EDUCATION & RESOURCES

Above-ground storage tank
Storage tank that is not buried. Compare Underground storage tank. Unburied tanks are more prone to physical damage, and leaks are released to the air or ground, rather than the soil surrounding a buried tank.

Accelerant
Flammable fuel (often liquid) used by some arsonists to increase size or intensity of fire. May also be accidentally introduced when HAZMAT becomes involved in fire.

Accelerator (also exhauster)
Portion of dry-pipe system that bleeds air or shunts air pressure below the clapper valve when sprinkler pipe pressure drop is sensed, thus speeding operation of the valve to fill the system with water.

Accountability
The process of emergency responders (fire, police, SAR, emergency medical, etc…) checking into and making themselves announced as being on-scene during an incident to an incident commander or acountability officer. Through the accountability system, each person is tracked throughout the incident until released from the scene by the incident commander or accountability officer. This is becoming a standard in the emergency services arena primarily for the safety of emergency personnel. This system may implement a name tag system or personal locator device(tracking device used by each individual that is linked to a computer).Willoughbyccfd5 23:52, 3 December 2006 (UTC)

Adapter
Plumbing accessories for connecting hoses and pipes of incompatible diameter, thread, or gender. See also reducer, increaser, double male, double female, water thief. May contain combinations, such as a double-female reducer. Adapters between multiple hoses are called wye, Siamese, or distributor, which see below.

Aerial apparatus
Fire truck having an attached extension ladder, nozzle, man-lift-bucket, or similar device raised using power from the truck. May also carry other portable ladders and tools.

Aerial canopy
Fuel type comprised of trees having few low branches, making it less susceptible to ignition by low-intensity fires.

Aerial firefighting (or air attack)
Use of aircraft in support of ground resources to combat wildfires, often most effective in initial attack in light fuels.

Air drop
Delivery of supplies or retardant from the air. Supplies can be dropped by parachute. Retardant is dropped in a single salvo, or one or more “trails”, the size of which is determined by the wind and the volume speed and altitude of the airtanker (usually no less than 200 feet above the drop zone).

Air monitoring meter
Electronic device for measuring the presence of one or more chemicals in air, such as oxygen, carbon monoxide, hydrogen sulfide or volatile organic compounds; may have preset danger threshold alarms.

Air operations
Group tasked with coordinating aerial-based observation, supply, rescue and suppression at a wildfire.

Air Tactical Group Supervisor or Air Attack
Coordinates air resources for attack of a fire.

Airbags
(1) inflatable device used for lifting or spreading; (2) vehicle safety device with potential explosion hazard during vehicle extrication if not already blown.

Airpack
Jargon for self-contained breathing apparatus (SCBA).

Airtanker
Fixed-wing aircraft certified by FAA as being capable of transport and delivery of 600 to 3,0000 gallons of water or other liquid or powder fire retardants. Formerly referred to as borate bombers” before borate-based retardants became less desirable. Often accompanied by a spotter plane.

Alarm
(1) system for detecting and reporting unusual conditions, such as smoke, fire, flood, loss of air, HAZMAT release, etc; (2) a specific assignment of multiple fire companies and/or units to a particular incident, usually of fire in nature; (3) centralized dispatch center for interpreting alarms and dispatching resources. See fire alarm control panel.

All companies working
Status report at fire scene indicating that available manpower is busy, and more resources may become necessary if incident is not controlled soon.

Ammonium nitrate
Component of ANFO; contents of two ships that exploded in Texas City Disaster, killing over 500 people, including all 28 volunteer firefighters at the scene.

Anchor point
An advantageous location, usually a barrier to fire spread, from which to start constructing a fireline. The anchor point is used to minimize the chance of being flanked (or outflanked) by the fire while the line is being constructed.

ANFO
Ammonium Nitrate Fuel Oil combination making a high explosive.

Apparatus
A term usually used by firefighters describing a piece of equipment, usually a company vehicle.

Apparatus
Fire engines, trucks, tankers, and combinations; can also refer to other equipment such as the SCBA.

APW
Air-pressurized water fire extinguisher, partially filled with water and then pressurized with an air pump; popular in the US in the 2 1/2-gallon size, rated 2A.

Aqueous Film-Forming Foam (AFFF)
(pronounced “A-Triple-F”, also called “Class A”) bubbles that act as surfactant to coat and penetrate ordinary fuels (e.g., wood, paper) to prevent them from burning at normal temperatures; also used on Class B” (oil/gasoline) fires to spread a non-volatile film over the surface of the fuel. Applied using educator or Compressed air foam system (CAFS) and pumped through firehose to a foam nozzle (or sometimes a less-effective fog nozzle).

Arson
The crime of maliciously (or perhaps recklessly) setting fire to property, especially a dwelling. Punishable in various degrees, depending upon the circumstances. Occasionally occurs as a psychotic act of a mentally ill firefighter.

Attack hose
(Attack Line) A use classification of a fire fighting hose connected to output of a pump or other pressure source (e.g., gravity). Firehose used to apply water or other fire fighting agent directly to a fire or burning substance. Typically of 2 1/2 inches (65 mm) diameter or less.

Attic ladder
Narrow, collapsible ladder used to access an attic space via a scuttle hole, which are often found in closets and other narrow passages. Also known as a closet ladder.

Authority Having Jurisdiction (or AHJ)
Organization or agency with legal authority over a given type of incident (e.g, fire, EMS, SAR, arson, HAZMAT); may change or overlap as incident changes, as where fire becomes arson investigation once danger is over, or Motor Vehicle Accident becomes police business after vehicle extrication, fire, and HAZMAT issues are complete.

Autoextended fire
Structure fire that has gone out a window or other opening on one floor and ignited materials above, on another floor or other space (attic, cockloft).

Automatic sprinkler
System of valves and pipes for automatically directing water to a fire when it is detected. May be normally pressurized with water (wet”) or with air (“dry”) depending upon the application. When a sprinkler-head (or sensor) detects fire/heat the valve opens releasing the water (hopefully onto the fire).

Available flow
Total amount of water that can be put on a fire, depending upon water supply, pump size, hoses, and distance to the fire. IC must assess available flow to determine whether additional apparatus or streams are required. See Fire flow requirement.

Back burning
Australian term, for Backfiring, above.

Backburn
Precautionary fire set downwind of main fire for controlled fuel clearing by backing” it into the main fire

Backdraft
A fire phenomenon caused when heat and heavy smoke (unburned fuel particles) accumulate inside a compartment, depleting the available air, and then oxygen/air is re-introduced, completing the fire triangle and causing rapid combustion.

Backfire
A fire set along the inner edge of a fireline to consume the fuel in the path of a wildfire and/or change the direction or force of the fire’s convection column.

Backfiring
A tactic used in wildland firefighting associated with indirect attack, by intentionally setting fire to fuels inside the control line. Most often used to contain a rapidly spreading fire, placing control lines at places where the fire can be fought on the firefighter’s terms.

Backflow preventer
Automatic valve used in hose accessories to ensure water flows only in one direction. Used in permanent fire department connections (FDC) to sprinklers and dry standpipes, as well as portable devices used in firefighting.

Bambi bucket
Collapsible bucket for lifting and moving water or other fire retardant with a helicopter. (Note: The name was in use many years before the trademark owner claimed it in 1983.)

Bank down
What the smoke does as it fills a room, banks down to the floor, creating several layers of heat and smoke at different temperatures — the coolest at the bottom.

Barrier
Any obstruction to the spread of fire. Typically an area or strip devoid of combustible fuel.

Base
(1) staging and/or command center location for fire operations; (2) starting location of a fire; (3) base camp location for eating, sleeping, etc., near staging or command center.

Bed ladder
The non-extending section of an extension ladder.

Berm
Soil heaped on the downhill side of a traversing fireline below a fire, to trap rolling firebrands.

Blackline
A condition where no combustible fuels remain between the fireline and the main fire.

Blowup
Sudden increase in fireline intensity or rate of spread of a fire sufficient to preclude direct control or to upset existing suppression plans. Often accompanied by violent convection and may have other characteristics of a firestorm.

Boiling liquid expanding vapor explosion (BLEVE)
Explosion of a pressure tank containing an overheated material when the vapor expansion rate exceeds the pressure relief capacity (e.g., steam boiler or LPG tank). If the contents are flammable, the rapidly released vapor may react in a secondary fuel-air explosion.

Boise Interagency Fire Center (BIFC)
The former name of the National Interagency Fire Center (see below); often pronounced as biff-see”.

Bomb Line
A preconnected attack line, typically 2 1/2 inch in diameter, used in the same manor and purpose as a Trash Line. Bomb Lines are stored either on the front bumper of the apparatus or in an exterior (exposed) side well. Bomb Lines are typically shorter length than Cross Lays, and are intended for use against dumpster fires, etc., where a longer length of hose (and consequent rebedding after the suppression is complete) is not desired.

Booster hose
Small-diameter fire hose (3/4-1 inch), often carried on booster reel, preconnected to pump of an engine (and the booster tank) for putting out small fires near the truck without having to connect to a fire hydrant; easily recovered with a motorized reel. Booster hose is also used for High Pressure Fog (HPF) applications.

Booster hose, booster pump, booster reel
Small solid hose on a reel connected to a small pump fitted to a water tank on a vehicle. Booster pump also refers to pump in a relay series for pumping uphill beyond the lift of the previous pump.

Box (Alarm)
Originally, a mailslot containing a notecard with a pre-planned response to an incident type. For example, a reported structure fire on Some Road would be tagged with Box 6; the notecard in Box 6 would contain the list of apparatus from various fire stations that should be dispatched to that incident. Assigning Boxes to areas (or even specific structures) significantly facilitated the process of getting the right tools to the right place on the initial dispatch, and helped eliminate the guesswork of which department has what on the fire scene. Boxes later evolved to contain escalation procedures – on the “2nd alarm”, the Box would contain the next group of apparatus from various fire stations etc. Modern CAD systems now abstract the Box Alarm concept and allow box definitions to be triggered based on arbitrary geographic area, time of day, incident type, weather and any other pre-planned situation. For a given hydranted area the “Summer” box will contain the usual response of Engine Truck and Rescue companies. In the winter, however, the box may be modified (automatically or manually) to include Water Tankers on the initial dispatch to handle the case of frozen hydrants.

Bresnan cellar nozzle
Rotating nozzle tip having two or more outlets forming water jets that propel the tip while spraying water in a circular pattern; conveniently attached to several feet (a meter) of rigid pipe with handles or legs for supporting the nozzle while it is suspended through a hole in the floor above.

Brush blade
Rake attachment for cutting or ripping brush and roots out of a fireline.

Brush hook
Cutting tool used to clear brush, longer than a machete, usually with a heavy, solid, curved blade bolted to the end of an arm’s-length handle.

Brush truck
Small fire truck outfitted for wildland fire. Also called a Type 6 Engine.

Bulk tank
Large tank designed to be transported to an incident and left; larger than a tote tank.

Bump up
To move to another location. Can refer to anything from moving to another location on a fireline, to an entire crew moving to another fire.

Bump back
Means to return to your previous location. In the “bump” system of fireline construction each firefighter works on a small piece of fireline with his or her tool perhaps slowly walking as the line progresses until a completed portion of line is encountered. Then the call to “bump up!” is heard and everyone ahead of the caller skips ahead one or more positions leaving the unfinished fireline for those coming up behind.

Bunkers (or “bunker gear”)
Colloquial term for protective pants and boots kept near a firefighters bunk (cot) for rapid deployment; more modernly includes firefighting jacket. Basis for command to Bunker up!” in preparation for hazardous duties. May also refer to entire protective clothing ensemble.

Burn out
Setting fire inside a control line to consume fuel between the edge of the fire and the control line.

Burning index
Relative measure of fire-control difficulty; doubling the index means twice the effort may be needed to control the fire (e.g., wind shift, heavier fuel load, etc.).

Burning period
The part of each 24-hour period when fires spread most rapidly; typically from 10:00 AM to sundown.

Bushfire
A bushfire is a wildfire that occurs in the forests, scrubs, woodlands or grasslands of Australia or New Zealand.

Call Fighter
Call firefighters respond as needed on a part time basis to all types of emergencies. Call firefighters train with their local engine companies in their districts. Call firefighters are utilized in three different ways. First Responder call firefighter units are those units that are staffed entirely by paid call firefighters. These firefighters respond to all emergency incidents within their jurisdictional areas and are supported by full-time companies from adjoining jurisdictions. “Supplemental” call firefighter units are those units that staff a second engine company from a station that is also staffed by a full-time company. These units respond to all multi-unit responses in their district and cover the station when the career companies are committed. “Augmentation” call firefighters are assigned to an existing career company and respond directly to the scene to augment that company’s staffing.

Cellar fire
Cellar fires are difficult to attack directly because firefighters have to pass through the hot gasses and smoke accumulated on the cellar’s ceiling to gain access to the cellar space. Cellars typically do not have good emergency egress points, adding to the danger.

Cellar pipe

Cellar Nozzle. A distributing type nozzle that is inserted through an opening in the floor and into the space below, typically a basement or cellar. The nozzle directs a broken stream horizontally, either extinguishing or controlling the fire enough to allow a direct attack to be safely made. Can also be used on top of other containers.

CFA 3-Thread
A type of coupling used by the CFA, it is used mainly on the Australian 64mm hose, it provides a very secure coupling, obviously the threading of the coupling is repeated 3 times, it is non-hemaphoradite.

Charged line
Fire hose under pressure from the pump at the engine.

Check valve
See backflow preventer

Chimney fire
Fast and intense fire in a chimney flue in which accumulated creosote and other combustion byproducts ignite.

Class A, B, C, D, K
Classes of fire extinguisher and corresponding type of fire they extinguish.

Closed area
An area in which specified activities or entry are temporarily restricted to reduce risk of human-caused fires.

Closed-circuit SCBA
See SCBA.

Closet hook
Pike pole under 5 ft long

Closet ladder
See Attic ladder.

Closure
Legal restriction, but not necessarily elimination, of specified activities such as smoking, camping, or entry that might cause fires in a given area.

CO2 extinguisher
Fire extinguisher that releases carbon dioxide gas to smother and cool a fire, such as a flammable liquid.

Cockloft
Structural space above ceiling and below rafters, often connecting adjacent occupancies and permitting fire to spread laterally, often unseen.

Cold trailing
A method of controlling a partly dead fire edge by carefully inspecting and feeling with the hand for heat to detect any fire, digging out every live spot, and trenching any live edge.

Collapse zone
The area around a structure that would contain debris if the building were to collapse.

Collyers Mansion
A modern firefighting term for a dwelling that is so filled with trash and debris that it becomes a serious danger to the occupants and emergency responders.

Combination nozzle
A low pressure Fog Nozzle (usually 120 to 150 lbf/in? or 820 to 1030 [[kilopascal|kPa)) that can be adjusted to produce a near straight stream. Also commonly referred to as a Taskforce Tip (TFT).

Company
Two or more firefighters organized as a team, led by a fire officer, and equipped to perform certain operational functions. Compare with platoon and unit.

Compartment Fire
An Isolated” fire or a fire which is “boxed in” or “closed off” from the rest of the structure. An example of this is a fire in a room where all the windows and doors are closed preventing the fire from spreading to other rooms.

Complex
Two or more individual incidents located in the same general area which are assigned to a single incident commander or unified command.

Compressed Air Foam System (CAFS)
A water / sofactant (foam) mixture, with compressed air forced into the mix. The result is a very homogeneous, small air bubble” distribution; the resulting suppression agent is the consistency of soggy shaving cream consisting of relatively pure surface area and little actual water. CAF is gaining favor in selected compartmental fire scenarios because of its high (explosive) conversion rate on top of the penetrative advantages of the sofactant. It is also inappropriate for many fire scenarios because of that conversion rate

Confine a fire
The least aggressive wildfire suppression strategy which can be expected to keep the fire within established boundaries of constructed firelines under prevailing conditions.

Conflagration
A large, typically urban, fire involving numerous structures; loosely defined as enveloping an area equivalent to one or more square blocks. Compare with firestorm.

Contain a fire
A moderately aggressive wildfire suppression strategy which can be expected to keep the fire within established boundaries of constructed firelines under prevailing conditions.

Control line
An inclusive term for all constructed or natural barriers and treated (retardant) fire edges used to control a fire.

Controlled burn
See Prescribed Burn.

Coyote tactics
A progressive line construction duty involving self-sufficient crews which build fireline until the end of the operational period, remain at or near the point while off duty (in a spike camp), and begin building fireline again the next operational period where they left off.

Crash Tender
A pump capable of spraying foam used at airports.

Creeping fire
Fire burning with a low flame and spreading slowly.

Cross lay
Arrangement of hose on a pumper such that it can be quickly unloaded from either side of the apparatus; often pre-connected to a pump outlet and equipped with a suitable nozzle.

Crown fire
A fire that advances from top to top of trees or shrubs more or less independent of a surface fire. Crown fires are sometimes classed as running or dependent to distinguish the degree of independence from the surface fire.

Crown out
A fire that raises from ground into the tree crowns and advances from treetop to treetop. To intermittently ignite tree crowns as a surface fire advances.

Dalmatian
Firehouse dog.

Dead lay
A load of hose on a pumper, but not connected to a pump outlet. Often used for larger supply lines.

Dead Man Zone
Unburnt areas around edges of brush fire.

Deck gun
A master stream device mounted to top deck of pumper.

Deflagration
An explosion with a propagation front traveling at subsonic speeds, as compared to supersonic detonation.

Deluge gun
A master stream device that can be positioned on the ground based on the need of the incident commander.

Deluge system
Type of sprinkler system in which sprinkler heads do not have individual valves, and the water (or other extinguishing agent) is disbursed from all sprinkler heads simultaneously when a central (or zoned) valve is triggered by a sensor (or manually). Typically reserved for industrial areas where rapid fire spread must be prevented at the cost of damaging non-burning materials.

Demob
Demobilization, or a crew being removed from working a fire.

Denver Door opener
Heavy pry bars connected with a hinge, one with an adjustable foot, used for prying open doors.

Denver tool (also called TNT tool)
A combination axe, sledgehammer, pry tool, ram, and D-handle pull tool used to gain forcible entry to buildings, automobiles, etc. during emergency situations.

Detection system
See Alarm system.

Detergent foam
See Aqueous Film Forming Foam.

Direct Attack
Any treatment applied directly to burning fuel such as wetting, smothering, or chemically quenching the fire or by physically separating the burning from unburned fuel.

Direct attack
Putting the wet stuff on the red stuff.” A form of fire attack in which hoses are advanced to the fire inside a structure and hose streams directed at the burning materials.

Discharge flow
The amount of water flowing from a fire hydrant when it is opened; compare to static flow and residual flow.

Dispatch
Refers to person or place designated for handling a call for help by alerting the specific resources necessary.

Distributor pipe
Portion of fire hydrant or sprinkler system connecting main loops to smaller loops where outlets are located.

Double female
Firehose adapter for connecting two male” couplings together; may also adapt different sizes on either side.

Double male
Hose coupling adapter with two male-threaded connectors back-to-back; used for connecting two female couplings together.

Dozer line
Fireline constructed by the front blade of a bulldozer or any tracked vehicle with a front mounted blade used for exposing mineral soil. Also catline.

Draft
The process of pumping water from a static source below the pump.

Drafting
Using a suction pump to lift water from below the pump, using a semi-rigid suction hose, typically to fill a portable reservoir that has other suction pumps (to relay) or siphon hoses running downhill to their nozzles.

Drills
Training during which an emergency is simulated and the trainees go through the steps of responding as if it were a real emergency.

Drip torch
Hand-carried fire-starting device filled with flammable liquid that is poured across a flaming wick, dropping flaming liquid onto the fuels to be burned.

Dry chemical
A fire extinguishing agent. It works by breaking the chemical chain reaction in the fire tetrahedron”.

Dry hydrant
A fire hydrant with a valve located at the bottom of the barrel, near the water main. The barrel of the hydrant remains dry until used. The prevents the hydrant from freezing in sub-zero temperatures. A dry hydrant is also an unpressurized pipe that can be used to draft water from a pond or lake.

Dry powders
Fire extinguishing agents for use on flammable metals. Each agent is typically designed for use on either a single metal or very similar metals.

Dry sprinkler
A sprinkler system having pressurized air (rather than water) in the distribution pipes until a heat-activated sprinkler head opens and releases the pressure, which opens a water valve (and possibly an accelerator valve) to flow water to the open head; used where the protected premises are not heated during freezing temperatures or where pressurized water in overhead sprinkler pipes could create another hazard.

Duff
Layer of decaying forest litter consisting of organics such as needles, leaves, plant and tree materials covering the mineral soil. Duff can smolder for days after a fire. Extinguishing smoldering duff is key to successful mop-up operations.

Eckert hook
Sharp hook on pike pole for cutting metal siding or roofs.

Eductor
Suction device operated by hose pressure to pull fluid from a reservoir and mix it with the hose stream; often used to add foaming or other materials to water streams.

Ejector
See Smoke ejector.

Electrical fire
A fire in which the primary source of heat is electricity, resulting in combustion of adjacent insulation and other materials; may be hazardous to attempt to extinguish using water.

Elevator key
Control panel override key to take elevator car to desired floor. May also refer to special tool used to open elevator shaft-protection doors from outside.

EMS
Emergency medical service(s).

Encapsulated suit
HAZMAT protective clothing used with SCBA inside the suit to protect a firefighter (HAZMAT technician) from gaseous contaminants. Also known as a Gas Suit.

Encoder
(1) Device for converting an input to a coded output; (2) tone-generating system for broadcasting one or more tone codes on a radio frequency to alert selected pagers and alarms; (3) alarm-system component that transmits coded sensor and subscriber information to a monitoring center to be processed into address and alarm-type information.

Engine
A fire suppression vehicle that has a water pump and, typically, is designed to carry firehose and a limited supply of water.

Engine
A truck outfitted for firefighting, specifically one outfitted to pump water. Generally, vehicles outfitted to pump water are called engines, while those which do not pump water (ladder trucks, tankers, rescues, for example) are not. Many rural fire engines carry a reservoir of water to pump, and use drafting and tankers to obtain further supply. Historically, an enjin” was a machine that only pumped water.

Engine
Any ground vehicle providing specified levels of pumping, water, and hose capacity but with less than the specified level of personnel.

Engine Company
A group of firefighters assigned to an apparatus with a water pump and equipped with firehose and other tools related to fire extinguishment.

Engine crew
A number of personnel trained and supervised to respond to incidents using an engine. Typically much smaller than a hand crew.

Engine house
[archaic] A firehouse housing an engine company.

Engine pressure
The pressure in a fire hose measured at the outlet of the pump.

Enhanced 9-1-1
Electronic system for automatic correlation of physical telephone lines with information about the location of the caller — a useful tool for dispatchers when the caller has an emergency but cannot speak.

Escape fire
An intentional fire ignited by a fire crew, usually in a grassland environment, to escape a dangerous situation.

Escaped fire
A fire, which has exceeded or is expected to exceed initial attack capabilities or prescription.

Evacuation
Removal of personnel from a dangerous area, in particular, a HAZMAT incident, burning building, or other emergency. Also refers to act of removing firefighters from a structure in danger of collapsing.

Evolution
Uniform sequence of practiced steps by squad carrying out common tasks such as selection and placement of ladders, stowing hoses in hose bed, putting hoses and tools into service in particular patterns; intended to result in predictability during emergencies.

Exothermic reaction
Chemical reaction giving off heat in the process, such as combustion.

Exposure
Property near fire that may become involved by transfer of heat or burning material from main fire, typically by convection or radiation. May range from 40 feet to several miles, depending on size and type of fire or explosion.

Extended attack
Situation in which a fire cannot be controlled by initial attack resources within a reasonable period of time. Committing additional resources within 24 hours after commencing suppression action will usually control the fire.

Extension ladder
A 20-60 foot ladder with one or more movable sections that extend beyond a base section, typically using a halyard rope and pulley mechanism for lifting and locking cams to latch the moving sections at a selected height.

Extinguisher
Device containing fire suppressant, often pressurized to expel suppressant when triggered by operator or an automatic release mechanism. Important to properly select type of extinguisher appropriate to type of material burning (wood, grease, electrical, etc.). May be portable or permanently installed for special suppression purposes, such as fires in aircraft engines, restaurant exhaust hoods, or computer rooms.

Extrication
Removal of a trapped victim such as a vehicle extrication, confined space rescue, or trench rescue; sometimes using hydraulic spreader, Jaws of Life, or other technical equipment.

Extrication gloves
Work gloves designed for vehicle extrication and other rescue applications, but not rated for firefighting. They resemble mechanics gloves but are made of tougher material, often Kevlar, and designed to protect against cuts from glass and metal.

FAST (or F.A.S.T.)
Firefighter Assist and Search Team (also called Rapid Entry Team or Rapid Intervention Team) firefighters assigned to stand by for rescue of other firefighters inside a structure; an implementation to support the Two-in, two-out rule; may have specialized training, experience and tools.
FDC (Fire Department Connection)
Location in which pumping apparatus hooks to a buildings standpipe and or sprinkler system. Usually a 3 female connection.

FFFP
Fluoroprotein film forming foam.
Fire alarm control panel
System for receiving and announcing location of fire based upon input from smoke, flame or heat detectors, or manual call points or pull stations.

Fire axe
There are two main types of axes used in firefighting, a flathead axe, which just has a wedge for cutting into objects. The second type is a pickhead axe which has a cutting wedge on one side, and then a pointed pick for penetration of objects.

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

Fire camp
Temporary camp established at large fires to provide food, rest, and other necessities to fire crews.

Fire code ( Fire safety code)
Regulations for fire prevention and safety involving flammables, explosives and other dangerous operations and occupancies.

Fire department keys
Special keys provided to firefighters to access a lockbox, located on some commercial buildings, containing additional keys required for entry or other safety features.

Fire edge
The boundary of a fire at a given moment.

Fire engineering
Scientific design of materials, structures and processes for fire safety

Fire escape
A building structure arranged outside to assist in safe evacuation of occupants during an emergency; may connect horizontally beyond a fire wall or vertically to a roof or (preferably) to the ground, perhaps with a counter-weighted span to deny access to intruders.

Fire extinguisher
See Extinguisher above.

Fire flow
The amount of water being pumped onto a fire, or required to extinguish a hypothetical fire. A critical calculation in light of the axiom that an ordinary fire will not be extinguished unless there is sufficient water to remove the heat of the fire.

Fire grenade
Glass bottle filled with carbon tetrachloride or similar fire extinguishing fluid; meant to be thrown and shatter at base of fire to mix with air to produce non-combustible mixture; Similar to extinguishers comprised of glass fixtures with spring-loaded clapper released by heat-fusible link. Limited effectiveness, and phased out in 1950s when better extinguishers became available.

Fire hazard
Materials, structures or processes that may result in creating a fire, permitting a fire to grow undetected, or preventing people from escaping a fire.

Fire hydrant
See hydrant.

Fire hydraulics
The study of pumps, hoses, pipes, accessories and tools for moving water or other extinguishing agents from a water supply to a fire.

Fire inspector
A person responsible for issuing permits and enforcing the fire code, including any necessary premises inspection, as before allowing (or during) a large indoor gathering.

Fire line
A boundary of a fire scene established for public safety and to identify the area in which firefighters may be working.

Fire load (Btu/sq ft)
An estimate of the amount of heat that will be given off during ordinary combustion of all the fuel in a given space; e.g., a bedroom or a lumberyard.

Fire Lookout
A person that keeps an eye for possible fire starts and conditions. They can work in a Fire Lookout Tower or perform the duty as a role for a fire crew on the fireline.

Fire lookout tower
A structure located at a high vantage point to house and protect the person performing the duties of a Fire Lookout.

Fire marshal
Administrative and investigative office for fire prevention and arson investigation.

Fire point
Temperature at which materials give off flammable gases that will sustain fire, typically higher than flash point. Temperature at flashover.

Fire prevention
Fire safety; standards for minimizing fire hazards.

Fire retardant
Any substance (except plain water) that by chemical or physical actions reduces flammability of fuels or slows their rate of combustion. See retardent slurry, AFFF, and Foam as examples.

Fire shelter
An aluminized tent offering protection by means of reflecting radiant heat and providing a volume of breathable air in a fire entrapment situation. Carried as a safety tool, fire shelters should only be used in life threatening situations, as a last resort, as severe burns or asphyxiation often result.

Fire shirt
Distinctive yellow shirts made of Nomex or other lightweight materials of low combustibility, used as uniform PPE of wildland firefighters.

Fire station alert system
Fire department dispatching system using radio controls to activate remote signals at designated fire stations and to transmit emergency information via audio or digital channels.

Fire streams
Water (possibly mixed with foam) emitted at nozzle and directed at burning materials.

Fire tetrahedron
The fire tetrahedron is based on the components of igniting or extinguishing a fire. Each component represents a property necessary to sustain fire: fuel, oxygen, heat, and chemical chain reaction. Extinguishment is based upon removing or hindering any one of these properties.

Fire triangle
Model for understanding the major components necessary for fire: heat, fuel and oxygen.

Fire wall
Building structure designed to delay horizontal spread of a fire from one area of a building to another; often regulated by fire code and required to have self-closing doors, and fireproof construction.

Fire watch
Fixed or mobile patrols that watch for signs of fire or fire hazards so that any necessary alarm can be quickly raised or preventive steps taken.

Fire weather
Weather conditions that affect fire vulnerability, fire behavior and suppression.

Fire-resistant
Materials designed or treated to have an increased fire point.

Firebreak
A natural or constructed barrier used to stop or check fires that may occur, or to provide a control line from which to work.

Firefighter
People who respond to fire alarms and other emergencies for fire suppression, rescue, and related duties.

Firefighter Assist and Search Team
See FAST.

Fireground
The operational area at the scene of a fire; area in which incident commander is in control. Also used as name of radio frequency to be used by units operating in the fireground, as in Responding units switch to fireground.

Firehose
See also hose, below.

Firehouse
Another term for Fire station. Where fire apparatus is stored and where full-time firefighters work.

Fireline
The part of a control line that is scraped or dug to mineral soil. Also called fire trail. More generally, working a fire is called being on the fireline.” May also refer to a “wet line” where water has been used to create a burn boundary in light fuels such as grass.

Fireline handbook
A small red booklet carried by U.S. firefighters on the firelines, as a quick reference on various firefighting topics.

Fireman’s key
Set of tools used for opening elevator doors from the lobby during rescues; come in many different shapes and sizes, each designed for a specific elevator type.

Firestorm
A conflagration of great enough proportions to noticeably create its own wind conditions.

Firestorm
Extreme fire behavior indicated by widespread in-drafts and a tall column of smoke and flame, where added air increases fire intensity, creating runaway fire growth.

Fit test
Periodic test of how well the facepiece of an SCBA fits a particular firefighter.
Flammable range, limits
The percentage mixture of fumes with air that will sustain fire; outside the limits the mixture is either too lean or too rich to burn.

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

Flare-up
Any sudden acceleration in rate of spread or intensification of the fire. Unlike blowup, a flare-up is of relatively short duration and does not radically change existing control plans.

Flash fuels
Fuels such as grass, leaves, draped pine needles, fern, tree moss and some kinds of slash, which ignite readily and are consumed rapidly when dry.

Flash point
Lowest temperature at which a material will emit vapor combustible in air mixture. Lower than fire point of same material.

Flashover
Simultaneous ignition of combustible materials in a closed space, as when materials simultaneously reach their fire point; may also result in rollover.

Fly
The moving portions of an extension ladder.

Foam
The aerated solution created by forcing air into, or entraining air in water containing a foam concentrate by means of suitably designed equipment or by cascading it through the air at a high velocity. Foam reduces combustion by cooling, moistening and excluding oxygen.

Fog nozzle
A nozzle that discharges water in small droplets. Oftentimes, the nozzles are adjustable, permitting the pattern to range from a straight stream to a narrow fog to a wide fog stream. Can also be designed to automatically adjust pressure depending upon selected pattern.

Fog Stream
A fire stream characterized by small droplets of water. The droplets are unable to travel very far, but absorb heat very quickly because of the high surface area they present.

Foot valve
Backflow preventer at inlet of suction hose used in drafting; helps avoid losing prime by keeping water from running back out of the suction hose.

Forcible entry
Gaining entry to an area using force to disable or bypass security devices, typically using force tools, sometimes using tools specialized for entry (e.g., Halligan, K-tool).

Forward lay
Procedure of stringing water supply hose from a water source toward a fire scene; compare with reverse lay.

Freelancing
Dangerous situation at an incident where an individual carries out tasks alone or without being assigned; violation of personnel accountability procedures.

Friction loss
Reduction of flow in a firehose caused by friction between the water and the lining of the hose. Depends primarily upon diameter, type and length of hose, and amount of water (GPM) flowing through.

Frontage
The size of a building facing a street.

Fuel load
The mass of combustible materials available for a fire usually expressed as weight of fuel per unit area (e.g., 20 tons per acre).

Fuel moisture
Percent water content of vegetation, an important factor in rate of spread, ranging from dead-fuel and fine-fuel moisture (FFM), of 10 percent or less, to live-fuel moisture (LFM), of 60 percent or more. FFM can be estimated by weighing calibrated wood sticks.

Fuel type
An identifiable association of fuel elements of distinctive species, form, size, arrangement, or other characteristics that will cause a predictable rate of spread or resistance to control under specified weather conditions.

Fuelbreak
A natural or manmade change in fuel characteristics which affects fire behavior so that fires burning into them can be more readily controlled.

Fully involved
Term of size-up meaning fire, heat and smoke in a structure are so widespread that internal access must wait until fire streams can be applied.

Gamewell
Brand of wind-up, fire alarm telegraph system for sending coded pulses to alert central alarm station of fire alarm activation; often still found in red boxes on street corners.

Gate valve
See also Hydrant Gate”. Valve in which the shutoff device slides across the flow of liquid to obscure the orifice usually activated by a screw mechanism. Compare “ball valve.

Glas-Master tool
Brand of specialized vehicle extrication tool, most notably including a glass cutting saw for removal of automobile windshields.

Goer
An incident with persons reported.

GPM
Gallons Per Minute or how many gallons are being pumped out of a piece of equipment every minute
GPM method (gallons per minute”)
Calculation of how much water, in GPM, will be necessary to extinguish a given volume of fire, under the circumstances (e.g., fuel class, containment, exposures, etc.).

Gravity tank
Water storage tank for fire protection; arranged above protected area to provide flow of water by gravity when needed.

Grease fire
A fire involving any manner of cooking oil or other flammable cooking or lubricating materials.

Ground fire
Fire that consumes the organic material beneath the surface litter ground, such as peat fire.

Ground ladder
A portable ladder designed to rest on the ground. Compare aerial ladder and roof ladder.

Halligan tool (or “Hooligan”)
Forcible entry tool with a pointed pick and a wedge at right angles on one end of a shaft and a fork or cat’s paw at the opposite end. Used in combination with maul or flat-headed axe for forcing padlocks, doors and windows. Based upon original design by Hugh Halligan of FDNY. Forms the irons” when nested with a flathead axe. Various shaft lengths provide mechanical advantage. Derived from the claw tool (fork and hook).

Halon
Chemical gas fire extinguishing or liquid agent for diminishing the combustion reaction rate by acting as a thermal ballast; used mainly in closed computer rooms, aircraft, and other high-value installations where corrosive chemicals or water extinguishers are judged inappropriate. Effective at low concentrations (5%) as compared with CO2 (34%). Being phased out with suitable replacements in most applications, with very restricted exemptions, due to international environmental concerns with this and other CFCs.

Halyard
Utility rope for raising or lowering moving parts of extension ladder.

Hand crew
A number of individuals that have been organized and trained and are supervised principally for operational assignments on an incident. In the United States, a typical hand crew is 20 in number.

Hard Line
A smaller hose about one inch in diameter used by firefighters to clean apparatus.

Hard suction hose
Non-collapsible sections of hose, usually 10 feet long, used when drafting.

Hazard
A source of danger of personal injury or property damage; fire hazard refers to conditions that may result in fire or explosion, or may increase spread of an accidental fire, or prevent escape from fire. Under worker safety and health regulations, employers have a general duty to provide a workplace free of hazards. See also fire prevention, and HAZMAT.

HAZMAT
Hazardous materials, including solids, liquids, or gasses that may cause injury, death, or damage if released or triggered.

Head of a fire
The most rapidly spreading portion of a fire’s perimeter, usually to the leeward or up slope.

Heavy fuels
Fuels of large diameter such as snags, logs, large limb wood, which ignite and are consumed more slowly than flash fuels.

Helispot
A natural or improved takeoff and landing area intended for temporary or occasional helicopter use, typically in remote areas without other access.

Helitack
A fire crew trained to use helicopters for initial attack, and to support large fires through bucket drops and the movement of personnel, equipment and supplies.

Higbee cut (Higby cut)
A tapered thread termination in a firehose coupling for avoiding cross-threading, the location of which is indicated by a notch cut into a single lug on a hose coupling. If the notches are aligned on mating couplings, the Higbee cuts are aligned and the threads will immediately engage when the swivel fitting is turned.

High Pressure Fog (HPF)
A suppression technique consisting of finely atomized water droplets at several hundred pounds per square inch of pressure. By far, one of the most efficient suppression techniques available. Advantages include a *very* high conversion rate, unmatched atmospheric cooling and control of thermal layers, very little wasted water (and consequent water damage), and the ease of managing a small diameter booster line (defined above) during application. Disadvantages are lack of distance, lack of penetration into various materials, and high risk of burns to the attack crew. HPF is quite popular in Europe, but was discarded in the U.S. due to different building construction and the resulting increase in disadvantages.

High-pressure system
A supplemental pump system used to pressurize the water supply, sometimes used during a large fire, or whenever more than one hydrant is being used.

High-rise building
Any building taller than three or four stories, depending upon local usage, requiring firefighters to climb stairs or aerial ladders for access to upper floors.

High-rise pack
A shoulder load of hose with a nozzle and other tools necessary to connect the hose to a standpipe.

High-rise pack
Hose bundle prepared for carrying to a standpipe in a high-rise building, usually consisting of 50 or more feet of 1 3/4-inch hose and a combination nozzle.

Hook
Forged steel hook at end of insulated pole of varying lengths; used for piercing and pulling building materials away from walls and ceilings. Similar to nautical gaff hook. Short hook with a pointed tip is a pike pole; longer hook on a San Francisco hook; two offset hooks on either side of tip is a universal hook; long p-shaped hook is a Boston rake for pulling plaster and lath; short hook with claw on opposite side of tip is either a gypsum hook or the narrower ceiling hook; pike pole with a short handle is a somewhat useless closet hook.

Hose
Flexible conduit for moving liquids under pressure; made of various materials including cotton, rubber or plastic (such as PVC); construction may be braided, woven, wrapped or extruded, often in layers (liner and jacket); hose construction and size differs according to its intended use (e.g., hard suction, attack, forestry, booster); typically stocked in standard lengths and coupled together with standardized fittings. See hose coupling.

Hose bed
Part of fire engine (or hose wagon) where hose is stored for transport and easy access; stocked in layers or rows for quick selection of the desired length, diameter and type of hose; may include hoses pre-connected” to pump outlets on the engine.

Hose bridge
Mechanical ramps permitting vehicle tires to roll over top of hose without pinching or damaging the hose. Sudden hose-pinch can cause dangerous backpressures in a running hose and at the pump and release of the pinch can cause a staggering surge at the nozzle end.

Hose cart
See Hose wagon.

Hose coupling
Rigid interlocking end-pieces on fire hose; used for connecting hose to hydrants or fire engine pumps and other hose appliances (nozzles, wyes, manifolds, strainers, etc); standardized sizes and threads or other (non-threaded) pressure-sustaining interlocks (e.g., Storz” or other “quarter-turn” connectors); lugs cams or pins are used to tighten and loosen couplings by hand or with a hose wrench.

Hose roller
Rigid frame with rollers designed to fit over windowsill or roof parapet to prevent chafing as hose is pulled across it. Can also refer to a machine designed for rolling hoses in preparation for storage.

Hose tower
Structure for hoisting hoses to permit them to drain and dry.

Hose wagon
A handcart, vehicle, or trailer adapted for storing and hauling hose and related equipment; used by industrial fire brigades with large buildings, or where supplemental hoses are needed beyond that normally carried on a fire engine; also used for taking attack hose into a high-rise and for returning dirty, wet hose to the station instead of loading the hose bed with it. Vehicular hose wagon may carry 1,000 to 3,000 feet of hose. May also include small booster pump.

Hose wrench
Tool for holding hose couplings against opposite turning forces (tighten/loosen); may be one of several designs for different shapes of cleats or lugs on couplings (round, flat, recessed, etc.), and also of different sizes according to the couplings being handled, and come in various combinations to minimize the number of different tools necessary on the fire ground. Also known as a Spanner wrench”.

Hot spot
A particularly active part of a fire.

Hot zone
Contaminated area of HAZMAT incident that must be isolated; requires suitable protective equipment to enter and decontamination upon exit; minimum hot zone distance from unknown material with unknown release is 330 feet (United Nations Emergency Response Guidebook); surrounded by warm zone” where decontamination takes place.

Hotshot crew
An extensively trained group of approximately twenty people which specializes in wildfire suppression with little or no outside logistical support.

Hotshot crew
Intensively trained fire crew used primarily in hand line construction, and organized primarily to travel long distances from fire to fire as needed rather than serving only one geographic location.

HPF
See High Pressure Fog.

Hurst tool
See Hydraulic spreader.

Hydrant
Pressurized water source for fire engine. May also be a dry hydrant” for drafting from static water source. Compare “standpipe”.

Hydrant Assist Valve
A valve connected to the hydrant by the first due engine allowing the second due engine to boost the pressure in the intake line. Used for hydrants with low pressure, attaching multiple engines to one hydrant, or boosting pressure in the intake line to accommodate for friction loss.

Hydrant Gate
A gate valve used to control water flow through one of the discharge ports on a hydrant with two or more ports. Typically, one fire hose is initially connected to one discharge and the hydrant gate is connected to one or more of the other outlets. This allows a second hose to be connected to a hydrant that is flowing water without shutting down the main valve to make the connection.

Hydrant wrench
Tool for opening valve of fire hydrant; may be simple spanner, box wrench, or adjustable wrench, or a specialized tool for use on anti-vandalism” valves. For example some valves require a magnet to activate a cam in order for the valve to be turned on.

Hydraulic spreader (Jaws of Life)
Mechanical levering device with hydraulic cylinders powered by a pump; used for forcible entry or spreading vehicle or structure parts to permit extrication of a victim. Also called Hurst Tool which is a type that includes cutter and ram/jacking features.

IAFF
Acronym, International Association Of Fire Fighters”.

IDLH
Any situation deemed Immediately Dangerous to Life and Health. More narrowly defined by OSHA. See main IDLH article. An area of maximum danger to firefighters.

IFSTA
Acronym, International Fire Service Training Association”. A major publisher of firefighter training materials.

Incident Command System (ICS)
System first developed to provide a command structure to manage large wildfires in the United States, now widely used by many emergency management agencies.

Incident Commander
The officer in charge of all activities at an incident. See Incident Command System.

Incident Safety Officer
The officer in charge of scene safety at an incident. See Incident Command System.
Indian pump
(aka Indian Tank) A brand of five-gallon water can, or back-pack bladder, featuring a short hose and hand pump for use in wildland firefighting.
Indian pump
Water vessel carried on one’s back, either a rigid can or collapsible bag, with a hose and telescoping squirt pump. Contains 5 US gal, and is used on hot spots and during mop up. Also called bladder bag (if collapsible), piss pump, or Fedco.
Indirect attack
A method of suppression in which the control line is located some considerable distance away from the fire’s active edge. Generally done in the case of a fast-spreading or high-intensity fire and to utilize natural or constructed firebreaks fuel breaks and favorable breaks in the topography. The intervening fuel is usually backfired; but occasionally the main fire is allowed to burn to the line, depending on conditions.
Indirect attack
Method of firefighting in which water is pumped onto materials above or near the fire so that the splash rains onto the fire, often used where a structure is unsafe to enter.
Infrared (IR) detector
A heat detection system used for fire detection, mapping, and hotspot identification.
Initial attack
First point of attack on a fire where hose lines or fuel separation are used to prevent further extension of the fire.
Initial attack
The actions taken by the first resources to arrive at a wildfire to protect lives and property, and prevent further extension of the fire.
Intake
Part of pump where water enters when pump forms partial vacuum.
Interface zone
Where urban firefighting meets wildland firefighting. Structures at the edges of wildlands are threatened and require skills and equipment of both disciplines.
Interface zone (also wildland/structural interface or urban/wildland interface)
The zone where wildfires threaten structures or structural fires threaten wildlands, such as in residential areas adjacent to forests. This requires both wildland firefighting and structural firefighting in the same location, which involve very different tactics and equipment.
Irons
The flathead axe mated with the halogon bar
Irons, or Set of irons
Pairing of a flat-head axe and a Halligan tool. A common combination used in forcible entry operations to gain access for search and rescue as well as interior fire attack.
ISO Rating
(Insurance Services Office Fire Insurance Rating) This is a rating published by the Insurance Services Office. Insurance companies use this number to determine homeowner insurance premiums.

J-bar
A stiff, j-shaped tool for reaching an inside door handle.

Jack-knifing
Jargon for position of articulated aerial ladder such that tractor is at an angle to the trailer; provides improved stability when ladder is hoisted, rotated and extended.

Jaws of Life
A Hurst tool. See hydraulic spreader.

Jet siphon
A venturi appliance used for moving large amounts of water from one reservoir tank to another by pumping a small amount of pressurized water into the jet to create a vacuum to move larger amounts of water.

K-tool
A forcible entry tool for disabling cylinder locks; used with a Halligan.

Kelly tool
A prying tool much like a Halligan tool without the right-angle pointed tip.

Knock down
To reduce the flame or heat on the more vigorously burning parts of a fire edge.

Ladder company
A group of fire fighters, officers and engineers that staff a ladder truck.

Ladder fuels
Flammable vegetation that helps a ground fire move into the canopy.

Ladder pipe
Nozzle attached to aerial ladder and used to direct heavy stream from advantageous height.

Ladder truck
A truck outfitted for fire which is operated by a ladder company, and in most cases is not outfitted to pump water. Not to be confused with engine.

Large Diameter Hose
(LDH) Fire hose with a diameter of 4 inches or greater. LDH is typically used to supply water from a fire hydrant to fire apparatus such as an engine or tanker.

LCES
Firefighter safety mnemonic for Lookouts, Communications, Escape routes, Safe zones.

Lead plane
Aircraft with pilot used to make trial runs over the target area to check wind, smoke conditions, topography and to lead air tankers to targets and supervise their drops.

Leatherhead (helmet)
A cover or protetive device worn by fire fighters in some countries, also slang denoting a fire fighter.

Left Handed Smoke Shifter
A device used to torture probationary firefighters during an overhaul phase; a crew chief will send his Probie to fetch one, but no such device actually exists. Each truck the probie visits will consequently “Not have one”, or “Another crew just took it”, but each truck operator will know for certain that, “THAT” truck might have one over there… The process will repeat until the probie has been to each truck looking for the device while the crew chief increasingly chides him to “hurry up” over the radio. Similar to military non-objects such as Relative Bearing Grease or winter air for tyres.

Let-burn policy
Administrative decision to defer fire suppression, perhaps because of wilderness and long-term forest conservation considerations.

Level A, B protective clothing
Different levels of encapsulation of firefighters used during HAZMAT incidents to minimize contamination.

Level I, II, III Incident
A HAZMAT term denoting the severity of the incident and the type of response that may be necessary, where Level III is the largest or most dangerous.

Life line
A trademark for a wireless emergency call unit that triggers a telephone call to an emergency dispatcher when a button is pressed.

Life net
Portable net for attempting to catch victims falling or jumping from upper floors of burning structure.

Life safety code
NFPA publication.

Life safety line
A rope used where its failure could result in serious injury; a rope used for connecting a firefighter/rescuer to a fixed anchor point or to another person.

Light ’em, fight ’em
Derogatory term for wildland crew with a reputation for igniting its prescribed burns carelessly.

Light Water
An additive to use with water in the extinguishing of petroleum and similar fires.

Line loss
See friction loss.

Litter
Surface buildup of leaves and twigs.

Live line
A fire hose under pressure from a pump. Also, an energized electrical line that may cause a hazard to firefighters.

Loaded stream
A hose stream that has had a surfactant added to assist in penetrating burning materials.

Longline
Helicopter arrangement for lowering external loads into areas not available for landing.

Lookouts
(1) Safety person positioned to monitor the location and behavior of a fire, ready to signal a crew to escape; (2) Fire lookout tower or fire tower, often on mountain-tops, for viewing the surrounding countryside and watching for signs of fire; (3) Fire lookout, the person who works in the fire lookout tower; (4) The L” of “LCES” safety mnemonic.

Mass casualty incident (MCI)
Any incident that produces a large number of injured persons requiring emergency medical treatment and transportation to a medical facility. The exact number of patients that makes an incident mass casualty” is defined by departmental procedures and may vary from area to area.

Master box
An alarm system in which a local fire-alarm system triggers a fire alarm box (the master box) to signal the fire condition to a central monitor.

Master stream
A large nozzle, either portable or fixed to a pumper, capable of throwing large amounts of water relatively long distances.

Mattydale
A volunteer fire department, located north of Syracuse, NY, credited with the invention of the Mattydale Lay. The Mattydale Lay is often simply referred to as a “Mattydale” or (now) a “Cross Lay”. The engine on which the Mattydale was invented and installed is currently on display at the FASNY museum

Mattydale Lay (Mattydale Load)
The concept of storing preconnected Attack Lines on an engine, as well as storing them such that they are presented at the sides of the apparatus instead of the rear. Commonly called a Cross Lay, the technique allows for rapid deployment of attack lines from either side of the apparatus.

McLeod
Hand tool used in fireline construction, consisting of a combination rake and hoe.

Means of egress
The way out of a building during an emergency; may be by door, window, hallway, or exterior fire escape; local fire codes will often dictate the size. location and type according to the number of occupants and the type of occupancy.

Medium-diameter hose
A hose with diameter between 2 1/2 and 4 inches.

Mop-up
Extinguishing or removing burning material near control lines, felling snags, and trenching logs to prevent rolling after an area has burned, to make a fire safe, or to reduce residual smoke.

Multigas detector
Measuring device designed to indicate concentrations of four selected gases, such as oxygen, carbon monoxide, volatile organic compounds, hydrogen cyanide, etc.

Multiple alarms
A request by an incident commander for additional personnel and apparatus. Each department will vary on the number of apparatus and personnel on each additional alarm.

Mutual aid
An agreement between nearby fire companies to assist each other during emergencies by responding with available manpower and apparatus.

Mutual aid
Cross-jurisdictional assistance with emergency services by pre-arranged agreement.

National Fire Protection Association (NFPA)
Fire and safety standards organization; issues various wildfire-oriented standards related to clothing, tactics, equipment, etc.

National Hose (NH)
National Standard Thread (NST) design of threaded couplings used on fire hose in various diameters.

National Interagency Fire Center (NIFC)
Coordination facility in Boise, Idaho, operated by several U.S. agencies to provide logistics, weather information and resource coordination for wildfire suppression across the U.S. (formerly BIFC).

National Wildfire Coordinating Group
Coordination agency located in Washington, D.C. which sets national standards for firefighter training and publishes training manuals.

NFPA
Acronym “National Fire Protection Association”. A standards and best practice body for the fire service. Slang: Not For Practical Application. This is firefighter slang referring to the seemingly ‘useless’ regulations of the NFPA. This phrase is commonly used by rural fire departments whose chiefs or officers operate “old school”, instead of “by the book”. Slang: “No Free Publications Available” referring to publications that “all are encouraged to practice” yet are prohibitively expensive, as in “That standards document is NFPA.” The NFPA slang is typically used in smaller fire departments where such a purchase would be a non-reimbursed out of pocket personal expense.

NFPA
The National Fire Protection Association, a research group which sets a number of standards and best practices for *firefighting, equipment, and fire protection in the United States, and also adopted in many other countries. Also, slang for No Free Publications Available”; used to reference any “must-have” documents that are prohibitively expensive.

NIFTI
Naval InFrared Thermal Imager. A device used aboard naval ships to help locate hotspots where fire or personnel may be located in a dense smoke environment.

NIOSH
National Institute for Occupational Safety and Health. A U.S. agency responsible for investigation of workplace deaths, including firefighters.

Nomex
Brand of approved, fire retardant, synthetic, aramid cloth and thread used in personal protective equipment for wildland firefighting, and jumpsuits.

Nozzle
A device attached to the end of a fire hose that directs, shapes and regulates the flow of the water or fire fighting agent pumped into the hose. May have a control valve.

Nozzle pressure
Pressure in a fire hose measured at the nozzle.

Nozzle reach
The distance a fire stream will travel from the nozzle tip before breaking up or evaporating due to air friction or heat.

Nozzle reaction
The force felt when water is pumped through a nozzle, e.g., 350 US gallons per minute (22 L/s) would produce a force of 40 pounds force (180 N) against the firefighter holding the nozzle.

Nozzle tip
Portion of firehose that forms the fire stream as it leaves the hose. Can be solid, fog, or other specialty nozzle (e.g., piercing, Bresnan cellar nozzle, wand tip, etc.).

Occupancy
Zoning and safety code term used to determine how a structure is permitted to be used and occupied, which in turn dictates the necessary safety structures and procedures.

Occupancy class
General categories of structures for purpose of safety planning, such as for hospital, assembly, industrial, single-family dwelling, apartment building, commercial, etc. Further broken down by types of hazards associated with particular occupancies, such as gas stations.

Occupant use hose
Light-weight firehose coupled to standpipe for emergency use by building occupants prior to arrival of firefighters. Often accessible by breaking glass to unlock secure enclosure.

Offensive attack
Method of firefighting in which water or other extinguisher is taken directly to the seat of the fire, as opposed to being pumped in that general direction from a safe distance.

On-call
Personnel who can be summoned (and paid) when necessary to respond to an incident; a type of volunteer” fire department.

One-hour fuel
Vegetation with large surface-to-mass ratio, a so-called fine fuel” (along with 10-hour) that quickly reaches critical (inflammable) moisture levels (fine fuel moisture FFM) when exposed to heat; compare with 100-hour or 1000-hour fuels (i.e. live fuel moisture LFM) which take much more heat to ignite.

Open-circuit SCBA
See SCBA. Exhaled air is not reused by the system.

OSHA
U.S. government agency concerned with regulating employee safety, particularly in hazardous occupations such as firefighting.

Outside fire
Urban fire not inside a building or vehicle, often found to be burning trash which could extend to nearby structures or vehicles if not dealt with properly. A suburban, interface, or rural outside fire could also be a wildland fire.

Outside stem and yoke valve (OS&Y)
Type of gate valve actuator arranged such that the valve stem moves in and out of the handle, thus externally indicating whether the valve is open or shut, unlike the more common gate valve wherein the stem rotates and only the gate moves up and down inside the fixture.

Overhauling
Late stage in fire-suppression process during which the burned area is carefully examined for remaining sources of heat that may re-kindle the fire. Often coincides with salvage operations to prevent further loss to structure or its contents, as well as fire-cause determination and preservation of evidence.

Overhead
Personnel assigned to supervisory positions, including Incident Commander, Command Staff, General Staff, Branch Directors, Supervisors, Unit Leaders, Managers, and staff.

Oxidizer
A hazardous material containing oxygen that can combine with adjacent fuel to start or feed a fire.

Palmer drought severity index (PDI)
Technique for measuring impact of soil moisture changes on vegetation, for predicting fire danger and fire behavior.
Panic doors, panic hardware
Fire safety appliance permitting locked doors (typically self-closing) to be opened from the inside when pressed with sufficient force, thus permitting a person to open the door without having to turn a knob or lever.

Parallel attack
Fire containment method where crews constructs fireline at some distance from the edge of the fire (e.g., 100 yards) and then burn out the fuel in the buffer as the fireline is completed.
PASS device, personal alert safety system
An alarm device which signals that a firefighter is in trouble. It can be activated manually by the firefighter, or activates automatically if the firefighter stops moving. May be integral to SCBA or separately activated.

Passport (accountability)
System in which each firefighter has an identification document that is collected by the person in charge of accounting for the current location of the respective individuals, and returned to the firefighter when he or she leaves the dangerous area.

Perennial grasses
An extremely volatile fuel, after curing, in May, June, July, which can lead to large, fast fires that may reach larger fuels.

Personal alert safety system
See PASS device in Glossary of firefighting equipment.

Personnel accountability report
End-result of personnel accountability system. Best report is all hands, AOK worst is squad missing.

Personnel accountability system
Tag, ‘passport’, or other system for identification and tracking of personnel at an incident, especially those entering and leaving an IDLH area; intended to permit rapid determination of who may be at risk or lost during sudden changes at the scene.

Pickheaded axe
Standard fire axe having a 6 or 8 pound (2.7 to 3.6 kg) steel head with a cutting blade on one edge and a square, pointed pick on the opposite side. Come in various handle lengths.

Pike pole
See Hook.

Platoon
A subdivision of a fire company, led a fire officer of either the rank captain or lieutenant, such that one of several platoons is assigned to duty for a specified period. Also called a watch”.

Plec-Tron
Jargon, brand-name of early radio-frequency paging system for summoning firefighters.

Point of origin
An element of fire behavior, indicating where a fire began, supporting further analysis of where the fire went or will go; evidence of specific origin is often obscured or destroyed by suppression tactics.

Pompier ladder
A style of ladder that is also known as a Scaling Ladder”. It is used to climb from one window to another. It differs from other ladders in that it does not rest on the ground it instead uses a large hook at the top to attach to a window sill. The word “Pompier” is French for fireman.

Portable water tank
Collapsible reservoir used for storing water transported to fireground by tanker. May be inflatable or supported by a frame.

Positive pressure
Pressure at higher than atmospheric; used in SCBA facepieces and in smoke-proof stairwells to reduce entry of smoke or fumes through small openings.

Positive Pressure Ventilation (PPV)
Ventilation of an area by the use of a fan to push clean air into that space and controlled use of openings for the escape of smoke and gasses.

Post indicator valve (PIV)
A type of valve used for underground sprinkler shutoff, having a lockable actuator atop a post with a window indicating open” or “shut” status of the valve.

Pre-fire, pre-incident planning
Information collected by fire prevention officers to assist in identifying hazards and the equipment, supplies, personnel, skills, and procedures needed to deal with a potential incident.

Pre-planning
Fire protection strategy involving visits to potentially hazardous occupancies for inspection, follow-up analysis and recommendations for actions to be taken in case of specific incidents.

Preconnect
Firehose on a fire engine which has one end connected to a pump outlet, and usually a nozzle attached to the other end. May also be a preconnected inlet hose (e.g., soft suction). Reduces steps at scene of fire.

Prescribed burn
Deliberately ignited fire for the purpose of forest or prairie management, often to remove heavy fuel buildup or simulate natural cycles of fire in an ecosystem. Also called controlled burn even if it becomes uncontrollable.

Probie
(also rookie) new firefighter on employment probation (a period of time during which his or her skills are improved, honed, tested, and evaluated).

Progressive hose lay
A method of deploying hoses along firelines during suppression and as they are built and reinforced, typically using 1 1/2-inch supply lines, gated wyes and 1-inch lateral lines with nozzles (or at least spigot valves) every 100 feet or so. As the line progesses, more hoses and valves are added.

Project fire
Any large fire requiring extensive management and the establishment of a temporary infrastructure to support firefighting efforts, such as fire camps.

Public alarm
Means for public to report a fire, includes telephone, street-corner pull-boxes, building pull-stations, and manual bells or sirens in rural areas.

Pulaski
Combination axe and grub hoe tool with a straight handle, used for building handline. Also known as P-tool”.

Pump operator, technician
(also a chauffeur) person responsible for operating the pumps on a pumper and typically for driving the pumper to an incident.

Pumper
Vehicle apparatus for pumping water and other fire suppressants. See fire engine.

Pumper company
Squad or company that mans a fire engine (pumper) and carries out duties involving getting water to the fire.

Pyrolysis
Process of converting a solid substance to combustible fumes by raising its temperature. See also vaporization of liquids.

Quint
Type of firefighting apparatus with five defining attributes. The Quint Truck is both a Pumper and a Ladder Truck. A Quint” has: 1. a pump, 2. hose, 3. a water tank, 4. ground ladders, and 5. an aerial ladder.

Rabbit Tool
A hand powered portable hydraulic ram, specially designed for insertion between a door and its frame for rapid forcible entry.

Radiant extension
Fire that has transferred ignition heat to adjacent materials across open space. One reason some city fire codes prohibit windows facing each other in adjacent warehouses.

Rapeller
Crew of specialist hot-shot firefighters who are trained to access a fire area by sliding down ropes suspended from a hovering helicopter. Also used for delivering wilderness first aid if a rapeller is an EMT.

Rapid entry team
See FAST.

Rapid intervention team
See FAST.

Ready team
A company of firefighters waiting to be relieve another company.

Reburn
(1) Repeat burning of an area over which a fire has previously passed, but left fuel that later ignites when burning conditions are more favorable; (2) An area that has re-burned.

Recovery
Location and removal of deceased victims. Also, the time needed for a firefighter to spend in rehab before being considered ready to continue working the incident.

Red card
Credentials issued to qualified wildland firefighters, listing their qualifications and specialties.

Red-flag day
Weather conditions creating a critical fire hazard, may require closing the forest to non-emergency activities in order to minimize the risk of accidental wildland fires.

Reducer
Plumbing adapter for connecting hoses of two different diameters; may also be double male or double female connections of different sizes.

Reflash Watch
A person assigned to observe and monitor an extinguished fire, to ensure that it does not reflash or re-kindle.

Reflash, re-kindle
A situation in which a fire, thought to be extinguished, resumes burning.

Rehab, Rehabilitation sector
An area for physical and mental recuperation at a fire scene, usually equipped with beverages, and chairs, isolated from environmental extremes (cold, heat, noise, smoke). This rest area enables firefighters to relax, cool off (or warm up) and regain hydration by way of preventing injury. An EMT may be assigned to monitor firefighter vitals when they enter and leave rehab.

Relief valve
A valve set to open at a specified pressure so as to not exceed safe operating pressure in hoses or pumps.

Rescue
Physical removal of a live person or animal from danger to a place of comfort.

Rescue company
Squad of firefighters trained and equipped to enter adverse conditions and rescue victims of an incident. Often delegated to a truck company.

Rescue Engine
A single piece of fire apparatus that can operate as either a rescue or an engine. This apparatus normally is outfitted with heavy rescue equipment, hoselines, pump, water tank, etc.

Residential sprinkler system
A sprinkler system arranged for fire suppression in a dwelling.

Residual pressure
The amount of pressure in a hydrant system when a hydrant is fully open, such as during a fire; should be engineered to provide domestic supply of water to homes and businesses during a large fire in the district.

Reverse lay
The process of stringing hose from a fire toward a source of water, i.e., a fire hydrant.

Ringdown (radio)
A radio, incorporating a selective calling capability, has an attention-getting device triggered by a dispatching center. A triggered device emits a sound alerting staff at a fire station, in an ambulance, on a vehicular radio or at a vehicular data terminal that an emergency call is pending. The act of ringing down a station may ring bells, activate a klaxon, turn off gas-fired cooking appliances, activate a volunteer alerting siren, turn on lights, and activate loudspeakers over which the call details are announced. Some systems use the voice path of a private line telephone circuit or a voice channel on a microwave radio instead of a two-way radio. Ringing down a vehicle may cause the radio or data terminal itself to beep continually until an acknowledge” button is pressed.

Ringdown (telephone)
An Automatic ringdown circuit consists of two phones at different locations. When either phone goes off-hook, the one at the other end instantly rings.

Roof ladder
A single-section ladder with hooks on one end. The hooks are put over the ridge or peak of a roof to hold the ladder in place. Compare with aerial ladder and ground ladder.

Rope hose tool
Short strap or rope with a hooks at both ends for wrapping around a charged hose to secure it in position or to assist in moving it.

Run card system
A system of pre-planning for fire protection in which information about specific detectors, hazards, or other emergency response plans is indexed by location, for rapid reference during an alarm.

S-130/S-190
The basic wildland fire training course given to all U.S. firefighters before they can work on the fire lines.

Safety zone
An area cleared of flammable material used for escape in the event the line is outflanked or in case a spot fire causes fuels outside the control line to render the line unsafe. In firing operations, crews progress so as to maintain a safety zone close at hand allowing the fuels inside the control line to be consumed before going ahead. Safety zones may also be constructed as integral parts of fuel breaks; they are greatly enlarged areas which can be used with relative safety by firefighters and their equipment in the event of blowup in the vicinity.

Salvage, salvage cover
Heavy-duty tarpaulins folded or rolled for quick deployment to cover personal property subjected to possible water or other damage during firefighting.

SAR
See Search and rescue.

Sawyer
Chainsaw crew, may also include faller” or “feller” who is qualified to cut down trees or snags perhaps while the tree or snag is burning.

SCBA
Self Contained Breathing Apparatus, or air-pack, worn by firefighters to protect against breathing toxic fumes and smoke, or where the air has insufficient oxygen. Often incorrectly called oxygen mask” by laypersons. Typically of open circuit style with a supply of compressed air where expired air is exhausted, rather than closed circuit where it is filtered, re-oxygenated from compressed oxygen, and inhaled again which is used where an air supply is needed for an extended period (up to four hours).

Scene safety
Steps taken at or near an emergency scene to reduce hazards and prevent further injuries to workers, victims or bystanders.

Scuttle hatch
Ready-made opening in roof that can be opened for vertical ventilation.

Search and rescue (or SAR)
Entering a fire building or collapse zone for an orderly search for victims and removal of live victims. Becomes recovery” if victims are not likely to be found alive.

Secondary line
Any fireline constructed at a distance from the fire perimeter concurrently with or after a line already constructed on or near to the perimeter of the fire. Generally constructed as an insurance measure in case the fire escapes control by the primary line.

Sector
A physical or operational division of an incident; an area supervised as a branch in the Incident Command System. A typical system for structure fires names the front” of the building “sector “A” and continues clockwise around the building (B, C, D) with interior sectors denoted by the floor number (1, 2, 3, etc.) . A “rehab” sector is one example of an operational division at an incident where personnel are assigned after strenuous work in another sector.

Self-contained breathing apparatus
See SCBA

Shoulder load
The amount of hose a single firefighter can pull off a hose wagon or pumper truck and carry toward the fire.

Shove knife
Semi-rigid metallic blade of various shapes and sizes used for forcing spring latches during forcible entry.

Siamese
Hose coupling for merging two streams into one, i.e., two female coupling inlets and one male coupling outlet.

Sides A, B, C, and D
Terms used by firefighters labeling the multiple sides of a building starting with side A or Alpha being the front of the structure and working its way around the outside of the structure in a clockwise direction. This labels the front side A or Alpha, the left side B or Bravo, the rear side C or Charlie, and the right side D or Delta.

Size-up
Initial evaluation of an incident, in particular a determination of immediate hazards to responders, other lives and property, and what additional resources may be needed. Example: Two-story brick taxpayer with heavy smoke showing from rear wooden porches and children reported trapped.

Skidder unit
Pre-configured tank, pump, hose for attachment to a logging skidder (large 4-wheel-drive tractor with a dozer blade, winch or grapple) to be carried to a fireline.

Slash
Debris resulting from such natural events as wind, fire, or snow breakage; or such human activities as road construction, logging, pruning, thinning, or brush cutting. It includes logs, chunks, bark, branches, stumps, and broken under-story trees or brush.

Slip-on
A small water pump and tank that can be temporarily mounted on a pickup or other truck.

Slopover
Fire spreading outside the boundaries of a control line.

Slug
Humorous pejorative term for those believed to be doing less work than you. Heli-slug” for helitack, “camp slug” for fire camp support personnel, “engine slug” for engine crew member, etc.

Slurry bomber
See Airtanker.

Small-diameter hose
Generally accepted to be fire hose 3 or less in diameter.

Smoke detector
(1) part of a fire alarm system that detects and signals presence of smoke; (2) self-contained household device for same purpose as (1) but with its own noisemaking device.

Smoke ejector
Powerful fan for moving large amounts of air and smoke as part of ventilation task while fighting fire in a burning structure. May be operated by electricity or gas motor for positive or negative pressure ventilation.

Smoke explosion
See backdraft.

Smoke-proof stairwell
Building structure which isolates escape stairwells with relatively fireproof walls, self-closing doors, and positive pressure ventilation, to prevent smoke or fumes from entering the stairwell during evacuation of occupants during a fire or other emergency.

Smokechaser
Colloquial term for a wildland firefighter. Now mostly archaic, except in Minnesota where state Department of Natural Resources firefighters are officially known by that name.

Smokejumper
A specifically trained and certified firefighter who travels to remote wildfires by fixed-wing aircraft and parachutes into a jump spot – that may include trees – close to the fire.

Smoldering
A fire burning without flame and barely spreading.

Soda-acid extinguisher
Weak water/acid solution inside a pressure vessel which activates bicarbonate of soda when triggered, expelling water” (mixture) under pressure from the resulting carbon dioxide. Obsolete and often replaced with an APW or multipurpose extinguisher.

Soft suction hose, soft sleeve
A short piece of fire hose, usually 10 to 20 feet long, of large diameter, greater than 2.5 inches (65 mm) and as large as 6 inches, used to move water from a fire hydrant to the fire engine, when the fire apparatus is parked close to the hydrant.

Solid Stream
A fire stream emitted from a smooth-bore nozzle. This fire stream has the greatest reach and largest drops of water.

Solid stream
Fire stream from round orifice of nozzle. Compare straight stream.

Spanner
Rigid tool for tightening or loosening firehose couplings.

Special egress control device
Locking device on doors used for delaying opening for short period (10-15 seconds) after release is pressed. Permitted as panic hardware in limited circumstances. May also refer to a security system that releases electronic door locks when a fire alarm is activated, such as in stairwells of a high-rise building.

Spike camp
Remote camp usually near a fireline, and lacking the logistical support that a larger fire camp would have.

Spotting
Behavior of a fire producing sparks or embers that are carried by the wind and which start new fires (spot fires) beyond the zone of direct ignition by the main fire. A cascade of spot fires can cause a blowup.

Spray nozzle
See fog nozzle.

Sprinkler system
Fire suppression system in a building, typically activated by individual heat-sensitive valves, or remotely controlled by other types of sensors, releasing water onto the fire. May be wet” (water-filled) or “dry” (air-pressurized).

Staging
Sector of incident command where responding resources arrive for assignment to another sector. Often an essential element in personnel accountability program.

Standard operating procedure, guideline (SOP or SOG)
Rules for the operation of a fire department, such as how to respond to various types of emergencies, training requirements, use of protective equipment, radio procedures; often include local interpretations of regulations and standards. In general, procedures” are specific, whereas “guidelines” are less detailed.

Standpipe
System of pipes inside a building for conducting water for firehose attachments; may be pressurized with water (wet”) or remain “dry” until activated in an emergency; supplied either from a fire hydrant attachment or from a fire engine’s pump. Permits firefighters to reach higher levels of tall buildings without having to run hoses up the stairs.

Static pressure
The pressure in a water system when the water is not flowing.

Steamer connection
A Siamese inlet to a standpipe or sprinkler system. Named for early application of steam engines for pumps.

Steamer outlet
Large outlet of fire hydrant.

Storz coupling
A type of coupling used on fire hose. The coupling is sexless, and secures with a 1/4 turn of the coupling. The coupling may or may not have some sort of locking device.

Straight Stream
A fire stream generated by a combination nozzle, characterized by a long reach and large water drops. It is essentially the narrowest of fog patterns that can be produced.

Straight stream
Round, hollow stream formed as water passes a round baffle through a round orifice (e.g., on an adjustable nozzle.) Compare solid stream.

Strainer
1) A large metal device attached to the end of a suction hose that prevents debris from entering the hose or the pump. 2) A stationary accumulation of debris in a moving body of water.

Stretch
Command to lay out (and connect) firehose and nozzle.

Strike team
Specified combinations of the same kind and type of resources, with communications, and a leader.

Structure fire (or structural fire”)
A fire in a residential or commercial building. Urban fire departments are primarily geared toward structural firefighting. The term is often used to distinguish them from wildland fire or other outside fire, and may also refer to the type of training and equipment (e.g., structure PPE”).

Suction hose
A large, semi-flexible and non collapsible hose used to move water from a static source such as a pond, pool or storage tank to a fire pump by means of suction. The whole process is often known as drafting”. Should not be used to connect pressurized hydrants to pumps.

Supply line, supply hose, large-diameter hose
Fire hose, usually larger than 2.5 inches in diameter, used to transport water from one source to another, such as from a hydrant to a fire engine or from one engine to another. Short pieces of this hose used to attach to a hydrant are often called Soft Suction” (see above).

Suppression
All the work of extinguishing or confining a fire beginning with its discovery.

Suppression crew
Two or more firefighters stationed at a strategic location for initial action on fires. Duties are essentially the same as those of individual firefighters.

Surface fire
Fire that burns loose debris on the surface, which include dead branches, leaves, and low vegetation.

T-Boner
A car crash situation, where one car has hit the side of another which is travelling at an angle horizontal to the car which has struck the other car, generally these crashes are quite severe and much fuel is spilled.

Tag accountability
System in which each firefighter is issued two identification tags, one of which is then collected by a safety officer and held while the firefighter is in a hazardous area. To reclaim the tag, the firefighter must present the matching tag upon exit from the hazard. Any unclaimed tags after an event” (such as a collapse or explosion) means the corresponding firefighters are missing. May be implemented as passport system in which first tag is presented to staging officer upon arrival (for tracking) and second tag is held by IDLH safety officer

Tailboard
Portion at rear of fire engine where firefighters could stand and ride (now considered overly dangerous), or step up to access hoses in the hose bed.

Tanker, Tender
Large, mobile tank of water or other firefighting agent; may be airborne, as used in wildland firefighting, or truck-mounted. Essential in rural areas lacking hydrants.

Task force
Any combination or single resources assembled for a particular tactical need, with common communications and a leader. A Task Force may be pre-established and sent to an incident, or formed at an incident.

Taskforce Tip
(TFT) a popular brand of adjustable fog stream Combination Nozzle, now a ubiquitous term for that type of nozzle.

Taxpayer
1 to 2 story store, or place of business, auto repair, supermarket etc.

Thermal Imaging Camera (TIC)
Ruggedized infrared equipment used by some firefighters to detect hidden people, animals, heat sources (i.e., fire) and structural compromise.

Tower ladder
See aerial ladder.

Trash Line
A preconnected attack line that is typically 1 3/4 diameter and stored either on the front bumper of the apparatus or in an exterior (exposed) side well. Trash Lines are typically shorter length than Cross Lays and are intended for use against dumpster fires, etc. where a longer length of hose (and consequent rebedding after the suppression is complete) is not desired.

Tree jump
A Smokejumper can sometimes parachute into the tree canopy if a clearing is not available or suitable.

Triple combination engine company
Apparatus carries water, pumps water, carries hose and other equipment; firefighters who may carry out direct attack or support other engine companies.

Triple Lay (Triple Fold” “Triple Load”)
A method of loading preconnected attack line into a hose bed or crosslay, often facilitating rapid hose deployment in a pre-flaked configuration.

Truck company
A group of firefighters assigned to an apparatus that carries ladders, forcible entry tools, possibly extrication tools and salvage covers, and who are otherwise equipped to perform rescue, ventilation, overhaul and other specific functions at fires; also called ladder company”.

Truckie
A firefighter typically responsible for tactical aerial operations, ventilation, search, and overhaul.

Trunkie
Truck” + “Monkey” = “Truck Monkey

Turn Around
A widened part of a fire break used for turning vehicles around, also used as a safe area during entrapment.

Turnout Gear
The protective clothing worn by firefighters

Turnout gear
The protective clothing worn by firefighters, made of a fire-resistant material such as Nomex or Aramid, and designed to shield against extreme heat. Sometimes called bunker gear. See PPE. Includes helmet, jacket and boots, and some departments include fire-resistant pants.

Turntable
Rotating base of an aerial ladder that permits the ladder to be elevated and extended in any direction from a fixed location.

Two-in, two-out (or two in/two out)
Refers to the standard safety tactic of having one team of two firefighters enter a hazardous zone (IDLH), while at least two others stand by outside in case the first two need rescue thus requiring a minimum of four firefighters on scene prior to starting interior attack. Also refers to the buddy system” in which firefighters never enter or leave a burning structure alone.

Type I, II, III, IV, V Building
U.S. classification system for fire resistance of building construction types, including definitions for: “resistive” Type I, “limited combustible” Type II, “ordinary” Type III, heavy timber Type IV and “wood frame construction” Type V (i.e. made entirely of wood).

Understory burn
A controlled burn of fuels below the forest canopy, intended to remove fuels from on-coming or potential fires.

Universal precautions
The use of safety barriers (gloves, mask, goggles) to limit an emergency responder’s contact with contaminants, especially fluids of injured patients.

Urban interface
The Interface zone where man-made structures inter-mingle with wildlands, creating risk of structural involvement in a wildland fire incident.

Utility rope
A rope not designed or maintained for life safety purposes.

Valve
Mechanical means for stopping and starting flow in a conduit; many types used in firefighting, including gate, foot, clapper (backflow preventers), sprinkler-heads, etc.

Vapor suppression
Process of reducing the amount of flammable or other hazardous vapors, from a flammable liquid, mixing with air, typically by careful application of a foam blanket on top of a pool of material.

Vehicle fire
Type of fire involving motor vehicles themselves, their fuel or cargo; has peculiar issues of rescue, explosion sources, toxic smoke and runoff, and scene safety.

Ventilation
Important procedure in firefighting in which the hot smoke and gases are removed from inside a structure, either by natural convection or forced, and either through existing openings or new ones provided by firefighters at appropriate locations (e.g., on the roof). Proper ventilation can save lives and improper ventilation can cause backdraft or other hazards.

Ventilation saw
A high-powered saw with metal-cutting teeth or disc for quickly making large openings in roofing materials.

Venturi effect
Creating a partial vacuum using a constricted fluid flow, used in fire equipment for mixing chemicals into water streams, or for measuring flow velocity.

Vertical ventilation
Ventilation technique making use of the principle of convection in which heated gases naturally rise.

Voids (building)
Enclosed portions of a building where fire can spread undetected.

Vollie
A volunteer firefighter.

Volunteer fire department
A group of part-time firefighters who are not paid when on-call, during incidents, or drills. Often professionally trained and equipped with state-of-the-art equipment.

Wall-indicator valve
Type of control valve for sprinkler systems which is mounted to an outside wall and indicates open” or “shut” in an indicator window on the valve body.

Watch out situations
A list of 18 situations for firefighters to be aware of, which signal potential hazards on the fire line.

Water curtain nozzle
A nozzle designed to throw a fan of water droplets to form a curtain” in an attempt to reduce radiated heat from igniting a nearby exposure.

Water drop
A forest fire fighting technique when an aircraft drops a supply of water onto an exposed fire from above.

Water flow alarm
An audible alarm indicating that one or more sprinkler heads have been activated.

Water hammer
Large, damaging shock wave in a water supply system caused by shutting a valve quickly, or by permitting a vehicle to drive across an unprotected fire hose.

Water mist fire suppression
A sprinkler-like system that uses a very fine mist featuring much lower water flow than conventional sprinklers to suppress, rather than extinguish, a fire[1].

Water tender
Any ground vehicle capable of transporting specified quantities of water.

Water thief (valve)
Type of gated wye having one or more outlets smaller than the largest outlet.

Wedges
Wooden blocks for temporary shut-off of activated sprinkler heads or holding doors open during firefighting or rescue operations.

Wet line
Temporary control line using water or other fire retardant liquid to prevent a low-intensity fire from spreading in surface fuels.

Wet pipe sprinkler system
Sprinkler system containing pressurized water rather than air, such that water will flow immediately upon release of a heat-sensitive head.

Wet water
Water into which a surface tension reducing agent has been introduced. The resultant mixture, with its reduced surface tension, is more able to penetrate burning product more deeply and extinguish deep seated fire.

Wildfire
A fire occurring on wildland that is not meeting management objectives and thus requires a suppression response.

Wildfire or Wildland fire
Fire in forests, grasslands, prairies, or other natural areas, not involving structure fires (although wildland fires may threaten structures or vice versa – see interface zone.) For a complete list of terms used in wildland fire, see Glossary of wildland fire terms.

Wildland
An area in which development is essentially nonexistent, except for roads, railroads, power lines, and similar transportation facilities. Structures, if any, are widely scattered.

Windfall
Tree knocked over or broken off by wind, increases fuel loading and hampers building fireline. Also sometimes called blowdown.

Working fire
A fire that is in the process of being suppressed; often a cue for dispatch of additional resources.

Wye
Device used to split a larger supply line hose into smaller attack line hoses. A gated wye contains valves so that certain lines can be turned on and off.

Wye
Hose coupling for splitting one line into two or more outlets, often a larger line split into two smaller ones; often a gated wye having separate valves for each outlet. Not to be confused with Siamese, which is used to bring two smaller lines together into one.

Y-connect
See wye.

Yield
What other drivers are supposed to do when they see or hear emergency vehicles approaching with lights and/or sirens activated.

Z-adapter
Large hose appliance for connecting supplemental pumps into long supply lines, in the form of a Z”; may be improvised from two gated wye valves and a double female between two of the gated outlets or from a siamese that has one inlet connected to one outlet of a gated wye.

Zone
Section of structure indicated on fire alarm control panel where sensor was activated.