The traditional responsibility of the Fire Department is the suppression of hostile fires while protecting life and property. Fire suppression techniques are varied, usually based on the type of product or material that is burning.
Firefighters are taught early in their careers that three elements must come together to make fire; oxygen, heat and fuel. By knowing the three basic elements of fire, simply removing one of them will put the fire out.
That seems overly simplistic, but it is the baseline technique used in fire fighting. The tough job is actually removing one or more of the elements.
For example, a burning piece of paper is quickly extinguished with water. The water is a cooling agent, capable of absorbing many times its temperature in heat. When the heat of the burning paper is pulled below the papers ignition temperature, the fire goes out.
Another good example is a pan of grease on fire. The grease is considered a flammable liquid and would react voilently with water. The temperature of the grease is usually too high to use cooling as an extinguishing method. Instead of removing the oxygen is the easiest way to extinguish the fire. To remove the oxygen, simply place a lid on the pan. Within a few minutes the fire will consume all of the available oxygen under the lid and the fire will go out.
In a larger flammable liquid fire, fire fighters would use a special type of water-based foam that is designed to blanket the burning fuel and prevent oxygen from reaching the fire, thus extinguishing the fire.
An example of removing the fuel of a fire is an electrical fire. In an electrical fire the fuel is actually the electrons moving through the conductor or wire. As long as the electricity is on the electrons and continue to move through the wire, it will burn in a very hot arc. To extinguish this fire we turn off any electrical power moving through the circuit, then any remaining fire can be cooled with water.
When firefighters respond to fires they are just like the examples illustrated above, only larger. Larger fires are extinguished in the same manner using better techniques and larger hoses.
The most common fire hose we use is a Pre-Connected Hand Line. It's a fire hose that is connected directly to the fire pump on the truck and is usually 1 3/4 inches in diamter. It is capable of flowing from 100 to 250 gallons of water per minute depending on the type of fire or the amount of water needed by the firefighters.
Usually, once the fire truck arrives at the scene of a fire, the driver gets out of the truck and operates the fire pump. Two other fire fighters pull the 200 foot hose out of the hose bed and approach the fire. Just before they get to the fire, the pump operator opens valves to let water flow into the hose. It sounds simple, but is actually takes many hours to learn how to coordinate pulling hose, flowing water, and entering a burning building...safely.
In Georgetown, our trucks carry between 750 to 1000 gallons of water and are capable of pumping from 1250 to 2000 gallons per minute. If we placed them parallel to each other, we could pump over 6000 gallons per minute.
Each truck also carries a compliment of special equipment, extension and roof ladders, axes, ceiling poles, hand lights, breathing air equipment, smoke removal fans, salvage covers to protect furniture, electrical generators and four different sizes of fire hose.