Glossary

Adaptor

A fitting used to couple different sized hoses, hose of the same size with different threads, or different types of couplings, or to connect the male to male, or female to female parts of the same type of coupling.

Adsorption (as it relates to fuel)

The taking up of moisture during the cool, still, humid conditions of night.

Air attack

The direct use of aircraft in the suppression of bushfire.

Allocated resources

Resources working at an incident.

AMG

Australian Map Grid.

Anchor point

An advantageous location from which a fireline can be constructed. It is used to minimise the possibility of being outflanked by a fire while the line is being constructed.

Appliance

A firefighting vehicle, usually equipped with a pump and water supply.

Assets

Anything valued by people which includes houses, crops, forests and, in many cases, the environment.

Asset Protection zone

Using intensive fuel treatment, the Asset Protection Zone (APZ) aims to provide the highest level of localised protection to human life and property and key community assets. The goal of fuel treatment is to reduce radiant heat and ember attack in the event of a bushfire.

Back (heel or rear)

The section of the perimeter opposite to and usually upwind or down slope from the head of the fire.

Backburning

A fire ignited along the inner edge of a control line to consume the fuel in the path of a bushfire.

Backing fire

The part of a fire which is burning back against the wind, where the flame height and rate of spread is minimal.

Blacking out

See mopping up.

Branch

A device fitted to the end of a hose line to allow the water or other extinguishing medium travelling through the hose to form an effective firefighting spray or jet.

Breakaway

The points at which a fire, after it has been contained, escapes into unburnt areas across a fireline or fire edge.

Burning out

The deliberate burning of small patches of unburnt fuel within the fire perimeter. It can also mean burning small patches of unburnt fuel between the fire control line (constructed or natural)

Bush

A general term for forest or woodland, but normally used to describe indigenous forest.

Bushfire

An unplanned fire. A generic term which includes grass fires, forest fires and scrub fires.

Bushfire Moderation zone

This zone aims to reduce the speed and intensity of bushfires. This zone complements the APZ in that the use of planned burning in the BMZ is designed to protect nearby assets, particularly from ember spotting during a bushfire.

Bushfire Risk Engagement Area (BREA)

BREAs identify parts of the landscape where managing bushfire fuels is most effective in reducing risk. This helps to indicate the priority areas in our region where we can work with communities to reduce bushfire fuels.

Candle bark

Long streamers of bark that have peeled from some eucalypt species that form fire brands conducive to very long distance spotting.

Canopy cover/canopy density

The foliage cover from the crowns of the trees in a forest. It is usually expressed as a percentage of the area of ground covered.

Centrifugal pump

A pump using centrifugal force to increase the pressure of liquid. Centrifugal force causes the liquid to move along the vanes of an impeller thus acquiring kinetic energy. This is transformed into energy at the pump casing.

Chemical chain reaction

This is the fourth dimension of the fire tetrahedron. In the combustion process, a chemical chain reaction occurs between the fuel and oxygen and is promoted by heat.

Class A foam

A firefighting medium produced by adding Class A concentrate to water and passing it through a foam or spray nozzle.

Combustion

A chemical reaction between the vapours of a combustible material and oxygen. It releases heat, light and/or flames.

Contained

A fire is contained when its spread has been halted, but it may still be burning freely within the perimeter or the control lines.

Containment

Operations designed to restrict fire and stop it spreading to surrounding structures or areas.

Control line (fire line)

A natural or constructed barrier, or treated fire edge, used in fire suppression and prescribed burning to limit the spread of fire.

Controlled

The time at which the complete perimeter of the fire is secured and no breakaway is expected.

Convection column

The rising column of smoke, ash, burning embers and other matter generated by a fire.

Crew

The basic unit of a bushfire suppression force. It normally consists of two or more personnel.

Crown fire

A fire which burns in the tree tops ahead of and above an intense fire in the undergrowth. A fast travelling fire that is most destructive and usually consuming all available fuel in its path.

Dehydration

Excessive loss of water from the body’s tissues. Dehydration may follow any condition in which there is a rapid depletion of body fluids.

Delivery hose

Hose made of fabric in various diameters and used to transport water under pressure. Delivery hose may not be internally or externally lined with rubber or plastic.

Delivery valve

On a pump, the valved outlet through which water is discharged.

Desorption

The loss of moisture to the atmosphere from dead plant material.

Direct attack

A method of bushfire attack where wet or dry firefighting techniques are used. It involves suppression action right on the fire edge which becomes the control line.

Dozer

A crawler tractor fitted with a blade which can be transported to a fire on a tray truck or trailer.

Drip torch

A canister of flammable fuel fitted with a wand, a burner head and a fuel flow control device. It is used for lighting fires for prescribed burning and backburning.

Dry firefighting

The suppression of a fire without the use of water. This is normally achieved by removing the fuel by the use of hand tools or machinery.

Eastings

These are lines running north–south (top to bottom) on a map.

Elevated dead fuel

Dead fuel forming part of, or being suspended in, the shrub layer.

Energy

Source of power which may be released in forms such as heat, light and movement.

Escape route

A pre-planned route away from danger areas at a fire.

Evaporation

To change or cause to change from a liquid or solid state to a vapour.

Fine fuel

Grass, leaves, bark and twigs less than 6 mm in diameter.

Fingers

Narrow slivers of the advancing bushfire which extend beyond the head or flanks.

Fire behaviour

The manner in which a fire reacts to the variables of fuel, weather and topography.

Fire brand

A piece of burning material, commonly bark from eucalypts.

Fireground

The area in the vicinity of fire suppression operations, and the area immediately threatened by the fire.

Fire perimeter

The entire outer boundary of a fire area.

Fire retardant

A chemical generally mixed with water, designed to retard combustion. It is applied as a slurry from the ground or the air.

Fire spread

Development and travel of fire across surfaces.

Fire tetrahedron

An instructional aid in which the sides of the tetrahedron (comprising four triangular shaped figures) are used to represent the four components of the combustion and flame production process – fuel, heat, oxygen and the chemical chain reaction.

Fire triangle

A figure illustrating the three components necessary for a fire to burn and continue to burn – oxygen, heat and fuel.

Fire whirl

A spinning column of ascending hot air and gases rising from a fire and carrying aloft smoke, debris and flame. Fire whirls range in size from less than a metre in diameter to small tornados in intensity.

Firefighting vehicle

Any vehicle used by fire agencies to fight fires, regardless of its intended purpose.

Fireline

A natural or constructed barrier, or treated fire edge, used in fire suppression and prescribed burning to limit the spread of fire.

Flame height

The vertical distance between the tip of the flame and ground level, excluding higher flame flashes.

Flammable

Capable of burning with a flame

Flammable vapours

The vapours given off by solids and liquids that combine with oxygen and burn if ignited.

Flank attack

Attempting control of a fire by attacking its side (flanks).

Flanks of a fire

Those parts of a fire’s perimeter that are roughly parallel to the main direction of spread.

Foam – Class A

A firefighting medium produced by adding Class A concentrate to water and passing it through a foam or spray nozzle.

Forest fire

A fire burning mainly in forest and/or woodland.

Friction loss

Loss of water pressure during the passage of fluid through a pipe or hose. Loss due to friction depends on factors such as the length of the hose or pipe, its diameter, the rate of flow and the restrictions, such as corrosion in a pipe or the number of bends in a hose.

Fuel

Any material such as grass, leaf litter and live vegetation which can be ignited and sustains fire. Fuels can be categorised as fine or heavy.

Fuel management exclusion zones

See Planned burning exclusion zones

Fuel Management Zones

Areas of public land where fire is used for specific asset, fuel and overall forest and park management objectives.  They can also be applied to private and community land through a community process.

Fuel moisture content

The water content of a fuel particle expressed as a percent of the oven dry weight of the fuel particle (%ODW).

Fuel type

An identifiable association of fuel elements of distinctive species, form, size, arrangement or other characteristics that will cause predictable rate of spread or difficulty of control under

specified weather conditions.

Going fire

Any fire expanding in a certain direction or directions.

Grass fire

A fire in predominantly grass vegetation.

Grid north

The direction along the north–south grid lines on a map.

Ground fire

A fire burning in thick layers of humus and vegetation, found in forest or swampy ground or peat.

Hand crew

A fire suppression crew, trained and equipped to fight fire with hand tools.

Head of the fire

The part of the fire where the rate of spread, flame height and intensity are greatest, usually when burning downwind or up slope.

Heat cramps

Common muscular cramps that may occur in the heat, especially when an unfit person has worked hard and perspired a lot.

Heat exhaustion

A form of shock, due to depletion of body fluids resulting from over exposure to a hot environment.

Heat stress

Illness caused by the body overheating.

Heat stroke

A life-threatening condition that develops when the body’s temperature-regulating and cooling mechanisms are overwhelmed and body systems begin to fail.

Heavy fuels

Dead woody material, greater than 6 mm in diameter, in contact with the soil surface (fallen trees and branches).

Heel (back or rear)

The section of the perimeter opposite to and usually upwind or down slope from the head of

the fire.

Hose lay

The practice of running out firefighting hose to enable fire suppression by the application of water. May be conducted from a firefighting vehicle using hose bins and/or hose reels, or the act of bowling out a length of hose that is rolled up (hose on the bight).

Hot spots

Areas of burnt ground that are still hot and could re-ignite.

Ignition

The process of starting combustion.

Indirect attack

A fire control strategy where the fire is intended to be brought under control a considerable distance away from its current position, but within a defined area, bounded by existing or planned fire control lines. A common method of achieving this is by backburning.

Initial attack

The first suppression work on a fire.

Junction zone

An area of greatly increased fire intensity caused by two fire fronts (or flanks) burning towards one another.

Knock down

The rapid application and concentration of water or foam, intended to reduce fire intensity prior to manual follow-up action.

Ladder fuels

Fuels that provide vertical continuity between strata. Fire is able to carry surface fuels into the crowns of trees with relative ease.

Landscape Management zone

Within this zone, planned burning will be used for three broad aims:

  • bushfire protection outcomes by reducing the overall fuel and bushfire hazard in the landscape
  • ecological resilience through appropriate fire regimes
  • management of the land for particular values including forest regeneration and protection of water catchments at a landscape level.

Litter

The top layer of the forest floor composed of loose debris of dead sticks, branches, twigs, and recently fallen leaves and needles, little altered in structure by decomposition. (The litter layer of the forest floor.)

Magnetic north

The direction to the magnetic north i.e. the direction a compass points to. It moves around the true North Pole.

Map scale

The relationship between a unit of measurement on a map and the equivalent distance on the ground.

The scale of a map can be expressed in words (e.g. one centimetre equals one kilometre), graphically by the use of a linear scale or scale bar, and in numbers written as a ratio (e.g. 1:100,000) or as a representative fraction (e.g. 1/100,000).

Mineral earth

A term used to describe the ideal condition of a constructed firebreak, being completely free of any vegetation or other combustible material.

Mopping up (blacking out)

Making a fire safe after it has been controlled, by extinguishing or removing burning material along or near the fireline, felling stags, trenching logs to prevent rolling, and the like.

Northings

These are lines of a map running west–east (left to right) on a map.

Nozzle

A fitting at the end of a hose line used to control the volume of water and/or pattern of the discharge of water or extinguishing medium.

Objective

A goal statement of what is to be achieved.

Oxygen

Colourless, odourless gas, making up about one fifth of the air volume of the atmosphere. It is the supporter of combustion in the air.

Parallel attack

A method of suppression in which a fireline is constructed approximately parallel to and just far enough from the fire edge to enable firefighters and equipment to work effectively. The line may be shortened by cutting across unburnt fingers. The intervening strip of unburnt fuel is normally burnt out as the control line proceeds, but may be allowed to burn out unassisted where this occurs without undue delay or threat to the line.

Patrol

(a) To travel over a given route to prevent, detect and suppress a fire.

(b) To go back and forth vigilantly over the length of a control line during and/or after construction, to prevent breakaways, to control spot fires and extinguish overlooked hot spots.

(c) A person or group of persons who carry out patrol activities.

Perimeter

The entire outer boundary of a fire area.

Planned burning exclusion zones (also known as Fuel management exclusion zones)

This zone excludes the use of planned burning and other forms of fuel management primarily in areas intolerant to fire.

Point of origin

The area where the fire started.

Priming the pump

Removing air from a main pump casing and suction hose line so that atmospheric pressure can force water from a static water supply up the hose into the pump.

Rakehoe (McLeod tool)

A hand tool used for bushfire firefighting, consisting of a combination of a heavy rake and hoe.

Rate of spread

The forward progress per time unit of the head fire or another specified part of the fire perimeter. The key variables affecting rate of spread are the type, arrangement and quantity of fuel, the dead fuel moisture content,wind speed at the fire front, the width of the fire and the slope of the ground.

Rear (heel or back)

The section of the perimeter opposite to and usually upwind or down slope from the head of

the fire.

Relative humidity (% RH)

The amount of water vapour in a given volume of air, expressed as a percentage of the maximum water vapour the air can hold at that temperature.

Representative fraction

See map scale.

Retardant

Chemicals mixed with water to inhibit combustion.

Ribbon bark/Candle bark

Long streamers of bark that have peeled from some eucalypt species that form fire brands conducive to very long distance spotting.

Safe

The stage of fire suppression or prescribed burning when it is considered that no further suppression action or patrols are necessary.

Safety zone

An area cleared of flammable materials used for escape if the line is outflanked or in case a spot fire outside the control line renders the line unsafe. In fire operations, crews progress so as to maintain a safety zone close at hand, allowing the fuels inside the control line to be consumed before going ahead. Safety zones may also be constructed as integral parts of fuelbreaks.

They are greatly enlarged areas which can be used with relative safety by firefighters and their equipment in the event of a blow up in the vicinity.

Spot fire

Isolated fires started ahead of the main fire by sparks, embers or other ignited material, sometimes to a distance of several kilometres.

Spotting

The ignition of spot fires from sparks or embers.

Stag

A large, old tree either dead or with significant dead upper branches. Often hollow with an opening at ground level. Once alight, a stag represents a major hazard.

Standard operating procedures

A set of organisational directives that establish a standard course of action on the fireground to increase the effectiveness of the firefighting team. They are written, official, applied to all situations, enforced and integrated into the agency’s management of incidents.

Static water supply

A dam, lake, river, creek, pool or tank.

Strategy

A statement detailing how an objective is to be achieved.

Suction hose

Hose, made in various diameters, of reinforced rubber or plastic, used to draught water from a static supply i.e. ponds, dams, creeks, tanks or rivers.

Sunburn

Injury to the skin, including redness of the skin, tenderness, and sometimes blistering, following excessive exposure to unfiltered ultraviolet rays produced by sunlight.

Surface fire

A fire which travels just above ground surface in grass, low shrub, leaves and forest litter.

Tactics

The tasking of personnel and resources to implement the incident strategies

Task

A job given to any firefighting force or unit.

Topographical map

A map that shows contours, mountains, valleys, patterns of rivers and all other natural and manmade

features on the landscape.

Topography

The surface features of a particular area or region. It may include mountains, rivers, populated areas, roads, railways and vegetation.

Transmission lines

Overhead conductors generally supported by steel towers that may operate at extra high voltage (66,000 volts to 500,000 volts).

True north

The direction to the North Pole.

Volute

A part of the casing in a centrifugal pump, shaped like the shell of a snail where the water exits the pump.

Water hammer (shock)

The shock caused by opening and shutting off a hydrant, pump delivery or controlled branch too quickly.

Wetting agent

A chemical added in low concentration to water. It is used in firefighting to break down the surface tension of water and improve its penetration into fuels.