Fire Department

and Fire Fighter's

Acronyms, Terminology

Disclaimer: These definitions are intended to give the layperson a general understanding
 of fire equipment, procedure and operations.  
They are not official or statutory definitions of any jurisdiction.
No definition herein is intended to be relied on in any legal matter.

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A

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.

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.

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.

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 accountability 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).

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.

Advanced Life Support
Advanced life support (ALS) is medical care provided by paramedics trained to assess a patient's condition, administer drugs, defibrillate and provide advanced airway management prior to transportation to the hospital.

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.  

AFA
Automatic Fire Alarm/Actuating Fire Alarm

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.
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).

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.

ANFO
Ammonium Nitrate Fuel Oil combination making a high explosive.

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

Appliance
Term for fire engine or trucks. Term commonly used for first response vehicles which are crewed by firefighters.  

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.

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). Fire hose 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.

Aqueous Film-Forming Foam (AFFF) (pronounced "A-Triple-F", also called "Class B")
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.

Attic Ladder
A ladder usually 8-10 feet long that usually can be folded so that the two beams touch each other. Also called a scuttle hull or pencil ladder in some parts of the country.

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.

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B
 

BA:
Royal Navy abbreviation for Breathing Apparatus. Otherwise known as SCBA.

BA Set:
Breathing Apparatus Set comprising of a face-mask and oxygen cylinder

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.

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.

Back burning:
Australian term, for Backfiring, above.

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.

Basic Life Support:
Basic life support (BLS) is a level of care provided to patients requiring transportation to the hospital. BLS does not include extensive medical supervision or treatment.

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.

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

Big Guns:
Reference the term applied to high volume water/foam delivery devices typically associated with Footprint (TM) process methodologies for storage tank firefighting.

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.

Bomb Line:
A preconnected attack line, typically 2 1/2 inch in diameter, used in the same manner 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 Line
Booster line is a hose that is usually one inch in diameter and rubber jacketed. They are used on small fires using the water carried in an apparatus' booster tank and are usually stored on reels. Also referred to as a red line.

Booster Tank:
The tank on a pumper or quint that supplies booster lines and hand lines at a fire until a connection with a water source can be made. The booster tank on most pumpers is between 500-1,000 gallons. The tank on a quint is usually smaller, carrying only a couple of hundred gallons.

Box (Alarm):
A box alarm is the response to a report of fire or smoke inside or coming from a structure. Usually, multiple companies are dispatched at the same time on a box alarm. Some departments have Haz-Mat and Rescue Boxes for hazardous materials and rescue calls.

The term "Box" comes from the fire alarm pull boxes that were commonplace in major cities for well over fifty years. This was a telegraph system that involved bells to ring out the box number. This system was in place from the 1920's (or earlier) to well into the 1960s and 1970s in some cities. Boston was one of the first (if not THE first) major U.S. Cities to have a telegraph alarm system. They installed it in 1852. The Boston Fire Department still uses this system of paper rolls and bells. The modern use of "box cards" based upon an imaginary box location for dispatch or move up is often known as the "Phantom Box System". A typical structure box alarm would include two or more engine companies, one or more ladder companies, a rescue company and a chief officer.

A mailslot or other file system containing a notecard with a 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 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.

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

Bunkers (or "bunker gear"):
Colloquial term for protective pants and boots kept near a firefighter’s bunk (cot) for rapid deployment; more modern terminology includes firefighting jacket. Basis for command to "Bunker up!" in preparation for hazardous duties. May also refer to entire protective clothing ensemble.

Bus:
Another term for ambulance,

Bushfire:
Australian term, for Wildfire, below.

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C

Call Firefighter:
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.

Career Firefighter:
A person whose primary employment is as a firefighter for a municipality or other agency or company and who derives the majority of his earned income working in the fire service.

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-hermaphrodite.

Charge a hose:
To make water pressure available on a hose in final preparation for its use. This is done on the scene after the hose is deployed.

Charged hose:
A hose that is filled with water and pressurized; ready to use. This is done after the hose is deployed.

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

Chauffeur:
See Engineer.

Check valve:
See backflow preventer

Chimney fire:
Fast and intense fire in a chimney flue in which accumulated creosote and other combustion by-products ignite.

Chicago thread:
Hydrant thread that is different from any of their suburban hydrants.

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

Class A:
A fire involving combustibles such as wood, paper, and other natural materials. See Fire Classes.

Class B:
A fire involving hydrocarbons. See Fire Classes.

Class C:
An electrical fire. See Fire Classes.

Class D:
A fire involving metals, such as sodium, titanium, magnesium, potasium, uranium, lithium, plutonium and calcium. See Fire Classes.

Class E (Europe/Australia):
A composite Class A/Class B fire that is not also a Class C fire.

Class F (Europe/Australia):
See Class K.

Class K:
A fire involving cooking oils. Technically, this is a subclass of Class B.

Closed-circuit SCBA:
See SCBA.

Closet hook:
Pike pole under 5 ft long

Closet ladder:
See Attic ladder.

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.

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

Combustion:
1. The process of burning.
2. A chemical change, especially oxidation, accompanied by the production of heat and light.

Combination nozzle:
A low pressure Fog Nozzle (usually 120 to 150 lbf/in² 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.

Company officer:
A fire officer, typically a lieutenant or captain, who leads a team of two or more firefighters in a company.

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.

Compressed Air Foam System (CAFS):
A water / surfactant (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 surfactant. It is also inappropriate for many fire scenarios because of that conversion rate, as an unmanaged steam expansion path will cook the firefighters. Secondary advantages are a graceful degradation during equipment failure; CAFs, without a compressed air supply, emit classic foam; without foam, water.

Confined space:
A confined space is any space:
1) that has limited or restricted means of entry or exit;
2) is large enough for a person to enter to perform tasks, and
3) is not designed or configured for continuous occupancy.

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.

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

Crew Resource Management (CRM):
Training developed by NASA based on the concept that the primary cause of the majority of aviation accidents is human error and problems with interpersonal communication in particular. The training has been adapted for the fire service and teaches firefighters the correct way to question orders on an emergency scene. It also helps supervisors understand that the questioning of an order should not be interpreted as a threat to their authority.

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. Also know as Mattydale Lay.

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D

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.

Deck Gun:
A master stream device mounted to top deck of pumper.  Deck guns deliver larger amounts of water than hand-held hose. (See also Master Stream).

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

Delivery:
Term for any hose which conveys water onto a fire e.g each outlet from a fire appliance supplies a delivery with water.

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.

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:
"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.

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

Determinate:
A code given by dispatch(Alpha -Echo)showing the sevrity of a call and how you should respond.

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

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.

Draft or Drafting:
Drafting is the pulling of water from a source other than accepting pressurized water from a hydrant or another fire apparatus. Cisterns, lakes, ponds and swimming pools are often used in drafting operations. Many departments in rural areas without fire hydrants use drafting.

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 (or draw) 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.

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

DSU:
Distress Signal Unit another term for a type of PASS device.

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E

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.

Ejector Pump:
Pumps that use the venturi principle to pump water on a fire ground. Can be used for salvage by removing flood waters or supply water to a fire appliance from an open water source. Water in the appliance is used to supply a flow of water to the ejector pump which uses high pressure nozzles to entrain an increased volume of water in the hose returning to the fire appliance.

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 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. In most cases, an engine carries small ground ladders, supply line to connect it with a hydrant, hand lines to fight the fire with and a tank holding between 500 and 1,000 gallons, or more, of water.

Engineer:
A firefighter responsible for driving the engine to the scene of the call and operation of the pumps on an engine, to provide sufficient water to the firefighters on the hose. The term may be either a position title or a rank; usage varies among departments.

Engine Company
An engine company is a combination of a fire engine and the manpower used to staff it. A standard engine company will include an officer, driver/engineer and two firefighters on a pumper truck.

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 correllation 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.

ETOH:
The chemical symbol for alcohol, also used to describe someone believed to be intoxicated.

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.

Explorer:
A young adult who's age is between 14 and 21 who learns the basics of firefighting.

Exposure:
Exposures are buildings or structures that are near the structure on fire and that are placed at risk by the fire, typically by convection or radiation. A primary focus of the responding fire department will be to protect the exposures, thus reducing the risk of the fire spreading and causing additional damage to life & property. May range from 40 feet to several miles, depending on size and type of fire or explosion.

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.

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F

FAST (or F.A.S.T.):
Firefighter Assist and Search Team (also called Rapid Entry Team or Rapid Intervention Team/Crew) — 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. While all of these versions of the name for a firefighter rescue crew either have been used or continue to be used in several areas, the National Incident Management System (NIMS) has determined that Rapid Intervention Crew, ("RIC") will be the national term. Current U.S. federally mandated training programs are in the process of standardizing this and other terms under DHS and FEMA.

FAST (Firefighter Assist and Safety Team) Truck
A FAST truck is a company of firefighters (usually from a truck or rescue company) whose sole function at a fire is to stand by in case a firefighter becomes injured or trapped and needs assistance. The company assigned to the FAST truck is usually a highly trained group and reports only to the incident commander. In some departments, this group is call a RIT (Rapid Intervention Team).

Fast Attack
Fast attack is when the first arriving engine company attacks the fire using water carried in the booster tank, relying on the second company to secure a water supply.

FDC (Fire Department Connection):
Location in which pumping apparatus hooks to a buildings standpipe and or sprinkler system. Usually a 3" female connection.

Feeder
A line used for water supply. Usually 4" or 5" LDH.

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 Buff:
A fire buff is not to be misconstrued with the pyromaniac who starts fires.
A unique individual with a special interest in the fire service and the fire fighters who protect us 24 hours a day.
Over the years fire buffs have dedicated themselves to the prevention of fire, and the safety and well being of those who fight fires.  Fire Buffs have a solid reputation for community service, and are frequently known as the strongest, most enthusiastic supporters of the local volunteer and full time paid fire companies.  Quite often a strong bond exists between buffs, fire department officers, fire administration, and runs all the way down to the newest recruit.  This bond is built on years of experience and mutual trust that can only come with the passage of time.  In many cities buffs are considered to be part of the close-knit fire fighting family.

Fire Break:
Especially in hilly or mountainous areas, roads or paths cut through brush with a tractor, bulldozer or other construction equipment. The purpose of these is to have an area with no brush, and thus, no fuel, so that a fire will hopefully burn out rather than jumping to another area with brush. Also to ensure vehicular access to brush areas.

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 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 verically 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 Fighter Fatality Investigation and Prevention Program (FFFIPP):
Program administered by the National Institute for Occupational Safety and Health (NIOSH), a department of the Center for Disease Control (CDC). It performs independent investigations of firefighter fatalities in the United States, also referred to as line of duty deaths (LODD).
The programs goals are:
1.) to better define the characteristics of line of duty deaths among firefighters,
2.) to develop recommendations for the prevention of deaths and injuries, and
3.) to disseminate prevention strategies to the fire service.

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

Firefighter Assist and Search Team:
See FAST.

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.

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.”

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.

Firehose:
See also hose.

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

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 hydrant:
See hydrant.

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.

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.

Fire Marshal:
Administrative and investigative office for fire prevention and arson investigation.

Fire officer:
See Company officer

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

Fire Police:
Special constables attached to a fire department, tasked with ensuring the safety and security of emergency scenes as well as general assistance to the fire department and other agencies.

Fire prevention:
Fire safety; standards for minimizing fire hazards.

Fire pump:
A pump installed in a building specifically for the fire water system.

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

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.

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

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. See also fire tetrahedron for a more comprehensive model.

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 warden:

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.

Fit test:
Periodic test of how well the facepiece of an SCBA fits a particular firefighter.

Flameover:
Also known as rollover. The ignition of heated fire gasses at the ceiling level only. While dangerous to firefighters, this is not as deadly as Flashover.

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.

Flash point:
Lowest temperature at which a material will emit vapor combustible in air mixture. Higher than Flame point of same material.

Flashover
The sudden ignition of all flammable material in a room or structure. As the fire burns and heat is generated and stored in the room on fire, it is possible for the heat to accumulate faster than it can use fuel. Once this reaches critical mass, the heat then turns all the flammables in a room into fuel at one time. The danger is that this causes an inversion of the thermal layers because the new fuel is almost always near the floor. Despite superb protective gear, a firefighter has less than two seconds to evacuate a room that has a flashover.

Fly:
The moving portions of an extension ladder.

Foam
Foam is a concentrate mixed with water or air and applied to any material that is on fire or could potentially catch fire. The foam creates a barrier between the material and the heat, preventing ignition of flammable gases. Foam is commonly used on flammable liquid fires (gas or oil), but is also being used in some areas for automobile & structure fire applications.

Foam Concentrate:
Raw foam liquid as it rests in it storage container before the introduction of water and air.

Fog nozzle:
A nozzle that discharges water in small droplets. Often, 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.

Footprint (TM):
Application method for extinguishing large diameter storage tank fires or fuels in product depth.

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
The act of gaining access to a structure through means other than an open window or door. Frequently, firefighters must force open doors that are locked or remove security doors and bars in order to enter a structure to search for victims & extinguish a fire. A variety of hand, power & hydraulic tools can be used for forcible entry (e.g., Halligan, K-tool).

Forestry Line
A forestry line is a small-diameter, cotton-jacketed handline used to fight brush and forest fires. Its construction reduces the weight a firefighter has to pull and therefore reduces fatigue.

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.  Exception to violation would be the freelancing fire photographer

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.

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. Usually 50% of the structure or more.

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G

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.

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. Also known as a Class B, F or K fire.

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

Goer:
An incident with persons reported.

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H

Handline:
A handline is a small diameter hose usually used inside a burning structure to directly apply water on to the fire. Handlines are usually 1.5 or 1.75 inches in diameter. Lines as large as 2.5 inches in diameter (also called the "deuce and a half") can be used for heavy fire conditions.

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.

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

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

Head pressure:
How the pressure of a water stream is mesured. By mesuring the 'breakover' point, the point where the water stream breaks apart and begins to fall back to the ground, of a stream of water aimed vertically into the air. This is typically done with a one inch diameter hose and a fixed nozzle. Therefore, if a water stream breaks over at 50ft, then it is said the pump has 50 feet of head pressure. Current measurements of pumping capacity are now in GPM, Gallons Per Minute.

Helmet:
Developed in the early 1800s, the original firefighter helmets were felt caps and did nothing more than keep water off the firefighters face. Later editions of the fire helmet included leather, metal, fiberglass, and most departments are currently using a form of plastic composite. More information under Bunker gear.

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-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.

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.

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 strap:
Similar in purpose to a Rope Hose Tool, a hose strap is typically a single closed loop of nylon webbing, which can be secured to a hose via a girth hitch to aid with hose control and movement.

Hose tower:
Structure for hoisting hoses to permit them to thaw, 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 the along with dirt and corrosive moisture. 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".

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

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.

HPF:
See High Pressure Fog.

Hurst tool:
See Hydraulic spreader.

Hux tool:
Largely obsolete hydrant wrench made of stamped metal with holes sized for the hydrant valve.

Hydrant
An upright metal casting connected to a water supply system and equipped with one or more valved outlets to which a pumper or hoseline can be connected.  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.
 

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I

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.

IAFF:
Acronym, "International Association Of Fire Fighters".

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

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

Incident Command System (ICS)
A management system of procedures for controlling personnel, facilities, equipment and communications from different agencies to work together towards a common goal in an effective and efficient manner. Is the chain of leadership and command at the scene of an emergency.

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.

Intake:
Part of pump where water enters when pump forms partial vacuum.

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.

Initial attack:
First point of attack on a fire where hose lines or fuel separation are used to prevent further extension of the fire.
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, 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. Firefighters often refer to these as the Crossed Irons, or Married Irons, because the Halligan Bar can fit to the Axe head.

ISO Rating:
(Insurance Services Office Public Protection Classification Rating) This is a rating published by the Insurance Services Office. Insurance companies, in many states, use this number to determine homeowner insurance premiums. Recently some insurance companies, including State Farm, have now adopted a per-zip-code, actual loss, based system in several states and no longer use the ISO (PPC) system.
 

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J

Jake
A term used to refer to a good firefighter. One story has the term originating from the corruption of the phrase, "J-key." Years ago, the bed was the most expensive piece of furniture in a dwelling. Since firefighters weren't as good at stopping fire as they are today, they would attempt to remove as many belongings as possible. The bed was too large to carry out in one piece and had to be disassembled using a bed key. The key was shaped like the letter J and called a J-key.

Jaws
A generic term applied to a type of rescue tool that can cut, push or pull material (most often pieces of an automobile). Jaws of Life is a synonym, but is the copyrighted product name of Hurst. Holmatro and Amkus are also major manufacturers of jaws.

Jaws of Life:
A Hurst tool. See hydraulic spreader.

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

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.

Jockey pump:
A small pump connected to a fire sprinkler system and is intended to maintain pressure in a fire protection piping system to an artificially high level so that the operation of a single fire sprinkler will cause an appreciable pressure drop which will be easily sensed by the fire pump automatic controller, causing the fire pump to start. The jockey pump is essentially a portion of the fire pump's control system.

Jump Line
A jump line is a handline stored in an extended bumper (also called a jump bumper) and preconnected to the engine to allow for a quicker attack.

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K

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

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

L

Ladder Company
A ladder company is a combination of a fire truck with an aerial ladder, an assortment of ground ladders and forced entry tools and the manpower used to staff it. Ladder trucks can have straight aerial ladders as short as 65 feet or longer ladders with platforms (buckets) on the end. In many department's ladder companies are responsible for ventilation and forcible entry duties. A standard ladder company will include an officer, driver/operator and two firefighters on a ladder truck.

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.

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

Landing Valve:
Globe Valves which be installed on hydrants branch and hose is connected to coupling of it.

Large Diameter Hose
The biggest hose used by firefighters, large diameter hose (LDH) is sometimes referred to as a water main above ground. LDH is usually 4-5 inches in diameter and is used to supply water from the hydrant to pumper trucks. See also supply hose.

Leader Line
A leader line is a line usually having a gated wye on the end. Leader lines are usually 3 or 2.5 inches in diameter and the wye usually feeds two or three 1.5 or 1.75 inch attack lines.

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 non-existant 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 "Will 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 tires.

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

Life safety code:
NFPA publication.

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

Line loss:
See friction loss.

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

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

LMR:
Abbreviation for Land Mobile Radio. Component of New Zealand Fire Service communications system between a communications center and a fire appliance over a radio network

Loaded stream:
An obsolete fire extinguisher stream that has had a chemical fire suppression agent added and is discharged by compressed gas or by inverting the tank to mix chemicals to produce gas pressure. Now outlawed by OSHA regulation 1910.157(c)(5). [Not to be confused with air pressurized water extinguishers with a Class A foam generating concentrate added at one-half of 1% by volume. Class A foam formed when mixed with air upon discharge produces surfactant-containing tiny bubbles which break surface tension to quickly penetrate and extinguish wood, paper, cloth and other common materials.]

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M

Make Pumps:
To raise the number of pumps at an incident E.G. Make Pumps 10

Maltese Cross:
The emblem of the fire service is often referred to as a “Maltese Cross”. But the actual origin of the current or common emblem in the U.S. remains uncertain. While it is true that the Knights Hospitalers of Jerusalem (AKA Knights of St. John) did wear a cross emblem and a version of that cross has been used as a fire service icon, it bears little resemblance to the current form in use in much of the United States. It is possible to accept that the current design is just a stylized artistic embellishment of the original form. The current design may have also been influenced by the design of the cross of Saint Florian. (See: Maltese Cross)

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:
A primary fire alarm relay box connected to a building alarm system which monitors fire alarm pull stations and detectors throughout the building and automatically relays any in-building alarm to the local municipal fire department. Usually accompanied by an Annunciator Panel which records by indcator lights or other devices exactly where the pull station or detector that has been activated is located within the building. Common in multi-story office and apartment buildings equipped with sprinkler systems or smoke and heat detectors.

Master Stream
A master stream is a large and fixed stream of water. Master streams are used on the end of aerial ladders on ladder trucks and on top of pumper trucks. Master streams can deliver larger amounts of water than hand-held hose.

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; a brief blurb and photo of the piece can be seen near the bottom of http://www.fasnyfiremuseum.com/fireapparatus.php .

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.

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 2½ and 4 inches.

MDT:
Abbreviation for Mobile Data Terminal. Allows data transmission between communication centres and fire appliances over a radio network.

Monitor:
Firefighting delivery designed to be established and then left unattended. Typical uses include ground monitors which can be established to deliver water onto large fires or provide a water curtain. Deck Monitors tend to be attended and used to deliver very large water quantities onto the fire. A type of master stream similar to a deck gun, also known as deluge guns, but removable from the apparatus. Hose can be laid into it, making it mobile.

Multigas detector:
Measuring device designed to indicate concentrations of multiple (typically 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.

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N

NFPA:
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 by traditional methods, 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.

NH:
National Hose thread, also known as NST (National Standard Thread). Commonly used in fire hose couplings, it has a slightly larger thread diameter and coarser pitch (fewer threads per inch) than the alternative NPSH thread. The threads specified in NFPA 1963 are "NH".[1]

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.

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 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).

NPSH:
National Pipe Straight Hose thread, also known as IPT (Iron Pipe Thread, or International Pipe Thread). Like NH threads, NPSH threads are commonly used in fire hose couplings, but the two types are not interchangeable with each other and cannot be connected together without adapters. NPSH threads have a slightly smaller diameter and more threads per inch than NH, but NPSH hoses can be fitted to NPT (National Pipe Tapered) plumbing fixtures, as the diameters and thread pitches are similar. [2]

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O

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.

On The Green:
Pump Only Shout

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

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.

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.
Commonly viewed as "cleaning up" after a fire, overhaul is the process of putting a structure in the safest condition following a fire. Additionally, it is during the overhaul phase of an incident that firefighters verify that the fire has not extended into unknown areas and that hidden "hot spots" are extinguished.

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

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P

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.

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 respective individuals in a dangerous area, and returned to the firefighter when he or she leaves the dangerous area.

Penciling:
The penciling technique is created by adjusting the nozzle to a straight stream pattern and using series of short bursts of water directed at burning materials. This helps reduce the production of flammable gases by cooling the burning walls and ceiling below their ignition point.

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

Personnel Accountability Report ("PAR"):
End-result of personnel accountability system. Best report is all hands, AOK, worse is squad missing. You will often hear command ask for a "PAR" when something has changed on the fireground. Often the reply will be something like, "Engine 4, PAR." or "Engine 4 has PAR."

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.

Pike pole:
See Hook.

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.

Platoon:
A subdivision of a fire company, led a fire officer of either the rank of captain or lieutenant, such that one of several platoons is assigned to duty for a specified period. Also called a "watch". In many areas the word "platoon" is used to describe the different shifts in the fire department. For example, A, B or C Platoon.

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

Pineapple:
Tool used in order to assist in suppressing a basement fire.

Plug:
Slang term for a fire hydrant. This survives from the days when water mains actually had holes in the tops that were plugged. Many firefighters would like to keep this word while many others think it should be replaced with the accurate term, "hydrant".

Plug:
Slang term for a fire hydrant. This survives from the days when water mains actually had holes in the tops that were plugged. Many firefighters would like to keep this word while many others think it should be replaced with the accurate term, "hydrant".

POC:
Paid On Call - Usually refers to full time and not volunteer status.

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. High volume, portable Positive Pressure Ventilation fans are now carried by fire departments and used to pressurize the fire building during interior attack to control smoke and heat ventilation at desired points.

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.

PPC:
Paid Per Cal - Usually refers to the volunteer

PPE:
Personal Protective Equipment

Pre-arrival instructions:
Directions given by a dispatcher to a caller until emergency units can arrive.

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. Not to be confused with post-planning.

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.

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

"Professional Firefighter:"
All firefighters are classified as "professionals" by both the International Association of Fire Chiefs (IAFC) and the International Association of Fire Fighters (IAFF trade union). All firefighters are required by most state laws and general practice to meet the same training and equipment standards, take the same examinations for promotion and perform the same work under the same hazards. There are two accepted categories of Professional Firefighters--Volunteer Firefighters who may or may not receive pay for services and Career Firefighters whose primary employment and source of earned income is in the fire service.

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.

Pumper
In most cases, a pumper carries small ground ladders, supply line to connect it with a hydrant, hand lines to fight the fire with and a tank holding between 500 and 1,000 gallons of water. Same as an Engine.
Pump operator, technician:
(also a chauffeur): person responsible for operating the pumps on a pumper and typically for driving the pumper to an incident.

Pump Escape:
Appliance carrying a wheeled ladder

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.

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Q

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;
5. an aerial ladder.

R

Rabbet 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.

Rapid entry team:
See FAST. Rapid Intervention Crew/Group/Team (RIC, RIG, or RIT): This is a standby crew whose purpose is to go in for the rescue of firefighters in trouble. While all of these versions of the name for a firefighter rescue crew either have been used or continue to be used in several areas, the National Incident Management System (NIMS) has adopted the term Rapid Intervention Crew/Company, ("RIC") to be the standard in the Incident Command System (ICS). Currently, U.S. federally required training programs, from DHS and FEMA, are in the process of standardizing many terms and procedures under NIMS. See: FAST

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

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.

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

Red Line
Red line is a hose that is usually one inch in diameter and rubber jacketed. This type of hose is used on small fires using the water carried in an apparatus' booster tank and are usually stored on reels. Same as booster line.

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

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

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. See: Fire department 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 Company
A rescue company is a term used to describe a rescue truck and the firefighters used to staff it. A rescue company is equipped and trained to handle a variety of duties including search and rescue, medical treatment of victims, suppression at the scene of a fire and the extrication of victims in motor vehicle accidents. The actual duties of a rescue company can vary in different parts of the country as does the term to describe one. A Rescue Company is called a Squad in some areas while other areas use the term when referring to their ambulances.

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
When supply hose is laid from the fire to the water source, placing the pump at the source of water. (See also forward lay)

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.

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.

RIT (Rapid Intervention Team)
Same as FAST Truck.

Rollover:
See flameover, above.
Also refered to a vehicle that has rolled over in an accident.

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.

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.

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.

Running Call:
A call 'Shout' with persons reported

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S

SAR:
See Search and rescue.  

Salvage
The process of protecting the contents of a building from fire, smoke and water damage. Tools used include salvage covers that are placed over furniture, preventing damage from water and debris.

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.

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

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).
Part of a firefighter's PPE.

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 containment:
A system to contain a hazardous material should the primary means of containment (container) fail, e.g. by leakage. The secondary container is required to hold 110% of the capacity of the primary container.

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

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."

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.

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

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.

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.

Stick
The aerial of a ladder truck. Aerials vary in length depending on the needs and finances of a department. Some are as short as 65 feet, while others reach lengths greater than 100 feet.

Still Alarm
A still alarm is a call requiring only one company. Examples of a still alarm include a small fire or a medical call.

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-fighting water 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.

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

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

Strike Team:
A grouping of fire apparatus with a focused goal in a large fire situation. The term is commonly used for structure protection teams during wildland fire operations.

Strike the Box
To transmit or strike an alarm over the radio for a full first alarm assignment.

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, 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"

Supply Hose
Hose line used to supply water from a hydrant to fire apparatus. Many departments use large diameter hose (see above) for this purpose. LDH is sometimes referred to as a water main above ground and is usually 4-5 inches in diameter. However, some departments use smaller 3-inch hose to supply water at a fire.

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T

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, as above.

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:
An aircraft equipped to carry water or fire retardant for use in wildland fire suppression. Archaic: see "Tender", below.

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.

Taskforce Tip:
(TFT) Task Force Tips a popular brand of adjustable fog stream Combination Nozzle, now a ubiquitous term for that type of nozzle.
Thermal Imaging Camera (TIC) - Ruggedized infrared equipment used by some firefighters to detect hidden people, animals, heat sources (i.e., fire) and structural compromise.

Taxpayer:
1 to 2 story store, or place of business, usually with a residence attached: auto repair, supermarket, tailor, etc.

Tender (also "Water Tender"):
A wheeled fire apparatus equipped to carry large volumes of water to a fire. Often used in areas without an adequate or universal water supply system, such as rural areas without hydrants. Tenders may have pumps and associated hardware to facilitate their mission. Some departments refer to these apparatus as "Tankers."

Tones:
A series of two or three musical notes, used as an auditory alert over a radio or radio-paging system to indicate that a particular fire company, district, or territory is dispatched to service on a particular incident.

Toned out:
A term used to indicate when a fire company is or was dispatched to an incident. See tones above. Can be used in present tense ("We've been toned out, I've got to go.") or past tense ("We were toned out at 2300 on that run.")

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.

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.

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, "non-combustible" Type II, "ordinary" Type III, heavy timber Type IV, and "frame construction" Type V (i.e., made entirely of wood).

Trash Line:
Same as jump line, although not necessarily carried on the front bumper.

Truck Company:
See Ladder Company.

Under Control:
Fire or spill etc. is no longer spreading. The situation is contained. This term should not be confused with a report that the fire is out.

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U

Underground storage tank:
A tank that happens to be underground.

U.S.A.R:
Urban Search and Rescue.

United States Fire Administration (USFA):
Division of the Federal Emergency Management Agency (FEMA), which in turn is managed by the Department of Homeland Security (DHS).

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

Up and Over:
A standard ventilation operation conducted by a team of firefighters wherein ladders are raised at a working fire involving a rowhouse-type dwelling to gain access to the roof to allow the firefighters to ventilate the involved dwelling. The intent is to get the upper floor opened up as quickly as possible. This is accomplished by opening skylights and/or scuttles and ensuring windows in the rear and front are taken out at the same time. The advantage of this operation is that many times, it is difficult to bring portable ladders to the rear of a row-type dwelling in some areas due to trash-strewn, overgrown, narrow, winding alley-ways. A 6-foot hook allows the one firefighter venting the rear to reach down (carefully where wires are involved) and take out (break) the windows. Any blinds, curtains, or drapes can be snagged with the hook to remove them and thereby facilitate the speedy evacuation of super-heated smoke and gases.

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

Utility Truck:
Usually manned by an engine company and responds to utilty calls like water main breaks. Some small departments use them to respond to medical calls to save gas money.

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V

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 pressure:

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:
Ventilation is the systematic removal of smoke from a building. Ventilation is usually accomplished with one of two methods: positive and negative pressure ventilation. Positive pressure ventilation increases the atmospheric pressure in the building until it is grater than the pressure outside the building. With negative pressure ventilation, the pressure inside the building is reduced until its less than the pressure outside the building. (e.g., on the roof). Proper ventilation can save lives and improper ventilation can cause backdraft or other hazards. Car fire ventilation standards were improved by Kevin "Center Punch" Tomaszewski on Feb. 5,2008.

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:
An organization of part-time firefighters who may or may not be paid for on-call time or firefighting duty time, but who in nearly all states are held to the same professional training standards and take the same examinations to advance in rank as career firefighters. [In some regions, particularly eastern New York, New Jersey, Pennsylvania and Maryland volunteer fire departments and fire protection districts have independent taxing authority and are equally as well equipped and paid while working as career fire department members.]

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W

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.

Water columning:

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:
A vehicle that contains a substantial tank of water as well as a pump.

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.

Well 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.

Wet down ceremony:
A traditional ceremony for the placing of new apparatus in service. There are several versions of this but it usually includes: pushing the old apparatus out, wetting down the new vehicle and pushing it back into the station. It may also include the moving of the bell to the new apparatus, photos, etc.

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 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.

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

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.

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X

Y

Y-connect:
See wye.

Z

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.


 

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