London Fire Brigade Guide
Pure - FivePD
Director Support Services
Understanding the Fire Triangle
A fire needs 3 elements in order for it to ignite – oxygen, fuel and heat – and a fire can be extinguished by removing one of these elements. For instance, covering a fire with a fire blanket removes the oxygen supply, therefore putting the fire out.
Identification of which fire extinguisher to use for which fire
Water: Ideal for class A fires and office, shop or warehouse environments.
Foam: Use on class A or B fires on electrical or material based fires.
CO2: Perfect for Class B fires like those caused by flammable liquids or electrical appliances.
Wet Chemical: Ideal for kitchen related fires with cooking oils and fats involved.
How to use a fire extinguisher
1 Pull the pin out.
2 Aim the nozzle at the base of the fire
3 Squeeze the lever slowly.
4 Keep at a distance and sweep the nozzle from side to side, moving closer as the flames decrease until the fire is completely out.
Fire Fighting Techniques
The hose uses a fog setting to extinguish a fire – ideal for closed compartment fires where there is no wind.
This technique is used particularly in closed compartment fires, and it works by using the fog nozzle of the hose, rather than a jet to extinguish the fire. This technique can be very effective in non-ventilated spaces, but where there is wind, its effectiveness is greatly reduced.
Aimed at the ceiling, the water drops down and extinguishes the fire from above.
Like the fog attack, this method is most effective in closed compartment fires, such as high rise environments. Instead of aiming the stream of water directly at the fire, it is aimed at the ceiling or wall above the flames, allowing the water to drop down and extinguish the blaze. It works twofold:
The Water will cool the ceiling, which disrupts the thermal balance, and the vapour will absorb energy . The rest of the water falls like rain , which helps to extinguish the fire.
This suffocates the flames as the water is aimed at the base of the fire.
Aiming the stream of water at the base of the fire, this technique works best using a concentrated, powerful jet of water that suffocates the flames. In order for this to work effectively, You must have a clear and direct line of sight to the fire. If this method is used on a fire in a non-vented area, then there will be less steam and the fire will be extinguished faster.
This uses both indirect and direct attacks to combat the overhead gases and the flames simultaneously.
This method consists of using both indirect and direct methods. One of the main benefits of this technique is that it simultaneously combats the overhead gases, as the indirect method does, whilst directly attacking the fire itself, extinguishing it quickly and minimising the risk of it spreading.
The ‘two lines in’ method
This uses two hoses and two teams, combining a fog nozzle and a solid stream of water – used only for fires that are subject to high winds.
This technique is used only for fires in high energy (wind driven) situations. The technique requires two teams of two, with each team operating a different kind of hose. One team operates a low pressure/high fog nozzle, and the other uses a nozzle with a solid, concentrated stream. One team should focus on attacking the flame directly, while the other should concentrate on preventing any advancing flame from spreading.