hot, dry stinging breaths, but we could breath, and drink water at the same time (and scream like babies).
As mentioned earlier radiant heat is the killer. At a conservative guess the flame height in the nearby bush was 20-30 metres.
Avoidance is my policy these days. That and being well informed. High, dry fuel loads, NW winds, stay home or go to the beach.

The advice to head downhill is good and if possible head for the the damper, greener South side of a ridge or spur.

[Xplora]

Thanks for the info Xplora, it was my first encounter with a fire in the same valley as I was walking in.

I think you have highlighted an important issue. Many are like you and have very little experience with bushfires. Feeling safe is also important and if you do not feel safe then you should know your options. Some good advice from many experienced people has been offered.

Smoke is dangerous enough without fire. Even a small amount of smoke could trigger an asthma attack.

[Neo]

Having a set of merino thermals in your backpack will double as fire clothes.

I take thermals all year round as a sleep set, just in case of a cold snap.

(only have polypros, I'm yet to upgrade to merino for the above!)