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Our unique laboratory is dedicated to the study and testing of fundamental bushfire dynamics. The objective is to derive accurate results that support the management of bushfires.

The National Bushfire Behaviour Research Laboratory at Black Mountain, Canberra.

The laboratory houses the CSIRO Bushfire Behaviour and Risks research team and is home to the CSIRO Pyrotron and the CSIRO Vertical Wind Tunnel (VWT).

The Pyrotron is a combustion wind tunnel designed to enable the safe and repeatable investigation of the mechanisms of flame propagation in bushfire fuels such as grass, forest litter and shrubs, under a range of burning conditions. This includes conditions such as those of an extreme fire danger day. Factors such as wind speed, fuel type and structure, fuel load and fuel moisture content can be precisely varied or strictly controlled.

The VWT is designed to study the combustion and aerodynamic characteristics of burning bark and other firebrands at their terminal velocity. Firebrands ignited in a bushfire are lofted in the fire’s plume and carried ahead by the wind where they fall to the ground and start spotfires. Such firebrands and subsequent spotfires are the main cause of bushfires escaping containment as well as house loss and damage.

The Pyrotron and VWT allows us to:

  • gain a better understanding of the physical processes involved in the behaviour and spread of bushfires under a range of conditions
  • utilise a range of scientific instrumentation to quantify specific physical attributes of the behaviour and spread of fires and firebrands, including IR thermography, turbulence, and thermal characteristics
  • explore the effects of a broad range of weather and fuel conditions on flame propagation, including those associated with extreme wildfires
  • develop better models of the influence of key parameters such as fuel moisture, wind speed and ignition configuration on fire behaviour to improve effectiveness and safety of firefighting
  • improve the design and execution of large-scale field experiments, particularly of specific instrumentation used for such experiments
  • develop a better understanding of likely emissions from bushfires in different fuel and burning conditions
  • develop better models of the fire spotting process through improved understanding of the aerodynamics and combustion characteristics of firebrands.

The Pyrotron and VWT facility were previously located at CSIRO’s Yarralumla site until they were moved in 2021 to the larger purpose-built laboratory at CSIRO Black Mountain. The VWT was first opened by CSIRO CEO Dr Malcolm McIntosh in 1997. The Pyrotron was first opened by Hon. Senator Kim Carr in 2008.

The bushfire lab is a CSIRO-owned national facility. It is available for use by arrangement by any external organisations to better understand fire behaviour and their impacts.

[Music plays and a split circle appears and photographs of various CSIRO activities are shown in either side and then the circle morphs into the CSIRO logo]

[Image changes to show the National Bushfire Behaviour Research Laboratory, and then the image changes to show a close view of the top of a tree]

[Image changes to show Dr Andrew Sullivan talking to the camera, and text appears: Dr Andrew Sullivan, Bushfire Behaviour and Risks Team Leader]

Dr Andrew Sullivan: Bushfires are a natural part of life in Australia

[Image changes to show a view looking down on an area of bushland]

but when fire weather becomes dangerous they can threaten homes, lives, and livelihoods.

[Images move through to show an aerial view looking down on the National Bushfire Behaviour Research Laboratory, a close view of a fire burning, and footage of firefighters at a fire]

At CSIRO we’ve studied bushfire behaviour for decades to assist firefighters to better prepare for, and respond to bushfire threats.

[Images move through to show an aerial view looking down on the Laboratory, the CSIRO sign on the Laboratory, an explanatory sign about the Laboratory, and digital bushfire simulations]

With climate change increasing the bushfire risks for people and the environment, this research has never been more important but it’s also extremely difficult.

[Images move through to show footage of a fire burning, a firefighter walking through the smoke, and then a close view looking down on the Laboratory, and text appears: National Bushfire Behaviour Research Laboratory]

Changing conditions in the field make it difficult to obtain detailed measurements and the mechanisms that drive bushfires.

[Image changes to show a view of the Laboratory]

So, we built a world class laboratory at the Black Mountain site of Australia’s National Science Agency.

[Images move through to show the Pyrotron, and then the Vertical Wind Tunnel inside the building, and text appears: The Pyrotron, Vertical Wind Tunnel]

It’s home to two unique apparatus, the Pyrotron, and the Vertical Wind Tunnel.

[Images move through of a male looking at a computer, graphs on the computer screen, the male’s hands on a computer mouse, and a side view of the male at work]

These tools allow us to investigate the effect of real world conditions on fire behaviour, from wind speed to fuels, and all the physics in between in a safe and repeatable manner.

[Image changes to show Andrew walking alongside the Pyrotron and pointing to the glass observation area and talking to the camera]

The Pyrotron is an aluminium steel fireproof combustion wind tunnel with a large glass observation area.

[Images move through of a “Bushfire Research” sign, a large fan, the glass observation area of the Pyrotron, and Andrew walking towards the Pyrotron and adjusting a lock on the side]

At one end is a large fan that provides the wind. The tunnel removes most of the turbulence so that the air that reaches the fire is consistent.

[Images move through to show a rear view of Andrew putting on a fireproof coat, and then the image changes to show Andrew talking to the camera and pointing to the fuel bed]

The fuel bed is where we conduct our experimental fires.

[Image changes to show Andrew arranging leaves and bark on the fuel bed, and the camera zooms in on his hands on the fuel bed, and then zooms out to show Andrew and a colleague touching the fuel]

We use natural bushfire fuels such as forest leaves, twigs, and bark

[Images move through to show a close view of the leaves, a hand touching a lighter to the leaves, the leaf litter beginning to catch alight, and a view looking down on the leaf litter alight]

but we can also use other fuels such as pine needles, grasses or shrubs because if we put the fuel bed as a key factor in the spread of a bushfire we know that all results must be tested in the field at the scale that the bushfires occur.

[Image changes to show Andrew pointing to the Vertical Wind Tunnel and talking to the camera]

Next to the Pyrotron we have the Vertical Wind Tunnel.

[Image changes to show a close facing view of Andrew talking to the camera]

This tunnel allows us to investigate the aerodynamic and combustion characteristics of bits of burning bark and debris called fire brands.

[Image changes to show a view of a bushfire at night, and then the image changes to show a fire brand blowing through the air]

In a real bushfire fire brands are the primary cause of spot fires

[Images move through to show a fire brand moving up the Vertical Wind Tunnel, Andrew talking to the camera, a close view of a fire brand, and then a fire brand moving along the Vertical Wind Tunnel]

The working section allows us to observe a fire brand at its terminal velocity, the speed that that fire brand rises and falls.

[Image shows a close view of hands holding a fire brand in a pair of tongs, and then letting it go in the Vertical Wind Tunnel, and the image shows the fire brand moving up the Vertical Wind Tunnel]

It’s terminal velocity will determine how high a fire brand may be lofted and how far it will travel.

[Image shows the fire brand moving in the Vertical Wind Tunnel]

As the fire brand burns it will lose mass and its terminal velocity will decrease meaning it will travel a greater distance from the original fire.

[Images move through of the fire brand moving up the Vertical Wind Tunnel, and then the image changes to show a fire brand being held in a pair of tongs, and then being let go]

However, we know that firebrand will only start a spot fire if it completes its journey while it’s still alight. Determining the maximum distance it can travel and remain alight is critical to know in how far spot fires could go during a bushfire.

[Image changes to show Andrew walking along next to the Pyrotron and talking to the camera, and then the image changes to show a close view of a burning fire brand over a gas burner

Both the Pyrotron and the Vertical Wind Tunnel gives us glimpses into the mechanisms by which one of our most dangerous natural phenomena propagates

[Images move through to show Andrew looking down, a close view of a gas burner, and then an aerial view looking down on a bushfire at night]

The research conducted in this laboratory will help firefighters better understand, predict and combat real bushfires.

[Music plays and the image changes to show the CSIRO logo on a white screen, and text appears: CSIRO, Australia’s National Science Agency]

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About the Pyrotron

This national research apparatus builds on over 60 years of experience CSIRO has with conducting large-scale field experiments for fire behaviour studies. It enhances research on bushfire behaviour by enabling observations of flame propagation and fire behaviour not possible in field experiments due to limited and uncontrollable burning conditions, reduced access, and safety concerns.

The Pyrotron is a 29-m-long combustion wind tunnel with 2 m × 2 m cross-section. It has a 7.2-m-long working section that provides for a 1.5-m-wide fuel bed for any surface fire fuels, such as forest litter, grasses or small shrubs. Fuels can be preconditioned in the large oven to approximate a wide range of fuel moisture contents. The large capacity centrifugal fan can generate air speeds at the fuel level of up to 20 km/h, equivalent to about 60 kilometres an hour in the open.

Using the Pyrotron at the National Bushfire Behaviour Research Laboratory at CSIRO Black Mountain, Canberra. February 2022

The Pyrotron allows us to gain a better understanding of the physical processes involved in the propagation of flames in bushfire fuels and their behaviour under a range of burning conditions. We conduct highly structured experiments with strong statistical bases that will assist us to develop better models of the factors that influence fire behaviour. This improves effectiveness and safety of fire-fighting. It also improves the design and operation of instrument packages intended for large-scale field experiments.

Selected publications

Since it was opened in 2008, publication of research conducted at the Pyrotron has helped build the nation's knowledge. A selection of research articles are provided below:

Features of the Pyrotron


Recent burns using the Pyrotron at the National Bushfire Behaviour Research Laboratory at CSIRO Black Mountain, Canberra. February 2022

  • 29 m long
  • 4 m² in cross section
  • Flame-proof aluminium and steel construction.


  • 2 tonne fan capable of moving 22 cubic metres of air a second
  • Variable wind speed of up to 5 metres per second, equivalent to ~60 kilometres per hour in the open if considered under a medium-tall eucalypt canopy
  • Computer controlled and programmable fan speed
  • Low turbulence intensity (<0.6%).

Plan schematic of the Pyrotron. Air flows left to right.

Fuel bed

  • 1.5 m wide by 7.2 m long
  • Insulated with flame-resistant ceramic tiles
  • Ethanol point or line ignition sources with electronic initiation
  • Toughened-glass viewing doors for observing the fire
  • Artificially illuminated, so that the fuel will be visible against the light from flames
  • Can hold fine surface fuels up to a load of 25-30 tonnes/ha, equivalent to a very long unburnt forest

  • Can accommodate different fuel types, such as small logs, shrubs, leaves, forest litter or grasses
  • Fuels can be artificially dried to replicate extreme burning conditions associated with wildfires.

Instrumentation and observations

  • A wide range of sensors in the working section ensure correct and accurate measurement
  • Data is captured by a high-speed multi-channel data acquisition system that provides real-time output of sensors to a multi-display system
  • Multiple high definition video cameras above and from the side of the Pyrotron, a high speed camera capable of shooting HD footage at 1000 frames per second, and a high resolution infra-red thermal imaging camera capture details of combustion.

Other details

  • Relies upon ambient temperature and humidity, meaning that experiments can be conducted on days of high heat and low humidity to observe fire behaviour in extreme conditions regardless of wind speed or fire danger.
  • Experiments last about 15 to 20 minutes, depending on fuel and burning conditions and generally yield about as much smoke as a wood-fired backyard barbecue.

About the Vertical Wind Tunnel (VWT)

The VWT is a 10.7 m-tall apparatus designed to allow the study of untethered burning firebrands falling in an air stream at their terminal velocity.

Firebrands are any bits of bark or other vegetation debris that are ignited in a bushfire, lofted in the fire’s plume, and carried ahead by the wind to start spotfires downwind of the originating fire. Firebrands, embers and the spotfires they start are the main cause of escape of bushfires from containment and the damage and loss of houses in a bushfire. Spotfires also enable a bushfire to cross significant breaks in topography and fuel such as roads and rivers.

For a given set of burning conditions and behaviour of an originating fire, the distance that a viable firebrand (one that can start a spotfire) may be lofted and carried downwind depends on its mass, area and aerodynamics which vary as the firebrand combusts and its terminal velocity (the speed with which it falls through the air) changes. Understanding the change in terminal velocity of a firebrand as it combusts at its terminal velocity is essential to accurately determining the potential distance that a firebrand may travel. The duration which a firebrand remains viable, and the ignition potential of the fuel in which the firebrand lands, are critical to determining the probability that the firebrand will start a spotfire.

The Vertical Wind Tunnel (VWT) at the National Bushfire Behaviour Research Laboratory at CSIRO Black Mountain, Canberra

Selected publications

Features of the VWT


  • 10 m long, 10.7 m tall; minimum path length is 18.1 m
  • Diverging 4.25 m long working cross-section, from 0.77 × 0.77 m at its base to 1.0 × 1.0 m at the exit
  • A 90° turning section consisting of vanes with a radius of curvature of 350 mm and chord length of 500 mm
  • Large observation windows allow visual and video recording of firebrand characteristics
  • A non-axially-symmetric Borger-profile contractor section is fabricated from laminated 3‑mm high density particle board coated in fibreglass.


Schematic plan of Vertical Wind Tunnel (VWT)

  • 1.25 tonne fan capable of moving 11 cubic metres of air per second
  • Variable air speeds up to 20 metres per second using variable fan speed controller
  • Divergent working section creates velocity gradient at a fixed fan speed
  • Low turbulence intensity (<0.5%)
  • Screens can be fitted to modify air flow within working section to facilitate firebrand flight.


  • Broad range of firebrand materials can be studied, including bark, seed pods, twigs, etc
  • Firebrands up to 150 mm in length can be studied untethered (i.e. in free-fall)
  • Firebrands up to 300 mm in length can be studied tethered (i.e. attached at one end).

Read more

Summaries of critical new research results from CSIRO’s Bushfire Behaviour and Risks team are regularly updated at CSIRO’s PyroPage.

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