Wildland Fire Terminology

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  • ABSORPTION – The act of absorbing or being absorbed.
  • ACCEPTABLE BURN – See Allowable Burn. (ONT)
  • AERIAL DETECTION – A system for or the act of discovering, locating and reporting Forest Fires from Detection Aircraft. (ONT, WI, MI, MN)
  • AERIAL FUELS – The standing and supported forest combustibles not in direct contact with the ground. (ONT, WI, MI, MN)
  • AERIAL-GROIUND DETECTION – A fire detection system combining coverage of key areas by ground detectors supplemented by aerial patrol. (ONT. WI)
  • AERIAL IGNITION – A technique whereby forest fuels are ignited by dropping ignition agents from aircraft. (ONT, MN)
  • AERIAL OBERSERVER – A person specifically assigned to discover, locate and report Forest Fires from a Detection Aircraft and to observe and describe conditions concerning detected fires. (ONT, MN)
  • AERIAL TORCH – An ignition device suspended under a helicopter, capable of dispensing ignited fuel to the ground for assistance in burnout or backfiring. (MN, WI)
  • AGENCY REPRESENTATIVE – Individual assigned to an incident from an assisting or cooperating agency who has been delegated full authority to make decisions on all matters affecting that agency’s participation at the incident. Agency representatives report to the incident liaison officer. (MN)
  • AGENT CONCENTRATE – The fire chemical product – as received from the supplier – that, when diluted with water, becomes foam solution.
  • AGENT SOLUTION – The dilute, working form of foam concentrate to which air is added to produce foam.
  • AIR ATTACK – A fire control operation involving the use of aircraft to drop Suppressants or Retardants with the objective of suppressing or retarding the spread of Forest Fires. Synonym – Fire Bombing. Also note Water Bombing. (ONT, MN)
  • AIR ATTACK BOSS – A person responsible for directing the coordinating more than one group of Air Tankers in an Air Attack operation. Note Birddog Officer. (ONT, MN)
  • AIR ATTACK LEADER – See Birddog Officer. (ONT)
  • AIR ATTACK OFFICER – The person responsible for all Air Attack activities, including associated ground operations. (ONT)
  • AIR CARGO – All items for transport and delivery by aircraft. (ONT, MN)
  • AIR OPERATIONS OFFICER – The person responsible for all air operations (Air Attack, Aerial Detection, Cargo Dropping, transport, etc.) within an administrative unit or from an operating base. (ONT, MN)
  • AIR TANKER – A fixed wing aircraft equipped to drop Suppressants or Retardants on a Forest Fire. Synonyms – Fire Bomber, Water Bomber. Also note Helitanker. (ONT, MN)
  • ALIDADE – A straight edge equipped with sights used to determine direction; in modified form is sued in locating fires. Note Fire Finder. (ONT)
  • ALLOCATED RESOURCES – Resources dispatched to an incident that have not yet checked in with the incident communications center. (MN)
  • ALLOWABLE BURN – A standard or objective of protection effort set for an area; the maximum annual loss in acreage burned that is considered an acceptable loss for a given area under organized Fire Control. Synonym – Acceptable Burn. (ONT, WI)
  • ANCHOR POINT – An advantageous location, usually a barrier to fire spread from which to start constructing fireline. Used to minimize the chance of being flanked by the fire while the line is being constructed. (ONT, MI, WI, MN)
  • ANEMOMETER – An instrument used to measure the velocity of wind. (ONT, WI, MI, MN)
  • AREA IGNITION – The ignition of a number of individual fires throughout an area either simultaneously or in quick succession and so spaced that they soon influence and support each other to produce a hot, fast-spreading fire throughout the area. Note Simultaneous Ignition. (WI)
  • ASPECT – The direction a slope faces. (ONT, WI, MI, MN)
  • ASPIRATE – To draw in air; nozzle-aspirating systems draw air into the nozzle to mix with the agent solution.
  • ASSIGNED RESOURCES – Resources checked in and assigned work tasks on an incident. (MN)
  • ASSISTING AGENCY – An agency directly contributing suppression, rescue, support, or service resources to another agency. (MN, MI)
  • ATMOSPHERIC STABILITY – A meteorological term to describe the resistance of the atmosphere to vertical motion. (1) The greater the stability, the greater the damping effect exerted on turbulence and vertical air motion. (2) The less stable the air the more easily convection can build up. (ONT, MI)
  • ATTACK – The actual physical fire fighting operation. Note Fire Suppression. (ONT, MI, MN)
  • AVAILABLE FUEL – The quantity of fuel, from mineral soil to the highest level, that would actually burn under existing conditions. (ONT, MI)
  • AVAILABLE FUEL ENERGY – The amount of energy released when the Available Fuel burns. (ONT)
  • AVAILABLE RESOURCES – Resources assigned to an incident and available for an assignment. (MN, WI, MI)
  • AZIMUTH – The horizontal angle between true north and the line of sight on a point, measured from 0 to 360 degrees in a clockwise direction. May be referred to as the bearing of a point. Note Fire Finder. (ONT, MN, MI)
  • AZIMUTH CIRCLE – A circle graduated in degrees from 0 to 360 degrees in a clockwise direction from true north. (ONT)B
  • BACK-PACK PUMP – A portable water container equipped with hand pump and back-pack straps; used mainly in fire fighting. Synonyms – Back Tank, Pack Pump. See illustration in Appendix I. (ONT, WI, MI, MN)
  • BACKFIRE – A fire burning, or set to burn, against the wind. Note Head Fire. (ONT, WI, MI, MN)
  • BARRIER, EXISTING OR NATURAL – Any obstruction to the spread of fire. Typically, an area or strip devoid of flammable fuel. (WI, MI, MN)
  • BASE CAMP – A strategically located camp through which personnel, equipment and supplies are assembled and distributed to Line Camps. (ONT)
  • BASE OF FLAME – The flame source; that point where the flame and fuel seem to touch. (MI)
  • BATCH MIX – Manual addition of foam concentrate to a water storage container or tank to make foam solution.
  • Bc – Back cans (WI)
  • BD – Bulldozer, any type (WI)
  • BEAUFORT WIND SCALE – An empirical scale for visually estimating wind velocity using wind effect on leaves, smoke, etc. (ONT, MI)
  • BERM – Outside or downhill side of a ditch or trench, debris piled by dozer along side of line. (WI)
  • BIODEGRADATION – Decomposition by microbial action, as with some detergents.
  • BIRDDOG AIRCRAFT – An aircraft carrying the person in charge of Air Attack operations over a fire. Also referred to as the Birddog. (ONT) See also Lead Plane (MN).
  • BIRDDOG OFFICER – A person designated to direct a group of Air Tankers in Air Attack. Synonym (in Ontario) – Air Attack Leader. Also note Air Attack Boss. (ONT)
  • BLOW-UP – Sudden increase in fire intensity or rate of spread toward tornadolike- forces. Often accompanied by magnified suction, creating violent convection. A large fire explosion. (ONT, MI, WI)
  • BOARD OF REVIEW – Committee selected to review results of Fire Control action within a given area, or the specific action taken on a given fire in order to identify reasons for both effective or ineffective action, and to recommend or prescribe ways and means of doing a more effective and efficient job in the future. Synonym – Fire Post Mortem. (ONT)
  • BRANCH – That organizational level having functional/geographic responsibility for major segments of incident operations. The branch level is organizationally between section and division/troop. (MN)
  • BREAKOVER – A fire edge that crosses a control line or natural barrier intended to confine the fire. Also called slopover. (WI)
  • BROADCAST BURNING – Intentional burning of debris on a specified area on which the fuel has not been piled or windrowed. (ONT)
  • BUBBLE – The building block of foam; bubble characteristics of water’s content and durability influence foam performance.
  • BUILDUP – The cumulative effects of weather factors which dry forest fuel and thereby heighten Fire Danger. (ONT, WI, MI, MN)
  • BUILDUP INDEX (BUI) – A numerical rating of the total amount of fuel available for combustion. (ONT, WI, MN)
  • BURNED AREA – All area inside of the control line that has been consumed by the fire. (WI)
  • BURNING CONDITIONS – The state of the combined factors of environment that affect fire in a given fuel association. (MI, MN)
  • BURNING OFF – A Fire Suppression operation where fire is set to consume islands of unburned fuel inside the Fire Edge during Mop-up operations. Note Burning Out. (ONT)
  • BURNING OUT – A Fire suppression operation where fire is set along the inside edge of a Control Line to consume unburned fuel between the line and the Fire Edge. Note Burning Off. (ONT, MI, WI, MN)
  • BURNING PERIOD – That part of each 24-hour period when fires will spread most rapidly. Typically, this is from 10:00 a.m. to sundown. (ONT, WI, MI, MN)
  • BURNING TORCH – A flame torch used to ignite forest fuels. See illustration in Appendix I. (ONT)C
  • CALCULATION OF PROBABILITIES – Evaluation of all existing factors pertinent to probable future behavior of a going fire and of the potential ability of available forces to carry out control operations on a given time schedule. 9WI)
  • CAMP – A geographical site, within the general incident area, separate from the base, equipped and staffed to provide food, water, and sanitary services to incident personnel. (MN)
  • CAMPAIGN FIRE – A fire of such size and/or complexity that it requires a large organization and several days or weeks to suppress. Synonym – Project Fire. (ONT)
  • CANADIAN FOREST FIRE DANGER RATING SYSTEM – The national system of rating Fire Danger in Canada, replacing the Canadian Forest Fire Behaviour System. (ONT)
  • CANADIAN FOREST FIRE WEATHER INDEX TABLES – Tables of codes and indices for rating Fuel Moisture Content, relative Rate of spread and relative Fire Intensity in a standard fuel complex, thereby providing a uniform assessment of Fire Weather severity across Canada. (ONT)
  • CANDLE OR CANDLING – A single tree or a very small clump of trees which is firing (flaring) up. Synonym – Torch or Torching. (ONT, WI, MI, MN)
  • CARCINOGENIC – Cancer causing.
  • CARGO DROPPING – The dropping of equipment or supplies from an aircraft in flight. Note Free Drop and Para-drop. (ONT)
  • CENTER FIRING – A technique of broadcast burning in which fires are set in the center of the area to create a strong draft. Additional fires are then set progressively nearer the outer control lines as in-draft builds up to draw them towards the center. See Simultaneous and Area ignition. (WI)
  • CENTRIFUGAL PUMP – A pump which expels water by centrifugal force through the ports of a circular impeller, rotating at high speed. With this type of pump, the discharge line may be shut off while the pump is running. See Appendix II for illustration. (ONT, MI, MN)
  • CHARGED LINE – A line of fire hose filled with water under pressure and ready to use. (ONT, MN)
  • CHECK-IN – Locations where assigned resources check in at an incident. The locations are: incident command post (resources unit, incident base, camps, staging areas, helibases, and division supervisors (for direct line assignments). Check in at one location only and complete the ICS form 211. (MN)
  • CLASS A FIRE – Fire in “ordinary” combustible solids. (However, if a plastic readily melts in a fire, it might be Class B rather than Class A.)
  • CLASS B FIRE – Fire in flammable liquids, gases, and greases.
  • CLASS A FOAM – Foam intended for use on Class A or woody fuels; made from hydrocarbon-based surfactants – therefore, lacking the strong filming properties of Class B foam, but possessing excellent wetting properties.
  • CLASS B FOAM – Foam designed for use on Class B or flammable liquid fires; made from flourocarbon-based surfactants – therefore; capable of strong filming action, but incapable of efficient wetting of Class A foam.
  • CLASS OF FIRE – The allocation of a Forest Fire to a group by reason of its size. Usually divided into five classes, from A (smallest fire) through E (very large fire), although the number of classes and class limits vary from agency to agency. (ONT, WI, MI, MN)
  • CLEAR TEXT – The use of plain English in radio communications transmissions. No ten codes, or agency specific codes are used when using clear text. (MN, WI, MI)
  • CLOSED AREA – An area in which specified activities or entry are temporarily restricted to reduce risk of man-caused fire. In some provinces, a Closed Area is called a Restricted Travel Zone or a Restricted Fire Zone. (ONT)
  • COLD TRAILING – A method on controlling a partly dead fire edge by carefully inspecting and feeling with the hand to detect any fire, digging out every live spot, and trenching any live edge. (ONT, WI, MN)
  • COMBINATION NOZZLE – Also called an “adjustable fog nozzle,” this nozzle is designed to provide either a solid stream or a fixed spray pattern suitable for water or wet water application.
  • COMM. UNIT – (Communications Unit) A vehicle (trailer or mobile van) used to provide the major part of an incident communications center. (MN)
  • COMMAND – The act of directing, ordering and/or controlling resources by virtue of explicit legal, agency, or delegated authority. (MN, MI)
  • COMMAND STAFF – The command staff consists of the information officer, safety officer, and liaison officer, who report directly to the incident commander. (MN)
  • COMMISSARY – Items such as tobacco, cigarette papers, clothing, etc., that are made available for sale to fire fighters working on a Forest Fire. Synonym – Van. (ONT, MN)
  • COMPANY – Any piece of equipment having a full complement of personnel. (MN)
  • COMPRESSED AIR FOAM SYSTEMS (CAFS) – A generic term used to describe foam systems consisting of an air compressor (or air source), a water pump, and foam solution.
  • CONCENTRATE – A substance that has been concentrated; specifically, a liquid that has been made denser, as by the removal of some of its water.
  • CONDITION OF VEGETATION – Stage of growth or degree of flammability of vegetation that forms part of a fuel complex. Herbaceous stage is at times used when referring to herbaceous vegetation alone. In grass areas minimum qualitative distinction for stages of annual growth are usually green, transition, and dry or cured. (MI, MN)
  • CONTAINMENT – Stopping or containing the advancement of a wildfire within man-made and/or natural barriers. (MI, MN)
  • CONTROL A FIRE – To complete a Control Line around a fire, any Spot Fires therefrom, and any interior islands to be saved; Burning Out any unburned areas adjacent to the fire side of the Control Lines; Burning Off any unwanted islands inside the Control Lines; and cooling down all Hot Spots that are immediate threats to the Control Line until the lines can reasonably be expected to hold under foreseeable conditions. Stages of Control are: Out of Control – A Wildfire not responding to any suppressive action. In some provinces this is referred to as Not Yet Under Control (NYUC). Being Held – Sufficient Suppression action has been taken so that the fire is not likely to spread beyond predetermined boundaries. Synonym – Partial Control (although this is not recognized in some provinces). Under Control – Sufficient Suppression action has been taken to ensure no further spread of the fire. Out – Fire extinguished. (ONT. WI, MN)
  • CONTROL LINE – An inclusive term for all constructed or natural fire barriers and treated fire edge used to control a fire. (ONT, MI, WI, MN)
  • CONVECTION – The mass movement of parts of a fluid within the fluid because of differences in the density, temperature, etc. of the parts. In meteorology, atmospheric motions that are predominantly vertical, resulting in vertical transport and mixing of atmospheric properties. (ONT, MI)
  • CONVECTION COLUMN – The thermally produced ascending column of gases, Smoke and debris produced by a fire, which is definable in vertical form. (ONT, MI, MN)
  • COOPERATING AGENCY – An agency supplying assistance other than direct suppression, rescue, support, or service functions to the incident control effort (e.g. Red Cross, law enforcement agency, Telephone Company, etc.) (MN, MI)
  • COORDINATION – The process of systematically analyzing a situation, developing relevant information, and informing appropriate command authority (for its decision) of viable alternatives for selection of the most effective combination of available resources to meet specific objectives. The coordination process (which can be either intro- or interagency) does not in and of itself involve command dispatch actions. However, personnel responsible for coordination may perform command or dispatch functions within limits as established by specific agency delegations, procedures, legal authority, etc. (MN)
  • CORROSION – Result of chemical reaction between a metal and its environment (i.e., air, water, and impurities in same).
  • COVER – The growing and dead vegetation that makes up a forest area. (MI)
  • COVER TYPE – The designation of a vegetation complex according to its dominant species, age, or form. (ONT, MI, MN)
  • CREW BOSS – A person in supervisory charge of usually 5 to 30 fire fighters and responsible for their performance, safety, and welfare for the duration of their assignment to him. (WI, MI, MN)
  • CROSS BEARINGS – Intersecting lines of sight from two or more points on the same object; used to determine the location of a Forest Fire from Lookouts. Synonym – Cross-Shots. (ONT)
  • CROWN FIRE – A fire that advances from top to top of trees or shrubs more or less independently of the surface fire. Sometimes crown fires are classed as either running or dependent, to distinguish the degree of independence from the surface fire. (MI, WI, MN)
  • CROWN OUT – Fire burning principally as a surface fire that intermittently ignites the crowns of trees or shrubs as it advances. (WI)D
  • DAMAGE APPRAISAL – A method of determining financial or other losses resulting from a Forest fire. Note Fire Damage. (ONT)
  • DEGRADATIION – The act of degrading or being degraded in rank, status, or condition.
  • DENSITY ALTITUDE – The pressure altitude corrected for temperature deviations from the standard altitude. Density Altitude bears the same relation to pressure altitude as true altitude does to indicated altitude. It takes account of the fact that at a given elevation the performance of an aircraft is less, the warmer the air temperature. Note Down Loading. (ONT)
  • DETECTION – A system for or the act of discovering, locating and reporting Forest Fires. (ONT, WI, MI, MN
  • DETECTION AIRCRAFT – An aircraft used for the purpose of discovering, locating and reporting Forest Fires. (ONT, MI, MN)
  • DEW POINT – The temperature to which a parcel of air must be cooled to reach saturation. (ONT, WI, MI, MN)
  • DIRECT ATTACK – A series of related actions to cool, drown, smother, starve, beat out, or otherwise directly extinguish the flames of a going fire. All control action is carried on directly against the fire edge. (MI, WI, MN)
  • DIRECTIONAL FIRE – A fire which possesses a definite head. (MI)
  • DISCOVERY – Determination that a fire exists at a specific location; in contrast to Detection, reporting of the fire is not required. (ONT)
  • DISPATCH – The implementation of a command decision to move a resource or resources from one place to another. (MN, MI)
  • DISPATCH CENTER – A facility from which resources are directly assigned to an incident. (MN)
  • DIVISION – That organization level having responsibility for operations within a defined geographic area or with functional responsibility. The division level is organizationally between the strike team and the branch. (See also Group) (ONT, MN, WI)
  • DIVISION BOSS – A person responsible to the Fire Boss or Line Boss, depending upon the degree of organization required, for the conduct of all Suppression work on a Division. Supervises two or more sector Bosses. Synonym – Division Foreman. (ONT, WI)
  • DOWN LOADING – A reduction in aircraft gross weight made to compensate for loss of performance due to increase in Density Altitude. (ONT)
  • DOZER COMPANY – Any dozer with a minimum complement of two persons. (MN)
  • DROP – That which is dropped in a Cargo Dropping or Air attack operation. Also refers to the operation itself, i.e., the Drop was successful. (ONT)
  • DRAINAGE TIME – The time (minutes) it takes for foam solution to drop out from the foam mass, for a specified percent of the total solution contained in the foam to revert to liquid and drain out of the bubble structure.
  • DROUGHT CODE (DC) – A numerical rating of the average Moisture Content of deep, compact, organic layers. (ONT)
  • DROUGHT INDEX – Keetch Byram or Palmer (MI)
  • DRY LIGHTNING STORM – a lightning storm with negligible precipitation reaching the ground. (ONT, WI, MI, MN)
  • DUFF – The partly decomposed organic material of the forest floor beneath the litter of freshly fallen twigs, needles, and leaves. See litter. (ONT, MI, WI, MN)
  • DUFF MOISTURE CODE (DMC) – A numerical rating of the average Moisture Content of loosely compacted organic layers of moderate depth. (ONT)E
  • EDUCTOR – a mixing system that uses water pressure to draw the fire chemical into the water stream for mixing; enables a pump to draw foam concentrate, as well as water, into the hose line.
  • ELAPSED TIME – The difference in time between the beginning of any action and its actual accomplishment; in Fire Control it is customarily divided into: Discovery Time – The period from start of a fire (estimated or known) until the time of Discovery. Report Time – The period from Discovery of a fire until the first person charged with initiating Suppression action is notified of its existence and location. Get-Away Time – The period from receipt of report of a fire by the first person responsible for Suppression until departure of the initial attack force. Travel Time – The period between departure of the initial attack force for a fire and its arrival at the fire. Attack Time – The period from receipt of first report to start of attack on the fire; includes both Get-Away and Travel Time. Control Time – The period from Initial Attack until the fire is controlled. Mop-up Time – The period from achievement of control until enough Mop-up work has been done to make reasonably sure that the fire will not break out again. Patrol Time – The period from completion of Mop-up until the fire is declared out. (ONT)
  • EJECTOR – Occasionally an injector is used to proportion mixes; this type of equipment is frequently referred to as an “ejector”, though sometimes as an “injector”.
  • ELAPSED TIME STANDARDS – Maximum amounts of time allowed by administrative rule for given steps of fire Suppression. (ONT)
  • ENGINE – Any ground vehicle providing specified levels of pumping, water, and hose capacity but with less than the specified level of personnel. (MN)
  • ENGINE COMPANY – Any ground vehicle providing specified levels of pumping, water, hose capacity, and personnel. (MN)
  • ENVIRONMENT – Something that surrounds; surroundings – such as air, water, or natural resources.
  • EXPANSION – The ratio of the volume of the foam in its aerated state to the original volume of the non-aerated foam solution.
  • EXTRA FIRE FIGHTERS (EFF) – Personnel other than regular employees or pre-arranged Suppression Crews, hired on a casual basis expressly to fight fires. (ONT)
  • EXTRA-PERIOD FIRE – A fire not controlled by 10:00 a.m. of the day following discovery. (WI, MI)F
  • FEEL FOR FIRE – Examining burned material or areas after fire is apparently out, by feeling with bare hands to find any live coals. (MI)
  • FINE FUEL MOISTURE CODE (FFMC) – A numerical rating of the Moisture Content of Litter and other cured Fine Fuels. (ONT)
  • FINE FUELS – Fuels, such as grass, leaves, needles, small twigs, etc., which when dry ignite readily and are consumed rapidly by fire. Synonym Flash Fuels. (ONT, MI, MN)
  • FINGER – A long, narrow projection of fire extending out from the main body of a forest fire. (MI, WI, MN)
  • FIRE – (1) Simultaneous release of heat, light and flame, generated by the combustion of flammable material. (2) In a wider sense, any outbreak of fire. Also note Forest Fire. (ONT, MI, MN)
  • FIRE ATLAS – A collection of associated maps, charts and statistics, used in Fire Control Planning. A Fire Atlas may be considered part of a Fire Control plan for a defined area. (ONT)
  • FIRE BEHAVIOR – The manner in which fuel ignites, flame develops, and fire spreads and exhibits other phenomena. Common terms used to describe Fire Behaviour include the following: Smoldering – Making no appreciable spread and burning without flame. Creeping – Spreading slowly, usually with low flame. Running – A rapidly spreading Surface Fire. Spotting – Spreading rapidly with sparks and embers falling outside the fire area and starting Spot Fires. Crowning – A fire ascending into the crowns of trees and/or spreading from crown to crown. (ONT, MI, WI, MN)
  • FIRE BEHAVIOUR INDEX – A numerical rating of expected Fire Behaviour in a specific Fuel type, based on meteorological measurements and topography, which provides either a relative or absolute quantitative measure of one or more fire Behaviour characteristics such as Rate of Spread, Fire Intensity, flame length
  • and crowing potential. Synonym – Burning Index. (ONT)
  • FIRE BOSS – The person responsible for all Suppression and service activities on a fire. Depending upon the size of the fire and the complexities of the Suppression operation the Fire Boss may carry out all duties directly or may assign line and staff duties to subordinates. Synonyms – Fire Foreman and (in British Columbia) Fire Superintendent. (ONT, WI, MI) (In MN Incident Commander)
  • FIRE BRAND – Any burning ember or material which becomes airborne and is blown outside the fire line, causing spot fires. (MI)
  • FIRE BREAK – A natural or constructed barrier utilized to stop or check fires that may occur or to provide a control line from which to work. Sometimes called a fire lane. (ONT, MI, WI, MN)
  • FIRE CO-OPERATOR – A local person or agency, outside the Fire Control organization, who has agreed in advance to perform Fire Control services and who has received advanced training or instructions in giving such services. (ONT)
  • FIRE CONTROL – All activities concerned with the protection of people, property and forest areas from Wildfire; includes Prevention, Detection, Presuppression and Suppression. (ONT, WI, MI, MN)
  • FIRE CONTROL EQUIPMENT – All tools, machinery, vehicles, special devices and general support equipment used in Fire Control. (ONT, WI)
  • FIRE CONTROL MAP – A map used by Fire Control personnel for locating and plotting forest Fires reported, burning and out. (ONT, MI)
  • FIRE CONTROL PLANNING – The systematic technological and administrative management process of determining the organization, facilities, resources and procedures required to protect forest areas from fire. (ONT)
  • FIRE DAMAGE – The loss, expressed in monetary or other terms, caused by fire. (ONT, MI, MN)
  • FIRE DANGER – A general term used to express an assessment of fixed and variable factors such as Fire Risk, fuels, weather and topography, which influence whether fires will start, spread and do damage, and also the degree of difficulty of control to be expected. Note Fire Hazard and Fire Risk. (ONT, MI, WI, MN)
  • FIRE DANGER CLASS – A segment of a Fire Danger Index scale identified by qualitative terms such as, Low, Moderate, High, Very High and Extreme. (ONT, MI, MN)
  • FIRE DANGER INDEX – A numerical rating, based on one or more fire danger factors such as Fire Risk, fuels, weather and topography, which is used to judge day-to-day Preparedness and Suppression requirements and as a basis for providing information on Fire Danger to the general public. (ONT)
  • FIRE DANGER RATING – The process of evaluating Fire Danger by using a system of numerical scales. (ONT, MI, WI, MN)
  • FIRE DAY (DAILY BURNING CYCLE) – A standard 24-hour period during which most forest fires undergo a predictable slowing-down and speeding-up of burning intensity, depending primarily upon the influence of fuel and weather factors. (MI)
  • FIRE ECOLOGY – The relationships between fire, the environment and living organisms. (ONT, MI, MN)
  • FIRE EDGE – the boundary of a Going Fire at any given moment. Note Fire Perimeter. (ONT, MI, MN)
  • FIRE EFFECTS – Any consequence resulting from fire. Synonym – Fire Impact. (ONT, MI)
  • FIRE ENVIRONMENT – The surrounding conditions, influences and modifying forces of topography, fuel and air mass that determine Fire Behaviour. (ONT)
  • FIRE EQUIPMENT CACHE – A supply of fire fighting tools and equipment in planned quantities or standard units at a strategic point for exclusive use in Fire suppression. Synonym – Fire Tool Cache. (ONT, MN)
  • FIRE FINDER – A device or instrument used to determine the horizontal bearing and sometimes the vertical angle of a fire from a Lookout. Note Alidade. (ONT)
  • FIRE FINDER MAP – A map situated on a Fire Finder and used to establish the location of Forest Fires from a Lookout.
  • FIRE FLANKING -Attacking a fire on the flanks, attempting to pinch off the head of steer it into a barrier of fuel where it can be controlled. (MI)
  • FIRE FLAP – A situation in which numerous fires are burning in a locality and the Fire Control Organization is extended to its limits. (ONT)
  • FIRE FRONT – The strip of burning fuel at the Fire Perimeter, together with the accompanying flames. May apply to any part of the perimeter as distinct from the different regions of the Fire Perimeter defined under Forest Fire. (ONT, MMI, MN)
  • FIRE HAZARD – A fuel complex defined by kind, arrangement, volume, condition and location that forms a special threat of ignition or of Suppression difficulty. Note Fire Danger and Fire Risk. (ONT, MI, MN)
  • FIRE INTENSITY, FRONTAL – The rate of energy release, or rate of heat release, per unit time per unit length of Fire Front. Numerically, it is equal to the product of the available fuel Energy and the forward Rate of Spread. (ONT)
  • FIRE LINE – Part of a control line raked, scraped, or dug down to bare mineral soil to form a safe barrier against the spread of forest fire and to provide a safe base from which to conduct burning out. (ONT, MI, WI, MN)
  • FIRE LINE OVERHEAD – A collective term for all Fire Line supervisory positions. The following is a summary of common and key Fire Line positions in general, although not in overall use across Canada. Note that because of the wide variation in Fire Suppression organization used in Canada, specialist and support positions have not been defined; instead, general descriptions of the main support functions are given. (ONT)
  • FIRE LOAD – The number and magnitude of fires requiring Suppression action during a given period within a specified area. (ONT)
  • FIRE MANAGEMENT – An extension of the concept of Fire Control which takes into account resource values, role of fire in the environment, the level of protection required, opportunities for prescribed use of fire, consideration of Fire Effects and the efficiency of the Fire Control operation (ONT, MI, MN)
  • FIRE OCCURRENCE – The number of fires started in a given area over a given period of time. Synonym – Fire incidence. (ONT, MI)
  • FIRE PERIMETER – The entire outer edge or boundary of a fire. (ONT, MI, WI, MN)
  • FIRE PLOUGH – (Fire Plow) A heavy duty plough of either the share or disc type, designed solely for constructing Fire Lines or Firebreaks. (ONT, MI, WI, MN)
  • FIRE PREVENTION – Activities directed at reducing Fire Occurrence; includes public education, law enforcement, personal contact, and reduction of Fire Hazards and Risks. (ONT, MI, MN)
  • FIRE PROGRESS MAP – A map maintained to show at given times, the location of the Fire Perimeter, deployment of Fire Suppression forces, and progress of Fire Suppression. (ONT)
  • FIRE PUMP – An engine driven pump, usually gasoline powered, specifically designed for use in Fire Suppression, which may either be carried by a person or transported on skids or a trailer. Synonym – Power Pump. May be either a Centrifugal Pump or a Positive Displacement Pump. (ONT, MI, MN)
  • FIRE REPORT – An official report of a fire, generally including information on cause, location, action taken, damage, costs, etc., from start of the fire until completion of suppression action. These reports vary in form and detail from agency to agency. (ONT, MI, WI, MN)
  • FIRE RETARDANT – A substance that by chemical or physical action reduces Flammability of combustibles. Note Long Term and Short Term Retardant. (ONT, WI, MI, MN)
  • FIRE RISK – The probability of fire starting determined by the presence and activities of causative agencies. Note Fire Danger and Fire Hazard. (ONT, WI, MN)
  • FIRE SCAR – (1) An injury or wound on a tree caused or accentuated by fire. (2) A scar on the landscape made by fire. (ONT, MI, MN)
  • FIRE SCOUNTING – Reconnaissance of a fire and its surroundings by any means to obtain information necessary for Fire Suppression planning. (ONT, MI, MN)
  • FIRE SEASON – The period or periods of the year during which fires are likely to occur, spread, and do sufficient damage to warrant organized Fire Control; a period of the year set out and commonly referred to in Fire Control legislation. (ONT, MI, WI, MN)
  • FIRE SHOVEL – Note Tools, Hand, Fire, (ONT)
  • FIRE SIMULATOR – A training device that imposes simulated Fire, Smoke, etc. on a projected landscape scene, for the purpose of instructing Fire Control personnel in different fire situations and Fire Suppression techniques. (ONT, WI, MI, MN)
  • FIRE STORM – A large continuous area of intense fire characterized by destructive surface winds, convection, and sometimes by tornado-like whirlwinds. (ONT. WI, MI, MN)
  • FIRE SUPPRESSION – All the work of extinguishing a fire following its Detection. Note Fire Control. Methods of Suppression are: Direct – A method whereby work is done on the burning edge of a fire. Indirect – A method whereby the Control Line is located along favorable topography in advance of the Fire Edge and the intervening strip is usually Burned Out. (ONT, MI, MN)
  • FIRE TYPE – A type of vegetative or forest growth that commonly follows or is otherwise dependent on fire. (ONT. MI)
  • FIRE WEATHER – Those weather conditions which influence fire starts, Fire Behaviour, or Fire Control. (ONT, MI, MN)
  • FIRE WEATHER FORECAST – A weather prediction specially prepared for use in Forest Fire Control work. (ONT, MI, MN)
  • FIRE WEATHER INDEX (FWI) – A numerical rating, based on meteorological measurements, of Fire Intensity in a standard Fuel Type. (The standard Fuel Type is representative of jack pine and lodgepole pine.) The FWI is comprised of three fuel moisture codes, covering classes of forest fuel of different drying rates, and two indices that represent Rate of Spread and the amount of Available Fuel, which collectively provide a uniform scale for rating Fire Weather severity. Note Canadian Forest Fire Weather Index Tables. (ONT.)
  • FIRE WEATHER STATION – A meteorological station equipped to measure Fire Weather elements. (MI, MN) A Primary Weather Station is one at which sufficient weather measurements are taken to compute ratings of burning conditions. A Secondary Weather Station does not provide this level of information, but rather gives fill-in information on weather conditions. (ONT)
  • FIREGUARD – See Firebreak. (ONT)
  • FIRING OUT – Also called firing. The act of setting fire to fuels between the control line and the main fire in either a backfiring or burning out operation. See Burning Out. 9WI)
  • FLAMMABILITY – The relative ease with which a substance ignites and sustains combustion. (ONT, MI, WI, MN)
  • FLANK FIRE – A fire set along a control line parallel to the wind and allowed to spread at right angles to it. (WI)
  • FLANKING – Attacking a fire by working along the flanks either simultaneously or successively from a less active or anchor point and endeavoring to connect the two lines at the head. (WI, MI, MN)
  • FLANKS – The parts of a forest fire’s perimeter that are roughly parallel to the main direction of spread. (MI, WI)
  • FLAREUP – Any sudden acceleration of fire spread or intensification of the fire. Unlike Blowup, a flareup is of relatively short duration and does not radically change existing control plans. (WI)
  • FLASH FUELS – Fuels such as grass, leaves, draped pine needles, fern, tree moss, and some kinds of small diameter slash fuel (1/4 inch or smaller) which ignite readily and are consumed rapidly when dry. Also called fine fuels. (MI, WI, MN)
  • FOAM – The aerated solution created by forcing air into, or entraining air in, a water solution containing a foam concentrate by means of suitably designed equipment or by cascading it through the air at a high velocity.
  • FOAM BLANKET – A body of foam – used for fuel protection – that forms an insulating and reflective layer from heat.
  • FOAM CONCENTRATE – The concentrated foaming agent as received from the manufacturer; use only those approved for use in wildland fire situations by the authority having jurisdiction.
  • FOAM GENERATION – The foam production process of solution agitation in a hose, mix chamber, or nozzle.
  • FOAM LINE – A body of foam placed along areas to be protected from fire; also used as an anchor for indirect attack in place of hand-made fire trail.
  • FOAM MONITOR – A turret-type nozzle usually mounted on an engine.
  • FOAM SOLUTION – A homogeneous mixture of water and foam concentrate in a proportion that meets the needs of the user.
  • FOAM SYSTEMS – The apparatus and techniques mused to mix concentrate with water to make solution, pump and mix air and solution to make foam, and transport and eject foam. (Systems defined here include compressed air foam and nozzle aspirated.)
  • FOAM VISCOSITY – An indication the ability of the foam to spread and cling, as well as to cling to itself, upon delivery.
  • FOLLOW-UP – The act of supporting the first fire fighters who go to a fire by sending additional personnel, equipment, aircraft and supplies. (ONT)
  • FOOD DISPENSER – Any vehicle capable of dispensing food to incident personnel. (MN)
  • FOREST CLOSURE – An official order by competent authority used to close a specified forest area. (Usually provided for in Fire Prevention legislation). Note Closed Area. (ONT)
  • FOREST FIRE – Any fire which is burning forest vegetation and which is not being used as a tool in Forest Protection or management in accordance with an authorized plan. Note Wildfire. (1) Types of Forest Fire are: GROUND FIRE a fire that burns in the organic material under the surface Litter, e.g. peat fire. SURFACE FIRE – A fire burning primarily the Litter on the forest floor, together with young trees, shrubs, etc. and spreading through these surface fuels, rather than from crown to crown. CROWN FIRE – A fire that advances through the tops of trees, more or less in conjunction with the Surface Fire. (2) The parts of a Forest Fire are: BAYS – Marked indentations in the Fire Perimeter. FINGERS – Extensions of the fire causing an irregular perimeter. FLANKS – Those parts of the perimeter of a fire between the Head and the Rear, and which are roughly parallel to the main direction of spread. HEAD – That portion of the edge of a fire with the greatest Rate of Spread. REAR – That portion of the edge of a fire opposite the Head, the slowest moving part of the fire. (ONT, MI)
  • FOREST PROTECTION – the activities connected with the control of damage to forests from fire, insects, disease and other harm-producing agencies. (ONT, MI, MN)
  • FORWARDER UNIT – (1) A self-contained unit consisting of a water tank, Fire Pump and hose specially designed to be carried on a logging forwarder for use in Forest Fire Suppression. (2) A box to hold firefighting tools and equipment specially designed to be carried on a logging forwarder. (3) The term usually applies to the special attachments, but it may also refer to the attachments and logging forwarder together. Note Skidder Unit. (ONT)
  • FREE-BURNING – Describes a fire or portion of the perimeter of a fire on which no work has been done to hinder or stop its spread. (ONT, MI)
  • FREE DROP – Cargo, not attached to a parachute, that is dropped intentionally from an aircraft in flight. Synonym – Free Fall. (ONT)
  • FRONT – A meteorological term for the transition zone between air masses of differing temperature and moisture characteristics. A colder air mass replacing a warmer one gives a cold front; the reverse, a warm front. Note Fire Front. (ONT, MI, MN)
  • FUEL ARRANGEMENT – The relationship of all combustible materials in both horizontal and vertical planes from mineral soil to the highest level. Note Fuel Type Pattern. (ONT, MI)
  • FUEL-BREAK – A wide strip or block of land on which the native vegetation has been permanently modified so that fires burning into it can be more readily extinguished. It may or may not have firelines constructed in it prior to fire occurrence. ONT, WI, MI, MN)
  • FUEL MANAGEMENT – The planned manipulation or reduction of living or dead forest fuels by fire, mechanical means or species modification for Hazard Reduction, silvicultural, wildlife management or other purposes. (ONT, MI, MN)
  • FUEL MOISTURE CONTENT – The quantity of moisture in fuel expressed as a percentage of the oven-dry weight of the fuel. (ONT, MI, MN)
  • FUEL TENDER – Any vehicle capable of supplying fuel to ground or airborne equipment. (MN)
  • FUEL TYPE – An identifiable association of fuel elements of distinctive species, form, size, arrangement, or or other characteristics that will cause a predictable rate of fire spread or difficulty of control under specified burning conditions. Note Fuel Type Pattern. (ONT, MI, WI, MN)
  • FUEL TYPE PATTERN – A mosaic of distinct Fuel Types on a given area. (ONT)G
  • GENERAL STAFF – The group of incident management personnel comprised or: The incident commander, logistics chief, operation chief, finance chief, planning chief 9MN)
  • GOING FIRE – A current fire during the period between time of start and being declared out. (ONT, WI MI MN)
  • GREEN FUELS – Living vegetation of high moisture content that ordinarily will not burn unless first dried out by excessive heat or lack of rain. (MI)
  • GROUND FIRE – Fire that consumes the organic material beneath the surface litter of the forest floor, such as peat fire. (MI, WI, MN)
  • GROUND FUEL – That fuel which is below the litter layer, usually called muck, peat, duff, or organic material which will burn. (MI)
  • GROUP – A functional division (e.g. air support, salvage, structure protection, etc.) (MN)
  • GUTTER TRENCH – A ditch dug down to the mineral soil on a slope below a fire, so as to trap rolling fire-brands, such as cones, logs, etc. (ONT)H
  • HAND CREW – Predetermined individuals that are supervised, organized, and trained principally for clearing brush as a fire suppression measure. (MN, MI)
  • HAZARD – A fuel complex defined by kind, arrangement, volume, conditions and location that forms a special threat of ignition or of suppression difficulty. (WI, MI, MN)
  • HAZARD REDUCTION – A treatment of fuels to diminish the chance of fire starting or spreading in them. 9ONT, MI, MN)
  • HAZARD STICK – A specially prepared, wooden stick of known dry weight that is continuously exposed to the weather and periodically weighed to determine changes in Moisture Content, as an indication of moisture changes in, and Flammability of, Fine fuels. Synonym – Fuel Moisture Indicator Stick. (ONT)
  • HAZE – Fine dust or particles in the atmosphere which diminish visibility. Note Smoke. (ONT)
  • HEAD – The most rapidly-spreading portion of a forest fire’s perimeter, usually influenced by wind or slope. (MI, WI, MN)
  • HEAVY EQUIPMENT TRANSPORT – Any ground vehicle capable of transporting a dozer. (MN)
  • HEAVY FUELS – Fuels of large bulk or thick consistency, such as duff, limbs, logs, snags, stumps, and rotted vegetation, which are not easily ignited unless quite dry, and which retain fire, once started, for a considerable time. (ONT, MI WI, MN)
  • HELD LINE – All worked control line that still contains the fire when mop-up is completed. Excludes lost line, natural barriers not back-fired, and unused secondary lines. (ONT, WI)
  • HELIBASE – A location within the general incident area for parking, fueling, maintenance, and loading of helicopters. (MN, WI)
  • HELIBASE CREW – A crew of 3 or more individuals who may be assigned to operations or to support helicopter operations. (MN)
  • HELIBUCKET – A specially designed bucket carried by a helicopter like a sling load and used to drop Suppressants or Retardants. (ONT)
  • HELICOPTER TENDER – A ground service vehicle capable of supplying fuel and support equipment to helicopters. (MN)
  • HELIPORT – A permanent or semi-permanent base for helicopters constructed to Ministry of Transport design criteria. (ONT)
  • HELISPOT – A location where a helicopter can take off and land. Some helispots may be used for temporary retardant loading. (ONT, MN, WI)
  • HELITACK – The initial attack phase of fire suppression using helicopters and trained airborne teams to achieve immediate control of wildfires. (ONT, MN)
  • HELITACK FOREMAN – A firefighter trained in the tactical and logistical use of helicopters for fire suppression. (MN)
  • HELITANK – A specially designed tank, generally of fabric or metal, fitted to a helicopter and used for transporting and dropping Suppressants or Retardants. (ONT)
  • HELITANKER – A helicopter equipped with a fixed tank or a suspended bucket type container that is used for aerial delivery of water or retardants. (ONT, MN)
  • HIGBEE CUT – A type of pipe thread with pat of the first or outside thread removed to create a blunt start. (ONT)
  • HOLDOVER FIRE – A fire that starts up again after appearing to have been extinguished. Note Sleeper Fire. (ONT, WI, MI, MN)
  • HOSE FRICTION LOSS – Reduction in efficiency of a hose due to friction between the water flowing through the hose and the inner surface of the hose (ONT, WI, MI, MN)
  • HOSE-LAY – The arrangement of connected lengths of fire hose and accessories on the ground beginning at the first pumping unit and ending at the point of water delivery. (ONT, WI, MI, MN)
  • HOSE STRANGLER – A crimping device for stopping the flow of water in a hose. (ONT)
  • HOT SPOT – A particularly active part of a fire. (ONT, MI, MN)
  • HOTSPOTTING – Checking the spread of fire at points of more rapid spread or special threat. It is usually the initial step in prompt control with emphasis on first priorities.
  • HYGROGRAPH – An instrument for measuring and recording automatically and continuously the variations of the Relative Humidity of the atmosphere. (ONT)
  • HYGROMETER – An instrument for measuring the Relative Humidity of the atmosphere. (ONT, WI)
  • HYGROTHERMOGRAPH – An instrument that records automatically and continuously both temperature and Relative humidity. Synonym – Thermohygrograph. (ONT, MI)I
  • IGNITION PATTERN – The manner in which a Prescribed Burn is set, determined by weather, fuel, geographic and other factors having influence on the fire and the job it is to do. (ONT, MI, MN)
  • IGNITION TEMPERATURE – The lowest temperature of a substance at which sustained combustion can be initiated. Synonym – Kindling Point. (ONT, MI)
  • INCENDIARY – (1) A fire which was deliberately set with malicious intent. (2) The person who sets such a fire. (ONT, MI, MN)
  • INCIDENT – An occurrence or event, either human-caused or natural phenomena, that requires action by emergency service personnel to prevent or minimize loss of life or damage to property and/or natural resources. (MN)
  • INCIDENT ACTION PLAN – The incident action plan, which is initially prepared at the first meeting, contains general control objectives reflecting the overall incident strategy, and specific action plans for the next operational period. When complete, the incident action plans will have a number of attachments. (MN)
  • INCIDENT BASE – that location at which the primary logistics functions are coordinated and administered. (Incident name or other designator will be added to the term Base.) The incident command post may be collocated with the base. There is only one base per incident. (MN)
  • INCIDENT COMMAND POST (ICP) – That location at which the primary command functions are executed and usually collocated with the incident base. (MN)
  • INCIDENT COMMAND SYSTEM (ICS) – The combination of facilities, equipment, personnel, procedures, and communications operating within a common organizational structure with responsibility for the management of assigned resources to effectively accomplish stated objectives pertaining to an incident. (MN, WI)
  • INCIDENT COMMANDER – The individual responsible for the management of all incident operations. (MN)
  • INDIRECT ATTACK – Control action conducted a variable distance from and usually parallel to the edge of a forest fire in such a manner as to deprive the advancing fire of fuel and thereby halt its further progress (MI, WI, MN)
  • INDUCTOR – A control mechanism that allows a regulated quantity of foam concentrate to be introduced into the main hose line.
  • INFRARED (IR) – A heat detection system used for fire detection, mapping, and hot spot identification. (MN, MI)
  • INFRARED (IR) GROUNDLINK – A capability through the use of a special mobile ground station to receive air to ground infrared imagery for interpretation. (MN)
  • INFRARED SCANNER – An optical-electronic system for securing infrared imagery from aircraft, so as to detect small fires, Hot Spots or Fire Perimeters through Smoke, Haze and forest canopy. May also be used for fire mapping. (ONT)
  • INGESTION – To take things into the body (food, drugs, etc.) by swallowing or absorption.
  • INGREDIENT -Each chemical component used in the formulation of a product.
  • INITIAL ACTION – The steps taken after the report of a fire and before actual fire fighting begins on it. Note Initial Attack. (ONT, MI, WI)
  • INITIAL ATTACK – The action taken to Control a Fire by the first fire fighting force to arrive at the fire. Note Initial Action. (ONT, MN)
  • INITIAL SPREAD INDEX (ISI) – A numerical rating of the relative spread of a fire that can be expected soon after ignition. It is the combined effect of wind and FFMC on Rate of Spread, without the influence of variable quantities of fuel. (ONT)
  • INVERSION – In meteorology, an abbreviation for inversion of the vertical gradient of temperature. The temperature of the air is ordinarily observed to become lower with increasing height, but occasionally the reverse is the case, and when the temperature increases with height there is said to be an Inversion. The air is then very stable. (ONT, MI, MN)J
  • JURISDICTIONAL AGENCY – The agency having jurisdiction and responsibility for a specific geographical area. (MN)K
  • KNOCKDOWN – Reducing the advancing flame heights and intensity to the point where close-in follow-up efforts can contain the fire. Usually done on the hotterburning fires. (MI)L
  • LEAD PLANE – An aircraft carrying the person in charge of Air Attack operations over a fire. Also leads the air tankers on each drop on the fire line. (MN). See also Birddog (ONT).
  • LIGHTNING STROKE COUNTER – An electronic sensor to record the number of lightning strokes within a pre-determined range and over a given period of time. (ONT)
  • LINE BOSS – The person responsible to the Fire Boss for supervising, directing and inspecting the Suppression effort on the entire Fire Line. Synonyms Line Foreman and (in some provinces) Suppression Boss. (ONT)
  • LINE CAMP OR FIRE LINE CAMP – A camp with minimum facilities, established along a Fire Line or near a Forest Fire to accommodate and supply personnel actively engaged in Fire Suppression or Mop-up work; does not include Base Camp. (ONT)
  • LINE HOLDING – Making sure that the established fire line has completely stopped the progress of the fire. This is done with follow-up forces scouting the fire line for spot fires or breaks in the line. (MI)
  • LINE LOCATOR – A person who selects and marks the location where Fire Lines are to be constructed. (ONT)
  • LIQUID CONCENTRATE (LC.) – A Long Term Retardant additive in liquid form. (ONT, MI, MN)
  • LITTER – The top layer of forest floor, composed of loose debris of dead sticks, branches, twigs, and recently fallen leaves and needles little altered in structure by decomposition. (ONT, MI, WI, MN)
  • LOADING PAD – A cement pad at a Retardant Base on which aircraft stand when being loaded with Slurry. Synonym – Loading Ramp. (ONT)
  • LONG TERM RETARDANT – A substance that by chemical or physical action reduces the Flammability of combustibles and remains effective after application, even after water content has evaporated. Long Term Retardants depend on certain flame-inhibiting chemicals for their effectiveness. (ONT, MI, MN)
  • LOOKOUT – (1) A person designated to detect and report fires from a vantagepoint. Synonym – Towerman. (2) A location and associated structures from which fires can be detected and reported. Note Lookout Tower. (ONT, WI)
  • LOOKOUT CABIN – A building constructed solely to provide living quarters for a Lookout. Synonym – Towerman’s Cabin. (ONT)
  • LOOKOUT CUPOLA – A small building normally equipped with glass walls or windows permitting an unobstructed view on all sides, but not designed for living quarters. It may be located on a Lookout Tower, or other artificial or natural elevation. Synonym – Tower Cupola. (ONT)
  • LOOKOUT TOWER – A tower built to raise a Lookout above nearby obstructions to sight. It is usually capped by a Lookout Cupola. Synonym – Fire Tower. (ONT)
  • LOST LINE – Any part of a Control Line that fails to stop the spread of a fire (ONT)
  • LOW-PROFILE FUELS – Burnable materials consisting of litter and grass, leaves, shrubs, etc., up to 12” above the ground. (MI)M
  • MANAGEMENT BY OBJECTIVE (MBO) – Topdown management so that all involved know and understand the objectives of the operation. (MN)
  • MESSAGE CENTER – The message center is part of the communications center and is collocated or placed adjacent to it. It receives, records, and routes information about resources reporting to the incident, resource status, and administration and tactical traffic. (MN)
  • MIX RATIO – The ratio of liquid foam concentrate to water, usually expressed as a percent.
  • MIXED SOLUTION – The combination of water and foam concentrate used to produce the foam used for fire suppression.
  • MIXING CHAMBER – A tube drilled, with deflectors or baffles, that produces tiny, uniform bubbles in a short distance (1 to 2 ft).
  • MIXMASTER – The person in charge of Fire Retardant mixing operations, with responsibility for quantity and quality of the Slurry and for the loading of aircraft in land based Air Tanker operations. (ONT)
  • MOBILIZATION CENTER – An off incident location at which emergency service personnel and equipment are temporarily located pending assignment, release, or reassignment. (MN)
  • MOP-UP – The act of making a fire safe after it is controlled, such as extinguishing or removing burning material along or near the control line, felling snags, trenching logs to prevent rolling, etc. (ONT, MI WI, MN)
  • MULTIAGENCY COORDINATION SYSTEM (MACS) – The combination of facilities, equipment, personnel, procedures, and communications integrated into a common system with responsibility for coordination of assisting agency resources and support to agency emergency operations. (MN)
  • MUTAGENIC – Any agent or substance capable of noticeably increasing the frequency of mutation.N
  • NATIONAL INTERAGENCY INCIDENT MANAGEMENT (NIIMS) – Consists of five major subsystems which collectively provide a total systems approach to allrisk incident management. The subsystems are: the incident command system; training; qualifications and certification; supporting technologies; and publications management. (MN)
  • NOAA WEATHER STATION – A mobile weather data collection and forecasting facility (including personnel) provided by the National Oceanic and Atmospheric Administration which can be utilized within the incident area. (MN)
  • NON-DIRECTIONAL FIRE – A slow-burning fire which does not have a definite head or direction. (MI)
  • NOZZLE ASPIRATED FOAM SYSTEM – A foam generating device that mixes air at atmospheric pressure with foam solution in a nozzle chamber.
  • NOZZLEMAN – The man who handles the nozzle and applies water to suppress the fire. (MI)O
  • OPERATIONAL PERIOD – The period of time scheduled for execution of a given set of operation actions as specified in the incident action plan. (MN)
  • OPERATIONS COORDINATION CENTER (OCC) – The primary facility of the Multiagency Coordination System. It houses the staff and equipment necessary to perform the MACS functions. (MN)
  • ORIGIN – The exact location where ignition first took place. The spot where the fire started. (WI, MI, MN)
  • ORTHOPHOTO MAPS – Aerial photographs corrected to scale such that geographic measurements may be taken directly from the prints. They may contain graphically emphasized geographic features and may be provided with overlays of such features as: water systems, important facility locations, etc. (MN)
  • OUT-OF-SERVICE RESOURCES – Resources assigned to an incident but unable to respond for mechanical, rest, or personnel reasons. (MN)
  • OVERHEAD PERSONNEL – Personnel who are assigned to supervisory positions which includes incident commander, command staff, general staff, directors, supervisors, and unit leaders. (MN, MI)
  • OVERWINTERING FIRES – Fires that persist during winter months through to the opening of a Fire Season. (ONT)P
  • PARA-CARGO – That portion of Air Cargo which is to be delivered by Para-drop. (ONT)
  • PARA-DROP – Cargo, attached to a parachute, dropped from an aircraft in flight. (ONT)
  • PARALLEL METHOD – A method of suppression in which fire line is constructed approximately parallel to and just far enough from the fire edge to enable men and equipment to work effectively, though the line may be shortened by cutting across unburned fingers. The intervening strip of unburned fuel is normally burned 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. (MI, WI, MN)
  • PARALLEL PUMPING – a procedure whereby the flow from two Fire Pumps is combined into one hose line. (ONT)
  • PATROL – (1) To inspect a section of Fire Line or a portion of a fire to prevent escape of the fire. (2) To travel a given route to inspect, prevent, detect and suppress fires. (ONT, WI, MI, MN)
  • PATROL UNIT – Any light, mobile unit, having limited pumping and water capacity. (MN)
  • PATROLMAN – A member of a fire control agency assigned to Patrol a specified area. (ONT)
  • PERIMETER – The outside edge of the fire. The boundary line of the fire which is made by the fire itself. When the fire is burning, the perimeter is constantly expanding. When the fire is contained, the perimeter becomes the outside edge of the burned area. There should be no unburned material left inside the control line at the outside edge or perimeter of the fire. The only safe line is a completely burned out or black line. (WI, MI, MN)
  • PERIOD OF ALERT – A period of time when fire fighters, Fire Control Equipment and aircraft are kept ready for deployment on short notice; usually when the Fire Danger reaches a predetermined degree of severity. May also involve an increase in Fire Prevention activities; often preceding a Forest Closure. Note Standby. (ONT)
  • PINCH-OFF HEAD – An extension of the parallel method whereby the attack is continued right on around the head of the fire. Also used when the fire is too intense to attack at the head immediately. (MI)
  • PISTON PUMP – A Positive Displacement Pump employing reciprocating pistons to force water from the pump chamber. (ONT. MI)
  • PLANNING MEETING – A meeting, held as needed throughout the duration of an incident, to select specific strategies and tactics for incident control operations and for service and support planning. (MN)
  • PLANS FUNCTION – The part of the Fire Suppression organization (reporting to the Fire Boss) that is responsible for gathering and compiling all information needed for planning Fire Suppression action and for determining control force requirements. May involve Fire Weather, analysis of expected fire Behaviour, development of Tactics and overall fire intelligence. (ONT)
  • POSITIVE DISPLACEMENT PUMP – A Rotary Gear or Piston Pump which moves a given quantity of water through the pump chamber with each revolution of the driveshaft. With this type of pump, the discharge line should not be shut off while the pump is running, otherwise damage to pump or hose may result. Note rotary Gear Pump and Piston Pump. (ONT, MI, MN)
  • PRE-WETTING – A suppression technique where fuels out in front of the running fire are wet down to slow or put out the flames. (MI)
  • PRECIPITATION – The fall of rain, hail, sleet, or snow. Lack of precipitation increases flammability of forest fuels. (MI, MN)
  • PREPAREDNESS – Condition or degree of being able and ready to cope with an anticipated fire situation. (ONT)
  • PRESCRIBED BURNING – The burning of forest fuels on a specific area under predetermined conditions so that the fire is confined to that area to fulfill silvicultural, wildlife management, sanitary or Hazard Reduction requirements. Note Ignition Pattern. (ONT)
  • PRESUPPRESSION – Those Fire Control activities in advance of Fire Occurrence, concerned with the organization, training and management of a Fire Control force and the procuring, maintenance and inspection of improvements, equipment and supplies, to ensure effective Fire Suppression. (ONT, MI, MN)
  • PROJECT FIRE – Usually refers to a fire requiring manpower and equipment
  • beyond the resources of the protection unit on which it originates. (WI)
  • PROPORTIONER – An instrument incorporating wet and dry bulb thermometers and used to determine the Relative Humidity of the atmosphere. (ONT, MI, MN)
  • PTO – Power take-off. (WI)R
  • RADIO CACHE – A cache may consist of a number of portable radios, a base station, and in some cases, a repeater stored in a predetermined location for dispatch to incidents. (MN)
  • RAIN GAUGE – An instrument for measuring the amount of precipitation, may be recording or non-recording. (ONT, MI, MN)
  • RATE OF SPREAD – The amount of expansion of a forest fire perimeter in a specified period of time, usually expressed in chains per hour. (ONT, MI, WI, MN)
  • RE-BURN – A surface fire which starts and burns again over the old burn, consuming the previously wet or unburned fuels. Can occur any time after the initial burn, until all fire on burn area is dead out. (ONT, MI, WI, MN)
  • REAR – The portion of a forest fire perimeter opposite the head. (MI, WI, MN)
  • REINFORCED ATTACK – Those resources requested in addition to the initial attack. (MN)
  • RELATIVE HUMIDITY – The ratio of the amount of moisture in a given volume of air to the amount that volume could hold if it were saturated. Affects burning intensity of forest fires. (ONT, MI, WI, MN)
  • RELAY TANK – A tank, usually collapsible, used as a reservoir in the relay of water from one fire Pump to another. (ONT, MI, MN)
  • REPORTABLE FIRE – Any wild fire that requires suppression action to protect natural resources or values associated with natural resources, or was destructive or potentially destructive to natural resources. (WI, MI, MN)
  • REPORTING LOCATIONS – Any one of six facilities/locations where incident assigned resources may check in. The locations are: incident command post -resources unit (RESTAT), Base, camp, staging area, helibase, or division supervisor for direct line assignments. (Check in at one location only.) (MN)
  • REPRODUCTIVE – The process, sexual or asexual, by which animals and plants produce new individuals.
  • RESCUE MEDICAL – Any manned ground vehicle capable of providing emergency medical services. (MN)
  • RESISTANCE TO CONTROL – The relative difficulty of constructing and holding a control line as affected by resistance to line construction and by fire behaviour. Also called difficulty of control. (ONT, WI)
  • RESOURCES – All personnel and major items of equipment available, or potentially available, for assignment to incident tasks on which status is maintained. (MN)
  • RESTAT – An acronym for resource unit – A unit within the planning section. (MN)
  • RETARDANT BASE – The ground facilities for mixing, storing and loading Fire Retardant into Air Tankers. (ONT)
  • REVERSIBLE SIAMESE – A hose fitting that performs the functions of either a Siamese or a Wye, i.e., to combine the flow from two lines into a single line or to permit two lines to be taken from a single line. Synonym – Simwye. Note: For threaded fittings, adapters must be added to change toe sexes of the ports of the fitting to meet different Hose-Lay requirements. For fittings with spring-loaded valves, the valve handles must be removed and valve positions changed relative to handle to permit control of flow in a reverse direction. (ONT)
  • RISK – The chance of fire starting as determined by the presence and activity of causative agents. A causative agent. (WI, MI)
  • ROTARY GEAR PUMP – A Positive Displacement Pump employing closely fitting rotors or gears to force water through the pump chamber.S
  • S.A.F.E. SYSTEM – The preliminary and continuing appraisal of the over-all fire situations for purposes of determining appropriate control actions. (ONT)
  • S.A.F.E. SYSTEM – Safety Always For Effectiveness. (MI)
  • SCOUT – A person in a Fire Suppression organization assigned duties of gathering and reporting timely information, such as existing location and behaviour of a fire, progress in control, and the physical conditions that affect the planning and execution of the Suppression job. (ONT, WI)
  • SCRATCH LINE – An unfinished preliminary control line hastily established or constructed as an emergency measure to check the spread of a fire. (WI)
  • SCRUBBING – The process of agitating foam solution and air within a confined space (usually a hose) that produces tiny, uniform bubbles – the length and type of hose determine the amount of scrubbing and, therefore, foam quality.
  • SECTION – That organization level having functional responsibility for primary segments of incident operations such as: operations, planning, logistics, and finance. The section level is organizationally between branch and incident commander. (MN)
  • SECTOR – A designated segment of fire perimeter or control line comprising of the suppression work unit for two or more crews under one sector boss. (ONT, WI)
  • SECTOR BOSS – A person responsible to a Division Boss, Line Boss or Fire Boss, depending upon the degree of organization required, for the conduct of all Suppression work on a Division. Supervises two or more Sector Bosses. Synonym – Division Foreman. (WI)
  • SEEN AREA – Synonym – Visible Area. VISIBLE – The ground or the vegetation growing thereon that is directly visible from an established or proposed Lookout.
  • SCREENED – The ground or vegetation thereon not directly visible, but over which the Lookout’s line of sight passes at an elevation not in excess of a given standard. BLIND – Areas that are not visible to the Lookout and are more than a given standard elevation below the line of sight. Screened areas at the limit of visibility and not having a good background are also classed as Blind. All observations are made under specified visibility conditions. (ONT)
  • SEEN AREA MAP – A map showing the different classes of Seen Area covered by a Lookout or Lookouts. It may differentiate between directly visible area, screened and blind areas; or only two classes – visible and blind – may be recognized. (ONT)
  • SERVICE FUNCTION – The part of the Fire Suppression organization (reporting to the Fire Boss) that is responsible for the procurement, maintenance and distribution of personnel, equipment and supplies at the time and place called for in the Suppression plan. May involve record keeping, accounting, provision of food and lodging, safety and first-aid, transportation, etc. (ONT, MN)
  • SHOCK CREW – A specially trained and equipped crew for Initial Action and Initial Attack on a fire. Synonym – Initial Attack Crew. Also note Suppression Crew. (ONT)
  • SHORT TERM RETARDANT – A viscous, water based substance wherein water is the fire retarding agent. Generally regarded as a Suppressant and used in Direct Attack. (ONT, MI, MN)
  • SIAMESE – (a) with valves – A hose fitting to combine the flow from two supply lines into a single discharge line. Valves located in the intake ports permit complete control over both supply lines to control pressures or to shut off one or both as desired. Note Reversible Siamese and Wye. (b) less valves – A hose fitting to combine the flow from two supply lines into a single discharge line, with no provisions to control pressures or stream flow. (ONT, MI, MN)
  • SIMPLE HOSE-LAY – A hose-lay consisting of consecutively coupled lengths of hose without laterals. The lay is extended by inserting additional lengths of hose in the line between pump and nozzle. (WI)
  • SIMULTANEOUS IGNITION – A technique of Broadcast Burning (or Burning Out) by which the fuel on an area to be burned is ignited at many points simultaneously and the sets are so spaced that each receives timely stimulation by radiation from the adjoining sets. By such techniques, all burn together quickly and a hot clean burn is possible under unfavorable conditions where single sets would not burn. Note Area Ignition. (WI)
  • SIMWYE – See Reversible Siamese. (ONT)
  • SITSTAT – An acronym for the situation unit – A unit within the planning section.
  • (MN)
  • SIZE-UP – The preliminary and continuing appraisal of the over-all fire situations for purposes of determining appropriate control actions. (MI, WI, MN)
  • SKIDDER UNIT – (1) A self-contained unit consisting of a water tank, Fire Pump and hose specially designed to be carried on a logging skidder for use in Forest Fire Suppression. (2) A basket to hold fire fighting tools and equipment specially designed to be carried on a logging skidder. (3) The term usually applies to the special attachments, but it may also refer to the attachments and logging skidder together. Note Forwarder Unit. (ONT, MN) (Specially adapted skidder with integral tank, pump, and hydraulically activated fire plow.
  • SLASH – Debris left after logging, pruning, thinning or brush cutting; it includes logs, chips, bark, branches, stumps and broken understory trees or brush. (ONT, WI, MI, MN)
  • SLASH DISPOSAL – treatment of Slash to reduce the Fire Hazard or for silvicultural or other purposes. (ONT, MI, MN)
  • SLEEPER FIRE – A fire that remains dormant for a considerable time after it starts. Note Holdover Fire. (ONT)
  • SLING – A net attached by a lanyard to a helicopter cargo hook and used to haul supplies. (ONT, MN)
  • SLING PSYCHROMETER – A portable instrument for obtaining wet and dry bulb thermometer readings in order to determine Relative Humidity. (ONT, WI, MI, MN)
  • SLIP-ON TANK – A self-contained unit consisting of a water tank, Fire Pump and hose designed for quick loading on conventional trucks. (ONT, MI) (SLIP-ON UNIT MN)
  • SLOPE – Any rise of ground above level or flat, such as a hill or mountain. Affects rate of spread of a going fire. (MI)
  • SLUG FLOW – In CAFS only, when foam solution is not rich enough to mix with air, inadequate mixing occurs; this sends pockets (or plugs) of water and air to the nozzle.
  • SLURRY – A suspension of insoluble matter in water. In Fire Control, it is a general term applied to any Long Term or Short Term Retardant after the mixing process has been completed. (ONT)
  • SMOKE – (1) A visible airborne cloud of fine particles, the product of incomplete combustion. (2) A term often used when reporting a fire or probable fire in its initial stages. 9MI) In Fire Control the following types of Smoke are recognized: LEGITIMATE SMOKE – Smoke from any authorized use of fire or other permissible sources, such as permitted debris burning, locomotives, industrial operations, etc. FALSE SMOKE – Any phenomenon mistaken for smoke. DRIFT SMOKE – Smoke moved by air currents from its point of origin into other areas. INTERMITTENT SMOKE – Smoke which becomes visible occasionally.
  • SMOKE HAZE – Haze caused by Smoke. SMOKE COLUMN – A smoke that is definable in vertical form. (ONT)
  • SMOKECHASER – A member of a small force trained and equipped to locate and extinguish small fires; may also be carried on Aerial Detection patrols for Initial Attack. (ONT, MN)
  • SMOKE JUMPERS – Fire fighters trained and equipped to parachute to fires in remote areas for Initial Attack. (ONT)
  • SMUDGE – A spot in a fire or along a fire’s edge which has not yet been extinguished, and which is producing Smoke; a term commonly used during the Mop-up stage of a fire. (ONT)
  • SNAG – A standing dead tree or part of a dead tree from which at least the leaves and smaller branches have fallen. Often called stub, if less than 20 feet tall. (ONT, MI, WI, MN)
  • SPAN-OF-CONTROL – The supervisory ratio of from three to seven individuals with five being established as a general rule of thumb. (MN, WI)
  • SPOT FIRE – (1) A fire started outside the perimeter of the main fire by sparks or embers carried from the main fire by convective air currents. Synonym Jump Fire. Also note Fire Behaviour. (2) In some provinces, this term is also used to identify a very small class “A” fire, usually one which requires little time to extinguish. (ONT, MI, WI, MN)
  • SPOTTING – Behaviour of a fire producing sparks or embers that are carried by the wind and start new fires beyond the zone of direct ignition by the main fire. (WI, MI, MN)
  • STAGING AREA – That location where incident personnel and equipment are assigned on a three (3) minute available status. (MN, MI)
  • STANDBY – A state of readiness to take immediate action following the Detection of a fire. Note Period of Alert. (ONT, MI, MN)
  • STRATEGY, FIRE SUPPRESSION – Determining where and how to fight a fire, having regard to staffing and servicing the control organization, in relation to the Behaviour of the fire as a whole. It presupposes a certain choice of Tactics but leaves the final determination of their application to decisions on the ground. (ONT)
  • STRAW BOSS – Note Fire Line Overhead. (ONT)
  • STRIKE TEAM – Specified combinations of the same kind and type of resources, with common communication and a leader. (MN)
  • STRIP BURNING – (1) Burning by means of strip firing. (2) In hazard reduction burning narrow strips of fuel and leaving the rest of an area untreated by fire. (WI, MN)
  • STRIP FIRING – Setting fire to more than one strip of fuel and providing for the strips to burn together. Frequently done in backfiring against a wind where inner strips are fired first to create drafts which pull flames and sparks away from the control line. (WI, MN)
  • SUCTION HOSE – A hose, reinforced to prevent collapse due to atmospheric pressure, used to draft water into a Fire Pump. Synonym – Intake Hose. (ONT, MI, MN)
  • SUPPRESS A FIRE – Extinguish a fire or confine the area it burns within fixed boundaries. (WI, MI, MN)
  • SUPPRESSANT – An agent used to extinguish the flaming and glowing phases of combustion by direct application to burning fuels. Note Short Term Retardant. (ONT)
  • SUPPRESSION – All the work of extinguishing or confining a fire, beginning with its discovery. (MI, MN)
  • SUPPRESSION CREW – Two or more persons stationed at a strategic location, either regularly or in an emergency, for Initial Attack and/or continuing work on fires. Synonym – Fire Crew. (ONT)
  • SURFACE FIRE – Fire that burns the surface litter, other loose debris of the forest floor, and small vegetation. (MI, WI, MN)
  • SURFACE FUEL – That fuel on and above the soil in the form of litter, twigs, branches, grass, low shrubs, and trees, etc. (MI)
  • SURFACE-TO-VOLUME RATIO – The ratio of the surface area of a fuel to its volume, using the same linear unit for measuring area and volume. (ONT, MI)
  • SURFACE TENSION – The elastic-like force in the surface of a liquid, tending to minimize the surface area and causing drops to form. (Expressed as Newton’s per meter or dynes per centimeter; there are 1,000,000 dynes per Newton.)
  • SURFACTANT – A surface active agent; any wetting agent.
  • SYNOPTIC CHART – A chart or map on which is represented the distribution of selected meteorological elements over a large area at a specified instant of time. Synonym – Weather Map. (ONT)T
  • TACTICS, FIRE SUPPRESSION – Determining exactly where and how to build fire Lines and what to do along these and other Control Lines in order to extinguish a fire, as determined by conditions of the moment and of the fire. (ONT)
  • TANDEM – A term to designate the use of two or more units of the same type (Fire Pumps, bulldozers, crews of fire fighters, etc.) working one in front of the other to accomplish a specific Fire suppression job. (ONT, MI)
  • TANK TRAILER – A specialized trailer on which is mounted a tank, a Fire Pump, hose and ancillary equipment. (ONT, MN)
  • TANKER – A specialized truck on which is mounted a tank, a Fire Pump, hose and ancillary equipment. (ONT, MI)
  • TASK FORCE – A group of resources with common communications and a leader temporarily assembled for a specific mission. (MN)
  • TECHNICAL SPECIALISTS – Personnel with special skills who are activated only when needed. Technical specialists may be needed in the areas of fire behaviour, water resources, environmental concerns, resource use, and training areas. (MN)
  • TEST FIRE – A controlled fire set to evaluate such things as fire behaviour, detection performance, control measures, etc. (WI)
  • THERMAL IMAGERY – the display or print-out of an Infrared Scanner operating over a burning fire. (ONT)
  • THERMOGRAPH – A recording thermometer or an instrument that records automatically and continuously the temperature on a chart. (ONT)
  • THUNDERHEAD – A cloud associated with an electrical storm, characterized by a large vertical column topped by a mushroom or anvil-shaped head. (ONT. MI)
  • TOOLS, HAND, FIRE – ADZE HOE (OSBORNE PATTERN) – A fire-trenching or digging tool, similar to a grub hoe, but with a sharp, tempered blade which is useful for heavy grubbing, trenching and cutting. FLAIL, FIRE any manufactured or improvised tool used to beat out a fire. Synonym – Swatter, Fire. MCLEOD TOOL – A short handled combination back-to-back rake and hoe. Particularly useful for scraping, raking and cutting in light Fine fuels as found in open pine stands and in hardwood regions. MOBERLEY TOOL – Similar to aMcLeod Tool but with shorter teeth and narrower cutting edge. PULASKI A combination chopping and trenching tool, which combines a single-bitted axeblade with a narrow adze-like trenching blade fitted to a straight handle. Useful for grubbing or trenching in Duff and matted roots. Well balanced for chopping. RAKE, FIRE (ASPHALT PATTERN) – A ten-tine rake with a combination steel and wood handle. Useful for fast removal of light dry cover such as leaves, Duff and needles. RAKE, FIRE (RICH TYPE) – a long-handled combination rake and cutting tool, the blade of which is made up of a single row of mowing-machine cutter teeth. Useful for trenching, scraping and cutting, particularly in leaves, pine needles and light Duff. Also known as a Rich Tool. SHOVEL, FIRE – A type of shovel specifically designed for use in constructing a Fire Line, having a tapered blade with both edges sharpened. Used for scraping, digging, grubbing and cutting. STEVENSON HOE – A long-handled raking and trenching tool having a broad, coarse-toothed cutting edge. (ONT)
  • TOPOGRAPHY – The physical form of any specified area of land. One of the factors affecting forest fire behaviour. (MI, MN)
  • TRACTOR PLOW – Any tracked vehicle with a plow for exposing mineral soil, with transportation and personnel for its operation. (MN, WI, MI)
  • TRAVEL TIME MAP – A map zoned to indicate the time required for fire fighting forces to reach a specified area from a specified fire headquarters. (ONT)
  • TREE FIRE – A fire in an individual tree or snag. (MI)U
  • UNDERCUT LINE – A fireline below a fire on a slope. Also called underslung line. (WI)
  • UNIFIED COMMAND – A method for all agencies or individuals who have jurisdictional responsibility, and in some cases those who have functional responsibility at the incident, to contribute to: Determining overall objectives for the incident, Selection of a strategy to achieve the objectives. (MN)
  • UNIT – That organization element having functional responsibility for a specific incident planning, logistic, or finance activity. (MN)
  • UNIT, HEAVY (BIG) – In Wisconsin DNR a complete fire fighting unit consisting of: (1) Heavy truck 2, 3, or 5 ton with water tanks and full complement of tools. (2) Heavy duty trailer capable of hauling a crawler tractor. (3) Crawler tractor (with or without blade) equipped with middle buster fire plow. (WI)
  • USE LEVEL – The appropriate ratio of liquid foam concentrate to water recommended by the chemical manufacturer for each class of fire.V
  • VISCOSITY – The relative ability of a fluid to resist flow. (ONT)W
  • WATER BOMBING – The act of dropping water or Short Term Retardant on a Forest Fire from an aircraft in flight. Note air Attack. (ONT)
  • WATER TENDER – Any ground vehicle capable of transporting specified quantities of water. (MN)
  • WATER THEIF – A type of bleeder valve designed for installation at convenient points in hose lines to permit drawing off water for filling Back-pack Pumps or other use without interfering with pump or nozzle operation. (ONT)
  • WET WATER – Water with added chemicals, called Wetting Agents, that increase spreading and penetrating properties of water by reducing its surface tension. (ONT, WI, MI, MN)
  • WETTING AGENT – A chemical that reduces the surface tension of water and causes it to spread and penetrate more effectively. (ONT, WI, MI, MN)
  • WILDFIRE – (1) An unplanned fire requiring suppression action, as contrasted with a prescribed fire burning within prepared lines enclosing a designated area, under prescribed conditions. (2) A free burning fire unaffected by fire suppression measures. (ONT, WI, MI, MN)
  • WINDFALL – Trees that have been uprooted or broken off by wind. (ONT)
  • WYE – (a) with valves – A hose fitting permitting two discharge lines to be taken from a single supply line. Valves located in the discharge ports permit complete control over both discharge lines to control pressures or to shut off one or both as desired. Note Reversible Siamese and Siamese. (b) Less valves – A hose fitting permitting two discharge lines to be taken from a single supply line, with no provisions to control pressures or stream flow. (ONT, MI, MN