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In which way does slope affect the amount of fuel available to burn?

3.1 Slope. The slope, or degree of inclination or steepness of an area, can affect the amount of fuel available and can also lead to greater rates of fire spread. The steeper the slope, the greater the preheating of fuels that can occur, and the faster the fire will spread.

What burns hottest and fastest of all fuel types?

Note: Grasses burn the hottest and fastest of all the fuel types.

Which type of topographic direction causes fire to spread more quickly?

Because of the local, up-slope winds, wildfires usually burn up-slope. The steeper the slope, the more rapidly the fire will burn up-slope (and more intensely).

Which method of heat transfer is most important to fire behavior on steep slopes?

The steeper the slope, the faster the fire burns. This is because the fuels above the fire are brought into closer contact with the upward moving flames. Convection and radiant heat help the fuel catch fire more easily.

What are the 4 main factors influencing fire spread?

Interior finish in a room, fuel continuity, feedback, material ignitability, thermal inertia of the fuel, proximity of flames to walls are the major factors that influence fire growth.

What has the greatest influence on fire behavior?

Fuel characteristics strongly influence fire behavior and the resulting fire effects on ecosystems. A fuel’s composition, including moisture level, chemical makeup, and density, determines its degree of flammability. Moisture level is the most important consideration.

What is a serious concern of fires burning on a steep slope?

Although fire doesn’t usually move downhill quickly, one serious concern about fires burning down steep slopes is the possibility of burning material rolling downhill, which can ignite fuels below starting another fire.

What is the fastest spreading part of a fire?


What are 6 variables that affect fuel as it relates to fire?

Rate of burning and heat output for surface and crown fires are influenced by fuel load, fuel moisture, topography, ignition method, air temperature, wind, and relative humidity. Heat output and burn rate for smoldering are influenced, in part, by the fuel moisture and inorganic content of the duff (Frandsen 1989).

What are the six signs of arson?

Common Signs of Arson

  • A large amount of damage.
  • No “V” burn pattern present, unsual burn patterns and high heat stress.
  • Lack of accidental causes.
  • Evidence of forced entry.
  • Absence of valuable items.
  • The same person shows up at unconnected fires.
  • Low burning point with unidentifiable point of origin.
  • Multiple points of origin.

What are the 4 factors that affect weather?

Weather can be defined as the condition of the atmosphere at any given time and place. Weather conditions are determined by six major factors: air temperature, air pressure, humidity of the air, amount and kind of cloud cover, amount and kind of precipitation, and speed and direction of the wind.

What are the three factors causes fire?

Oxygen, heat, and fuel are frequently referred to as the “fire triangle.” Add in the fourth element, the chemical reaction, and you actually have a fire “tetrahedron.” The important thing to remember is: take any of these four things away, and you will not have a fire or the fire will be extinguished.

What are the 4 stages of fire?

Compartment fire development can be described as being comprised of four stages: incipient, growth, fully developed and decay (see Figure 1).

What are the 3 categories of evacuation?

In care premises, evacuations fall into three categories:

  • Single-stage: If all residents are deemed independent of help, all residents can evacuate immediately with minimal assistance.
  • Progressive horizontal: Occasions when most residents are dependent on staff assistance for a successful evacuation.

What is tetrahedron of fire?

A tetrahedron can be described as a pyramid which is a solid having four plane faces. Essentially all four elements must be present for fire to occur, fuel, heat, oxygen, and a chemical chain reaction. Each of the four sides of the fire tetrahedron symbolise the Fuel, Heat, Oxygen and Chemical Chain Reaction.

What is the best defense against fire?


What are the 4 elements of the fire tetrahedron?

These fire tetrahedron elements include:

  • Oxygen.
  • Heat.
  • Fuel.
  • Chemical reaction.

What is a type of fire classification?

Classes of fire Class A – fires involving solid materials such as wood, paper or textiles. Class B – fires involving flammable liquids such as petrol, diesel or oils. Class C – fires involving gases. Class D – fires involving metals.

What are the 5 fire classifications?

Fires can be classified in five different ways depending on the agent that fuels them: Class A, Class B, Class C, Class D, and Class K. Each type of fire involves different flammable materials and requires a special approach.

What are the 3 methods of extinguishing a fire?

All fires can be extinguished by cooling, smothering, starving or by interrupting the combustion process to extinguish the fire. One of the most common methods of extinguishing a fire is by cooling with water.

What are the six classes of fire?

There are currently six classes of fire i.e., Class A, B, C, D, Electrical and F. Fires are classified according to the material that ignites the fire. Below we provide a brief overview of each class of fire and a Fire Extinguisher Classification Chart.

What is the most dangerous in terms of fire?

Class C Fires

What are the 4 types of fire extinguishers?

There are four classes of fire extinguishers – A, B, C and D – and each class can put out a different type of fire. Multipurpose extinguishers can be used on different types of fires and will be labeled with more than one class, like A-B, B-C or A-B-C.

What is an example of a Class C fire?

A Class C fire is the burning of flammable gases, which can be very dangerous and highly explosive. These include gases such as butane and propane in gas canisters, which you’d expect to find in certain building trades. You will also find these with gas camping stoves and gas barbeques.

How do you fight a Class C fire?

Fighting Class C Fires Carbon dioxide fire extinguishers, and those loaded with a dry chemical like PKP, are effective. Conductive substances such as water or foam can put the fire fighter at risk.

What is the symbol for a Class C fire?

Class C extinguishers do not have a numerical rating. The C classification means the extinguishing agent is non-conductive. The geometric symbol indicating Class C is a blue circle. Class D fire extinguishers are commonly found in a chemical laboratory.

How do you extinguish a type C fire?

Extinguish a Class C fire by shutting off the electrical power, which serves as the fuel source for the electrical fire. Non-conductive chemicals like carbon dioxide should also be used to suppress the flames.

What is the best agent to extinguish a Class C fire?

Carbon Dioxide

What does ABC mean in fire extinguisher?

Dry Chemical Extinguishers

Is there risk in attempting to extinguish a fire?

Attempting to extinguish even a small fire carries some risk. Fires can increase in size and intensity in seconds, blocking the exit path of the fire fighter and creating a hazardous atmosphere. Therefore, individuals should attempt to fight only very small or incipient stage fires.