3 Principles of Fire
3 Principles of Fire are also known as the Fire Triangle and consist of Oxygen, Heat, and Fuel. All three of these principles need to be present and working in harmony to create, maintain, and accelerate fire.
3 Principles of Fire
- Oxygen - Needed to sustain combustion
- Heat - Raise the fuel to its ignition temperature and maintain for burn
- Fuel - Combustible material that will be consumed
When these 3 Principles are put into practice you will have created the chemical, exothermic reaction that is fire.
In contrast, to extinguish a fire you only need to remove one or more of these principles. A fire extinguisher removes the oxygen and will thus extinguish a fire. Water can remove the heat also extinguishing most fires. Drowning a fire in water will also deprive the fire of oxygen causing the same effect, except in cases of chemical fires where water would only serve to increase or accelerate the chemical reaction. Lastly, you could remove the fuel, limiting the ability for the fire to continually burn. Understanding the 3 Principles of Fire will help you to create, maintain and manage, as well as extinguish fire.
Applying the 3 Principles of Fire
When any one of these principles are in greater abundance than another, the fire may grow out of control. For instance on a hot day in Texas it may be quite easy to get a fire started, but the proper management of that fire is to be able to control the heat, oxygen/air flow, and fuel. Given that you cannot control the Texas heat that leaves you with two options - Fuel and Oxygen/air flow. If the wind kicks up, your fire will grow quickly and if you do not clear out fuel wood, debris, and scrub grasses and construct a wind break or fire ring around your fire you will quickly have a fire that can get out of control. This is why it is important to consider this information prior to constructing a fire.
When constructing a fire you will need to focus on each of the 3 Principles separately. Fuel is the most time consuming of the 3 Principles to process. You will need tinder, kindling, fuelwood. Tinder will be the most critical as you will need to provide a material that will heat up easily and grow an ember. In concept this seems relatively easy, but in reality can be very meticulous. It is preferred to create a tinder bundle which can consist of grasses, shavings, bark, char material, and whatever can be processed down to provide a lot of surface area or fluff. Once you have an adequate tinder bundle you will need to gather some kindling. Kindling is a bundle of sticks ranging from pencil thickness up to the size of your finger. A kindling bundle may also be called Squaw Sticks. It may be necessary to split fuel wood to make additional kindling. After you have sufficient kindling you will need to gather fuel wood. This is typically wood that is larger than your finger and the size of your wrist or arm. This is what will sustain your fire so do not skimp on this. It may be necessary to split some fuel wood so that it will dry next to the fire and will burn more consistently. Finally, you will need to construct a proper wind break that will direct the air flow to the base of your fire and can help provide a break if the wind kicks up. When we have processed our fuel, and have insured proper oxygen/ air flow, then we are ready to begin the ignition.
Igniting a fire is more difficult than it may seem. We often get so caught up on this task that we forget the 3 principles and assume the ignition source is all that is needed. When all 3 principles have been considered and applied can we then begin to apply ignition. The ignition could be anything from lighting a match, to mixing chemicals, to refocusing the suns light, to creating friction between two pieces of wood, or anything that will provide direct flame, or an ember. A spark thrown on a piece of char cloth is as efficient in lighting a fire as flicking a lighter. When done correctly either can present the same result.
When using an ember to light your fire you will need an adequate tinder bundle to place your ember. Once you have successfully placed your ember into the tinder bundle you will need to grasp the tinder bundle firmly and slowly feed oxygen into the ember. This can be done by simply waving the tinder bundle back and forth. The more smoke that is created the more oxygen will be needed to blow the ember into a flame. Once the flame appears you can place the tinder bundle into the kindling and cover. The rule is that you can add more kindling and fuel wood when the flames emerge above the burning kindling, until the desired size is reached. Remember to keep your fire attended at all times.
Since fire in some places can be a constant threat, it is important to understand that by controlling or managing fuel and ignition sources, we can reduce the risk of fire. This is true in areas that are under constant threat of forest fires. The local fire departments often advise residents to clear trees brush and debris/slash from within 100' of any buildings or structures. This limits the ability for the fire to spread to those structures.
Even if you do everything correctly it is still possible for your fire to get out of control, so be sure to always keep an easy way to extinguish your fire, and keep your fire manageable by limiting your fire's fuel. Do not build a huge fire to boil a pot of water. Keep your fire proportionate to how you intend to use it.
Never leave a fire unattended or leave a campsite with your fire still smoldering. Be sure to completely extinguish all fires before leaving.