Episode 2 Wildfires 2014: Inside the Inferno

Welcome to Australia. We're in the Blue Mountains just west of Sydney

in New South Wales, and we're here at the peak of the wildfire season.

We've been given incredible access

to one of the world's biggest firefighting forces

at its busiest time of the year.

Every year, they battle thousands of fires in an area larger than France.

We're following their operations to discover why wildfires

are so frequent and so hard to control.

-Oh, look out! Low side of the road!

-Whoa, whoa, whoa, whoa!

Last time, we revealed how fires ignite

and the astonishing ways they can spread.

Ooh! Erupts at the bottom.

The lightning channel generates a big pressure wave

and it's actually like fireballs.

And we explored the vast infrastructure put in place

to spot fires and stamp them out fast.

You're standing here looking at battles breaking out.

In this programme, we'll investigate why the wind

can be a firefighter's worst enemy.

This fire could go 40km or more,

and it could actually impact on people's properties.

We'll uncover the causes of the most extreme fires.

By drawing air in just through those gaps,

that causes the rotating motion that spins up to a high velocity.

We'll find out about an unexpected technique for controlling fires.

Whoo!

Between 20 and 30 seconds gives them plenty of time to clear

the helicopter and actually be on the ground when they catch on fire.

I can see how they're effective.

And we'll meet scientists unlocking the secrets of fire behaviour

to help those on the front line.

-We can already smell a little bit of...

-Oh, look, and actually it's starting to smoke.

-It's slightly...

What is smoking?

Lessons learnt in Australia are helping firefighters

tackle wildfires across the world.

Join us as we go inside the wildfire.

Wildfires are a global phenomenon

raging across six of the seven continents,

wiping out millions of acres of land

and affecting hundreds of thousands of people,

and New South Wales is one of the worst-affected areas on Earth.

During the height of the wildfire season here,

from October through to February,

this state can be hit by more than a hundred fires a day.

We've come here in January -

it's the peak of summer, and the peak of the fire season.

I'm with fire crews in the remote Wollemi National Park,

working to bring a new fire under control.

It's hardly rained here for ten weeks

and with temperatures in the 30s and winds regularly in excess of 30km/h

current conditions are perfect for wildfires.

Crusty, how far are we from the fire now?

Yeah, Simon, the fire's about 4km to the east of us now,

it's up on top of this escarpment.

'David Crust, known as Crusty,

'is coordinating the firefighting response.'

There's a great fog of smoke down there,

but I can see the fire through the trees.

'This is the biggest wildfire I've seen since I arrived.'

How do you think this fire started?

This is a lightning strike from about eight days ago

and obviously it hit a tree, the tree ignited,

and a branch has dropped out of the tree

and it's ignited the fields underneath.

It's almost like a fire time bomb - burning away gently, quietly,

and then all of a sudden it drops a branch and a fire erupts.

That's why we have to be so vigilant.

'The fire was first spotted by Crusty two hours ago.'

When we got here this morning, it was making a run.

What do you mean by that?

Well, it had an uphill run so it was pre-drying the fields.

It had the wind behind it,

so the fire was really behind it quite intensely.

The topography of the landscape it inhabits is a major influence

on how a fire behaves.

When a fire reaches an uphill slope, the heat and smoke rises,

drying out vegetation ahead which then ignites and burns more rapidly.

The speed of a fire can double

with every ten-degree increase in incline.

So far, the fire has travelled 6km.

The combination of wind and uphill terrain

means it could easily gain momentum and spread much further.

What are your concerns about this fire? What could go..?

-What could happen with it?

-This fire could go 40km or more.

-And it could actually impact on people's properties.

-40km?

Ah, it would travel 40km in a day, potentially,

and then we'd have weeks and weeks of work to contain it.

The potential speed at which this fire could travel

means Crusty has called in aerial reinforcements

from across the state to attack the fire front.

We've got a bucket going in now just beneath us.

So, the red helicopter is working with the ground crew,

so the boys on the ground are on the radio

and they're calling in that drop, and they're talking it in.

There it goes. He's dropping the water now.

Look at the skill involved in that.

There was real, absolute... It's a surgical strike, really.

So you've had how many helicopters on this today?

Six helicopters here today.

Six helicopters, and how many, how many fire-fighters on the ground?

Got over 20 guys on the ground

working very hard to stay on top of this.

'Each bucket can scoop up as much as 650 litres of water.

'They take it from wherever they can get it - creeks, rivers,

'billabongs, and even people's swimming pools.

'Dropping water from aircraft was pioneered by the Canadians during

'the Second World War and adopted by the Australians in the 1960s.

'To cope with this year's fire season, the RFS have had to

'expand their water-bombing fleet from 26 to 138.'

And that's the most effective method of getting a fire out?

Absolutely, it's all about getting water on the ground.

'Even if they manage to bring the fire under control

'this afternoon, the logistical challenges of getting fire-fighters

'into this remote location mean it could take days to extinguish.

'And this is just one of three fires

'within the park they're tackling at the moment.

'Already this season, the fire fight in the Wollemi has cost

'almost £5 million.'

This has been a really busy fire season, been a lot of fires

and large areas of burn.

So that's a one-in-ten-year event.

One-in-ten-year event?

So you haven't seen it like this for nearly a decade?

No, the, the conditions are just so dry.

I mean, we've been at this for about 12 weeks straight now,

so it's been a tough season.

It sounds exhausting.

Er, yeah, we're all looking forward to some rain and a rest.

'While Crusty's team use water-bucketing to control

'the fire in the Wollemi, 100km to the southwest,

'fire-fighters near the city of Bathurst are also dumping

'water on flames, but on a much bigger scale.'

This fire is one of three in the area started by a lightning storm.

Winds have been gusting at 40kms per hour, and have driven the fire

to within 30km of Bathurst and its population of 38,000.

The winds are expected to return this afternoon, and with people

at risk, heli-bucketing alone isn't sufficient defence.

So they've called in the most effective water-dropping weapon

in the Rural Fire Service fleet.

This beast behind me is known as the Skycrane,

it's the ultimate weapon in fighting wildfires.

It can suck up 9,000 litres of water in just 15 seconds.

It's thanks to these that the whole of New South Wales

is not on fire right now.

'With a top speed of 200 kms/hr

'and a range of 400km, this helicopter is unrivalled in its

'ability to get right to the heart of a fire fast and effectively.

'There are three in active service across New South Wales -

'they deliver the equivalent of 14 heli-buckets of water in one hit.

'They're deployed daily across the state to attack whichever fires

'pose most threat to life and property.'

It's out here that you really see the Skycrane come into its own.

It looks like such an unwieldy beast of a machine,

but in the hands of a skilled pilot it's incredibly manoeuvrable.

It's coming in now to the dam to refill...

..and he hovers like a giant dragonfly above the water,

and you can see the snorkel going in, sucking up

that 9,000 litres in seconds.

And off he goes, following the line of the valley...

..and approaching the areas of forest that are still smoking.

There are flames beneath the canopy.

And then he does his drop,

a great curtain of water...

..hitting the smoke with astonishing accuracy.

'It's hoped that the Skycrane can reduce the size of the fire

'before the winds pick up later.

'Just a twofold increase in wind speed could quadruple the rate

'at which the fire spreads.

'To find out more about why wind

'is such a critical factor in fire behaviour,

'I'm going back to the Rural Fire Service headquarters in Sydney.

'From here, they're monitoring the hundreds of fires that can

'occur at any one time.

'They make minute-by-minute decisions about where to send

'aerial resources like the Skycrane

'and a 70,000-strong crew of volunteer fire-fighters.

'Key to this process is in-house weather forecaster Simon Lewis.'

Weather really is critical for determining fire behaviour

and fire activity, so we look at the temperature,

how dry it is, how windy it is.

We're expecting an easterly surge in the winds just over

the southern ranges tomorrow. The stronger the winds we get,

the faster that pushes the fire flanks along,

and so you get faster rates of fire-spread.

To understand the impact of wind on a fire, you first need to know that

all fires move with a common shape and that it's not a straight line.

The hottest and quickest-moving part of the fire

is known as the front...

..while the sides or flanks burn more slowly

and less intensely.

Once a fire has ignited, the wind can control the speed

at which it moves, and determine in which direction it travels.

For Simon, keeping a close eye on wind direction,

especially any sudden changes, is vital.

One of the things I will do in here is track the position

of wind changes as they move across the state,

and I'll also monitor when we're expecting those to reach particular

fire grounds, which is really important for fire-fighter safety.

For Rob Rogers, the man in charge of operations

at the Rural Fire Service,

a rapidly changing wind is his worst nightmare.

You'll get fire-fighters operating on a side of a fire,

because often when it's really burning very hot

you can't put them at the front, it's just too dangerous,

so they'll go on the, what we call the flanks of the fire.

If there's a sudden wind change and the side becomes the front,

and you've got people sitting there, it's a really dangerous area,

and they call it the dead man zone, because in the past,

there have been fire-fighters killed in that sort of circumstance.

'It was a sudden shift in wind direction that helped to

'create one of the worst fires Australia has ever seen.

'Simon's going to meet a couple who managed to survive

'the full force of this blaze to discover just how rapidly a fire

'can change its behaviour.'

Let me just show you this, actually.

Can you see the sign here?

They have these outside almost every community in this part of Australia.

It's such a graphic illustration of the threat.

Everybody's conscious of it, fire danger today very high.

It was extremely hot conditions like this that led to huge numbers

of fires in the neighbouring state of Victoria

on Saturday 7th February 2009.

More than 300 grass and bushfires swept across the state

and around the city of Melbourne and its population of four million.

One fire which began at Kilmore East was being driven

southeasterly by strong winds.

30km away was the town of Kinglake West...

Ruth, Jason, hello.

'..home to Jason and Ruth and their two children.

'They'd lived in Kinglake West for 12 years.

'Weather conditions that day were exceptional,

'with temperatures in excess of 40 degrees by 11am.'

It was the hottest day ever, ever I've seen up here,

and the wind, we could hardly even stand up.

It was that strong, the wind.

'With the fire closing in on their house, the couple had to make

'a stark choice - evacuate or stay and prepare to defend their home.'

When you've got two children, one still in nappies...

..you've got to make a serious decision right on the spot

and think, 'Well, what am I going to do?'

So I decided I had to go.

'Ruth put the kids in the car and headed away from their home,

'but Jason decided to stay and defend.'

I'd seen it come from that direction, I could hear it first,

like a storm, and the roar, and things actually starting to explode.

It wasn't much smoke at all, it was just fire, it was all

riding on the top and it was like the air was on fire as well,

because you could... I can still almost smell it, it's like...

the burning oil, burning eucalyptus,

that was like above the trees on fire.

'Jason is describing what's known as a crowning fire.

'Flames leap from the ignited leaf litter on the ground

'up to the tree tops.

'Exposed to the full force of the wind, fire then spreads at terrifying

'speeds across the canopy, up to four times faster than a ground fire.

'At around six o'clock that evening, the wind changed direction,

'blowing the fire eastward...

'..and the flanks of the fire,

'stretching up to 55km in length,

'suddenly became a huge fire front heading straight for Kinglake West.'

I'd seen the hay shed go up,

and then when it got really intense I was actually using the hose

against the wind just to, to stop myself from...

-Perishing.

-Yeah, just being burnt, you know?

I was just holding it like at the flames, or at the front as it

kept coming, by now there were a lot of embers and stuff starting

to come as well, just holding it, you know, and then turning round

again and trying to spray the house, cos it was just drying on it.

That's when my hose failed.

'With some fires travelling up to 600m in 30 seconds,

'the fire wreaked devastation through community after community.

'Thick black smoke in some areas

'meant water-bucketing helicopters were grounded.'

Everything was on fire,

I couldn't think of anywhere else I could shelter.

I headed for the dam and I crawled down until I could feel

the water, and I turned round backwards and went in backwards

with my head out just on the bank, and that's where I just laid there.

'As soon as the fire had passed through, a major rescue operation

'was under way in the most appalling conditions.'

I remember the voices, and then I heard him say,

"Is someone down here?"

And I couldn't hardly move, but...

..I remember the feeling of the gloves they wear on my face,

and he held me hand and he said, "Can you squeeze my hand?"

And I squeezed his hand and he said,

"If you can squeeze my hand that means you'll make it."

Yeah.

There's very few natural events that could transport you

-so immediately from...

-Hmm-mm.

-Hmm.

-..paradise to hell, really.

-Yeah, that's right, yeah.

'Jason is extremely lucky to have survived an event that has

'become known as Black Saturday.

'Throughout Victoria, 173 people lost their lives,

'and more than 2,000 homes were destroyed.

'The sudden wind change was one of the factors that made the fire

'so hard to control, and it wasn't only residents that were caught out.

'Many fire-fighters also found their escape routes cut off.

'Six fire trucks were caught in burn-overs when the fire front

'passed directly over them, engulfing the trucks in flames.

'Fortunately, all the fire-fighters inside survived.

'The incident motivated Australian scientists to carry out

'the kind of critical research Kate's on her way to see

'at the Rural Fire Service Hot Fire Testing Centre in Mogo.'

'This is a Cat 7 fire truck.

'There are 1,200 in active service throughout New South Wales.

'Today, lead researcher Justin Leonard is using

'the only bushfire simulator of its kind in the world

'to subject the Cat 7 to an artificial burn-over.

'He's invited me to join him

'while he measures the levels of heat and smoke within the vehicle.

'These indicators help to assess what conditions

'are like for fire-fighters as a fire strikes,

'but this is the first time

'he's done it with anyone actually seated inside the cab.'

It's quite an odd mental process preparing yourself to

knowingly go into a burning truck, or at least one that's going

to be close enough to be very, very hot and uncomfortable.

I have no idea what it's going to be like.

I know... You know, you know about radiation, about radiated heat,

you light a fire at home, you can feel it,

but the idea of being stuck in a very small confined space

with the heat ever-increasing is terrifying.

But I'm sort of fascinated by the process as well, I'm kind of...

I have no idea how I'm going to react,

whether I'm going to completely panic or feel quite calm.

Um, just don't know at this stage.

'Justin has placed a number of sensors around this fire engine

'to monitor temperatures in and out of the cab and keep us safe.

'41 gas burners surrounding the truck

'will recreate the different stages of the burn-over.'

-Right, how are you feeling?

-Um, a bit nervous,

I wouldn't say my heart rate's at resting pace right now.

No, mine neither!

-Shall we get it over with?

-Yeah, good luck.

Thank you, you too.

Let us know how you're feeling

-in terms of the radiant heat load on your skin.

-OK.

OK, Martin, we're ready for the low stage of the burners.

OK, Justin, here we go.

Instant, it's an instant, the heat through the glass.

Yeah. My heart rate's definitely up.

'The scenario Justin is simulating now is stage one of a burn-over,

'when flames are approaching the truck.'

So we're seeing quite a filtered amount of heat coming through,

-so that's getting about half a kilowatt...

-OK.

..and we've got about 2.5 outside.

-Right.

-So this is sort of, um, already significantly hotter

-than a hot sunny day.

-Yeah.

-But, but tolerable.

Tolerable, yeah. I mean, it is like standing on Bonfire Night -

it's like standing, you know, kind of close enough but thinking,

"Mm, once I've got my baked potato I might take a step back."

That's right. Feel like going up a notch?

Yeah, go on, then.

-OK, so bring it up to the next level, Martin.

-OK.

-OK, that's now feeling...

-Now, now it's building, yeah.

Really... I'm, I'm kind of...

I can feel myself kind of just leaning away from the window.

Definitely, even just a few centimetres makes a difference.

We can already smell a little bit here.

Oh, look, and actually it's starting to smoke.

-What is smoking?

-It's slightly cloudy inside the truck.

So I'd say the plastic elements on the outside of the truck

are starting to be a bit, um...

Ooh, yeah, I can see...

Yeah. You want to briefly go up a notch just before

the truck gets a little bit too hot and burns?!

-OK!

-OK, go up one more notch.

OK.

OK, so we're now at... Oh, wow.

-So...

-OK, so the outside radiant heat is five and a half now,

-inside...

-So you'd now be feeling quite a lot of pain

-potentially on your skin.

-It's... You can't actually...

We've pretty much got two kilowatts on us now.

OK, yeah, you can't actually turn and look at the...

Looking at you, it's more comfortable.

We're pretty much at the threshold,

and now the smoke's getting a bit hard, yeah.

-The smoke's quite hard.

-OK, shut down.

Because there's a fair bit of smoke coming in the cabin,

-I'd say we're better off climbing out.

-OK, OK.

'This kind of testing is vital for offering fire-fighters

'who use Cat 7s the best advice in the event of a burn-over.'

If we hadn't got out when we did, what would've happened?

-We could feel a tingle in our mouths...

-Yeah.

And it was like we were...

We were 10 to 20 seconds away from that being really irritating.

At about 30 seconds, our eyes would've been really sore,

and, you know, we'd be feeling quite headachy, say, for a few hours

after that exposure if we didn't get out exactly when we did.

Right.

'Although the smoke in the cab was unpleasant,

'in a real fire at the same point, the radiant heat outside

'would actually be far more deadly.

'In a fire scenario like this one, fire-fighters are trained to

'stay in the cab, close all windows and vents,

'get low, and cover themselves with a woollen blanket.'

OK, we're ready,

we can bring on the pre-radiation burners on level one.

'But the other aim of the research is to improve the design

'of these trucks so they can keep their crews safe,

'even when conditions get more extreme.

'To demonstrate how this is done,

'the Cat 7 will now be subjected to the second stage

'of the burn-over, when the truck is engulfed in flames.

'Rural Fire Service chief engineer Andrew

'works closely with Justin.'

We wouldn't expect anyone to survive what we're about to witness,

so what we want to see from here is all the weak points, OK,

any fallibilities within the cab, on the vehicle.

Next level.

We're just upping the level.

The wheels are igniting. OK, so main burners on now.

Oh, my goodness!

So this is the main fire front now going to engulf,

engulf this side of the vehicle.

So we've just moved to the offside burners,

so the fire front's actually burning over the truck now.

OK, so this is, this is now replicating

a fire doing a literal burn-over.

-That's right.

-Crossing over the truck.

So it's as if you're on a track with fuel

and trees built up on both sides,

so the fire front actually moves fully over the top of the truck.

It's plain to see the impact... BANG! KATE GASPS

-Ah! Sorry! Ha-ha!

-That, that'll be a tyre.

-Yes, that's tyre number one.

-That's a tyre!

OK, we'll get suppression ready.

'Tests like these identify where the key safety advances

'need to be made.'

Well, I'm not sure you're going to be able to use this one again,

Andrew. Oof!

-Wow, it's like a horror film, isn't it?

-It is, isn't it?

What chills me the most is that volunteer fire-fighters

-are in these vehicles...

-Yeah.

..and um, we want to make sure that they never get into this situation.

What were the obvious things that...

You said, OK, there is serious room for improvement

in this particular scenario.

Yeah, it's the windows. As you saw, the windows are all gone.

-Yeah.

-Um, that allows too much flame, etc, to enter.

The doors - where the flame impacts on the door, melts everything inside,

and starts to put a lot of smoke inside the cab so you can't breathe.

-Yeah.

-The other thing is all of the rubbers and any fuel under the cab.

So tyres, that kind of thing.

Tyres, plastics, anything that will cause flame to propagate is

a fuel which will then impact inside the cab.

'This research is helping Andrew

'and Justin create a new generation of trucks.'

So if we look at the newer model,

um, I mean, obviously, it's a much bigger vehicle altogether.

Does size matter?

Not when it comes to crew protection, Kate, no, it doesn't.

Just to explain a couple of things that we've done on some of

the weak points that we saw on the older vehicle compared to this one -

we have a ring main at the top,

and those sprays up the top there are actually

shedding water down each window, so it keeps the glass very cool.

We have another spray under here, the tyres will be wet

and kept cool.

We changed the plastics, and we changed these to metal,

-all of that's metal.

-Everything's metal?

One more feature that we do on here, plastic door handles -

this is all metal now, so we replaced that with metal as well.

Ah.

And I'm assuming the blinds inside the windows are not decorative.

Oh, wow, OK.

This is reflecting back the radiant heat

away from the inside of the cab.

Exactly.

That in itself means that anyone trapped in a burn-over

in this vehicle has every reason to survive.

Well, they have a much greater chance of survivability

-than what they do in any other vehicle.

-Right.

'These new trucks will themselves be tested in a continual process

'to create ever-safer vehicles.'

'Throughout any fire season, there are peaks and troughs of activity,

'and the situation can vary in different parts of this vast state

'according to the particular weather conditions.

'Back at Bathurst, it's been much cooler in the past few days,

'bringing rain that has helped keep the fires under control.

'At the Wollemi, temperatures remain in the 30s. The fires there

'have now burnt through 470 square kilometres of wilderness.

'While the air team continue to drop water on the fire,

'ground teams in the park are now employing the next step

'in their fire-fighting strategy. It's called containment,

'and it involves using bulldozers to clear vegetation

'ahead of a fire to remove the fuel it needs to burn and spread.

'I've joined John in the driving seat.'

OK, are you right for this?

Yeah. Good for it, you knock it down.

-Takes it down like it was a matchstick!

-Yeah.

Ooh. The power of this machine!

Does a good job for its size.

-The thing is, you don't even feel it here in the cab, do you?

-No.

There's no pause, it just goes straight through and over.

'Each fire-break is around three to five metres wide,

'so as well as restricting the fire, they can also provide

'an access road for fire trucks.

'But making them isn't as easy as it looks.'

Oh, my goodness. OK. Nice and calm.

Now we're going to go forward.

'I've been given one job.'

Slowly, I'm engaging the boulder!

Oh, dear.

Maybe a bit too much of the road, I think.

I'm determined to get this rock off, yes, it's going! It's going!

I have sort of helped to clear the road,

and made a bit of a mess at the same time.

I think it's time I let the professional back in the cab.

I probably have seen worse.

-Have you?

-I probably have, but I'm not sure!

-I'm sorry.

-Practice, practice, mate.

What they're doing obviously isn't as sexy as fighting

the fire from a helicopter or from the sky, but it's an essential

part of preventing and stopping the fires that ravage these areas.

And they can fight the fire on their terms.

We captured the Rural Fire Service using this technique

to great effect at a fire in a pine plantation.

Using a combination of roads and containment lines, the crews

managed to stop the blaze in its tracks, allowing them to put it out.

Sometimes they'll allow contained wildfires

to burn out naturally, or be extinguished by rain.

But containment lines aren't only made with bulldozers.

In the Wollemi, they're using what appears to be

a paradoxical tactic to slow the progress of a wildfire.

They're deliberately lighting fires in its path.

It's a process called back burning, which is essentially

fighting fire with fire.

As the approaching fire front burns with greater ferocity,

it creates a pressure system.

The hot air rises,

and the smaller, deliberately lit fires

are pulled towards the fire front, burning everything in their way.

The process removes the fuel from the oncoming path of the fire...

..and increases the size of the fire-break ahead.

It's basically using a smaller fire to deprive a bigger fire of fuel.

These containment techniques, along with dropping temperatures

in New South Wales, mean that as we reach the last few days

of our time here, the number of active fires

has dropped from 106 to 42.

But in the neighbouring state of Victoria, the weather is hotting up.

I've travelled to Marlo Airbase,

south of the Snowy River National Park.

In this remote area, they're starting deliberate fires

from helicopters to ensure bushfires currently under control

don't take off again as the mercury rises.

Mike Irvine is the team's leader.

What we've had is quite a large fire.

There's not a lot of activity out there now in terms of flames,

but what it's left is a big unburnt patch in the middle.

If that really gets cranking

in the hotter weather, that can send up a lot of smoke,

and also embers, which can spot outside the original fire,

and then start a new fire or make the original fire bigger.

So we drop incendiary balls from the helicopter

to light up that unburnt area while the conditions are good

-and not too extreme.

-Can we go and see what they're doing?

Yeah, I'll show you, come over.

Hey, you guys, can you just pass me one of the balls? Thanks, Phil.

So, they're like little ping pong balls, you can have a look.

So it's got potassium permanganate powder inside,

-and then this machine behind us here, it's got glycol.

-Right.

Which is antifreeze you use in your car, and there's a needle

inside there, so the balls drop into a chute one at a time,

they're injected with glycol, and then they'll drop out

-the tube down the bottom there.

-Oh, this one just down here, yeah.

That's right, and then within 20 or 30 seconds, that'll ignite.

And if it lands in some fuel, which is quite likely

-where we're going today...

-So leaf litter or something like that?

Yeah, leaves and sticks

and that, it will actually start a little fire.

Thanks, guys, we'll crank it up.

-OK, Phil. Good?

-All right, yeah, all right. Go.

'The machine can fire as many as 90 balls in one minute,

'but a handful is enough to show how they work.'

The wire's on the top so they don't fly out and...

-BALL HISSES

-Woo!

..yeah, they don't shoot up in the air and sparks and that,

-but they do a great job on the ground.

-Yeah.

'When the chemicals within the ping pong ball combine,

'they prompt a thermal reaction which leads to ignition.

'Key to using the incendiaries properly is ensuring

'they ignite at the right moment.'

I can see how they're effective.

So that was about 23 seconds.

Between 20 and 30 seconds is quite good,

it gives them plenty of time to clear the helicopter

and actually be on the ground when they catch on fire.

And how accurate can you be?

How do you know that you're not accidentally going to

set off a fire in an area that you absolutely don't want to burn?

-We're very low, just above the tree tops.

-OK.

And the turbulence from the helicopter is pushing

straight down, so they're not really affected too much by the helicopter.

If we did a sharp turn,

it might shoot one out to the side a little bit,

but generally they'll drop straight down and where we want them, so...

'We're heading up to see the effect of the incendiaries

'they dropped this morning.'

-OK, everyone good to go?

-Yep.

-Yeah.

So, where we're heading to you can see the fire

off in the distance straight ahead.

-We'll go and show you what we've been up to.

-Great.

Suddenly you can start to smell the smoke.

We normally start off with just a little bit and then build up,

-cos obviously you can't take fire out once you've put it in...

-Yeah.

..but you can always add a little bit more if you need.

Wow, it's getting very smoky up ahead.

-So that stuff in there is what we lit two days ago.

-Yeah.

And the stuff out ahead of us, a bit more up to the left there,

is what we lit just before, and it's burning quite well, so...

It's really interesting looking down on them,

and it is following a very neat line.

What we do is light it up the top and let it just run down slowly,

so it doesn't do too much, too much damage,

but still burns out underneath, which is what we want.

We want it to be nice and safe, so nothing's going to spring up

and surprise us.

'Mike and his team are creating low-intensity fires

'before temperatures rise to burn away the leaf litter

'on the floor, removing the fuel source for any future ignition.

'This incendiary process is a simple

'but effective way of safely burning vast swathes of land.'

How many balls did you, did you drop this morning?

-Um, we put about 140 balls into that area...

-Right.

..and the area's probably about three or four kilometres

by three or four kilometres,

so that's like 140 little fires along the top of the ridge, and as

you can see they're starting to join up now and do a really good job.

So it looks quite hot on top of the ridges,

but once the ridges are burnt out,

they'll start to back down the ridges towards the gulleys

a little bit more gently, which is exactly what we want.

So you're pleased that today went well?

Yeah, very pleased. It's really good.

'While scientists and fire-fighters are constantly evolving

'better methods to control and contain wildfires,

'there's one fire that is so formidable

'it simply can't be contained.'

In January 2003, a massive fire hit Canberra,

Australia's capital city,

engulfing 2,600 square kilometres in a single day.

It was a huge fire, but what made it unusual was that it created

a massive spinning vortex of flame.

This phenomenon has been described as a giant fire whirl

or fire tornado.

Local residents Gary and Trish witnessed it first-hand.

The sky was blood-red, and then it just started...

just this big, swirling type black smoke

just appeared over there.

Shortly after that, I saw one of those big gum trees

at the top of the mountain snap, and that went

about 50m up in the air across the mountain

and then disappeared out the back there somewhere.

So it was behaving exactly like a tornado,

it was lifting stuff up and chucking it in the air?

Yeah. Then all of a sudden we saw that huge fireball,

it was like an explosion of fire.

Get in mate, quick steps.

The Canberra tornado proved that fires are capable of creating

their own extreme weather systems as dangerous as the fire itself.

Exactly what leads to this kind of event is debated by scientists.

But fire behaviour expert Jason Forthofer

has developed an ingenious method

to demonstrate one way they can be caused.

We lit these five different fires

and each fire is trying to suck air into the base of it

to replace the hot air that's rising.

And the only air that it can really draw in well

is through these gaps between the fires.

And by drawing air in just through those gaps,

that causes the rotating motion.

And then that rotating motion is stretched

and causes this fire whirl that spins up to a high velocity.

To grow, fires need a constant supply of oxygen

and they do this by sucking in air at their base.

Fire whirls can occur

when a number of fires burn in close proximity

and compete for air, creating a circular airflow.

This can happen in wildfires

when spotting fires, caused by flying embers,

ignite around the main fire front.

Using high-speed cameras

we can see how the flame behaves in intricate detail.

Slowed right down to 1/20 of normal speed

you can see the central flame spin

and then stretch vertically.

Rising hot air acts on that rotating motion.

It spins up into a really tight whirl.

In the real world

these fire whirls can get up to be 100mph or more.

They've been known to tear roofs off houses

and tip cars over.

Subsequent analysis of the Canberra tornado

revealed that the fire created its own superheated winds

travelling at 250kph.

Given the unstoppable power of tornadoes like this

Jason's research is focused on providing an early warning system.

Our hope with our research

is that we can give fire-fighters insight

into likely locations where they may form.

And then also to be aware when they do form

the kind of damage that they can do.

For Canberra residents Gary and Trish

it's an experience they're unlikely to forget.

It just happened so quick.

Dropped everything, ran in the house...

-30 seconds later, boom, it just...

-And it just hit.

-..hit.

And just that noise, the incredible jet engine noise,

was just roaring out.

If that fireball had been...

a couple of metres, or whatever, more towards the house

I'd...yeah, I would hate to think what happened.

What eventually halted the tornado is uncertain.

But it lasted for an hour,

travelling 40km before finally dying out.

Back in Bathurst, New South Wales,

the recent rainfall has helped to suppress the flames

and wind speeds have dropped,

allowing fire-fighters to get the upper hand.

The fires are now under control.

While the conditions are calmer

there's a brief opportunity to enter the scorched fire grounds

and make sure any remaining hot spots

are completely extinguished.

I'm joining the mopping-up operation.

At the moment we've got mopping-up operations

which is basically going in, hitting any hot spots,

any bits of fire that may be underground, in tree stumps,

in trunks of trees, etc,

and making sure that they're completely extinguished.

The crews out there today will actually be off the trucks,

walking through the burnt ground,

-feeling for any heat that's coming up out of the ground.

-Wow.

Is this a dangerous operation?

Any operation, any time, is always dangerous.

We've got falling trees. Especially with a bit of wind,

trees that are fire-damaged can fall at any time.

The bush is dry so if anything starts from an ember

it's going to spread fairly quickly.

So everyone has to be alert

-that fire could reignite at any time?

-Yeah.

-Well, we'll go and see what they do.

-Yes, let's go.

Crews work eight-hour shifts, covering the ground systematically.

You need eagle eyes

and it also helps to have an infrared camera like Chris's.

Kate, perhaps just have a look at this one.

Got a bit of a hot spot here.

-Oh, my goodness, yeah!

-Yeah.

-Wow! Over 300 degrees!

-Yeah, we cracked the 300-degree mark.

And you'd never...I mean, I was heading down

for the very obvious hot spots, the smoking areas.

-I would never ever have considered this.

-No.

The FLIR cameras were first used by the Rural Fire Service in 2008

and are now indispensable to front-line fire detection.

It really is helping us do things that you ordinarily might not see.

And if you did miss things like this,

how dangerous are they?

Well, it depends a bit on the weather conditions.

But this is a risky slope

because the unburnt is on the upslope side

and we've got quite a bit of leaf-fall which will happen.

-So you need to kind of nip this in the bud, basically...

-Yes.

..before it becomes another, as you say, flash point.

So we'll expose it with a rake in a minute.

-So you can do a bit of raking.

-OK, yeah, put me to work.

-OK!

And then we'll bring the hose line down,

-lay a bit of foam on it so we take the heat out of it.

-Yeah.

So you're exposing the fuel, removing the heat,

-smothering it with a bit of foam.

-OK.

-So that's your heat triangle - fuel, heat, air.

-Right.

-Get rid of them.

-So you've got rid of all those things.

-Yeah.

Right, OK, you'd better put me to work. Who's got a rake?

A hot spot like this is formed

when a fire has spread into the roots of a tree

and continues to burn beneath the ground.

So you're basically digging down into here,

exposing the hotter stuff.

You're starting to just see a little bit of smoke

-actually coming up from there, aren't you, now?

-Yeah,

-Look at this, Chris.

-Yeah.

-It's already glowing.

-Yeah, yeah.

That's certainly gone into an active flame stage

-because it's exposed to the air.

-Right.

-A little bit of air movement upslope...

-Yeah.

..and away it goes.

-Wow, it does boil up, doesn't it?

-Yeah. That's cos it's...

-It's like a kind of frothing cappuccino.

-..taken the heat out.

Sometimes we've got to be a bit cautious

with how much water we use because, you know,

we mightn't be able to quickly refill

so we're having some economy with water.

-If you rake it around a little bit now, while I spray it.

-OK.

-So what do you want me to do?

-Just dig it out.

Do you want me to push it back or dig it out?

And is this foam already...?

This is foam coming out, now.

So you're mixing the foam in automatically, kind of thing?

Yeah, up at the pump.

And the foam basically then keeps it sort of airtight, seals off?

-It'll just sit there for hours.

-Right.

That's still smoking a bit, there.

-No red...

-Probably nothing much over 30 there, now.

Brilliant, OK.

So one down, how many more do you reckon there are to go?

Well, that is the question!

Are you good at picking Lotto coupons, too?

Yeah, this is a hot one.

The departing fire leaves danger

not only beneath the ground but above it, too.

If you look up there at the canopy,

this looks like a perfectly healthy eucalyptus tree,

but if you come down to my level

and you look down into the roots

you can see that actually it is glowing.

And if I use the thermal imaging camera,

look at that!

It is upwards of...

..600 degrees in there.

This is what the RFS charmingly called a widow-maker.

And what happens, or what can happen, with these trees

is that they look perfectly healthy

but one big gust of wind...

and because its roots have basically been burnt out

it can just tumble like a matchstick.

A very, very easy thing to fall on someone's head.

So you can see why the widow-maker trees are the things

that the fire-fighters fear the most.

Chris and his colleagues continue to work until nightfall

and they'll be back again tomorrow.

It's incredible to imagine that across New South Wales

they have to repeat this process with thousands upon thousands

of individual fires throughout the season.

Every year, on average, wildfires burn through

half a million square kilometres of Australia.

And because wildfires have been part of the natural cycle here

for millions of years,

the native plants have had to evolve extraordinary adaptations

to survive being repeatedly scorched.

One of Australia's leading ecologists, Tina Bell,

studies the regeneration of forests after wildfires.

I'm meeting her in the Blue Mountains National Park,

just outside the town of Winmalee,

to see exactly what happens.

You're an ecologist, I would've thought that fire

would be a kind of nightmare for you.

No, no, it's the best thing that can happen.

It just shows you how dynamic a forest can be.

In one way or another, every species in this forest

is dependent on fire for regeneration,

either from a new individual as a seed

or new sprouts from a tree that looked dead before.

Only three months ago fire ripped through here,

burning everything in its way.

If you'd come here the day after, it would've been just black.

So all this greenery that we're seeing now

coming out of the ground or sprouting out of the trees

-has happened since the fire?

-Absolutely.

You know, you can see some green within a week after the fire.

There are flowers, Tina!

Yes, and that's one of the features

that this plant uses to survive in this area.

You know, grow fast after a fire,

be one of the first flowers around

and you've got the best chance of being pollinated.

There's nothing else for insects to feed on here.

What form would it have been effectively dormant in?

What this plant uses is an underground tuber.

And just being a couple of centimetres below the ground

is enough to protect it from the heat.

The blue Dampiera is one of the smallest benefactors

from the fire in the forest.

And this is one of the biggest.

Oh, my goodness, what a magnificent tree.

-Isn't it?

-What is it?

This is a Sydney red gum,

one of the iconic trees for this area.

-I can see why it's called red gum.

-Yes, look at that!

Isn't that just beautiful?

Some damage has been done during the fire

and exposed the tissue underneath.

And it's almost acting like blood coagulating.

-It's...

-And clots, so it's like a scab almost?

-Yeah. Yes, yes, it is.

-To heal the tree.

-It is indeed.

And it's got its own antiseptic properties as well.

-Really?

-Yeah.

Isn't that amazing?

And the bark...?

-You can see here it's black. So it was burnt...

-Yeah.

-And since then it's fallen off.

-Yeah.

The heat was enough to kill that living tissue

and now it's fallen away.

And the tree underneath it is going to be healthy because it,

-what, this bit wasn't burnt?

-That's exactly right.

But whilst nature has adapted to tolerate fire,

certain species actually need fire to survive.

-This is a Banksia.

-A Banksia?

Yeah, so it's a common species around this area.

And what this is is its seed pod

and the seeds are protected from the fire in there.

Normally they're closed up and this is covered in fur

and it looks like a mouse with a bad hair day!

When the fire comes through it burns it off, it kills this branch,

and that's enough to open up these follicles here

and the seed can pop out.

If you look around you'll be able to find a seedling or so.

-There.

-That's the one there.

It's come straight from the parent tree onto the ground

and germinated.

So this whole species of plant

is totally dependent on fire to be able to regenerate?

Yes. Yes, that's the only way

we'll get new plants of this particular tree.

The ability of plants to evolve in this way provides

an astonishing illustration of just how fundamentally

wildfire and the Australian landscape are linked.

And in the same way that plants have developed ways of living with fire,

so the people who inhabit this land

must continually develop more sophisticated technology

to allow them to live with it, too.

As our time in New South Wales comes to an end

I'm keen to know what the future of fire-fighting holds.

To find out I'm meeting Professor Kevin Tolhurst,

from the University of Melbourne,

an expert in fire ecology and management,

who's spent his career studying fire behaviour.

He's created what could become

the future of wildfire prediction across the world.

It's known as Phoenix Rapidfire.

We've got a huge screen in front of us, but Kevin, can I ask,

what is Phoenix Rapidfire?

Phoenix Rapidfire is a computer programme

that predicts the spread and the nature of fire.

So for every point across the landscape

it'll tell you how high the flames are,

how fast the fire's moving,

how many embers are being produced,

and it gives you a spatial and temporal description of fire

across the landscape.

So you're able to predict

what I would think of as being unpredictable - a wildfire?

But fires aren't unpredictable,

fires still follow the laws of science.

So whether it's physics or chemistry that's involved in fire behaviour,

you just need to understand what those relationships are

and how they interact.

Is there a button you can press to start it up

so we can see what's going to happen?

Well, we can run the model.

So what we're seeing displayed here

is how the fire is spreading across the landscape.

To model a fire in real-time

all Kevin needs to do is enter the location of the fire

and the time it started.

The computer then cross-references this info with a live weather feed

and stored data about topography, fire history and vegetation

to map the fire.

So the computer has just churned the data

and now it's mapping it.

The different colours are showing the activity of the fire.

So the purple areas are showing

where the fire has self-extinguished, gone out.

Yellow/brown colours are showing the relative flame height.

What makes the model truly ground-breaking

is that it can also predict how fire will spread up to six hours ahead.

Because of the strong southerly wind,

a significant growth of the fire to the north.

Knowing that this is the potential of the fire,

you would then allocate your resources in such a way

to make sure that the area of greatest impact is prevented.

So this is important intelligence

or important information for planning by the fire agencies.

And if you can't stop it then it's really important

to make sure you advise the community

what they're likely to be impacted by

so that they can take appropriate action to defend themselves.

Phoenix Rapidfire is able to predict fire behaviour with 90% accuracy

and that accuracy means

that it's now being used at the Rural Fire Service HQ.

On the main central command board

is an ominous column entitled "Time to Impact."

This is the time that remains before a wildfire will hit a community.

As Kevin's model proves its worth here

it's gradually being introduced

in other wildfire-affected parts of the world.

With more and more houses being built on land prone to fires,

tools like this will help to protect them.

And there's another reason

why all of the fire-fighting technology we've seen in Australia

is becoming more vital.

There's a lot of concern in Australia

that our climate is changing.

Are you seeing any evidence of that in the fires that you study?

The climate change that we're seeing, really,

is accentuating the extremes of conditions.

And what we can see in modelling and fire behaviour

is it's the extreme conditions that drive these large fire events.

And because the frequency is increasing,

therefore we're seeing more severe fires.

And as a consequence of that we're going to basically find

that people will not only see a bushfire once in their lifetime,

they may see it two or three times in their lifetime.

So in the past we've been very quick

at trying to rebuild a neighbourhood, rebuild a house,

rebuild our lives in the same way as it was before

to say "We can overcome this. We can rule over nature."

But the reality is that

with increasing severity of weather and associated fires

that's going to be a folly.

So we actually need to be even better prepared for fire

because it's going to be a more regular occurrence.

With fires expected to grow fiercer

and the population of this fire-prone state

predicted to grow by another million before 2020,

the need to better understand wildfire

and how to control it

is ever more pressing.

As we've seen, scientists are working with fire-fighters

to make sure that everyone stays one step ahead of the flames.

Our time in Australia is over,

but the battle to protect this magnificent landscape,

and the people who live here, against those wildfires will go on.