Definitions

A rapid, persistent chemical reaction that releases both heat and light.

A geometric shape used to depict the three components of which a fire is composed: fuel, oxygen and heat.

A geometric shape used to depict the four components required for a fire to occur: fuel, oxygen, heat, and chemical chain reactions.

Combining oxygen with another substance to create a new compound

A chemical process of oxidation that occurs at a rate fast enough to produce heat and usually light in the form of either a glow or a flame.

The destructive distillation of organic compounds in an oxygen-free environment by which the organic matter is converted into gases, liquids and char.

Heat transfer to another body, or within a body, by direct contact.

Heat transfer by circulation within a medium such as a gas or a liquid.

The emission and propagation of energy through matter or space by means of electromagnetic disturbances that display both wave- and particle-like behaviour.

The phase of fire development in which the fire is limited to the immediate point of origin.

The phase of fire development in which the fire spreads beyond the point of origin and beings to involve other fuels in the immediate area.

The phase of fire development in which the fire is free-burning and consuming much of the fuel.

The phase of fire development in which the fire has consumed either the available fuel or oxygen and is starting to die down.

The outcome of combustion in a confined space in which gases tend to form into layers according to temperature with the hottest gases at the ceiling and the coolest at the floor.

The lowest temperature at which a substance releases enough vapours to ignite and sustain combustion.

The minimum temperature of a liquid at which sufficient vapour is given off to form an ignitable mixture with the air, either near the surface of the liquid, or within the vessel used.

Minimum temperature a substance must attain to ignite under specific test conditions.

The condition where unburned fuel from the originating fire has accumulated in the ceiling layer to a sufficient concentration that it ignites and burns; it can occur without ignition of, or prior to the ignition of, other fuels separate from that which caused the event, also known as rollover.

A transition phase in the development of a compartment fire in which surfaces exposed to thermal radiation reach their ignition temperature more or less simultaneously and fire spreads rapidly throughout the space, resulting in full-room involvement or total involvement of the compartment or enclosed space.

A phenomenon that occurs when a fire takes place in a confined area, such as a sealed aircraft fuselage, and burns undetected until most of the oxygen contained therein is consumed.  The heat continues to produce flammable gases, mostly in the form of carbon monoxide.  These gases are heated above their ignition temperature, and when a supply of oxygen is introduced, the gases ignite with explosive force.

The weight of an airborne concentration or vapour or gas as compared to an equal volume of dry air.

The concentration of a combustible material in air below which ignition will not occur.  Mixtures below this limit are said to be "too lean", also known as lower explosive limit (LEL).

The highest concentration of a combustible substance in a gaseous oxidizer that will propagate a flame.

Boiling liquid expanding vapour explosion - An explosion that occurs when a tank containing a volatile liquid at the bottom and a flammable gas at the top is heated to the point of rupture.

A water-soluble flammable liquid, such as alcohol, acetone, ester and ketone.

A stream of water or other extinguishing agent as it leaves a fire hose nozzle until reaching the desired target.

The reduction in pressure caused by the water's contact with the side of the hose.  This contact requires additional force to overcome the drag created by the hose wall.

The surge of pressure that occurs when a high-velocity flow of water is abruptly shut off.  The pressure exerted by the flowing water against the closed system can be seven or more times that of the static pressure.

A flexible tube used by firefighters to carry water under pressure from the source of supply to a point where it is discharged.

A piece of hardware (other than a nozzle) that is generally intended to be connected to a fire hose to control or convey water.

The ratio of the weight of a given volume of gas to that of the same volume of air, both measured under the same conditions.

• -Truncating threads are cut in a "V" shape at 60 degree angle
• -Prevents binding and cross threading
• -Helps to clear grit from the threads

The largest diameter pipes in a water distribution system, which carry the greatest amounts of water

Smaller diameter pipes that connect the primary feeders to the distributors

Relatively small diameter pipes that delivery water to local users within a neighbourhood

The main structural side of a ground ladder

A ladder beam constructed of top and bottom rails joined by truss blocks that tie the rails together and support the rungs

The top or bottom piece of a trussed beam assembly used in the construction of a trussed ladder.  Each beam has two rails

A piece of metal that ties the two rails of a trussed beam ladder together and serves as the attachment point for the rungs

The ladder crosspiece on which a person steps while ascending or descending

Metal rod that runs from one beam of the ladder to the other to keep the beams from separating

The very top of the ladder

The end of the beam that is placed against the ground, or other lower support surface, when ground ladders are in the raised position

Metal channel reinforcement at the butt of a ladder

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

The lowest or widest section of an extension ladder

Part that is raised or extended from the bed section, each fly section extends from the previous section

Strips of metal that serve to guide a fly section during extension

Rope used on extension ladders for the purpose of raising a fly section(s)

• Method to gain access when normal means of entry cannot be used
• Requires strength, knowledge, proper techniques, and skill

• Beyond the reach of fire department aerial equipment
• Fires on upper floors must be fought from inside the building
• Poses the potential for significant "stack effect"
• Requires unreasonable evacuation time

The process of removing smoke, heat, and toxic gases from a burning building and replacing them with cooler, cleaner, more oxygen-rich air.

To work within the guidelines of the Incident Management System and complete tasks that have been assigned to the firefighter by their company officer

To enhance the margin of safety for all personnel working at the incident scene and to provide a means of accounting for the location and assignment of the personnel throughout the duration of the incident.

Size up is the mental evaluation and pre-planning made by all responding officers.

Rescue includes those operations which are required to remove human beings from involved buildings or other hazardous situations and convey them to a place of safety.

Exposure protection includes those operations which are required to prevent a fire from extending to uninvolved buildings, separate units, or other property.

Extinguishment includes those operations which are required to attack and extinguish the main body of fire.

Overhaul includes those operations that are required to complete the extinguishment of any remaining fire, prevent rekindling, and place the building in a fire safe condition.

Salvage is the saving of property.  It consists of those methods which reduce fire, water, and smoke damage during and after a fire with the goal of minimizing property damage.