Common Terms


A verb when used on the fire ground is an immediate action message to firefighters to get out of a building or area to safety. Similar to ships’ captain issuing an order to “Abandon Ship.” This is an emergency message indicating an extreme immediate action or the consequences will be dire.

air track

This is the chosen ventilation path of air through a structure, from the entrance to the exit port. Continual air track monitoring is critical to a safe and efficient PPA Attack.

auto extrication

the act of removing a patient from an auto


Predetermined milestones that signify progress on the fire ground. Examples of these benchmarks include: “fire knocked down”, “all clear” and” fire under control.”

bidirectional flow

When heat and fire gases are moving in more than one direction through a building (either in an opening or out an opening/exhaust) such as a door or window. Simply stated a bidirectional flow can be seen when heat and fire gases move out the top of an opening such as a door or window and cool fresh air can be seen moving in the bottom.

blitz line

A 2-1/2 inch pre-connected attack line.

combination attack

Utilizing an exterior fire attack line prior to entry for interior fire control operations. This generally involves pencilling the fire.

diagnostic space

The space that is left unsealed at the top of entrance port during PPA fire attack. This space is approximately one foot in depth. The purpose of the diagnostic space is to assess fire conditions inside the structure and to gauge the effectiveness of the air movement through the tract.


A Term used to describe removing occupants (civilians) from a building or occupancy.

fire knocked down

The point at which all visible fire has been extinguished from a room but extension may still be an issue.

fire struck

Occurs after knockdown. All possible routes of extension have been checked and the fire attack team is convinced that the fire is out.

flow path

Can be defined as the movement of heat and smoke from higher pressure within the fire area to all other low-pressure areas both inside and outside of the fire building. For firefighters, understanding how fire and smoke move throughout a building and the concept of flow paths is critical. One of the most dangerous places for a firefighter to be is between the fire and where the fire is going.

hardening the exterior of a building

Defensive control measures that are also commonly referred to as “surround and drown.” Hardening the exterior involves the use of master streams that are positioned outside of the collapse zone, for the purposes of fire control.

hi vol

4 inch or 5 inch supply lines

loss stop

All possible measures to limit damage to a structure and its contents have been taken.

marginal conditions

Interior fire attack and search at or near the end of the recreation time period.

neutral plane

The separation between the Over-Pressure region and the Under-pressure regions developed in a compartment fire (sometimes referred to as the smoke/air interface). The neutral plane can be seen quite clearly when thermal balance exists in the fire compartment.


Controlling the fire from an exterior position by utilizing a straight stream that is applied in short bursts. The intent is to “darken down” the fire without either upsetting the thermal balance or creating pressure through excess steam production. “Turning back the fire clock” will allow crews the time to properly set up for interior attack. Potentially this tactic delays the development of the fire from “a room and contents fire” to a “structural fire.”


Utilizing ventilation in concert with fire attack.


Pressuring a “box” in order to inhibit the spread of fire from an adjoining “box”. The theory is that fire will generally travel from a high-pressure area to an area of lower pressure.

rapid attack mode

This mode is sometimes broadcast at the end of the initial report or on an early update. This message signifies that the first arriving company officer has decided on an immediate aggressive interior attack.

recreation time

Safe time for an interior fire attack based on fire conditions and structural integrity.

softening the exterior of a building

Measures that are taken by RIT in order to gain access to a structure. The purpose of this access is to provide a secondary means of egress for interior companies.

strategic goals

Prioritized strategic goals must be formulated prior to the development of tactical assignments. Strategic goals are broad-based objectives that commonly answer the question “What needs to be done?” Rescue is an example of a strategic goal. The commonly used acronym for determining strategic goals is RECEOVS.

strategic mode

A clear statement of strategic mode is critical to safe fire ground operations. Action plan tactics are based on the chosen strategic mode. The options are offensive, transitional, defensive or non- intervention. Chief Brunicini likens being in two modes at once to “turning artillery on yourself.”

tactical objectives

Tactics are more specific than strategies but are based on strategic goals. Tactics commonly answer the question “How are we going to accomplish this goal?” For example, a “right-hand primary search” could be a tactic that would be chosen to support the strategic goal of rescue.

task level assignments

The task level involves the “doing part” of the action plan. This is based primarily on training, Operational Guidelines and established practices. Task level assignments also answer the questions “Who is going to do it and what will they need?” An example would be “Engine Four’s Company will conduct the primary search on the second floor with a charged hose line.”

unidirectional flow

When heat and fire gases are moving in one direction through a building (either in an opening or out an opening/exhaust) such as a door or window, then that flow is said to be unidirectional or moving in one direction. Simply stated a unidirectional flow can be described as, only heat out; or just fresh air in based on other openings or vent points.


The four characteristics of smoke that are critical to smoke reading (volume, velocity, density and colour)

wind driven fire

This situation occurs during windy conditions when the exit port for the fire is on the windward. The prevailing wind easily overcomes the PPA attack and the fire engulfs advancing fire attack teams.


A verb used to direct fire crews to (with urgency) to gather equipment, hose lines etc. and leave an area or building. Commonly used when deciding to make a strategic change on the fire ground, switch operational modes, or deciding to write off a structure or building.


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Emergency Scene Management I - FIRE-1114 by Justice Institute of British Columbia is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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