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(See Glossary Below)
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If you are studying for a United States Coast Guard Deck License exam which
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coupling device for connecting hoses of the nominal size, but which
have different type threads.
See mechanical foam.
Air foam nozzle (mechanical foam nozzle):
A special pick-up tube or nozzle incorporating a foam maker to
aspirate air into the solution to produce air foam.
Air line mask:
A face mask where the air is supplied through an air hose attached
to a blower outside of the contaminated space or area.
All-purpose nozzle (combination): A mechanical device
that fits on the end of a hose that controls the water pressure
inside the hose three ways by operating a single valve. The three
positions of the valve are:
2) vertical-HV /L V fog and
3) Back solid stream.
pipe or nozzle attachment that fits into the all-purpose nozzle high
velocity outlet. Applicators used aboard ship are 4', 10' and 12'
lengths and are equipped to change high velocity fog into low
velocity fog. The 4' and 10' applicators fit the standard 1 1/2"
nozzles and the 4' has a 60˚curve and
the 10' has a 90˚ curve on
the outlet end. The 12' applicator fits the standard 2 1/2" nozzle
and has a 90 ° curve at the outlet end.
Aqueous film forming foam (AFFF):
A fluorocarbon surfactant that acts as an effective vapor securing
agent due to its effect on the surface tension of the water. Its
physical properties enable it to float and spread across surfaces of
a hydrocarbon fuel with more density than protein foam.
electricity jumping across a gap in a circuit. The intense heat at
the arc may ignite any nearby combustible material or may fuse the
metal of the conductor.
Automatic alarm: An alarm usually activated by
thermostats, sprinkler valves or other automatic devices that
activate electrical circuits to the control station located on the
Automatic sprinkler system: A device that fulfills
both the functions of a fire detecting system and a fire
extinguishing system; the water is held back normally with a fixed
temperature seal in the sprinkler head, which melts or shatters at a
The man positioned directly behind the nozzleman; he takes up the
weight of the hose and absorbs some of the nozzle reaction so the
nozzle can be manipulated without undue strain.
Bleve (pronounced "blevey"): A
boiling liquid expanding vapor explosion; failure of a liquefied
flammable gas container caused by fire exposure.
Blitz attack: Firefighters hit the fire with
everything at their disposal.
Body harness: A series of web straps on the
protective breathing apparatus that position and stabilize the
Occurs when the heat from a fire in a tank travels down to the
bottom of the tank causing water that is already there to boil and
push part of the tank's contents over the side.
Breast plate: That part of the protective
breathing apparatus that holds the canister and protects the wearer
from the heat generated by the unit.
Breathing apparatus: A device that provides the user
with breathing protection; it includes a facepiece, body harness and
equipment that supplies air or oxygen.
Carbon dioxide (C02): A heavy, colorless,
odorless, asphyxiating gas that does not normally support
combustion. It is one and one-half times heavier than air and when
directed at the base of a fire its action is to dilute the fuel
vapors to a lean mixture to extinguish the fire. Normally carried on
board in 15 lb portable extinguishers and 50lb or 100lb cylinders in
the installed system.
Chain breaking: A method of fire extinguishment
that disrupts the chemical process that sustains the fire; an attack
on the chain reaction side of the fire tetrahedron.
Chain reaction: Series of events, each of which
cause or influence its succeeding event. For example, the burning
vapor from a fire produces heat which releases and ignites more
vapor; the additional vapor burns, producing more heat, which
releases and ignites still more vapor; and so forth.
Check valve: A valve that permits a flow in one
direction only and will close to prevent a flow in the opposite
Foam formed by mixing an alkali with an acid in water.
Class A fire: A fire involving common combustible
materials which can be extinguished by the use of water or water
solutions. Materials in this category include wood and wood-based
materials, cloth, paper, rubber and certain plastics.
Class B fire: A fire involving flammable or
combustible liquids, flammable gases, greases and similar products.
Extinguishment is accomplished by cutting off the supply of oxygen
to the fire or by preventing flammable vapors from being given off.
Class C fire: A fire involving energized
electrical equipment, conductors or appliances. Nonconducting
extinguishing agents must be used for the protection of
Class D fire: A fire involving combustible metals,
for example, sodium, potassium, magnesium, titanium and aluminum.
Extinguishment is accomplished through the use of heat absorbing
extinguishing agents such as certain dry powders that do not react
with the burning metals.
Combination combustible gas and oxygen indicator:
An instrument that measures the concentrations of both combustible
gas and oxygen; each is indicated on a separate meter.
Combination nozzle: See all-purpose nozzle.
Combustible gas indicator: An instrument used to
determine whether the atmosphere of a particular area is flammable;
also called an explosimeter.
A gas that, at normal temperatures, is entirely in the gaseous state
under pressure in its container.
The transfer of heat through a solid body.
The transfer of heat through the motion of heated matter, that is,
through the motion of smoke, hot air, heated gases produced by the
fire and flying embers.
The pattern in which convected heat moves. As the hot air and gases
rise from the fire, they begin to cool; as they do, they drop down
to be reheated and rise again.
A method of fire extinguishment that reduces the temperature of the
fuel below its ignition temperature; a direct attack on the heat
side of a fire tetrahedron (also see fire tetrahedron).
A gas that is liquefied in its container at a temperature far below
normal temperatures, and at low-to-moderate pressures.
Demand breathing apparatus:
A type of self-contained breathing apparatus that provides air or
oxygen from a supply carried by the user.
Dry chemical: A mixture of chemicals in powder
form that has fire extinguishing properties.
Dry powder: Extinguishing agents developed to
control and extinguish fires in combustible metals (class D fires).
Dry system: An automatic sprinkling system that
has air under pressure throughout installed piping in areas that
might be subjected to freezing temperatures. The operation of one or
more sprinkler heads releases the air pressure and activates the
control valve allowing water to flow into the system.
Electric fire sensor system: A device capable of
lighting a panel in the wheelhouse when it detects fire in a certain
area of the ship.
Protective clothing designed to protect the wearer from direct
contact with flames for a short time.
A simple one-way valve on a single-hose facepiece, consisting of a
thin disk of rubber, neoprene or plastic resin secured in the center
of the facepiece and designed to release exhaled breath; also called
a flutter valve.
combustible gas indicator.
Flammable range; the range of the mixture of air and flammable gas
or flammable vapor of liquids that must be present in the proper
proportions for the mixture to be ignited. The range has upper and
lower limits; any mixture above the upper explosive limit (VEL) or
below the lower explosive limit (LEL) will not burn.
Combustible materials that may be ignited by flames or radiated heat
from the fire.
portable equipment approved for use on certain types and classes of
A substance that will put out a fire and is available as a solid,
liquid or gas.
assembly that fits onto the face of the person using the breathing
apparatus, forming a tight seal to the face and transmitting air or
oxygen to the user.
chemical reaction known as rapid oxidation that produces heat and
light in the form of flames, gases and smoke.
A device that gives a warning when fire occurs in the area protected
by the device; it senses and sends a signal in response to heat,
smoke, flame or any indication of fire.
A self-contained unit, portable or semi portable, consisting of a
supply of the extinguishing agent, an expellant gas (if the
apparatus is not pressurized) and a hose with a nozzle.
Fire extinguishing system:
A means of putting out fires consisting of a supply of the
extinguishing agent, an actuation device (manual or automatic), and
the piping, valves and nozzles necessary to apply the agent.
The hot gases produced by burning materials.
Fire line automatic system: The system used to
detect fire in open spaces and to activate alarms and/or
firefighting equipment automatically, for example, a pneumatic tube
Fire-main system: A system that supplies water to all
areas of the vessel; it is composed of the fire pumps, piping (main
and branch lines), control valves, hose and nozzles.
Fire point: The temperature at which a liquid
fuel sustains combustion.
Consists basically of a fire hydrant (water outlet) with valve and
associated hose and nozzles.
A solid figure with four triangular sides illustrating how the chain
reaction sequence interacts with heat, fuel and oxygen to support
and sustain a fire.
A three-sided figure illustrating the three essential components of
fire: fuel (to vaporize, and burn), oxygen (to combine with fuel
vapor), and heat (to raise the temperature of the fuel vapor to its
Flame safety lamp:
An instrument used to test for oxygen deficiency; if there is enough
oxygen in the surrounding atmosphere to keep the flame burning,
there is enough oxygen to support life.
See explosive range.
ignition of combustibles in an area heated by convection, radiation
or a combination of the two. The action may be a sudden ignition in
a particular location followed by rapid spread or a "flash" of the
The temperature at which a liquid fuel gives off sufficient vapor to
form an ignitable mixture near its surface.
The part of the facepiece designed to carry fresh air or oxygen from
the canister to the facepiece and, in the facepiece with a dual
hose, to return exhaled breath from the facepiece to the canister.
See exhalation valve.
of bubbles that extinguishes fire mainly by smothering. The blanket
prevents flammable vapors from leaving the surface of the fire and
prevents oxygen from reaching the fuel. The water in the foam also
has a cooling effect.
Liquids of 3 % or 6 % concentrations that are mixed with water to
produce mechanical foam.
Devices for mixing chemical foam powders with a stream of water to
produce foam. Pressure type foam generators are closed devices
containing the necessary chemicals with provision for admission of
water when foam is needed.
A device that regulates the amount of foam concentrate and water to
form a foam solution.
The result of mixing foam concentrates with water.
Fog (spray) streams:
A method of projecting a stream of water in which a specifically
designed nozzle causes the water to leave the nozzle in small
droplets, thereby increasing the water's heat absorption efficiency.
Fresh-air breathing apparatus:
A hose mask; a facepiece connected to a pump by a long hose through
which air is pumped to the user. Mobility is limited by the length
and weight of the hose.
Any combustible material adding to the magnitude or intensity of a
fire; one of the essential sides of the fire triangle.
A smoke, vapor or gas given off by a fire which could be irritating,
offensive or dangerous to the fire fighter.
A substance that has no shape of its own but which will take the
shape of, and fill the volume of its container.
An area, tank or system previously used to carry inflammable or
poisonous liquids that has been entirely cleared of such liquids and
certified by a chemist as clear of any danger.
A sealing ring necessary to make a watertight connection between
female and male hose couplings.
A device that filters contaminants from air that is to be breathed;
it can only be used in an atmosphere that contains enough oxygen to
Directing a stream of water over the vessel's side, perpendicular to
the water surface.
the initials for "Gallons Per Minute" and is a measure of water
flow through the fire main system.
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Halogenated extinguishing agents:
Halon; made up of carbon and one or more of the halogen elements:
fluorine, chlorine, bromine and iodine.
See halogenated extinguishing agents.
A condition of fire potential defined by arrangement, size, type of
fuel and other factors which form a special threat of ignition or
difficulty of extinguishment. A "fire hazard" refers specifically to
fire seriousness potential and a "life hazard" to danger of loss of
life from fire.
That part of the mask designed to hold the facepiece in the proper
position on the face, with just enough pressure to prevent leakage
around the edge of the mask.
temperature above the normal atmospheric temperature, as produced by
the burning or oxidation process; one of the essential sides of the
fire triangle; often referred to as "ignition temperature" in fire
The movement and dispersion of heat from a fire area to the outside
atmosphere. An example of heat transfer would be fire fighting water
being converted into steam and expanding its volume, thus creating a
slight pressure and carrying the heat and heated water vapor to the
outside atmosphere also see connection, conduction, and radiation.
A foam that expands in ratios of over 100: 1 when mixed with water;
it is designed for fires in confined spaces.
High pressure fog (high velocity fog): Produced when using
the all purpose nozzle with the handle in mid-position. It is a high
capacity jet spray produced at very high pressure and discharged
through small holes of a cage type sprayer tip.
A flexible tube used to carry fluid from a source to an outlet.
Standard shipboard fire hoses are 1 1/2" or 2 1/2" in diameter. They
are normally 50 feet in length, with a female coupling installed on
one end and a male coupling on the other.
The covering over the inside liner of a hose. It is a woven jacket
(or jackets) of cotton or synthetic fibers.
See fresh-air breathing apparatus.
a permanently mounted fire hose installation which stows a fire hose
in a ready position. Normally found in engine spaces aboard ship.
See spanner wrench.
A dangerously high fever that can damage nerve centers. This
condition can result from exposure to excessive heat over an
extended period of time.
Mixture of vapor and air that is capable of being ignited by an
ignition source, but usually is not sufficient to sustain
The lowest temperature at which a fuel will burn without continued
application of an ignition source.
Overloading electrical wiring by trying to operate too many
appliances from it.
That part of the facepiece that allows the wearer a wide range of
A gas that, at normal temperatures, is partly in the liquid state
and partly in the gaseous state under pressure in its container.
LNG (liquid natural gas):
A natural gas, a hydrocarbon of fossil fuel, consisting mainly of
methane stored as a liquid and vaporized and burned as gas.
Lower flammable limit:
Minimum flammable concentration of a particular gas in the air.
Low velocity fog (low pressure fog): Produced by inserting an
applicator into an all purpose nozzle. It is a high capacity, low
pressure mist discharged at angles from 600 to 90 degrees; used to
cool down an area or to protect the fire fighting team from flames
LPG (liquefied petroleum gas): Anyone of several petroleum products
such as "butane" or "propane" stored under pressure as a liquid and
vaporized and burned as gas.
An outside threaded hose nipple which fits into the threads of a
swivel coupling of the same pitch and appropriate diameter. A
coupling to which nozzles and other appliances are attached.
Air foam; foam produced by mixing a foam concentrate with water to
produce a foam solution.
A large stream nozzle, normally found on tankers, fixed in various
locations above the main deck. They are operated by gear-driven
wheels or handles and have a 3600 arc. Can deliver a stream of water
or foam onto a deck type fire.
National standard thread:
All fire hose fittings and coupling screw threads are national
standard. The standard 21h" has 71/2 threads to the inch and the
outside diameter of the male couplings is 3 1 / 16".
Not subject to combustion under ordinary conditions of temperature
and normal oxygen content of atmosphere.
One that will not burn or support combustion.
An optional, removable part of the facepiece that fits into the
exhalation valve and is designed to reduce fogging of the lens.
A device with a control valve attached to the hose outlet to shape
and direct the stream.
The key member and leader of the hose team who controls the nozzle
and directs the stream onto the fire.
A procedure following a fire whereby the area is examined for hidden
fire and fire extension and the fire area is cleaned up.
A chemical process in which a substance combines with oxygen, giving
off energy usually in the form of heat. The rusting of iron is an
example of slow oxidation; fire is an example of rapid oxidation.
A material that releases oxygen when it is heated or, in some
instances, when it comes in contact with water. Substances of this
nature include: hypochlorites, chlorates, perchlorates, nitrates,
chromates, oxides and peroxides. Burning oxidizers cannot be
extinguished by removing their oxygen; extinguishment must be
accomplished by application of large amounts of water.
A gas present in the atmosphere in about 21 % concentrations, which
while not combustible is an essential element for combustion. It is
also the essential gas in respiration since the oxidation process
is basic to life.
Oxygen breathing apparatus (OBA): a type of self-contained breathing
apparatus that provides oxygen chemically.
Less than 16 % oxygen content in the atmosphere. Oxygen deficiency
can be caused by smoke, heat or gases of a fire.
A method of fire extinguishment that reduces the amount of available
oxygen below that needed to sustain combustion; an attack on the
oxygen side of the fire tetrahedron (also see fire tetrahedron).
An instrument used to determine whether the atmosphere contains
sufficient oxygen (15% or more) to sustain life.
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When hose is fed to the hose team to prevent excessive strain on the
firefighters. Normally hose is paid out by the backup men on the
Oils made by distillation (heating) of crude petroleum which produce
such products as gasoline, kerosene, fuel oil, lubricating oil and
The small tube with a metal end used to deliver the foam concentrate
from its storage (can) to the air foam nozzle.
Pike-head fire axe:
A versatile, portable. Firefighting tool with a blade and a pike
Pneumatic tube fire detector:
see fire line automatic system.
Portable fire extinguisher:
One that can be carried to the fire area for a fast attack; it
contains a limited supply of extinguishing agent.
A small gasoline driven pump used in emergencies to deliver water to
a fire, independent of the ship's fire main system.
A general term used to describe the ensemble of gear a firefighter
wears. Includes boots, foul weather gear, gloves, hat or special
Protective clothing that encases the wearer in a heat resistant
envelope and is worn when it is necessary to approach the fire
closely; it does not protect the wearer during direct contact with
The conversion of solid fuel to flammable vapor by heat.
An instrument for measuring temperatures too great for an ordinary
thermometer; it is used to find the temperature of a fire.
To put out; to extinguish by soaking the fuel with water or cooling
the fuel down below ignition temperature.
Pure energy; the heat that is released in the burning process. Like
the heat of the sun, it radiates, or travels, in all directions.
The travel of heat through space.
The heat from a fire that radiates back to the fuel causing
increased vapor production.
Slippery water; water to which small quantities of polyethylene
oxide have been added to reduce its viscosity and its friction in
hose lines, thereby increasing the reach of the stream.
The distance a straight stream travels before breaking up or
A coupling used to attach a smaller diameter hose to a larger
diameter hose or outlet and vice versa.
Reid vapor pressure method:
Method used by the American Society of Testing Materials to test
vapor pressure. It is a measure of the volatility, or tendency to
vaporize, of a liquid.
Seat of fire:
The area where the main body of the fire is located. It is
determined by the outward movement of heat and gases and where the
fire has burned through the deepest.
Self-closing fire door:
a fire resistant door (normally kept closed) which, when opened, is
returned to a closed position by a closing device.
Self-contained breathing apparatus: (SCBA): A device providing air or oxygen
to the user who wears the entire device; thus the user is completely
mobile. However, the device can supply air or oxygen for only a
limited amount of time.
Semiportable fire extinguisher:
One from which a hose can be run out to the fire. The other
components are fixed in place.
A visible product of fire made up of carbon and other unburned
substances in the form of suspended particles. It also carries the
vapors of water, acids and other chemicals, which can be poisonous
or irritating when inhaled.
Smoke detection system:
A device that samples the air to detect the presence of smoke
particles in the monitored area, and then sends an alarm.
To burn and smoke without flame, to exist ill a state of suppressed
A method of fire extinguishment that separates the fuel from the
oxygen; an attack on the edge of the fire tetrahedron where the fuel
and oxygen sides meet (also see fire tetrahedron).
See straight stream.
A special tool designed specifically for tightening or breaking
apart fire-hose connections.
That part of the facepiece, located directly in front of the
wearer's mouth that projects the wearer's voice with little or no
When burning flammable liquids spill onto the deck. Often involves
intense flame and heat due to the relatively large surface for
evaporation of liquids.
A fire that occurs without a flame, spark, hot surface or other
outside source of ignition.
Charges of electricity accumulated on opposing and usually moving
surfaces having negative and positive charges, respectively. A
hazard exists where the static potential is sufficient to discharge
a spark in the presence of flammable vapors or combustible dusts.
The water pressure available at a specific location where no flow is
being used and where there are no pressure losses due to friction.
A muster list outlining the special duties and duty station of each
member of the crew during emergencies, as well as the signals for
an installed system found on older ships used to protect spaces
where fire was likely to occur, such as engine room, cargo spaces,
paint lockers, and so forth.
An event that occurs when water is introduced into a tank of very
hot liquid, causing the liquid to froth and spatter.
Solid stream; a method of projecting a stream of water formed by a
nozzle that is fitted to a fire hose. The nozzle is tapered to a
size less than one-half the diameter of the hose end. This smaller
opening increases the velocity of the water and gives it greater
Wire or metal cages installed in the fire main system to keep debris
from clogging up the lines. Some strainers are located at the fire
stations for periodic cleaning out purposes.
the difference between the temperature of the surrounding air and
the temperature necessary to activate the fire detector.
Water that has been treated with a chemical to decrease its ability
to flow. It thus forms a thick wall that clings to burning material
and remains in place longer than ordinary water.
A device used to reduce the hoseline size and provide three outlets.
water that has been treated with a chemical agent to lower its
surface tension, thus allowing it to penetrate porous materials more
A device for measuring electrical resistance.
A device in the shape of a "Y" used to reduce the hoseline size and
separate the lines.
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