#joseph wright

Joseph Wright

Recognizing each stage allows you to describe with accuracy how a fire can quickly increase; later we will discuss fire characteristics, which will provide you with an opportunity to describe accurately the visual features of a fire scene.

THE 4 STAGES OF FIRE DEVELOPMENT

Incipient Stage

Also known as ignition.

This first stage begins when all 4 components have resulted in a fire starting.

Easiest to control and extinguish, and given the right circumstances, may possibly burn out on its own accord before it has a chance to reach the second stage.

Growth Stage

Shortest but most sudden of the 4 stages.

Combination of oxygen and any nearby combustible material will fuel the fire.

As it progresses, gases will rapidly increase in temperature, resulting in a build-up of pressure in the room.

Fully Developed Stage

When all the combustible materials have been consumed, the fire is at its peak and will be fully developed.

At this stage, the heat will be immense, and because the room will be engulfed in flames, there will be little hope of escape or survival.

Decay Stage

If the fire is left, then this final stage will be the longest, as the fire gradually finishes its consumption – think of a bonfire that is left to burn.

The heat still remains intense, and will do for some time, which is why firefighters remain so long at a fire scene even after the flames have been extinguished.

The fire may continue to smoulder and there is a risk of pyrolysis occurring, which may result in a secondary fire.

Source ⚜ More: Writing References

EDIT

Stage One: Ignition

When the 3 elements of the fire triangle (heat, fuel and oxygen) are involved in a balanced chemical chain reaction, a fire begins.

Can also be classed as the incipient stage if the reaction is unbalanced, leading to smouldering, low temperature fire with no visible flames. This type of fire still gives off toxic gases.

The fire easiest to control and extinguish, or as close to this stage as possible.

Stage Two: Growth

The fire begins to consume the available fuel in the area or compartment.

Heat rises rapidly, and in an indoor fire a smoke layer forms at the ceiling, descending as more fuel burns.

Where present, active fire protection systems such as sprinklers or smoke alarms will activate, and passive systems such as self closing fire doors will protect escape routes. An escape should be made in this stage, as the fire will reach lethal temperatures during the growth stage.

Once the fire reaches a hot enough temperature, a transitional event called Flashover occurs. Flashover is where the heat of the fire is enough that all fuel in the room reaches a combustible temperature more or less simultaneously, including the particles of fuel in the smoke layer.

Essentially, the room erupts into a fireball all at once and if you're still in the room when it does, you've caught fire too.

Demonstration of a "Flashover" [video]

Stage 3: Fully Developed

Now all fuel elements are combusting, the fire is at its peak and is considered fully developed.

At this stage, the heat is lethal without specialist equipment to survive it.

Stage 4: Decay

This final stage will be the longest, as the fire gradually finishes its consumption – think of a bonfire that is left to burn.

The heat still remains intense, and will do for some time, which is why firefighters remain so long at a fire scene even after the flames have been extinguished.

The fire may continue to smoulder and there is a risk of pyrolysis occurring, which may result in a secondary fire.

Sources & additional resources: 1 2

A Lighthouse on Fire at Night by Joseph Wright of Derby (1734–1797)

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And as we move away, we can see ourselves turning into memories. We are these memories. As of this moment, we’ll remember each other as we’ll remember a distant world disappearing into a blueness more blue than it used to be.

Andy Warhol, Vesuvius, Naples, ca. 1985

Joseph Wright, Vesuvius in Eruption, 1774