Thread: Bushfire bunker

What about air supply? Air shafts would just let in smoke....

Good idea, for something that may or may not happen again though. Post some pics if you actually get it going

Hey DB - already thought about that - I have 2 steel faber scuba tanks, as the wife works from home (abn, registered business, council approved etc) everything we get will need to be through the council and hopefully will be a tax deduction - was thinking about buying another and leaving it there (110 cubic feet of air) - should give 1 hour of good dry clean air for anyone in it.

I will probably need some sort of ventilation for normal times, and a way of turning it off during any emergency, probably a one way system, in one way out the other, so blocking the in during a fire and therfor not popping ears with positive preasure when using the tank


I live in an are that hasn't had a decent fire in 10 - 20 years and looking around if it does actually happen - I have nowhere to go (infact, I probably won't even be there due to the fact of where I work) so this is something that my wife wants

I just dont want to bung a really expensive moisture collecting tank underground that is useless in years time if it is ever needed (I was going to say water - but we haven't had any decent rain for almost a decade) or turn it into "just another shed - full o shit"



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Originally Posted by freakee1

or turn it into "just another shed - full o shit"

That's probably the biggest problem you'll come across in the whole venture, too

Originally Posted by freakee1

Hey DB - already thought about that - I have 2 steel faber scuba tanks, as the wife works from home (abn, registered business, council approved etc) everything we get will need to be through the council and hopefully will be a tax deduction - was thinking about buying another and leaving it there (110 cubic feet of air) - should give 1 hour of good dry clean air for anyone in it.

I will probably need some sort of ventilation for normal times, and a way of turning it off during any emergency, probably a one way system, in one way out the other, so blocking the in during a fire and therfor not popping ears with positive preasure when using the tank


I live in an are that hasn't had a decent fire in 10 - 20 years and looking around if it does actually happen - I have nowhere to go (infact, I probably won't even be there due to the fact of where I work) so this is something that my wife wants

I just dont want to bung a really expensive moisture collecting tank underground that is useless in years time if it is ever needed (I was going to say water - but we haven't had any decent rain for almost a decade) or turn it into "just another shed - full o shit"



f

Get a Helipad and a Chopper mate.

To be sure...to be sure...to be sure...

Originally Posted by z80

Get a Helipad and a Chopper mate.

To be sure...to be sure...to be sure...

thats a really good idea - might just do that, might go for a blackhawk

I'm so glad you decided to comment........

Originally Posted by ssrattus

The container would become an oven.... even with sprinklers.

Don Burke was on the local radio about DIY fire bunkers and they were made on a concrete pad using hollow bessa blocks, the air in the hollow is an insulator, concrete roof and yes a concrete door that opens inwards. No timber door frames. Siting of the bunker is important too... away from ridge line and bush etc. The fire front usually passes within 15 minutes, so no vents or air needed.

Heat would be a huge factor, a bush fire usually happens on a day with 40+ degree heat.

Still survivable for a human I reckon, assuming a quick fire front, remember some people survived in cars, some didn't. I reckon some thick glass fibre insulation on the inside of the exposed parts of the top should be alright, with reflective layer (sarking) beneath that, high reflectivity means no emissivity... it can get hot to touch but you wont get any infrared off it to cook you.

You could always test it with a bonfire built on it.

So long as the container was fully underground in a clearing with no debris, wouldn't it stay cool if a fire went over the top? Or have I no idea of how heat works?

I take it you want it fully underground freakee?

Here is an idea...










and another site click on the gallery link.

Underground sounds like the way to go...



"But I don't think anything would have survived well above ground.

"I think even reinforced concrete would just explode with that sort of heat that was there."

Originally Posted by PostScriptum

Heat would be a huge factor, a bush fire usually happens on a day with 40+ degree heat.

You're not living in it, it is just a shelter for when the fire passes, maybe in it for an hour. I'd sit in it for an hour at 60 degrees (with water of course) if it means surviving.

Hello freakee 1. Yes a good idea.. Thats exactly what I would be doing.
Appearently radiant heat travells in a straight line so bury on the flat and not into the side of a hill...entry could be a zig zag trench for same reason. I think if burried deep enough it might even give respite on an extremely hot day. Just hope the water table is deep enough so as not to pop it to the surface. I'm sure you do your research before building anyway.
regards flicker.

Originally Posted by Devil^Boy

So long as the container was fully underground in a clearing with no debris, wouldn't it stay cool if a fire went over the top? Or have I no idea of how heat works?

I take it you want it fully underground freakee?

yep

I was thinking completely buried (as per PostScriptum) - with at least a foot of soil above - also the entry/exit after a fire would need to have a clean area before any disaster, no use if everything falls on it and she can't get out.




f

Originally Posted by freakee1

yep

I was thinking completely buried (as per PostScriptum) - with at least a foot of soil above - also the entry/exit after a fire would need to have a clean area before any disaster, no use if everything falls on it and she can't get out.




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as mentioned before...think of it as a wine cellar..may as well fill it with cool wine as well...

It definitely needs to be underground I’ve seen photos of inside a fully concrete building no windows with steel door and a concrete roof that got so hot the plastic raw plugs drilled in to the roof to hold lights and stuff melted and it all fell down and plastic items in the room melted.

You would need to setup a couple of escape hatches that opened inwards so if the main exit was blocked you could open another and dig out. Letting to police and other know your there beforehand would also be good. A ventilation system of some sort would also be good to allow for extra air if you did become trapped.

You might also have trouble if you have a high water table in your area, as the container might tend to float up out of the ground. Corrosion would be another issue unless it was wrapped in plastic or something.

Might be worth doing a search on nuclear shelters for design ideas.

Another thing to consider with underground bunkers is oxygen displacement due to heavier gasses.ie if a bunker is unused for a long time there maybe a build up of co2 etc therefor depleting o2 out of the atmosphere in there.
So any sort of air supply sounds good.
My work place is very strict on confined space, even sticking your head in will lose you your job.
Side note - about half of all confined space deaths are second persons that come in to help first.

Good point crazy, you wouldn't put things in there that use oxygen (small engines for pumps etc).

Heavier gases sitting on the floor (LPG, propane etc) could be something to be careful of too.