FF Skills - Gloassary:2 Flashcards
Ladder fuels
Fuels that provide vertical continuity between the ground and the tops of trees or shrubs, thereby allowing fire to move with relative ease.
Ladder pipe
A monitor that attaches to the rungs of a vehicle-mounted aerial ladder. (NFPA 1964)
Laminar smoke flow
Smooth or streamlined movement of smoke, which indicates that the pressure in the building is not excessively high.
Laminated glass
Safety glass; the lamination process places a thin layer of plastic between two layers of glass so that the glass does not shatter and fall apart when broken.
Laminated wood
Pieces of wood that are glued together.
Large-diameter hose (LDH)
A hose 3.5 in. (89 mm) or larger that is designed to move large volumes of water to supply master stream appliances, portable hydrants, manifolds, standpipe and sprinkler systems, and fire department pumpers from hydrants and in relay. (NFPA 1410)
Latching device
A spring-loaded latch bolt or a gravity-operated steel bar that, after release by physical action, returns to its operating position and automatically engages the strike plate when it is returned to the closed position. (NFPA 80)
Lath
Thin strips of wood used to make the supporting structure for roof tiles.
LCES
A mnemonic that stands for Lookouts, Communications, Escape routes, and Safety zones. Fire fighters should ensure that the components of LCES are in place before attacking a wildland fire to reduce the risk associated with fighting these types fires.
Leader
The individual responsible for command of a task force, strike team, or functional unit. (NFPA 1026)
Legacy construction
An older type of construction that used sawn lumber and was built before about 1970.
Liaison officer
A member of the command staff responsible for coordinating with representatives from cooperating and assisting agencies. (NFPA 1561)
Lieutenant
A company officer who is usually responsible for a single fire company on a single shift; the first in line among company officers.
Life safety rope
Rope dedicated solely for the purpose of sup-porting people during rescue, firefighting, other emergency operations, or during training evolutions. (NFPA 1983)
Light-emitting diodes (LEDs)
Electronic semiconductors that emit a single-color light when activated. LEDs are used for operational displays in SCBA.
Light (low) hazard locations
Occupancies where the quantity, combustibility, and heat release of the materials are low, and the majority of materials are arranged so that a fire is not likely to spread.
Line detector
Wire or tubing that can be strung along the ceiling of large open areas to detect an increase in heat.
Liquid
A fluid (such as water) that has no independent shape but has a definite volume and does not expand indefinitely and that is only slightly compressible.
Live load
The load produced by the use and occupancy of the building or other structure, which does not include construction or environmental loads such as wind load, snow load, rain load, earthquake load, flood load, or dead load. Live loads on a roof are those produced (1) during maintenance by workers, equipment, and materials and (2) during the life of the structure by movable objects such as planters and by people. (NFPA 5000)
Load-bearing wall
A wall that supports any vertical load in addition to its own weight or any lateral load.
Loaded-stream fire extinguisher
A water-based fire extinguisher that uses an alkali metal salt as a freezing-point depressant.
Lock body
The part of a padlock that holds the main locking mechanisms and secures the shackles.
Locking mechanism
A device that locks a fire extinguisher’s trigger to prevent its accidental discharge.
Locking mechanism
A standard doorknob lock, deadbolt lock, or sliding latch.
Lockout and tagout systems
Methods of ensuring that electricity and other utilities have been shut down and switches are ÒlockedÓ so that they cannot be switched on, so as to prevent flow of power or gases into the area where rescue is being conducted.
Logistics section
Section responsible for providing facilities, services, and materials for the incident or planned event, including the communications unit, medical unit, and food unit within the service branch and the supply unit, facilities unit, and ground support unit within the support branch. (NFPA 1026)
Logistics section chief
The general staff position responsible for directing the logistics function. It is generally assigned on com-plex, resource-intensive, or long-duration incidents.
Loop
A piece of rope formed into a circle.
Louver cut
A cut that is made using power saws and axes to cut along and between roof supports so that the sections created can be tilted into the opening.
Low-angle operation
A rope rescue operation on a mildly sloping surface (less than 45 degrees) or flat land. In this scenario, fire fighters depend on the ground for their primary support, and the rope system is a secondary means of support.
Lower explosive limit (LEL)
The minimum concentration of a combustible vapor or combustible gas in a mixture of the vapor or gas and gaseous oxidant, above which propagation of flame will occur on contact with an ignition source. (NFPA 115)
Low-volume nozzle
A nozzle that flows 40 gallons per minute (151 L/min) or less.
Malicious alarm
An unwanted activation of an alarm initiating device caused by a person acting with malice. (NFPA 72)
Mallet
A short-handled hammer.
Manual drystandpipe system
A standpipe system with no permanently attached water supply that relies exclusively on the fire department connection to supply the system demand. (NFPA 14)
Manual pullstation
A device with a switch that either opens or closes a circuit, activating the fire alarm.
Manufactured (mobile) home
A structure, transportable in one or more sections, which, in the traveling mode, is 8 body-ft(2.4m)or more in width or 40 body-ft (12.2 m)or more in length or, when erected on site, is 320 ft2 (29.7 _) or more and which is built on a permanent chassis and designed to be used as a dwelling, with or without a permanent foundation, when connected to the required utilities, and includes plumbing, heating, air-conditioning, and electrical systems contained therein. (NFPA 5000)
Masonry
Built-up unit of construction or combination of mate-rials such as clay, shale, concrete, glass, gypsum, tile, or stone set in mortar. (NFPA 5000)
Mass arsonist
A person who sets three or more fires at the same site or location during a limited period of time.
Master stream appliance
Devices used to produce high volume water streams for large fires. Most master stream appliances discharge between 350 gpm (1325 L/min) and 1500 gpm (5678 L/min), though much larger capacities are available. These devices include deck guns and portable ground monitors.
Master stream nozzle
A nozzle with a rated discharge of 350gpm (1325 L/min) or greater. (NFPA 1964)
Maul
A specialized striking tool, weighing 6 lb (3 kg) or more, with an axe on one side of the head and a sledgehammer on the other side.
Mayday
A verbal declaration indicating that a fire fighter is lost, missing, or trapped and requires immediate assistance.
McLeod
A hand tool used for constructing fire control lines and overhauling wildland fires. One side of the head consists of a five-toothed to seven-toothed fire rake; the other side is a hoe.
Mechanical energy
A form of potential energy that can generate heat through friction.
Mechanical saw
A saw that usually is powered by an electric motor or a gasoline engine. The three primary types of mechanical saws are chainsaws, rotary saws, and reciprocating saws.
Mechanical ventilation
A process of removing heat, smoke, and gases from a fire area by using exhaust fans, blowers, air-conditioning systems, or smoke ejectors. (NFPA 402)
Mildew
A fungus that can grow on hose if the hose is stored wet. Mildew can damage the jacket of a hose.
Minuteman hose load
A hose loading method that allows a single fire fighter to flake out the necessary amount of hose from the shoulder while advancing toward the fire; this load avoids having to maneuver the hose lines around obstacles and helps to prevent sharp kinks.
Mobile data terminals (MDTs)
Technology that allows fire fighters to receive data while in the fire apparatus or at the station.
Mobile radio
A two-way radio that is permanently mounted in a fire apparatus.
Mobile water supply apparatus
A vehicle designed primarily for transporting (pickup, transporting, and delivering) water to fire emergency scenes to be applied by other vehicles or pumping equipment. (NFPA 1901)
Mortise locks
Door locks with both a latch and a bolt built into the same mechanism; the two locking mechanisms operate independently of each other. Mortise locks often are found in hotel rooms.
Multiple-jacket
A construction consisting of a combination of two separately woven reinforcements (double jacket) or two or more reinforcements interwoven. (NFPA 1962)
Multiplex channel
Simultaneous transmission of multiple data streams, most often voice signals, in either or both directions over the same frequency.
Multipurpose dry-chemical fire extinguisher
A fire extinguisher that uses an ammonium phosphate-based extinguishing agent that is effective on fires involving ordinary combustibles, such as wood or paper, and fires involving flammable liquids. It is rated to fight Class A, B, and C fires.
Multipurpose hook
A long pole with a wooden or fiberglass handle and a metal hook on one end used for pulling.
Municipal-type water system
A system having water pipes servicing fire hydrants and designed to furnish, over and above domestic consumption, a minimum of 250 gpm (946 L/min)at 20psi (138 kPa) residual pressure for a 2-hour duration. (NFPA 1141)
National Fire Incident Reporting System (NFIRS)
The standard national reporting system used by U.S. fire departments to report fires and other incidents to which they respond and to maintain records of these incidents in a uniform manner. (FEMA NFIRS)
National Fire Protection Association (NFPA)
The association that develops and maintains nationally recognized minimum consensus standards on many areas of fire safety and specific standards on hazardous materials.
National Incident Management System (NIMS)
A system mandated by Homeland Security Presidential Directive 5 (HSPD-5) that provides a systematic, proactive approach guiding government agencies at all levels, the private sector, and nongovernmental organizations to work seamlessly to prepare for, prevent, respond to, recover from, and mitigate the effects of incidents, regardless of cause, size, location, or complexity, so as to reduce the loss of life or property and harm to the environment. (NFPA 1026)
National Institute for Occupational Safety and Health (NIOSH)
The U.S. federal agency responsible for research and development on occupational safety and health issues.
Natural fire
A fire caused without direct human intervention or action, such as fire resulting from lightning, an earthquake, or wind.
Natural ventilation
The flow of air or gases created by the difference in the pressures or gas densities between the outside and inside of a vent, room, or space. (NFPA 853)
Negative-pressure ventilation
Ventilation that relies on electric fans to pull or draw the air from a structure or area.
Neutral plane
The interface at a vent, such as a doorway or a window opening, between the hot gas flowing out of a fire compartment and the cool air flowing into the compartment where the pressure difference between the interior and exterior is equal.
Nonambulatory patient
A term describing individuaIs who cannot move themselves to an area of safety owing to their physical condition, medical treatment, or other factors.
Nonbearing wall
Any wall that is not a bearing wall. (NFPA 5000)
Noncoded system
An alarm system that provides no information at the alarm control unit indicating where the activated alarm is located.
Normal operating pressure
The observed static pressure in a water distribution system during a period of normal demand.
Nose cups
An insert inside the face piece of an SCBA that fits over the user’s mouth and nose.
Nozzle
A device for use in applications requiring special water discharge patterns, directional spray, or other unusual discharge characteristics. (NFPA 13)
Nozzle shut-off valve
A device that enables the fire fighter at the nozzle to start or stop the flow of water.
Nuisance alarm
An unwanted activation of a signaling system or an alarm initiating device in response to a stimulus or condition that is not the result of a potentially hazardous condition. (NFPA 72)
Obscuration rate
A measure of the percentage of light transmission that is blocked between a sender and a receiver unit.
Occupancy
The purpose for which a building or other structure, or part thereof, is used or intended to be used. (NFPA 5000)
Occupational Safety and Hlealth Administration (OSHA)
The U.S. federal agency that regulates worker safety and, in some cases, responder safety. It is part of the U.S. Department of Labor.
Offensive operation
Actions generally performed in the interior of involved structures that involve a direct attack on a fire to directly control and extinguish the fire. (NFPA 1500)
Open-circuit self-contained breathing apparatus
An SCBA in which the exhaled air is released into the atmosphere and is not reused.
Open-end wrench
A hand tool that is used to tighten or loosen bolts. The end is open, as opposed to a box-end wrench. Each wrench is a specific size.
Operations section
Section responsible for all tactical operations at the incident or planned event, including up to 5 branches,25 divisions/groups, and 125 single resources, task forces, or strike teams. (NFPA 1026)
Operations section chief
The general staff position responsible for managing all operations activities. It is usually assigned when complex incidents involve more than 20 single resources or when command staff cannot be involved in all details of the tactical operation.
Operator lever
The handle, doorknob, or keyway of a door that turns the latch to open it.
Ordinary (moderate) hazard locations
Occupancies that contain more Class A and Class B materials than are found in light hazard locations. The combustibility and heat release rate of the materials is moderate.
Outside screw and yoke (OS&Y) valve
A sprinkler control valve with a valve stem that moves in and out as the valve is opened or closed.
Overhaul
The process of final extinguishment after the main body of a fire has been knocked down. All traces of fire must be extinguished at this time. (NFPA 402)
Oxidation
Reaction with oxygen either in the form of the element or in the form of one of its compounds. (NFPA 53)
Packaging
The process of securing a victim in a transfer device, with regard to existing and potential injuries or illness, so as to prevent further harm during movement. (NFPA 1006)
Padlocks
The most common types of locks on the market today, portable locks built to provide regular-duty or heavy-duty service. Several types of locking mechanisms are available, including key-ways, combination wheels, and combination dials.
Parallel attack
A method of attack in which the control line is located parallel to the fire edge, at a distance of about 5 to 50 ft (1.5to 15 m) from the fire. The intervening fuel usually burns out as the fire moves alongside the fire control line but can also burn out with the main fire.
Parallel chord truss
A truss in which the top and bottom chords are parallel.
Paramedic
EMS personnel with the highest level of training in EMS, including cardiac monitoring, administering drugs, insert-ing advanced airways, manual defibrillation, and other advanced assessment and treatment skills.
Parapet
The part of a wall entirely above the roofline. (NFPA 5000
Partition
A nonstructural interior wall that spans horizontally or vertically from support to support. The supports may be the basic building frame, subsidiary structural members, or other portions of the partition system. [ASCE/SEI 7:11.2] (NFPA 5000)
Party wall
A wall constructed on the line between two properties.
PASS
Acronym for the steps involved in operating a portable fire extinguisher: Pull pin, Aim nozzle, Squeeze trigger, Sweep across burning fuel.
Pawls
Devices attached to a fly section(s) to engage ladder rungs near the beams of the section below for the purpose of anchoring the fly section(s). Also called locks or dogs. (NFPA 1931)
Peak cut
A ventilation opening that runs along the top of a pitched roof.
Pendant sprinkler head
A sprinkler head designed to be mounted on the underside of sprinkler piping so that the water stream is directed in a downward direction.
Personal alert safety system (PASS)
A device that continually monitors for lack of movement of the wearer and automatically activates an alarm signal, indicating the wearer is in need of assistance; can also be manually activated to trigger the alarm signal. (NFPA 1982)
Personal flotation device (PFD)
A device manufactured in accordance with U.S. Coast Guard specifications that provides supplemental flotation for persons in the water. (NFPA 1006)
Personal protective equipment (PPE)
Consists of full person-al protective clothing, plus a self-contained breathing apparatus (SCBA) and a personal alert safety system (PASS) device. (NFPA 1001)
Personnel accountability report (PAR)
Periodic reports verifying the status of responders assigned to an incident or planned event. (NFPA 1026)
Personnel accountability system
A system that readily identifies both the location and function of all members operating at an incident scene. (NFPA 1500)
Personnel accountability system
A system that readily identifies both the locations and the functions of all members operating at an incident scene. (NFPA 1500)
Phosgene
A chemical agent that causes severe pulmonary dam-age; it is a by-product of incomplete combustion.
Photoelectric smoke alarm
A detector that use a light beam and a photocell to detect larger visible particles of smoke. When visible particles of smoke enter the inner chamber, they reflect some of the light onto the photocell, thereby activating the alarm.
Photoelectric smoke detector
A detector that use a light beam and a photocell to detect larger visible particles of smoke. When visible particles of smoke enter the inner chamber, they reflect some of the light onto the photocell, thereby activating the alarm.
Physical evidence
A physical or tangible item that proves or dis-proves a particular fact or issue; also referred to as real evidence.
Pick-head axe
A tool that has a head with an axe on one side and a pointed end (“pickÓ) on the opposite side.
Pick
The pointed end of a tool, which can be used to make a hole or purchase point in a door, floor, or wall.
Piercing nozzle
A nozzle that can be driven through sheet metal or other material to deliver a water stream to that area.
Pike pole
A pole with a sharp point (ÒpikeÓ) on one end coupled with a hook. It is used to make openings in ceilings and walls. Pike poles are manufactured in different lengths for use in rooms of different heights.
Pipe wrench
A wrench having one fixed grip and one movable grip that can be adjusted to fit securely around pipes and other tubular objects.
Pitched chord truss
A type of truss typically used to support a sloping roof.
Pitched roof
A roof with sloping or inclined surfaces.
Pitot gauge
A type of gauge that is used to measure the velocity pressure of water that is being discharged from an opening. It is used to determine the flow of water from a hydrant or nozzle.
Placards
Signage required to be placed on all four sides of high-way transport vehicles, railroad tank cars, and other forms of hazardous materials transportation that identifies the hazardous contents of the vehicle, using a standardized system: 1034-in. by 1034-in.diamond-shaped indicators.
Planning section
Section responsible for the collection, evaluation, dissemination, and use of information related to the incident situation, resource status, and incident forecast. (NFPA 1026)
Planning section chief
The general staff position responsible for planning functions and for tracking and logging resources. It is assigned when command staff members need assistance in man-aging information.
Plaster hook
A long pole with a pointed head and two retract-able cutting blades on the side.
Plate glass
A type of glass that has additional strength so it can be formed in larger sheets but will still shatter upon impact.
Platform-frame construction
Construction technique for building the frame of the structure one floor at a time. Each floor 10m
Plume
The column of hot gases, flames, and smoke rising above a fire; also called convection column, thermal updraft, or thermal column. (NFPA 921)
A deep indentation of unburned fuel along the fire’s perimeter, often found between a finger and the head of the fire.
Point of origin
The exact physical location within the area of origin where a heat source and a fuel first interact, resulting in a fire or explosion. (NFPA 921)
Polar solvent
A water-soluble flammable liquid such as alcohol, acetone, ester, and ketone.
Police powers
A legal authority based on the Tenth Amendment that grants state (and local) authorities the authority to establish and enforce laws protecting the greater good of the community.
Policies
Formal statements that provide guidelines for present and future actions. Policies often require personnel to make judgments.
Portable monitor
A monitor that can be lifted from a vehicle-mounted bracket and moved to an operating position on the ground by not more than two people. (NFPA 1965)
Portable radio
A battery-operated, hand-held transceiver.(NFPA 1221)
Portable tanks
Folding or collapsible tanks that are used at the fire scene to hold water for drafting.
Positive-pressure attack
The use of positive-pressure fans to control the flow of products of combustion while fire suppression efforts are underway.
Positive-pressure ventilation
Ventilation that relies on fans to push or force clean air into a structure after a structure fire has been controlled.
Possible cause
A hypothesis determined to have less than 50 per-cent probability of being true.
Post
One of the vertical support members or pillars of a vehicle that holds up the roof and forms the upright columns of the passenger compartment.
Post indicator valve (PIV)
A sprinkler control valve with an indicator that reads either ÒopenÓ or ÒshutÓ depending on its position.
Potential energy
The energy that an object has stored up as a result of its position or condition. A raised weight and a coiled spring have potential energy.
Pounds per square inch (psi)
The standard unit for measuring pressure.
Powered air-purifying respirator (PAPR)
An air-purifying respirator that uses a powered blower to force the ambient air through one or more air-purifying components to the respiratory inlet covering. (NFPA 1984)
Power take-off shaft
A supplemental mechanism that enables a fire engine to operate a pump while the engine is still moving.
Preaction sprinkler system
A sprinkler system employing a piping system that contains air that might or might not be under pressure, with a supplemental detection system installed in the same areas as the sprinklers. (NFPA 13)
Preaction valve
A type of sprinkler system valve that holds 11 sprinkler head activates, a fire detector activates, or a combination of sprinkler head and initiating device activation takes place.
Preconnected flat hose load
A hose loading method similar to the flat hose load used for supply lines, except the female end of the hose lie is preconnected to a pump discharge outlet, and a nozzle is attached to the male end of the hose line.
Preincident plan
A document developed by gathering general and detailed data that is used by responding personnel in effectively managing emergencies for the protection of occupants, responding personnel, property, and the environment. (NFPA 1620)
Preincident survey
The process used to gather information to develop a preincident plan.
Premixed foam solution
Solution produced by introducing a measured amount of foam concentrate into a given amount of water in a storage tank. (NFPA 11)
Pressure gauge
A device that measures and displays pressure readings. In an SCBA, the pressure gauges indicate the quantity of breathing air that is available at any time.
Pressure indicator
A gauge on a pressurized portable fire extinguisher that indicates the internal pressure of the expellant.
Primary cut
The main ventilation opening made in a roof to allow smoke, heat, and gases to escape.
Primary feeders
The largest-diameter water main pipes in a water distribution system that carry the greatest amounts of water.
Primary search
An immediate and quick search of the structures likely to contain survivors. (NFPA 1670)
Private water system
A privately owned water system that operates separately from the municipal water system.
Probable cause
A hypothesis determined to have greater than 50 percent probability of being true.
Projected windows
Windows that project inward or outward on a top or bottom hinge; also called factory windows. They are usually found in older warehouses or commercial buildings.
Proprietary supervising alarm system
A fire alarm system that transmits a signal to a monitoring location owned and operated by the facility’s owner.
Protected premises fire alarm system
A fire alarm system that sounds an alarm only in the building where it was activated; that is, no signal is sent out of the building.
Protection plates
Reinforcing material placed on a ladder at chafing and contact points to prevent damage from friction and contact with other surfaces.
Protective hood
A part of a fire fighter’s personal protective equipment that is designed to be worn over the head and under the helmet; it provides thermal protection for the neck and ears.
Protein foam
A protein-based foam concentrate that is stabilized with metal salts to make a fire-resistant foam blanket. (NFPA 402)
Pry axe
A specially designed hand axe that serves multiple purposes. Similar to a Halligan tool, it can be used to pry, cut, and force doors, windows, and many other types of objects. Also called a multipurpose axe.
Pry bar
A specialized prying tool made of a hardened steel rod with a tapered end that can be inserted into a small area.
Publicemergency alarm reportingsystem
A system of alarm-initiating devices, transmitting and receiving equipment, and communication infrastructure (other than a public telephone network) used to communicate with the communications center to provide any combination of manual or auxiliary alarm service. (NFPA 72)
Public information officer (PIO)
A member of the command staff responsible for interfacing with the public and media or with other agencies with incident-related information requirements. (NFPA 1026)
Public safety answering point (PSAP)
A facility equipped and staffed to receive emergency and non-emergency calls requesting public safety services via telephone and other communication devices. (NFPA 1061)
Public safety communications center
A building or portion of a building that is specifically configured for the primary pur-pose of providing emergency communications services or public safety answering point (PSAP) services to one or more public safe-ty agencies under the authority or authorities having jurisdiction. (NFPA 1061)
Pulaski axe
A hand tool that combines an adze and an axe for brush removal.
Pulley
A device with a free-turning, grooved metal wheel (sheave) used to reduce rope friction. Side plates are available for a carabiner to be attached. (NFPA 1670)
Pump tank fireextinguisher
A nonpressurized, manually operated water-type fire extinguisher that is rated for use on Class A fires. Discharge pressure is provided by a hand-operated, double-acting piston pump.
Purchase point
A small opening made to enable better tool access in forcible entry.
Pyrolysis
A process in which material is decomposed, or broken down, into simpler molecular compounds by the effects of heat alone; pyrolysis often precedes combustion. (NFPA 921)
Quint apparatus
Fire apparatus with a permanently mounted fire pump, a water tank, a hose storage area, an aerial ladder or elevating platform with a permanently mounted waterway, and a complement of ground ladders.
Rabbit tool
A hydraulic spreading tool designed to pry open doors that swing inward.
Radiation
The combined process of emission, transmission, and absorption of energy traveling by electromagnetic wave propagation (e.g., infrared radiation) between a region of higher temperature and a region of lower temperature. (NFPA 550)
Rafters
Joists that are mounted in an inclined position to support a roof.
Rail
The top or bottom piece of a trussed beam assembly used in the construction of a trussed ladder. Also, the top and bottom surfaces of an I-beam ladder. Each beam has two rails.
Rain-down method
A foam application method that directs the stream into the air above the fire and allows it to gently fall on the surface.
Rapid intervention crew/company (RIC)
A minimum of two fully equipped personnel on site, in a ready state, for immediate rescue of disoriented, injured, lost, or trapped rescue personnel. (NFPA 1500)
Rapid intervention crew/company universal air connection (RIC UAC)
A system that allows emergency replenishment of breathing air to the SCBA of disabled or entrapped fire or emergency services personnel. (NFPA 1407)
Rapid intervention pack
A portable air supply that provides an emergency source of breathing air for a single fire fighter who has run out of air or whose air supply is insufficient to safely exit from an IDLH atmosphere.
Rate-of-rise heat detector
A device that responds when the temperature rises at a rate exceeding a predetermined value.(NFPA 72)
Rear of the fire
The side opposite the head of the fire. Also called the heel of the fire.
RECEO-VS
An acronym developed for use by the incident commander for accomplishing tactical priorities on the fire ground.
Reciprocating saw
A saw that is powered by an electric motor or a battery motor and whose blade moves back and forth.
Reducer
A fitting used to connect a small hose line or pipe to a larger hose line or pipe. (NFPA 1142)
Regulations
Mandates issued and enforced by governmental bodies such as the U.S. Occupational Safety and Health Administration and the U.S. Environmental Protection Agency.
Regulator purge/bypass valve
A device or devices designed to bypass a regulator.
Rehabilitate
To restore someone or something to a condition of health or to a state of useful and constructive activity.
Reinhart
A hand tool used for constructing fire control lines and overhauling wildland fires. The tool is similar to an oversized gar-den hoe.
Rekindle
A return to flaming combustion after apparent but incomplete extinguishment. (NFPA 921)
Relative humidity
The ratio between the amount of water vapor in the gas at the time of measurement and the amount of water vapor that could be in the gas when condensation begins, at a given temperature. (NFPA 79)
Remote annunciator
A secondary fire alarm notification unit, usually located near the front door of a building, that provides event information and frequently has the same control functionality as the main fire alarm control unit.
Remote-controlled hydrant valve
A valve that is attached to a fire hydrant to allow the operator to turn the hydrant on without flowing water into the hose line.
Remote supervising station alarm system
A fire alarm system that sounds an alarm in the building and transmits a signal to the fire department or an off-premises monitoring location.
Repeater
A special base station radio that receives messages and signals on one frequency and then automatically retransmits them on a second frequency.
Rescue
Those activities directed at locating endangered persons at an emergency incident, removing those persons from danger, treating the injured, and providing for transport to an appropriate healthcare facility. (NFPA 1500)
Rescue company
A group of fire fighters who work as a unit and are equipped with one or more rescue vehicles. (NFPA 1410)
Rescue-lift air bag
An inflatable device used to lift an object or spread one or more objects away from each other to assist in freeing a victim. Various sizes and types are available.
Reservoir
A water storage facility.
Residential sprinkler system
A sprinkler system designed to protect dwelling units.
Residual pressure
The pressure that exists in the distribution system, measured at the residual hydrant at the time the flow readings are taken at the flow hydrants. (NFPA 24)
Resource management
Under the NIMS, includes mutual-aid agreements; the use of special federal, state, local, and tribal teams; and resource mobilization protocols. (NFPA 1026)
Respirator
The complete assembly, including the respiratory inlet covering air purification components, electronics, batteries, harness, cables, and hose where applicable; designed to protect the wearer from inhalation of atmospheres containing harmful gases, vapors, or particulate matter. (NFPA 1994)
Response
Immediate and ongoing activities, tasks, programs, and systems to manage the effects of an incident that threatens life, property, operations, or the environment. (NFPA 1600)
Reverse hose lay
A method of laying a supply line where the supply line starts at the attack engine and ends at the water source.
Rim locks
Surface-mounted, interior locks located on or in a door with a bolt that provide additional security.
Risk/benefit analysis
An assessment of the risk to rescuers versus the benefits that can be derived from their intended actions. (NFPA 1006,1008)
Rocker lugs
Fittings on threaded couplings that aid in coupling the hose. Also referred to as rocker pins.
Rocker panels
A section of a vehicle’s frame located below the doors, between the front and rear wheels.
Roll-in method
A foam application method that involves sweeping the stream just in front of the target. Also referred to as the sweep or roll-on method.
Rollover
The condition in which unburned fuel (pyrolysate) from the originating fire has accumulated in the ceiling layer to a sufficient concentration (i.e., at or above the lower flammable limit) that it ignites and burns. This can occur without ignition of, or prior to the ignition of, other fuels separate from the origin; also known as flameover. (NFPA 921)
Roof covering
The membrane, which may also be the roof assembly, that resists fire and provides weather protection to the building against water infiltration, wind, and impact. (NFPA 5000)
Roof decking
The rigid portion of roof between the roof sup-ports and the roof covering.
Roof hooks
The spring-loaded, retractable, curved metal pieces that allow the tip of a roof ladder to be secured to the peak of a pitched roof. The hooks fold outward from each beam at the top of a roof ladder.
Roof ladder
A single ladder equipped with hooks at the top end of the ladder. (NFPA 1931)
Roofman’s hook
A long pole with a solid metal hook used for pulling.
Rope bag
A bag used to protect and store rope so that the rope can be easily and rapidly deployed without kinking.
Rope record
A record for each piece of rope that includes a history of when the rope was placed in service, when it was inspected, when and how it was used, and which types of loads were placed on it.
Rotary saw
A saw that is powered by an electric motor or a gasoline engine and that uses a large rotating blade to cut through material. The blades can be changed depending on the material being cut.
Rotary saw
A saw that is powered by an electric motor or a gasoline engine and that uses a large rotating blade to cut through material. The blades can be changed depending on the material being cut.
Round turn
A piece of rope looped to form a complete circle with the two ends parallel.
Rubber-covered hose
Hose whose outside covering is made of rubber, which is said to be more resistant to damage. Also referred to as a rubber-jacket hose.
Run cards
Cards used to determine a predetermined response to an emergency.
Rung
The ladder crosspieces, on which a person steps while ascending or descending. (NFPA 1931)
Running end
The part of a rope used for lifting or hoisting.
Safe location
A location remote or separated from the effects of a fire so that such effects no longer pose a threat. (NFPA 101)
Safety data sheets (SDSs)
Formatted information, provided by chemical manufacturers and distributors of hazardous products, about chemical composition, physical and chemical properties, health and safety hazards, emergency response, and waste disposal of the material. (NFPA 1072)
Safety knot
A knot used to secure the leftover working end of the rope.
Salvage
A firefighting procedure for protecting property from further loss following an aircraft accident or fire. (NFPA 402)
Salvage cover
A large square or rectangular sheet made of heavy canvas or plastic material that is spread over furniture and other items to protect them from water runoff and falling debris.
San Francisco hook
A multipurpose tool that can be used for several forcible entry and ventilation applications because of its unique design, which includes a built-in gas shut-off and directional slot.
Saponification
The process of converting the fatty acids in cooking oils or fats to soap or foam; the action caused by a Class K fire extinguisher.
SCBA harness
The backpack or frame for mounting the working parts of the SCBA and the straps and fasteners used to attach the SCBA to the fire fighter.
SCBA regulator
The part of the SCBA that reduces the high pressure in the cylinder to a usable lower pressure and controls the flow of air to the user.
Scientific method
The systematic pursuit of knowledge involving the recognition and definition of a problem; the collection of data though observation and experimentation; analysis of the data; the formulation, evaluation, and testing of hypotheses; and, where possible, the selection of a final hypothesis. (NFPA 921)
Screwdriver
A tool used for turning screws.
SCUBA dive rescue technician
A responder who is trained to handle water rescues and emergencies, including recovery and search procedures, in both water and under-ice situations. (SCU-BA stands for self-contained underwater breathing apparatus.)
Search
Land-based efforts to find victims or recover bodies. (NFPA 1951)
Search and rescue
The process of searching a building for a victim and extricating the victim from the building.
Search rope
A guide rope used by fire fighters that allows them to maintain contact with a fixed point.
Seat belt cutter
A specialized cutting device that cuts through seat belts.
Secondary collapse
A subsequent collapse in a building or excavation. (NFPA 1006)
Secondary cut
An additional ventilation opening made for the purpose of creating a larger opening or limiting fire spread.
Secondary feeders
Smaller-diameter water main pipes in the water distribution system that connect the primary feeders to the distributors.
Secondary loss
Property damage that occurs due to smoke, water, or other measures taken to extinguish the fire.
Secondary search
A detailed, systematic search of an area that is conducted after the fire has been suppressed. (NFPA 1670)
Self-contained breathing apparatus (SCBA)
An atmosphere-supplying respirator that supplies a respirable air atmosphere to the user from a breathing air source that is independent of the ambient environment and designed to be carried by the user. (NFPA 1981)
Self-contained underwater breathing apparatus (SCUBA)
A respirator with an independent air supply that is used by under-water divers.
Self-expelling agent
An agent that has sufficient vapor pressure at normal operating temperatures to expel itself from a fire extinguisher.
Self-rescue
Escaping or exiting a hazardous area under one’s own power. (NFPA 1006)
Serial arsonist
A person who sets three or more fires with a cooling-off period between fires.
Seven, nine, eight (7, 9, 8) rectangular cut
A ventilation opening that is usually about 8 ft by 4 ft (1.2 m by 2.4 m) in size; it is primarily used for large commercial buildings with flat roofs.
Shackle
The U-shaped part of a padlock that runs through a hasp and then is secured back into the lock body.
Shock load
An instantaneous load that places a rope under extreme tension, such as when a falling load is suddenly stopped as the rope becomes taut.
Shoring
A structure such as a metal hydraulic, pneumatic/mechanical, or timber system that supports the sides of an excavation and is designed to prevent cave-ins.
Shove knife
A forcible entry tool used to trip the latch of out-ward swinging doors.
Shut-off valve
Any valve that can be used to shut down water flow to a water user or system.
Siamese connection
A hose appliance that allows two hose to be connected together and flow into a single hose.
Sidewall sprinkler head
A sprinkler that is mounted on a wall and discharges water horizontally into a room.
Simplex channel
A radio system that uses one frequency to transmit and receive all messages; transmissions can occur in either direction but not simultaneously in both; when one party transmits, the other can only receive, and the party that is trans-mitting is unable to receive.
Single-action pull station
A manual fire alarm activation device in which the user takes a single step-such as moving a lever, toggle, or handle-to activate the alarm.
Single command
A command structure in which a single individual is responsible for all of the strategic objectives of the incident. It is typically used when an incident is within a single jurisdiction and is managed by a single discipline.
Single-jacket
A construction consisting of one woven jacket.(NFPA 1962)
Single resource
An individual, a piece of equipment and its personnel, or a crew or team of individuals with an identified supervisor that can be used on an incident or planned event. (NFPA 1026)
Single-station smoke alarm
A detector comprising an assembly that incorporates a sensor, control components, and an alarm notification appliance in one unit operated from a power source either located in the unit or obtained at the point of installation. (NFPA 72)
Size-up
The process of gathering and analyzing information to help fire officers make decisions regarding the deployment of resources and the implementation of tactics. (NFPA 1410)
Slash
Debris resulting from natural events such as wind, fire, snow, or ice breakage; or from human activities such as building or road construction, logging, pruning, thinning, or brush cutting. (NFPA 1144)
Sledgehammer
A hammer that can be one of a variety of weights and sizes.
S.L.I.C.E.-R.S.
An acronym intended to be used by the first arriving company officer to accomplish important strategic goals on the fire ground.
Smoke color
The attribute of smoke that reflects the stage of burning of a fire and the material that is burning in the fire.
Smoke control system
A mechanical system that can create positive or negative pressure to control, alter, and limit the spread of smoke and gases.
Smoke density
The thickness of smoke. Because it has a high mass per unit volume, smoke is difficult to see through.
Smoke detector
A device that detects visible and invisible products of combustion (smoke) and sends a signal to a fire alarm control unit.
Smoke ejectors
A mechanical device, similar to a large fan, that can be used to force heat, smoke, and gases from a post-fire environment and draw in fresh air. (NFPA 402)
Smoke explosion
A violent release of confined energy that occurs when a mixture of flammable gases and oxygen is present, usually in a void or other area separate from the fire compartment, and comes in contact with a source of ignition. In this situation, there is no change to the ventilation profile, such as an open door or window; rather, it occurs from the travel of smoke within the structure to an ignition source.
Smoke inversion
The condition in which smoke hangs low to the ground because of the presence of cold air.
Smoke particles
The unburned, partially burned, and completely burned substances found in smoke.
Smoke
The airborne solid and liquid particulates and gas-es evolved when a material undergoes pyrolysis or combustion, together with the quantity of air that is entrained or otherwise mixed into the mass. (NFPA 1404)
Smoke velocity
The speed of smoke leaving a burning building.
Smoke volume
The quantity of smoke, which indicates how much fuel is being heated.
Smooth-bore nozzle
A nozzle that produces a solid stream, or a solid column of water.
Smooth-bore tip
A nozzle device that is a smooth tube, which is used to deliver a solid column of water. Different-sized tips can be attached to a single nozzle or appliance.
Socket wrench
A wrench that fits over a nut or bolt and uses the ratchet action of an attached handle to tighten or loosen the nut or bolt.
Soffit
The material covering the gap between the edge of the roof and the exterior wall of the house. The soffits in most modern houses contain a system of vents to maintain air flow to the attic area. Some attics may have sealed soffits to create a conditioned air space for energy conservation.
Soft sleeve hose
A short section of large-diameter supply hose that is used to provide water from the large steamer outlet (the large-diameter port) on a fire hydrant or other pressurized water source to the suction side of the fire pump.
Solar panels
A general term for thermal collectors or photovoltaic (PV) modules. (NFPA 780)
Solar photovoltaic (PV) systems
A power system designed to convert solar energy into electrical energy; may also be referred to as a PV system or a solar power system.
Solid beam
A ladder beam constructed of a solid rectangular piece of material (typically wood), to which the ladder rungs are attached.
Solid-core door
A door design that consists of wood filler pieces inside the door. This construction creates a stronger door that may be fire rated.
Solid stream
A solid column of water.
Solid
One of the three stages of matter; a material that has three dimensions and is firm in substance.
Sounding
The process of striking a roof with a tool to determine where the roof supports are located.
Spalling
Chipping or pitting of concrete or masonry surfaces. (NFPA 921)
Spanner wrench
A type of tool used to couple or uncouple hose by turning the rocker lugs or pin lugs on the connections.
Span of control
The maximum number of personnel or activities that can be effectively controlled by one individual (usually three to seven). (NFPA 1006)
Split hose bed
A hose bed arranged to enable the engine to lay out either a single supply line or two supply lines simultaneously.
Split hose lay
A scenario in which the attack engine forward lays a supply line from an intersection to the fire, and the supply engine reverse lays a supply line from the hose left by the attack engine to the water source.
Spoil pile
A pile of excavated soil next to the excavation or trench. (NFPA 1006)
Spoliation
Loss, destruction, or material alteration of an object or document that is evidence or potential evidence in a legal proceeding by one who has the responsibility for its preservation. (NFPA 921)
Spot fire
A new fire that starts outside areas of the main fire, usually caused by flying embers and sparks.
Spotlight
A light designed to project a narrow, concentrated beam of light.
Spot-type detector
A single smoke detector or heat detector device. These devices are often spaced throughout an area.
Spree arsonist
A person who sets three or more fires at separate locations with no emotional cooling-off period between fires.
Spring-loaded center punch
A spring-loaded punch used to break automobile glass.
Sprinkler piping
The network of piping in a sprinkler system that delivers water to the sprinkler heads.
Sprinkler stop
A mechanical device inserted between the deflector and the orifice of a sprinkler head to stop the flow of water.
Sprinkler wedge
A piece of wedge-shaped wood placed between the deflector and the orifice of a sprinkler head to stop the flow of water.
Stack effect
The vertical air flow within buildings caused by the temperature-created density differences between the building interior and exterior or between two interior spaces. (NFPA 92)
Staging area
Location established where resources can be placed while they await a tactical assignment.(NFPA 1026)
Standard operating procedure (SOP)
A written organization-al directive that establishes or prescribes specific operational or administrative methods to be followed routinely for the performance of designated operations or actions. (NFPA 1521)
Standards
Documents, the main text of which contain only requirements and which are in a form generally suitable for mandatory reference by another standard or code or for adoption into law. Nonmandatory provisions shall be located in an appendix or annex, footnote, or fine-print note and are not to be considered a part of the requirements of a standard. (NFPA 1)
Standing part
The part of a rope between the working end and the running end.
Standpipe system
An arrangement of piping, valves, and hose connections installed in a structure to deliver water for fire hose.
States of matter
The physical state of a material-solid, liquid, or gas.
Static pressure
The pressure that exists at a given point under normal distribution system conditions measured at the residual hydrant with no hydrants flowing. (NFPA 24)
Static rope
A rope generally made out of synthetic material that stretches very little under load.
Static water source
A water source such as a pond, river, stream, or other body of water that is not under pressure.
Staypoles
Poles attached to each beam of the base section of extension ladders, which assist in raising the ladder and help pro-vide stability of the raised ladder. (NFPA 1931)
Steamer port
The large-diameter port on a fire hydrant.
Step chocks
Specialized cribbing assemblies made of wood or plastic blocks in a step configuration. They are typically used to stabilize vehicles.
Stop
A piece of material that prevents the fly sections of a ladder from becoming overextended, leading to collapse of the ladder.
Stored-pressure fire extinguisher
A fire extinguisher in which both the extinguishing agent and expellant gas are kept in a single container and that includes a pressure indicator or gauge. (NFPA 10)
Stored-pressure water-type fire extinguisher
A fire extinguisher in which water or a water-based extinguishing agent is stored under pressure.
Storz-type (nonthreaded) hose coupling
A hose coupling that has the property of being both the male and the female coupling. It is connected by engaging the lugs and turning the coupling a one-third turn.
Straight stream
A stream made by using an adjustable nozzle to provide a straight stream of water.
Strike team
Specified combinations of the same kind and type of resources, with common communications and a leader. (NFPA 1026)
Strip cut
Another term for a trench cut.
Structural firefighting protective coat
The protective coat worn by a fire fighter for interior structural firefighting.
Structural firefighting protective pants
The protective trousers worn by a fire fighter for interior structural firefighting.
Subsurface fuels
Partially decomposed matter that lies beneath the ground, such as roots, moss, duff, and decomposed stumps.
Suction hose
A short section of supply hose that is used to sup-ply water to the suction side of the fire pump.
Supervising station alarm system
An alarm system that communicates between the protected property and a constantly attended location that will receive, interpret, and take the appropriate action to handle the alarm condition.
Supervisory signal
A signal that results from the detection of a supervisory condition that indicates the need for action. (NFPA 72)
Supplemental restraint system (SRS)
A system that uses supplemental restraint devices such as air bags to enhance safety in conjunction with properly applied seat belts. Seat belt pretensioning systems are also considered part of an SRS.
Supplied-air respirator
An atmosphere-supplying respirator for which the source of breathing air is not designed to be carried by the user. Also known as an airline respirator. (NFPA 1989)
Supplied-air respirator (SAR)
An atmosphere-supplying respirator for which the source of breathing air is not designed to be carried by the user. Also known as an air line respirator. (NFPA 1989)
Supply hose
Hose designed for the purpose of moving water between a pressurized water source and a pump that is supplying attack lines.(NFPA 1961)
Supply lineoperations
The delivery of water from a water sup-ply source, such as a fire hydrant or a static water source, to an attack engine.
Surface fuels
Fuels that are close to the surface of the ground, such as grass, leaves, twigs, needles, small trees, logging slash, and low brush. Also called ground fuels.
Survivability profiling
An assessment that weighs the risks like-ly to be taken versus the benefits of those risks, of the viability and survivability of potentia1 fire victims under the current conditions in the structure.
Tag line
A separate rope that ground personnel can use to guide an object that is being hoisted or lowered.
Talk-around channel
A simplex channel used for onsite communications.
Tamper seal
A retaining device that breaks when the locking mechanism is released.
Task force
A group of resources with common communications and a leader that can be pre-established and sent to an incident or planned event or formed at an incident or planned event. (NFPA 1026)
Technical rescue incident (TRI)
Complex rescue incidents requiring specially trained personnel and special equipment to complete the mission. (NFPA 1670)
Technical rescuer
A person who is trained to perform or direct a technical rescue. (NFPA 1006)
Technical rescue team
A group of rescuers specially trained in the various disciplines of technical rescue.
Technical use life safety rope
A life safety rope with a diameter that is 3/8 in. (9.5 mm) or greater but is less than 1/2 in.(12.5mm),with a minimum breaking strength of 4496 lbf (20 kN). Used by highly trained rescue teams that deploy to technical environments such as mountainous and/or wilderness terrain.
Telecommunicator
An individual whose primary responsibility is to receive, process, or disseminate information of a public safety nature via telecommunication devices. (NFPA 1061)
Telephone interrogation
The phase in a 911 call during which the telecommunicator asks questions to obtain vitaI information such as the location of the emergency.
Temperature
The degree of sensible heat as measured by a thermometer or similar instrument.
Tempered glass
A type of safety glass that is heat-treated so that, under stress or fire, it will break into small pieces that are not as dangerous.
Temporal-3 pattern
A standard fire alarm audible signal for alerting occupants of a building.
Ten-codes
A system of predetermined coded messages, such as “What is your 10-20?” used by responders over the radio.
Ten standard firefighting orders
A set of systematically organized rules developed by the U.S. Department of Agriculture Forest Service task force to reduce danger to firefighting personnel.
Testimonial evidence
Verbal testimony of a witness given under oath in court or during specific legal proceedings.
Thermal column
A cylindrical area above a fire in which heated air and gases rise and travel upward.
Thermal conductivity
A property that describes how quickly a material will conduct heat.
Thermal imaging device
An electronic device that detects differences in temperature based on infrared energy and then generates images based on those data. It is commonly used in smoke-filled environments to locate victims as well as to search for hidden fire during size-up and overhaul.
Thermal layering
The stratification (heat layers) that occurs in a room as a result of a fire.
Thermal radiation
The means by which heat is transferred to other objects.
Thermoplastic material
Plastic material capable of being repeatedly softened by heating and hardened by cooling and, that in the softened state, can be repeatedly shaped by molding or forming. (NFPA 5000)
Thermoset material
material Plastic material that, after having been cured by heat or other means, is substantially infusible and cannot be softened and formed. (NFPA 5000)
Threaded hose coupling
A type of coupling that requires a male fitting and a female fitting to be screwed together.
Throwline
A floating rope that is intended to be thrown to a per-son during water rescues or as a tether for rescuers entering the water. (NFPA 1983)
Tie rod
A metal rod that runs from one beam of the ladder to the other to keep the beams from separating. Tie rods are typically found in wood ladders.
Time marks
Status updates provided to the communications center every 10 to 20 minutes. Such an update should include the type of operation, the progress of the incident, the anticipated actions, and the need for additional resources.
Tip
The very top of the ladder.
Topography
The land surface configuration. (NFPA 1051)
Trailers
Solid or liquid fuel used to intentionally spread or accelerate the spread of a fire from one area to another. (NFPA 921)
Training officer
The person designated by the fire chief with authority for overall management and control of the organization’s training program. (NFPA 1401)
Transfer of command
The formal procedure for transferring the duties of an incident commander at an incident scene. (NFPA 1026)
Transitional attack
An offensive fire attack initiated by an exterior, indirect handline operation into the fire compartment to initiate cooling while transitioning into interior direct fire attack in coordination with ventilation operations.
Trench cut
A roof cut that is made from one load-bearing wall to another load-bearing wall and that is intended to prevent horizontal fire spread in a building.
Triangular cut
A triangle-shaped ventilation cut in the roof decking that is made using a saw or an axe.
Trigger
The button or lever used to discharge the agent from a portable fire extinguisher.
Triple-layer hose load
A hose loading method in which the hose is folded back onto itself to reduce the overall length to one-third before loading the hose into the bed. This load method reduces deployment distances.
Truck company
A group of fire fighters who work as a unit and are equipped with one or more pieces of aerial fire apparatus. (NFPA 1410)
Trunked radios
A radio system that uses a computerized shared bank of frequencies to make the most efficient use of radio resources.
Truss
A collection of lightweight structural components joined in a triangular configuration that can be used to support either floors or roofs.
Truss block
A piece of wood or metal that ties the two rails of a trussed beam ladder together and serves as the attachment point for the rungs.
Trussed beam
A ladder beam constructed of top and bottom rails joined by truss blocks that tie the rails together and support the rungs.
TTY/TDD systems
User devices that allow speech-and/or hearing-impaired citizens to communicate over a telephone system. TTY stands for teletype, and TDD stands for telecommunications device for the deaf,; the displayed text is the equivalent of a verbal conversation between two hearing persons.
Turbulent smoke flow
flow Agitated, boiling, angry-movement smoke, which indicates great heat in the burning building. It is a precursor to flashover.
Twisted rope
Rope constructed of fibers twisted into strands, which are then twisted together.
Two-in/two-out rule
A safety procedure that requires a mini-mum of two personnel to enter a hazardous area and a minimum of two backup personnel to remain outside the hazardous area during the initial stages of an incident.
Two-way radios
Portable communication devices used by fire fighters. Every firefighting team should carry at least one radio to communicate distress, progress, changes in fire conditions, and other pertinent information.
Type I construction (fire resistive)
The type of construction in which the fire walls, structural elements, walls, arches, floors, and roofs are of approved noncombustible or limited-combustible materials that have a specified fire resistance.
Type II construction (noncombustible)
The type of construction in which the fire walls, structural elements, walls, arches, floors, and roofs are of approved noncombustible or limited-combustible materials without fire resistance.
Type III construction (ordinary)
The type of construction in which exterior walls and structural elements that are portions of exterior walls are of approved noncombustible or limited-combustible materials and in which fire walls, interior structural elements, walls, arches, floors, and roofs are entirely or partially of wood of smaller dimensions than required for Type IV construction or are of approved noncombustible, limited-combustible, or other approved combustible materials. (NFPA 14)
Type IV construction (heavy timber)
The type of construction in which fire walls, exterior walls, and interior bearing walls and structural elements that are portions of such walls are of approved noncombustible or limited-combustible materials. Other interior structural elements, arches, floors, and roofs are constructed of solid or laminated wood or cross-laminated timber without concealed spaces within allowable dimensions of the building code. (NFPA 14)
Type V construction (wood frame)
The type of construction in which structural elements, walls, arches, floors, and roofs are entirely or partially of wood or other approved material. (NFPA 14)
Ultrahigh-frequency (UHF) band
Radio frequencies between 300 and 3000 MHz.
Underwriters Laboratories, Inc. (UL)
The U.S. organization that tests and certifies that fire extinguishers (among many other products) meet established standards. The Canadian equivalent is Underwriters Laboratories of Canada.
Undetermined fire
A classification of fire when the cause can-not be proven to an acceptable level of certainty.
Unibody (unit body) construction
The frame construction most commonly used in vehicles. The base unit is made of formed sheet metal; structural components are then added to the base to form the passenger compartment. Subframes are attached to each end. This type of construction eliminates the rail beams used in body-over-frame vehicles.
Unified command
A team effort that allows all agencies with jurisdictional responsibility for an incident or planned event, either geographic or functional, to manage the incident or planned event by establishing a common set of incident objectives and strategies. (NFPA 1026)
Unit
The organizational element having functional responsibility for a specific incident operations, planning, logistics, or finance/administration activity. (NFPA 1026)
Unityof command
The concept by which each person within an organization reports to one, and only one, designated person. (NFPA 1026)
Unlocking mechanism
A keyway, combination wheel, or com-bination dial used to open a padlock.
Unwanted alarm
Any alarm that occurs that is not the result of a potentially hazardous condition. (NFPA 72)
Upper explosive limit (UEL)
The maximum amount of gaseous fuel that can be present in the air if the air/fuel mixture is to be flammable or explosive.
Upright sprinkler head
A sprinkler head designed to be installed on top of the supply piping; it is usually marked SSU (Òstandard spray upright”).
Utility rope
Rope used for securing objects, for hoisting equipment, or for securing a scene to prevent bystanders from being injured. Utility rope must never be used in life safety operations.
Vapor density
The weight of an airborne concentration (vapor or gas) compared to an equal volume of dry air.
Ventilation
The controlled and coordinated removal of heat and smoke from a structure, replacing the escaping gases with fresh air. (NFPA 1410)
Ventilation-limited fire
A fire in which the heat release rate and fire growth are regulated by the available oxygen within the space. (NFPA 1410)
Vertical ventilation
The vertical venting of structures involving the opening of bulkhead doors, skylights, scuttles, and roof cutting operations to release smoke and heat from inside the fire building. (NFPA 1410)
Very high-frequency (VHF) band
Radio frequencies between 30 and 300 MHz; the VHF spectrum is further divided into high and low bands.
Voice over Internet Protocol (VolP)
Technology that converts a person’s voice into a digital signal that can be sent via the Internet to another device.
Voice recording system
Recording devices or computer equipment connected to telephone lines and radio equipment in a communications center to record telephone calls and radio traffic.
Volatility
The ability of a substance to produce combustible vapors.
Volume
The quantity of water flowing; usually measured in gallons (liters) per minute.
Wall post indicator valve
A sprinkler control valve that is mounted on the outside wall of a building. The position of the indicator tells whether the valve is open or shut.
Warm zone
The control zone outside the hot zone where personnel and equipment decontamination and hot zone support takes place. (NFPA 1500)
Water catch-all
catch-all A salvage cover that has been folded to form a container to hold water until it can be removed.
Water chute
A salvage cover that has been folded to direct water flow out of a building or away from sensitive items or areas.
Water curtain nozzle
A nozzle used to deliver a flat screen of water that forms a protective sheet of water to protect exposures from fire.
Water flow
The amount of water flowing through pipes, hose, and fittings, usually expressed in gallons (liters) per minute (gpm or L/min).
Water flow alarm device
An attachment to the sprinkler system that detects a predetermined water flow and is connected to a fire alarm system to initiate an alarm condition. (NFPA 13)
Water hammer
The surge of pressure that occurs when a high-velocity flow of water is abruptly shut off. The pressure exert-ed by the flowing water against the closed system can be seven or more times that of the static pressure. (NFPA 1962)
Water knot
A knot used to join the ends of webbing together.
Water main
A generic term for any underground water pipe.
Water mist fire extinguisher
A fire extinguisher containing distilled or de-ionized water and employing a nozzle that dis-charges the agent in a fine spray. (NFPA 10)
Water mist system
A fixed fire protection system that discharges very fine water mist particles through specialized nozzles that extinguish by displacing oxygen, cooling, and blocking radiant heat.
Water-motor gong
An audible alarm notification device that is powered by water moving through the sprinkler system.
Water pressure
The application of force by one object against another. When water is forced through the distribution system, it creates water pressure.
Water shuttle operations
A method of transporting water from a source to a fire scene using a number of mobile water sup-ply apparatus.
Water supply
A source of water for firefighting activities. (NFPA 1144)
Water thief
A device that has a 212-in. (65-mm) inlet and a 21/2-in. (65-mm) outlet in addition to two 11/2-in.(38-mm) outlets. It is used to supply many hose from one source.
Webbing
Woven material of flat or tubular weave in the form of a long strip. (NFPA 1983)
Wedges
Material used to tighten or adjust cribbing and shoring systems. (NFPA 1006)
Wet-barrel hydrant
A hydrant used in areas that are not susceptible to freezing. The barrel of the hydrant is normally filled with water.
Wet-chemical extinguishing agent
Normally an aqueous solution of organic or inorganic salts or a combination thereof that forms an extinguishing agent. (NFPA 10)
Wet-chemical extinguishing system
A system that discharges a proprietary liquid extinguishing agent. It is often installed over stoves and deep-fat fryers in commercial kitchens.
Wet-chemical fire extinguisher
A fire extinguisher containing a wet-chemical extinguishing agent for use on Class K fires.
Wet pipe sprinkler system
The most common and least expensive type of automatic sprinkler system. As its name implies, the piping in a wet system is always filled with water. When a sprinkler head activates, water is immediately discharged onto the fire.
Wetting-agent fire extinguisher
A fire extinguisher that expels water combined with a concentrate to reduce the surface tension and increase its ability to penetrate and spread.
Wet vacuum
A device similar to a wet/dry shop vacuum cleaner that can pick up liquids. It is used to remove water from buildings.
Wheel chocks
Wedges or blocks of sturdy materials that are placed against a vehicle’s wheels to prevent accidental rolling during extrication.
Wheeled fire extinguisher
A portable fire extinguisher equipped with a carriage and wheels intended to be transported to the fire by one person. (NFPA 10)
Wilderness search and rescue (SAR)
The process of locating and removing a victim from the wilderness.
Wildland
Land in an uncultivated, more or less natural state and covered by timber, woodland, brush, and/or grass. (NFPA 901)
Wildland/brush company
A fire company that is dispatched to vegetation fires where larger engines cannot gain access. Wild-land/brush companies have four-wheel drive vehicles and special firefighting equipment.
Wildland fire
An unplanned fire burning in vegetative fuels. (NFPA 1051)
Wildland/urban interface
The line, area, or zone where structures and other human development meet or intermingle with undeveloped wildland or vegetative fuels. (NFPA 5000)
Wildland/urban intermix
An area where improved property and wildland fuels meet with no clearly defined boundary. (NFPA 5000)
Wired glass
A glazing material with embedded wire mesh.
Wooden beam
Load-bearing member assembled from individual wood components.
Wood truss
An assembly of small pieces of wood or wood and metal.
Working end
The part of the rope used for forming a knot.
Wye
A device used to split a single hose into two or more separate lines.
Youth firesetters
Recognized classifications of minors who ignite fires for various reasons. Based on age and specific psycho-logical characteristics, youth firesetters include child firesetters, juvenile firesetters, and adolescent firesetters.
Zoned system
A fire alarm system design that divides a building or facility into zones so that the area where an alarm originated can be identified.
