| Glossary of Rural Fire Terminology
March 1996
AUSTRALASIAN FIRE
AUTHORITIES COUNCIL
GLOSSARY OF RURAL FIRE
TERMINOLOGY
TERMINOLOGY DEFINITION
Adaptor A fitting used to couple different
sized hoses, hoses
of the same size with different threads, or
different
types of couplings.
Adsorption The taking in of water vapour
from the air by dead
plant material.
Advance Burn A prescribed fire that
reduces fuel through a forest
area before felling operations. It is intended
to
improve the safety of timber harvesting
operations
and as a silvicultural tool to protect
lignotubers and
standing trees.
Aerial Detection The discovering, locating
and reporting of fires from
aircraft.
Aerial Fuels The standing and supporting
combustibles not in
direct contact with the ground and consisting
mainly
of foliage, twigs, branches, stems, bark and
creepers.
Aerial Ignition The igniting of fine fuels
for prescribed purposes by
dropping incendiary devices or materials from
aircraft.
Aerial Observer A person specifically
assigned to discover, locate,
and report fires from an aircraft, and to
observe and
describe conditions at a fire scene.
Aerial Reconnaissance
The use of aircraft for observing fire
behaviour, the
threat to values, control activity, and other
critical
factors to facilitate command decisions on
strategies needed for suppression.
Agency Representative
An individual allocated to an incident
from an
assisting agency who has been delegated full
authority to make decisions on all matters
affecting
that agencys participation at the
incident.
Air Attack The direct use of aircraft in
the suppression of
wildfire.
Allocated Resources Resources working
at an incident.
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.
Anemometer A meteorological instrument
used to measure wind
speed.
Anti Cyclone (High) An area of relatively
high atmospheric pressure. In
the southern hemisphere, pressure gradients
and
the earths rotation will cause air to
move in an anticlockwise
direction around the anti-cyclone.
Aspect The direction towards which a slope
faces.
Assembly Area An area where resources are
organised and
prepared for deployment. It includes the
provision
of welfare and equipment maintenance
facilities.
Assisting Agency An agency directly
contributing suppression,
support or service resources to another
agency.
Atmospheric Stability
The degree to which the atmosphere resists
turbulence and vertical motion.
Automatic Dispatch See Pre Planned
Dispatch.
Available Fuel The portion of the total
fuel that would actually burn
under various specified conditions.
Available Resources The resources at an
incident and available for
allocation at short notice.
Back See Rear.
Backburning A fire started intentionally
along the inner edge of a
fireline to consume the fuel in the path of a
wildfire.
Backing Fire The part of a fire which is
burning back against the
wind, where the flame height and rate of
spread is
minimal.
Barometer A meteorological instrument
used to measure
atmospheric air pressure. Expressed in
hectopascals.
Beaufort Wind Scale A system of estimating
and reporting wind speeds
that originated in the nineteenth century for
marine
applications. In its present form for
international
meteorological use it equates:
· Beaufort force (or Beaufort number)
· wind speed
· descriptive term
· visible effects upon land objects or sea
surface.
Blacking Out See Mopping Up.
Blow Up A sudden increase in fire
intensity and rate of
spread, sufficient to preclude immediate
control, or
to upset existing suppression plans. It is
often
accompanied by powerful convection.
Bole Damage The damage to the trunk of a
living tree by fire,
mechanical equipment or disease.
Branch An attachment fitted to the end of
a hose to speed
up the water to form an effective jet or spray
pattern.
Breakaway The points at which a fire,
after it has been
contained, escapes into unburnt areas across a
fireline or fire edge.
Brigade A unit of personnel including
officers, crews and sub
brigades.
Broadcast Burning See Prescribed Burning.
Buffer A strip or block of land on which
the fuels are
reduced to provide protection to surrounding
lands.
Bulk Water Carrier A large tanker used for
replenishing water to
firefighting tankers.
Burn Plan The plan which is approved
for the conduct of
prescribed burning. It contains a map
identifying
the area to be burnt and incorporates the
specifications and conditions under which the
operation is to be conducted.
Burning Out Intentionally lit fires to
consume islands of unburnt
fuel inside the fire perimeter.
Burning Program All the prescribed burns
scheduled for a designated
area over a nominated period of time.
Burning Rotation The period between
reburning of a prescribed area
for management purposes.
Burning Unit A specified land area for
which prescribed burning
is planned.
Bush A general term for forest or
woodland, but normally
used to describe indigenous forest.
Bush Fire A general term used to describe
a fire in vegetation.
Byram-Keetch Drought
Index (BKDI)
A numerical value reflecting the dryness
of soils,
deep forest litter, logs and living
vegetation, and
expressed as a scale from 0 - 200.
Campaign Fire A fire normally of a size
and/or complexity that
requires substantial firefighting resources,
and
possibly several days or weeks to suppress.
Candle A tree (or small clump of trees) is
said to candle
when its foliage ignites and flares up,
usually from
the bottom to top.
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 on
the area of ground covered.
Central Ignition A method of prescribed
burning in which fires are
set in the centre of an area to create a
strong
convective column. Additional fires are then
set
progressively closer to the outer control
lines
causing indraft winds to build up. This has
the
effect of drawing the fires towards the
centre.
Class A Foam See Foam.
Cloud Cover The amount of sky covered or
obscured by cloud,
expressed in eighths. Eight eighths is
complete
cloud cover.
Coarse Fuels Dead woody material, greater
than 25mm in
diameter, in contact with the soil surface
(fallen
trees and branches).
Combatant Agency/Authority
The agency, service, organisation or
authority with
the legislative authority for the control of
the
incident.
Combustion Consumption of fuels by
oxidation, giving out heat,
and generally flame and/or incandescence.
Command The direction of members and
resources of an
agency in the performance of the agencys
role and
tasks. Authority to command is established in
legislation or by agreement within an agency.
Command relates to agencies and operates
vertically within an agency.
Compartment The basic administrative unit
of a forest.
Contained A fire is contained when its
spread has been halted,
but it may still be burning freely within the
perimeter
or fire control lines.
Control The overall direction of
response activities in an
emergency situation. Authority for control is
established in legislation or in an emergency
response plan, and carries with it the
responsibility
for tasking and coordinating other agencies in
accordance with the needs of the situation.
Control
relates to situations and operates
horizontally
across agencies.
Control Line See Fireline.
Controlled The time at which the complete
perimeter of a fire is
secured and no breakaway is expected.
Controlled Burning See Prescribed Burning.
Convection Column The rising column of
smoke, ash, burning embers
and other matter generated by a fire.
Coordination The bringing together of
agencies and elements to
ensure effective response to an incident or
emergency. It is primarily concerned with the
systematic acquisition and application of
resources
(agency, manpower, and equipment) in
accordance
with the requirements imposed by the emergency
or
emergencies. Coordination relates primarily to
resources and operates:
· vertically, within an agency, as a function
of the
authority to command;
· horizontally, across agencies, as a
function of the
authority to control.
Coupe A defined forest area in which
timber harvesting
takes place.
Crew The basic unit of a wildfire
suppression force. It
normally consists of five to ten personnel.
Crown Fire A fire burning in the crowns of
trees and usually
supported by fire in ground fuels. It is a
fast
travelling fire that usually consumes all
available
fuels in its path.
Crown Scorch Browning of the needles or
leaves in the crown of a
tree or shrub caused by heat from a fire.
Dead Fuels Fuels having no living tissue.
The moisture content
is governed almost entirely by atmospheric
moisture
(relative humidity and precipitation), air
temperature, and solar radiation.
Desorption The loss of moisture to the
atmosphere from dead
plant material.
Detection The discovery of a fire.
Individuals, fire towers,
reconnaissance aircraft and automatic devices
may
be used, either alone or in combination.
Dew The moisture which collects in small
droplets on the
surface of substances and vegetation by
atmospheric condensation, chiefly at night.
Die Back The progressive dying, from the
top downward, of
twigs, branches or tree crowns.
Direct Attack A method of fire attack
where wet or dry firefighting
techniques are used. It involves suppression
action
right on the fire edge which then becomes the
fireline.
Dispatch The act of ordering attack crews
and/or support
units to respond to a fire, or from one place
to
another.
Division A portion of the fire perimeter
comprising of two or
more sectors. The number of sectors grouped in
a
Division should be such as to ensure effective
direction and control of operations. Divisions
are
generally identified by a local geographic
name.
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.
Drought Index A numerical value, such as
the Byram-Keetch
Drought Index, reflecting the dryness of
soils, deep
forest litter, logs and living vegetation.
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.
Duff The mat of undecomposed or partly
decomposed
vegetation matter on the forest floor, the
original
vegetative structures still being
recognisable.
Ecosystem The interacting system of a
biological community,
both plant and animal, and its non living
surroundings.
Edge Burning A term used to describe
perimeter burning of an
area in mild conditions prior to large scale
prescribed burning. This practice is used to
strengthen buffers and to reduce mop-up
operations.
Elevated Dead Fuel Dead fuel forming part
of, or being suspended in,
the shrub layer.
Emergency Operations
Centre
A facility where the coordination of the
response
and support to the incident is provided.
Escape Route A pre-planned route away from
danger areas at a fire.
Extreme Fire Behaviour
A level of wildfire behaviour
characteristics that
ordinarily precludes methods of direct
suppression
action. One or more of the following is
usually
involved:
· high rates of spread
· prolific crowning and/or spotting
· presence of fire whirls
· a strong convective column
Predicability is difficult because such fires
often
exercise some degree of influence on their
environment and behave erratically, sometimes
dangerously.
Extreme Fire Danger The highest fire
danger classification.
Fall Back Fire Control
Line
Any fire control line which is at a
distance from the
fire perimeter, and is the second control line
at
which the fire perimeter may be stopped should
it
cross the first fire control line.
Field Control Point A selected location at
or near a fire which provides
coordination, control and communication for
the
sectors at the fireground.
Fine Fuel Grass, leaves, bark and twigs
less than 6mm in
diameter.
Fingers Long and narrow slivers of fire
which extend beyond
the head or flanks.
Fire The chemical reaction between fuel,
oxygen and
heat. Heat is necessary to start the reaction
and
once ignited, fire produces its own heat and
becomes self-supporting.
Fire Access Track A track constructed
and/or maintained expressly for
fire management purposes.
Fire Behaviour The manner in which a fire
reacts to the variables of
fuel, weather and topography.
Fire Bombing A technique of suppressing a
wildfire by dropping
water, foam or retardants on it from an
aircraft.
Fire Brand A piece of burning material,
commonly bark from
eucalypts.
Fire Break Any natural or constructed
discontinuity in a fuel
bed used to segregate, stop, and control the
spread
of a wildfire, or to provide a fireline from
which to
suppress a fire.
Fire Control See Fire Suppression.
Fire Control Line See Fireline.
Fire Crew A general term for two or more
firefighters organised
to work as a unit.
Fire Danger The combination of all factors
which determine
whether fires start, spread and do damage, and
whether and to what extent they can be
controlled.
Fire Danger Index (FDI)/Fire Danger Rating
A relative number denoting an evaluation
of rate of
spread, or suppression difficulty for specific
combinations of fuel, fuel moisture and wind
speed.
Fire Edge Any part of the boundary of a
fire at a given time.
NOTE: The entire boundary is termed the
"fire
perimeter".
Fire Effects The physical, biological and
ecological impact of fire
on the environment.
Fire Hazard Any fuel which if ignited, may
be difficult to
extinguish.
Fire Hazardous Areas
An area where the combination of
vegetation,
topography, weather, and the threat of fire to
life
and property create difficult and dangerous
problems.
Fire Intensity See Fireline Intensity.
Fire Management All activities associated
with the management of
fire-prone land, including the use of fire to
meet land
management goals and objectives.
Fire Perimeter The entire outer
boundary of a fire area.
Fire Prevention All activities associated
with minimising the
incidence of wildfire, particularly those of
human
origin.
Fire Progress Map A map providing
information on a fire, detailing the
location of its perimeter, deployment of
suppression
forces, and the progress of suppression
activities.
Fire Protection All activities designed to
protect an area (including
human life, property, assets and values) from
damage by fire.
Fire Regime The history of fire use in a
particular vegetation type
or area including the frequency, intensity and
season of burning. It may also include
proposals for
the use of fire in a given area.
Fire Report See Report of Fire
NOTE: Not to be confused with a written
report
completed after the fire for administrative
purposes.
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 Risk Processes, occurrences or
actions that increase the
likelihood of fires occurring.
Fire Run A rapid advance of a fire front.
It is characterised by
a marked transition in intensity and rate of
spread.
Fire Scar 1) A healing or healed-over
injury caused or
aggravated by fire on a woody plant.
2) A destructive mark left on a landscape by
fire.
Fire Season The period (s) of the year
during which fires are
likely to occur, spread and do sufficient
damage to
warrant organised fire control.
Fire Storm Violent convection caused by
a large continuous
area of intense fire; often characterised by
destructively violent surface indrafts, a
towering
convection column, long distance spotting, and
sometimes by tornado-like whirlwinds
Fire Suppression Organisation
The management structure, usually shown in
the
form of an organisation chart, of the
personnel
collectively assigned to the suppression of a
fire.
Fire Suppression Plan
See Incident Action Plan.
Fire Threat The impact a fire will have on
a community.
Fire Trap Any location or situation in
which it is highly
dangerous to implement fire suppression
activities.
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.
Fire Wind The inflow of air at the fire
source caused by the
action of convection. It is not to be confused
with a
prevailing wind.
Fireline A natural or constructed barrier,
or treated fire edge,
used in fire suppression and prescribed
burning to
limit the spread of fire.
Fireline Intensity The rate of energy
release per unit length of fire
front.
Fireline Sector A defined section of the
fireline being constructed
and/or used to contain or control a wildfire,
or being
constructed as a backup to other lines being
used to
control a wildfire.
Flame Angle The angle of the flame in
relation to the ground,
caused by wind direction or the effect of a
slope.
Flame Height The vertical distance
between the tip of the flame
and ground level, excluding higher flame
flashes.
Flammability The ease with which a
substance is set on fire.
Flank Attack Obtaining control of a fire
by attacking its side/s
(flank).
Flanks/Flanks Of A Fire
Those parts of a fires perimeter
that are roughly
parallel to the main direction of spread.
Flareup Any sudden acceleration of fire
spread, or
intensification of fire, or a part of the
fire. A flare up
is of relatively short duration and does not
radically
change existing control plans.
Flash Fire A fast moving fire consuming
most of the fine fuels
available.
Foam (Class A) A chemical concentrate
added to water that
combines foaming and wetting agents
specifically
formulated for extinguishing wildfires. The
foam is
biodegradable, non toxic and is used at very
low
concentrates.
Forest An area of land thickly covered
with an ecosystem
of trees and bushes.
Forest Fire A fire burning mainly in
forest and/or woodland.
Forest Type An description of the
predominant tree species in a
forest.
Forward Control Point
An area used as a location for
administration and
command by operations personnel combating a
fire.
Front See Head.
Front End Loader Earthmoving equipment
designed to move loose
earth and/or loads into vehicles. A
multi-purpose
bucket is fitted to articulated arms at the
front of the
vehicle. May be either wheeled or tracked.
Fuel Any material such as grass, leaf
litter and live
vegetation which can be ignited and sustains a
fire.
Fuel is usually measured in tonnes per
hectare.
Fuel Age The period of time lapsed since
the fuel was last
burnt.
Fuel Arrangement A general term referring
to the spacing and
arrangement of fuel in a given area.
Fuel Assessment The means of calculating
total and available fuel
present in a given area.
Fuel Break See Fire Break.
Fuel Load The oven dry weight of fuel per
unit area.
Commonly expressed as tonnes per hectare.
Fuel Management Modification of fuels by
prescribed burning, or other
means.
Fuel Modification Any manipulation
(including lopping, chipping,
crushing, mowing, piling, and burning) of
fuels for
the purpose of reducing their flammability.
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 Moisture Differential
A term used to describe the situation
where the
difference in the moisture content between
fuels on
adjacent areas results in noticeably different
fire
behaviour on each area.
Fuel Plan A plan showing areas of varying
fuel quantities and
types and usually indicates past fire history.
Fuel Profile The vertical cross section of
a fuel bed down to
mineral earth.
Fuel Quantity See Fuel Load.
Fuel Separation The action of
separating fuel for the purpose of
providing a mineral earth firebreak.
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.
Fuel Weight The oven dry weight of fuel
per unit area is usually
expressed in tonnes per hectare.
Going Fire Any fire expanding in a certain
direction or
directions.
Grass Fire A fire in predominantly grass
vegetation.
Grid Ignition A method of lighting
prescribed fires where ignition
points are set individually at a predetermined
spacing through an area.
Ground Crew See Hand Crew.
Ground Fire A fire burning in thick layers
of humus and
vegetation, found in forest or swampy ground
or
peat.
Habitat The place in which an animal or
plant lives.
Hand Crew A fire suppression crew, trained
and equipped to
fight fire with hand tools.
Hand Line A fireline constructed with hand
tools. Normally, it
is a narrow line constructed through country
too
rough or environmentally sensitive for the use
of
machines.
Hand Trail See Hand Line.
Hardwood A conventional term used to
describe a tree, or the
timber of a tree, belonging to the botanical
group of
flowering plants, such as red gum and jarrah.
Hazard See Fire Hazard.
Head See Head Fire.
Head Fire The part of a fire where the
rate of spread, flame
height and intensity are greatest, usually
when
burning downwind or upslope.
Heavy Fuels See Coarse Fuels.
Heavy Tanker See Tanker.
Heel See Rear.
Heel Fire See Backing Fire.
Heli Torch A machine slung underneath a
helicopter that drips
ignited, gelled petroleum and is used to
ignite
burns.
Hop Over See Breakaway.
Hose Bandage A means of affecting a
temporary repair to a canvas
or synthetic hose.
Hose Strangler A crimping device for
stopping the flow of water in a
hose.
Hot Spot A particularly active part of a
fire.
Hygrometer A meteorological instrument
used to measure
relative humidity.
Incident An event, accidentally or
deliberately caused, which
requires a response from one or more of the
statutory emergency response agencies.
Incident Action Plan A statement of
objectives and strategies to be taken
to control or suppress an incident, and
approved by
the Incident Controller.
Incident Control Centre
The location where the Incident Controller
and,
where established, members of the Incident
Management Team provide overall direction of
response activities in an emergency situation.
Incident Control System (ICS)
A command structure to systematically and
logically
manage suppression of emergency incidents
including wildfires, from small, simple
incidents to
large, difficult or multiple situations. It is
designed
to develop in modular fashion from the top
(Incident
Controller) downwards.
Incident Controller The individual
responsible for the management of
all incident operations.
Incident Management
Team
The group of incident management personnel
comprising the Incident Controller, and the
personnel he or she appoints to be responsible
for
the functions of Operations, Planning and
Logistics.
Indirect Attack The use of backburning as
a method of suppression
to confine the fire within a defined area
bounded by
existing or prepared control lines. Control
lines may
be a considerable distance ahead of the fire.
Induced Wind See Fire Wind.
Initial Attack The first suppression work
on a fire.
Instability See Atmospheric Stability.
Inversion A layer of the atmosphere in
which temperature
increases with increasing elevation. A
condition of
strong atmospheric stability.
Island An unburnt area within a fire
perimeter.
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.
Light Fuel An assessment of fuel quantity
indicating a low
weight.
Light Patrol Unit See Tanker.
Light Tanker See Tanker.
Lighting Formation See Lighting Pattern.
Lighting Pattern The lighting pattern
adopted by firelighters during
prescribed burning operations, or indirect
attack.
Lightning Fire A fire caused by lightning.
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).
Living Fuels Fuels made up of living
vegetation.
Logistics Provides facilities, services
and materials in support
of the incident.
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 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.
Needle Bed A fuel bed consisting mainly of
pine needles.
Objective A goal statement of what is
to be achieved.
Objective Strategy See Strategy.
Operations Officer The Officer responsible
for directing and
supervising all work on the fire ground under
the
direction of the Incident Controller.
Oven Dry Weight A technique used to
measure the weight of wood or
other cellular material which has been dried
in an
oven at
105° C until it ceases to lose moisture.
Parallel Attack A method of suppression in
which 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.
Parallel Fire Suppression
See Parallel Attack.
Parallel Method See Parallel Attack.
Patch Burning Prescribed burning for the
purpose of forming a
barrier to subsequent burning or for
conservation
management.
Patrol 1) To travel over a given route to
prevent, detect
and suppress a fire.
2) 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.
3) A person or group of persons who carry out
patrol activities.
Perimeter See Fire Perimeter.
Plan Of Attack See Incident Action
Plan.
Planned Burning See Prescribed Burning.
Pocket See Island.
Pre Planned Dispatch
The pre-planned dispatch of designated
suppression forces to fires in predetermined
zones.
It is usually dependent on the location of the
fire,
and the forecast fire danger.
Predicted Rate Of Spread
See Rate of Spread.
Preparedness 1) The degree to which an
agency is prepared to
respond to a potential fire situation.
2) A mental readiness to recognise changes in
fire
danger and to act promptly when action is
appropriate.
Prescribed Burn Plan See Burn Plan.
Prescribed Burning The controlled
application of fire under specified
environmental conditions to a predetermined
area
and at the time, intensity, and rate of spread
required to attain planned resource management
objectives.
Prescribed Fire See Prescribed Burning.
Prescription A written statement defining
the objectives to be
attained during prescribed burning. This
statement
considers the condition of temperature,
humidity,
wind direction and speed, fuel moisture, and
soil
moisture under which the fire will be allowed
to
burn. This is generally described within
acceptable
ranges of the various indices, and the limit
of the
geographic area to be covered.
Prevention See Fire Prevention.
Profile Moisture Content
See Fuel Moisture Content.
Pulsation See Flareup.
Pumper A firefighting vehicle equipped
with a large capacity
pump, water tank and hose. Generally intended
to
be operated when stationary, from reticulated
or
static water supplies.
Quick-Fill Pump A high volume water pump
used for filling tankers.
Rate Of Spread The forward progress per
unit time of the head fire
or another specified part of the fire
perimeter.
Reaction Time The time taken between the
report of a fire or
incident, and the departure of the crew. See
also
Response Time.
Readiness See Preparedness.
Rear The section of the perimeter opposite
to and
generally upwind (or downslope), from the head
of
the fire.
Reburn Burning of an area over which a
fire has previously
passed but left fuel which can be ignited.
Reconnaissance Inspection of a fire area
for the purpose of obtaining
information about current and probable fire
behaviour and fire suppression information.
Relative Humidity (RH)
The amount of water vapour in a given
volume of
air, expressed as a percentage of the maximum
amount of water vapour the air can hold at
that
temperature.
Relief Crew The replacement of personnel
whose period of time
at the incident has concluded.
Report Of Fire The notification of the
detection of a fire to the fire
service.
Resources All personnel and equipment
available, or
potentially available, for incident tasks.
Response Time The time taken between
the report of a fire or
incident, and arrival at the scene. It
includes both
reaction time and travel time.
Responsible Authority
See Combatant Authority.
Retardant Chemicals mixed with water to
inhibit combustion.
Risk See Fire Risk.
Safe The stage of fire suppression or
prescribed burning
when it is considered that no further
suppression
action or patrols are necessary.
Scorch Height The height above ground
level up to which foliage
has been browned by a fire.
Scout A person who checks and reports on
conditions in
the fire area.
Scrub Refers to vegetation such as heath,
wiregrass and
shrubs, which grows either as an understorey
or by
itself in the absence of a tree canopy.
Scrub Fire Fires burning in scrub.
Secondary Fire Control
Line
See Fall Back Fire Control Line.
Sector A specific area of a fire which is
under the control of
a Sector Commander who is supervising a number
of crews.
Seen Area The ground, or vegetation, that
is directly visible
from an established or proposed lookout point,
or
aerial detection flight route.
Situation Report
(SitRep)
Brief situation report of fire, usually given
at regular
intervals.
Slash Unusual concentrations of fuel
resulting from such
natural events as wind, fire, snow breakage,
or from
such human activities as logging, cutting or
road
construction.
Slash Burn A prescribed burn conducted to
consume slash for
fire hazard reduction or silvicultural
purposes.
Sleeper A fire that starts up again after
appearing to have
been extinguished.
Slip On Tanker See Tanker.
Slip On Unit See Tanker.
Smoker An isolated small burning item such
as a log, stump
or tree, in an area of fire otherwise mopped
up.
Softwood A conventional term used to
describe a tree, and
the timber of trees, belonging to the group of
plants
with cones, such as pine and cypress.
Soil Dryness Index See Drought Index.
Span Of Control A concept which relates to
the number of groups or
individuals controlled by one person. A ratio
of 1:5
is recommended.
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.
Staging Area A location close to the
incident where personnel
and equipment are available.
Stand By The period during which
personnel are to be
immediately available at home or other
location for
fire suppression purposes.
Stevenson Screen A white painted timber
box with louvred walls,
designed to give standardised conditions of
ventilation to weather recording instruments,
commonly thermometers.
Strategy A statement detailing how an
objective is to be
achieved.
Strike Team A set number of resources of
the same type that
have an established minimum number of
personnel.
Strike Teams always have a leader (usually in
a
separate vehicle), and have a common
communications system. Strike Teams are
usually
made up of five resources of the same type,
such as
· vehicles
· crews
· earth moving machinery.
Strip Burning Setting fire to a narrow
strip of fuel adjacent to a
fireline and then burning successively wider
adjacent strips as the preceding strip burns
out.
Strip Ignition See Strip Burning.
Stripping See Strip Burning.
Structure Fire A fire burning part, or all
of any building, shelter, or
other construction.
Supporting Agency An agency, service,
organisation or authority
providing assistance to the combatant
authority.
Surface Fire A fire which travels just
above ground surface in
grass, low shrub, leaves and litter.
Surface Fuel The loose surface litter
on the forest floor, normally
consisting of fallen leaves or needles, twigs,
bark,
cones and small branches that have not yet
decayed sufficiently to lose their identity.
Also
grasses, shrubs and tree reproduction less
than one
metre in height, heavier branchwood, down
logs,
stumps, seedlings and forbs (simple plant
structures) interspersed with or partially
replacing
the litter.
Tactics The tasking of personnel and
resources to
implement the incident strategies. Incident
control
tactics are accomplished in accordance with
appropriate agency procedures and safety
directives. Tactics are normally determined at
Division/Sector level with a corresponding
allocation
of resources and personnel.
Tail Fire See Backing Fire.
Tanker A mobile firefighting vehicle
equipped with a water
tank, pump, and the necessary equipment for
spraying water and/or foam on wildfires. Can
be
designated as follows:
· Heavy Tanker - a firefighting unit often on
a 4 x 4
chassis with a large water tank (over 2000
litres),
a pump, a number of lengths of hose and a
range
of equipment to assist with wildfire
suppression.
· Light Patrol Unit - a vehicle equipped with
a small
tank and pump designed for rapid initial
attack
and the patrol of fires.
· Light Tanker - a firefighting unit often on
a 4 x 4
tray body vehicle with a small water tank (400
-
650 litres), a pump and short length of hose.
· Slip on Tanker - a tank, a live hose reel
or tray,
an auxiliary pump, and an engine combined into
a single one-piece assembly that can be
slipped
onto a truck bed or trailer.
Task A job given to any firefighting force
or unit.
Task Force A combination of resources
assembled for a specific
purpose. Task Forces always have a leader
(usually in a separate vehicle), and have a
common
communications system. Task Forces are
established to meet tactical needs and may be
demobilised as single resources.
Temperature (Dry Bulb)
The ambient air temperature recorded by an
exposed thermometer.
Temperature (Wet Bulb)
Wet bulb temperature is measured by
placing a
moist, single-layer, muslin sleeve over the
bulb of a
dry bulb thermometer. The difference between
dry
and wet bulb readings is used to determine
relative
humidity and dewpoint values.
Test Fire A controlled fire ignited to
evaluate fire behaviour.
Thermal Imagery A display or print out
from an infra-red scanning
device.
Thermohygrograph An instrument that
simultaneously and continuously
measures and records temperature and relative
humidity, normally by tracing each onto a
revolving
chart. Charts can be either cater for one day
or one
week of continuous recording.
Tongues See Fingers.
Topography The surface features of a
particular area or region.
It may include mountains, rivers, populated
areas,
roads and railways and fuel types.
Tops Disposal
Burning
The burning of forest debris resulting from
harvesting operations.
Travel Time The time taken between the
departure of a crew,
and arrival at the scene of a fire or
incident. See
also Response Time.
Under Storey The lowest stratum of a
multi-storeyed forest.
Urban/Rural Interface The line, area,
or zone where structures and other
human development adjoin or overlaps with
undeveloped bushland.
Values At Risk The natural resources or
improvements that may be
jeopardised if a fire occurs.
Water Point Any natural or constructed
supply of water that is
readily available for fire control operations.
Water Tank A container capable of storing
a large volume of
water.
Wetting Agent A chemical added in low
concentration to water. It is
used in firefighting to break down the surface
tension of the water and to improve its
penetration
into fuels.
Wildfire An unplanned fire. A generic term
which includes
grass fires, forest fires and scrub fires.
Wildfire Control Plan See Incident Action
Plan.
Wind Direction The direction from which
the wind blows.
Wind Strength See Beaufort Wind Scale.
Windrow A long line of piled slash or
debris resulting from
forest or scrub clearing.
Windrow Burning The burning of windrows.
Woodland A plant community in which the
trees form only an
open canopy, the intervening area being
occupied
by lower vegetation, usually grass or scrub. |