A fire pump is a specialized water pump used in firefighting. While most water pumps are designed to distribute water at a set or variable pressure, a fire pump is part of a high-pressure system. The intense pressure maintained by a fire pump can deliver water quickly over a wide area or in a high-pressure stream on a concentrated area. Either method will aid fire containment. Fire pumps are part of building sprinkler systems and are also used on firefighting vehicles. They can distribute foam or other fire retardants as well as water.
Organized firefighting dates to ancient Rome, but for centuries amounted to bucket brigades that transported water by hand from available sources. In the 16th and 17th centuries, firefighters had to break into the municipal water supply, which was little improvement. The first fire pump was invented in the late 1600s, soon followed by the fire hose. Paris was the first city to have a fire brigade, established by the French king in 1716. French firefighters were called pompiers, or pumpers, and are still known by this name in modern times.
The fire pump aids firefighting by providing a pressurized flow of water, which firefighters can direct to strategic areas with fire hoses. Fire engines contain a portable fire pump for this purpose. Water from fire hydrants is diverted to the engine’s fire pump and then to the fire hoses. The pressurized stream of water extinguishes burning materials while cooling the surrounding area, preventing the fire from spreading. A pressurized stream is thus far more effective than water alone for putting out a fire.
Fire pumps are also essential parts of building fire sprinkler systems. When the sprinkler system is activated by a heat or smoke detector, sprinklers set into the walls or ceilings distribute water throughout the building. Again, high pressure is required to ensure the entire building or area is saturated. A smaller pump, called a jockey pump, is attached to the fire pump to maintain this high pressure while the sprinkler system is operating.
Varieties of fire pumps are available for specialized firefighting situations. For example, fireboats pump liquid directly from the surrounding body of water rather than tapping into municipal systems to fight fires on ships or shorelines. Other fire pumps allow for the addition of compressed air foam, a highly effective fire retardant. Added to water, compressed air foam is often used on oil or chemical fires or other blazes that would resist traditional water treatment methods.