Flashover [work in progress]

Flashover is used by the fire service to describe different forms of fire in a rapid movement.  It also relates to backdraft and smoke explosion. To the average Jake, the definitions are confusing.  The Average Jake is more interested with 'actions" that directly affect him/her. Flashover is a continuous fire that occurs in a ventilated compartment fire.  That compartment fire is well on its way to becoming totally envolved.  Any heat that is made will radiate down onto the stuff found in the compartment.  This causes ignition.  Backdraft is an event that happens when a compartment that is not very well ventilated causes gas to ignite... oftentimes in a very explosive mode. It's not sustained long.  It goes out usually after it's spent its energy.  Smoke-explosions are explosions that have a lot of flammable gases in the compartment AND oxygen, all mixed together.  Now you've got trouble.

Firefighters at FBVFD should know that flashover, backdraft, and smoke-explosions are usually caused by the Firefighter who acted or did not act.  One action for the Firefighter is to make entry.  Where he/she makes entry will directly relate to anything that happens. If this nothing does happen, this is most likely:

1.  Fuel is burning well.

2. The Fire is contained and is inside a sealed compartment.

3. Firefighters may have ventilated or not.  But it will be controlled somewhere else, usually above that particular compartment, like in a cockloft or attic.

Flammable gases are created when a ceiling falls.  It pushes gas down towards the "red". Firefighters may also be pushing gas ahead of them using a wide fog pattern.

Illinois fire

Cherry Road fire

Dorothy May fire

'It is most dangerous for any persons who happen to be in other rooms of the house, particularly those above and at he back, into which, after a front window has been cut through (broken), it is probable, if not almost certain, that the fire will penetrate before the firemen can reach them.........'

Chief Fire Officer Sir Eyre Massey Shaw (LONDON) in his book 'Fire Protection' 1876

Thanks to PAUL GRIMWOOD  of London's Fire Brigade.