Jones and Bartlett Firefighter Skills Flashcards
What type of construction is referred to as “ordinary construction”?
Type III
At what temperature will steel lose its strength and elongate, causing a support beam to collapse?
538 degrees C (1000 degrees F)
What is the term that relates to the decrease in wood strength from exposure to the high temperatures generated by a fire?
Pyrolysis
What type of construction is referred to as “fire-resistive” construction?
Type I
What type of construction is used for almost all modern wood-frame construction?
Platform-frame
What type of non load-bearing wall is an interior wall that extends from a floor to the underside of a floor above?
Fire barrier walls
When concrete is heated, the moisture inside the concrete converts to steam and expands, creating internal pressure and causing a section of the concrete to break off. This process is called __________
Spalling
What is the term for the weight of a building itself, without contents, as it sits on the foundation?
Dead load
What type of glass is often used in fire doors and windows designed to prevent fire spread?
Wired glass
In Canada, a good rule of thumb for identifying Type II structures is _______________
Visibly exposed structural steel elements
Which phase of fire suppression involves considering dispatch information along with pre-incident plan information about the location to determine what types of tools might be needed?
Response and size-up
What special equipment is needed for a rapid intervention company/crew?
Thermal Imaging Camera
What are the 3 ways that fire can spread?
Conduction, convection and radiation
What is conduction?
Transfer of heat through matter (ie. heat travelling up a metal spoon)
What is convection?
Circulatory movement that occurs in a gas or fluid. Convection currents in a fire involve hot gases generated by the fire that rise because they are lighter, creating a higher pressure. Cooler gases are denser and move to the lower areas.
What is radiation?
The transfer of heat through the emission of energy in the form of electromagnetic waves
What kind of fires are Class A fires?
Ordinary solid combustible materials (wood, paper, cloth)
What kind of fires are Class B fires?
Flammable or combustible liquids (gasoline, kerosene, diesel fuel, etc)
What kind of fires are Class C fires?
Energized electrical equipment
What kind of fires are Class D fires?
Combustible metals (sodium, magnesium, titanium)
What kind of fires are Class K fires?
Combustible cooking oils and fats in kitchens
What are the three primary factors that influence the combustion of solid fuel fires?
Composition of the fuel, the amount of fuel and the configuration of the fuel
What are the factors that influence the fuel configuration?
Surface-to-mass ratio, orientation of the fuel, continuity of the fuel
What are the four stages of fire development?
Incipient stage, growth stage, fully developed stage, decay stage
What happens during the incipient stage of a fire?
Fuel starts to burn; fire is confined to the area of origin and does not significantly affect the atmosphere in the fire compartment
What happens during the growth stage of a fire?
- Fire begins to involve fuels beyond the ignition point
- Fire begins to create a plume of hot gases
- Temperature in the fire compartment begins to rise and pyrolyze fuels close to the fire
- ## When pressure from the burning gases gets higher, the fire may begin to spread beyond the room of origin
What happens during the fully developed stage of a fire?
- All available fuel has ignited and heat is being produced at the maximum rate
- Some fires will not reach a fully developed stage because they become ventilation-limited
What happens during the decay stage of a fire?
Rate of burning slows down because less fuel is available or the oxygen supply is limited
What are some special conditions within the fire compartment?
- Thermal layering
- Roll-over
- Backdraft
- Flashover
- Rapid fire growth
- Ventilation-limited fires
What is thermal layering?
The property of gases in an enclosed space in which they form layers according to their temperature. Hottest gases travel by convection currents to the top level of the room
What is roll-over?
Ignition of the hot, unburned gases that have accumulated at the top of the fire compartment; can be a precursor to a flashover
What is a flashover?
Near-simultaneous ignition of most of the exposed combustible materials in an enclosed area
What is a backdraft?
Caused by a change of the ventilation profile, permitting the introduction of oxygen into an enclosure where superheated gases and contents are hot enough for ignition, but the fire does not have sufficient oxygen to cause their combustion
Why are modern structures at greater risk of backdrafts?
- More tightly sealed
- Constructed of lighter-weight materials
- Contain more plastics
The characteristics of flammable vapours can be described in terms of ____________________ and ____________________
Vapour density, flammability limits
What is a BLEVE?
Boiling liquid/expanding vapour explosion
Assessment of what four things assists firefighters to potentially predict the location of a fire and its stage of development?
- Smoke volume
- Velocity
- Density
- Colour
Smoke reading requires firefighters to evaluate the effect of ___________, ___________, and _____________ on the smoke
The building, the weather, ventilation
The risk of failure of a steel structure depends on ___________, ___________, and ___________
Mass of the steel components, loads placed on them, methods used to connect the components
What is the most important characteristic of wood?
High combustibility
What is Type I Construction?
Fire-resistive - commonly used in schools, hospitals, and high-rise buildings
What is Type II Construction?
Non-combustible - commonly used in single storey warehouses or factory buildings where fire spread is not an issue
What is Type III Construction?
Ordinary - used in a wide variety of buildings, ranging from strip malls to small apartment buildings
