Fire Fighting Systems

Fire fighting systems are those which intervene in the fire growth process once fire has occured. Such systems can be used by trained occupants or attending fire fighters and include a fire extinguisher, fire hose reel, or fire hydrant. Other systems may be automatic such as a fire sprinkler system. Automatic systems are considered to be superior, because they do not rely on people to manually operate them. Fire fighting systems are known as "DYNAMIC" systems because they do something; they actively intervene in the rate of fire growth.

The greater the extinguishing capability of the system and the earlier in the fire growth period it can be applied, the lower the fire impact, hence, the preference for sprinkler systems by most fire engineers and fire fighting professionals.

Fire Detection Alarm and Evacuation Warning Systems The simplest fire detection and alarm system is the residential smoke alarm now installed in most Australian homes. The smoke alarm alerts the building occupants that a fire has been detected. A fire detection system may, in addition to alerting occupants, automatically notify the fire brigade of the fire. If fire detection and alarm systems operate very early in the fire growth stage, building occupants may be able to extinguish a small fire.

Smoke Management Systems

In many buildings occupied by the public, especially large buildings such as shopping centres, smoke from a fire can spread and descend so as to block exits and make occupant escape difficult or, in the extreme, impossible. In such instances, the installation of a smoke management system, which will slow down the rate of smoke spread, is recommended. Such systems often involve exhausting the smoke at ceiling level where hot smoke will naturally collect because it is hot and therefore lighter than the surrounding air. Other methods employ the opening of apertures in the roof or panels at high level in the walls of a building. Provided fresh air is allowed to naturally flow into the building below any smoke layer, these measures will permit the smoke to escape from the building rather than fill it up. Another way to stop smoke infiltrating from floor to floor in a multi-storey building is to pressurise the non-fire floors with fresh air at a pressure higher than that of the fire floor.

Fire Brigade Response

The sub system taken for granted and often overlooked is the fire brigade response (notification, dispatch and travel time to the fire scene). How effective this response will be in saving life and property depends on how long the fire will have been burning before they are notified, how long they will take to arrive, how fast the fire will grow, how much equipment they will bring with them and how much water will be available for fire fighting. Generally, compared to metropolitan areas, the time taken to arrive in rural areas is longer, not as much equipment is initially available and water is often in limited supply. However, as time passes in both rural and metropolitan areas, more and more fire fighters and equipment will arrive as resources are brought in from further afield.