Fire Brigade is the act of trying to prevent spreading and extinguishing significant unwanted fires in buildings, vehicles, forests, etc. Firefighters suppress fires and rescue to protect lives, property and the environment. Firefighters can provide other services to their community.
Firefighters typically undergo high-level technical training. This involves general fire-fighting techniques and the development of specialized expertise in certain fire operations, such as fire fighting and illegal firefighting. In the US, the national certification is called Fire Brigade I/II.
One of the major dangers associated with firefighting operations is the toxic environment created by combustible materials. The four major risks are smoke, lack of oxygen, high temperatures, and toxic atmospheres. Additional hazards include falling and structural collapse that can exacerbate problems posed in toxic environments. To address some of these risks, firefighters carry self-contained breathing apparatus.
The first step in firefighting operations is surveillance to locate the origin of fires and to identify specific risks.
Fire may be extinguished by water, fuel or emptying of oxidants, or chemical fire inhibition.
Video Firefighting
History
The earliest firefighter was known to be in Rome. On December 60, the Emperor Nero founded the Corps of Vigils (Vigiles) to protect Rome after the fire. It consists of 7,000 people equipped with buckets and axes, and they fight fire and serve as police.
Historical tactics and tools
In the 4th century BC, a Greek Alexandrian named Ctesibius created a double-style pump called siphona . As the water rises in the room, it compresses the air inside, which forces the water to come out with a steady stream through the pipe and nozzle.
In the 16th century, syringes were also used as fire extinguishers, larger ones mounted on wheels. Another traditional method that survives is the bucket brigade, which involves two human lines formed between the source of water and fire. Usually, people in one of the rows will pass a bucket full of water to the fire while in another line women and children will return empty buckets to be refilled.
In the 17th century, 'fire engines' were made, especially in Amsterdam. In 1721, the British inventor Richard Newsham made a popular fire engine which was basically a rectangular box on wheels filled with bucket brigades to provide a reservoir while the hand-powered pumps provide enough water pressure to extinguish the fire in the distance.
Ancient Rome
Ancient Rome does not have a city fire department. Instead, private people rely on their slaves or supporters to take action. They will not only form brigade brigades or try to cover up smaller fires, but will also destroy or tear down nearby buildings to slow the spread of fire. However, no more fires are extinguished, but they are contained and burned out. The ancient Romans did not have an organized firefighters until Vigiles were formed during the reign of Augustus.
United Kingdom
Prior to the Great Fire of London in 1666, several parishes in Britain had begun holding an imperfect fire department. After the Great Fire, Nicholas Barbon introduced the first fire insurance. To reduce the cost of insurance, Barbon also formed its own fire brigade, and other companies followed suit.
In the early 1800s, insured buildings were identified with badges or signs indicating that they were eligible for firefighting services. Uninsured buildings with certain firms are abandoned by firefighters to be burned, unless they happen to be adjacent to the insured buildings, in this case often in the company's interest to prevent the fire from spreading. In 1833 the fire insurance company in London merged to form The London Fire Company Establishment.
Steam-powered apparatus was first introduced in the 1850s, allowing more water to be directed to fire; in the early 1930s they were replaced by a version powered by an internal combustion engine.
In World War II, the Office of Extra Fire, and later the National Fire Service, was established to complement the local fire service. At that time, there was no national standard for firefighting, procedures, rank, or equipment (such as a lapse hose). This was standardized after the war.
United States
In January 1608, fires destroyed many of the occupiers and dwellings of the invaders in Jamestown, Virginia. Boston, New York City, and Philadelphia were all plagued by fires, and volunteer fire brigades formed soon after the disaster.
In 1736, Benjamin Franklin founded the Union Fire Company in Philadelphia, which became the standard for voluntary firefighting organizations. The firefighter has two important tools: a lifesaving bag and what's called a bed key. Rescue bags are used to collect and store valuables quickly, and bed locks are used to separate the wooden frame of the bed (often the most valuable item at home at the time) into pieces for the safe and quick removal of the fire.
The first American attempt at fire insurance failed after a major fire in Charlestown, Massachusetts in 1736. Then in 1740, Benjamin Franklin organized the Philadelphia Contributions to provide fire insurance, which was more successful. The Contributionship adopts a "fire sign" to easily identify the insured building. Firefighters began to be formalized with rules to provide buckets, ladders and hooks, and with the formation of volunteer firms. A chain of command is also established.
Maps Firefighting
Firefighters
The purpose of firefighting is to save lives, property, and the environment. Fire can quickly spread and endanger many lives, but with modern fire-fighting techniques, disasters can often be avoided. To prevent fires from starting, a firefighter's job may include general education on fire safety and conduct a fire inspection of the site to verify their compliance with the local fire code.
Firefighting skills
Firefighters require skills in combating, extinguishing and preventing fires, responding to emergency calls, operating and maintaining fire-fighting equipment and fires, and extensive training in firefighting and rescue activities. Firefighters must also have, or may obtain, knowledge of departmental organizations, operations, and procedures, and the district or city road system to be negotiated to carry out their duties.
They must meet minimum physical fitness standards and learn various fire and rescue jobs within a reasonable time frame
The example is:
- Structural Fire Fighting: rescue, fire suppression and conservation of property in buildings, closed structures, vehicles, or property such as those involved in fire or emergency situations.
- Wildland Fire Fighting: fire suppression and property conservation in forests, forests, pastures, shrubs, pastures, and other vegetation, or any combination of vegetation, involved in fire situations.
Specialty expertise
Special areas of fire operation may require subject-specific training.
The example is:
- Battle of the Fire Brigade: fire suppression measures to save people and to control or extinguish a fire involving or adjacent to a plane on the ground.
- Fire Extinguisher Lantern Ship: rescue, fire fighting, and conservation of property on ships involved in fire or emergency situations.
- Proximity Fire Fighting: rescue, fire fighting, and property conservation in incidents involving fires that produce high levels of radiant heat and conductive and convective heat.
Clock shift
Firefighters usually follow a 24-hour shift schedule, although some fire departments work eight or 12 hours of shift. Australian firefighters work shift 10/14, where the day shifts work ten hours and the night shift works 14 hours. Firefighters are divided into alternating shifts. Typically, 24-hour shift is followed by two days off. Shift personnel arrive to be absent at a certain time, ready to complete routine tasks. When shift, firefighters remain in the firefighter unless released or assigned other tasks.
Fire keepers
In fire fighting, there are also people designated as firefighters, also known as chief officers. Their duties vary, some may ensure evacuation from the part of the building they are responsible for; others may be responsible for fire control in certain areas, directing crews in forest fire suppression, or serving as firefighters in the logging area.
The chief officer is responsible for his firefighters during a fire or emergency, and he is expected to lead and control the overall situation while effectively fighting fire or other emergencies. The main officer should be able to evaluate their firefighters, use good judgment when deciding when it is time to pull firefighters out of the fire, and react calmly in an emergency situation. The chief officer should direct the firefighting activities and oversee all firefighting activities. In addition, he must have extensive knowledge of the city, the location of roads, fire hydrants, fire alarm boxes, and main buildings. It should also have knowledge of explosives, hazardous chemicals, and quality of material combustion in buildings, homes, and industrial plants.
In certain jurisdictions, civilians may be certified as Fire Extinguishers, and some cities require certain types of buildings, such as tall buildings, to have a certain number of Fire Extinguishers. For example, the City of Houston, Texas, requires every tenant in a tall building to have at least one Fire Warden for every 7,500 square feet occupied, and a minimum of two Fire Supervisors per floor. In this example, their task involves investigating each fire alarm (see if there really is a fire and if so, its nature), ensuring the fire extinguisher is contacted, directing evacuation of the facility, activating or suspending activation of fire-fighting equipment such as halon and sprinkler (pending if there are false alarms), meet with firefighters and take them to the alarm location or to fire past security or locked doors, and, if necessary, against fire until the fire department arrives.
The hazards caused by fire
One of the major dangers associated with firefighting operations is the toxic environment created by combustible materials. Four major hazards are:
- Smoke, which is becoming increasingly dangerous due to the increasing variety and amount of synthetic household materials.
- The lack of oxygen, 21% O 2 normal, 19.5% O 2 is considered lack of oxygen.
- High temperature
- Toxic atmosphere
To cope with such hazards, firefighters carry self-contained breathing apparatus (SCBA: a positive open-circuit pressure system) to prevent smoke inhalation. This is not an oxygen tank (oxygen as a strong fire acceleration represents a great risk when combined with virtually anything flammable in the presence of fire) but uses compressed air in a manner similar to SCUBA's scuba gear. A firefighter's SCBA usually holds 30 to 45 minutes of air, depending on the size of the tank and the level of consumption during heavy activity. While these equipment help to eliminate risk, firefighters are still exposed to smoke, toxic dust and fumes that have contributed to firefighters to be 14% more likely to develop cancer.
The obvious risk associated with the enormous heat generated by fire, even without direct contact with fire (direct flame), such as conductive heat and radiant heat, can cause serious burns even from great distances. There are a number of relatively serious heat-related risks, such as burns from hot gases (eg, air), steam, and hot and/or toxic fumes. Thus, firefighters are equipped with personal protective equipment (APD) that includes fire-resistant clothing such as Nomex or polybenzimidazole fibers (PBIs) and helmets that limit heat transmission to the body. However, PPE can not fully protect the user from the effects of all possible fire conditions.
The heat can cause the flammable liquid contained in the tank to burst violently, resulting in a so-called BLEVE (a burst of boiling water vapor). Some chemical products such as ammonium nitrate fertilizers can also explode, potentially causing physical trauma from explosions or shrapnel injuries. Sufficient heat causes human flesh to burn as fuel, or water in boiling, leading to potentially severe medical problems.
Depending on the heat of the fire, burns can occur in a fraction of a second.
The additional fire risk is the blurring of vision due to smoke, potentially causing a fall or disorientation; caught in the fire; and structural collapse.
"Three hours of fire fighting tense arteries and impairing heart function in firefighters" according to a new study by Bo Fernhall, a professor in the department of kinesiology and public health at the College of Applied Health Sciences, and Gavin Horn, research director at the Illinois Fire Service Institute. Conditions (observed in healthy male firefighters) "are also clearly found in weight lifter and endurance..."
Reconnaissance and "read" fire
The first step in firefighting operations is surveillance to locate the origin of fires (which may be unclear for indoor fires, especially if there are no witnesses), to identify specific risks, and to detect possible casualties. The outside fire may not require reconnaissance, but fire in the basement or underground parking lot with only a few centimeters visibility may require long-range surveillance to identify the source of the fire.
The "reading" of fire is an analysis by firefighters about indications of thermal events such as flashover, backdraft, or smoke explosion. This is done during reconnaissance and fire prevention maneuvers.
The main signs are:
- Hot zones, which can be detected by gloves, for example by touching the door before opening it;
- The trap in the window, which usually means that incomplete combustion, and thus, the lack of air in the room;
- Smoke throbbed in and out around the door frame, as if fire were breathing, which usually also meant lack of air to support combustion.
Spraying water on the ceiling with short pulses of diffused spray (for example, a cone with an opening angle of 60 Â °) can be performed to test the heat of the smoke: If temperatures are present, water falls into drops with a rain-like sound; if the temperature is high, the water evaporates with hiss - a potentially very dangerous flashover sign.
Ideally, part of the reconnaissance is a consulting plan for a building that provides information about the structure, the dangers of firefighting, and in some cases the most appropriate strategy and tactics to fight fire in that context.
The blackout
There are four elements necessary to start and maintain fire and/or flame. It is a reducing agent (fuel), heat, oxidizing (oxygen), and chemical reactions. Fire can be extinguished by taking one of the four components.
Fuel is a substance that is oxidized or burned in the combustion process. The most common fuels contain carbon along with a combination of hydrogen and oxygen. Heat is the energy component of fire. When in contact with fuel, it provides the necessary energy for ignition, causing production and continuous ignition of the fuel or gas vapor so that combustion reactions can continue, and lead to the evaporation of solid and liquid fuels. Chemical chain reactions that occur independently are complex and require fuel, oxidizing, and heat energy to gather together in a very specific way. The oxidizing agent is a substance or substance that releases gas, including oxygen, when the right conditions exist. It is important to maintain fire or fire.
Using water is one of the common methods to extinguish the fire. Water extinguishes fire by cooling it, which removes heat because of its water's ability to absorb large amounts of heat when it turns into water vapor. Without heat, the fuel can not keep the oxidator from reducing fuel to maintain fire. Water also extinguished the fire by strangling it. When the water is heated to its boiling point, the water turns into water vapor. When this conversion occurs, it dilutes the oxygen in the air above the fire, thus removing any of the elements required by the fire to burn. This can also be done with foam.
Another way to extinguish the fire is the removal of fuel. This can be achieved by stopping the flow of liquid fuel or gas, by disposing of solid fuel in the fire lane, or by letting the fire burn until all fuel is consumed, at which point the fire will extinguish itself.
One of the last methods of blackout is chemical inhibition of fire. This can be achieved by applying dry chemicals or halogenated agents that interfere with chemical chain reactions and stop flaming. This method is effective on gas and liquid fuels because they must have fire to burn.
Sound waves have been successfully used in devices made by two senior engineering students George Mason University, Viet Tran and Seth Robertson, but the procedure is still awaiting a patent (2015).
Water usage
One common way to extinguish the fire is to spray it with water. Water has two roles: Evaporates when it comes in contact with fire, and this vapor replaces oxygen (water vapor volume 1.700 times larger than liquid water, at 1,000 Â ° F (538 Â ° C) expands more than 4,000 times). It leaves fire without enough fuel, and dies. Evaporation of water also absorbs heat; it thus cools the smoke, air, walls, and objects that can act as a further fuel, and thus prevents one of the means by which fire grows, by "jumping" to the nearest source of fuel to initiate a fire new, which then combine. Therefore, water-blackening is a combination of "asphyxia" (cut off oxygen supply) and cooling. The fire itself is suppressed by asphyxia, but cooling is the most important element in the control of fire in a closed area.
Water can be accessed from pressurized hydrants, pumped from water sources such as lakes or rivers, delivered by tanker trucks, or dropped from water bombers, which are aircraft adapted as tankers to combat forest fires. Armored vehicles (fire tanks) can be used if access to the area is difficult.
Open air fire
For outdoor fires, the fire place is sprayed with a straight spray: the cooling effect immediately follows the asphyxia caused by evaporation and reduces the amount of water required further. The spray is directly used so that water arrives massively to the fire place before it evaporates. Strong sprays may also have mechanical effects; it can disperse combustible products and thus prevent fire from starting again. The spray is always directed to the surface or objects. For this reason, this strategy is sometimes called a two-dimensional or 2D attack.
Outdoor fire is always fed with air, and the risk for people is limited because they can move away from it, except in cases of forest fires or forest fires where they risk being easily surrounded by fire. It may, however, be necessary to protect certain objects such as homes or gas tanks against infrared radiation, and thus use spray spreading between fire and objects. Respiratory devices are often necessary because there is still a risk of inhaling toxic fumes or gases.
Closed volume shot
Until the 1970s, fires were usually attacked when they declined, using the same strategy as for open air fires. Now the fire is attacked in their development phase because firefighters arrive faster at the scene of the fire and due to changes in building construction. The increasing use of thermal insulation limits heat, and modern materials, especially polymers, produce more heat than traditional materials such as wood, plaster, stone, and bricks. In this condition, there is a greater risk of backdraft and flashover.
Spraying directly from a fire chair in a closed area can have unfortunate consequences: the force of the water pushes the air in front of it, which supplies fire with extra oxygen before water. The most important issue is not against fire, but controlling the fire; for example, cooling the smoke so it can not spread and start firing further, and endanger the lives of people, including firefighters.
When a fire spreads outside its original building and spreads throughout the neighborhood, it is called "fire." Currently, fires are big fires that are beyond the ability of firefighting services.
The volume of fire should be cooled before the chair is attacked. This strategy, originally from Sweden (Mats Rosander & Krister Giselsson), was adapted by London Fire Officer Paul Grimwood after a decade of operational use in the busy London West End between 1984 and 1994 and was called a 3D or three-dimensional attack.
The use of diffuse sprays was first proposed by Chief Lloyd Layman of the Parkersburg Fire Department, in 1950 the Department of Instructors of the Fire Department (FDIC) held in Memphis. Using a 3D attack strategy modified by Grimwood, the ceiling was first sprayed with a diffuse diffuse diffuse pulse. It cools down the smoke which then tends not to light a fire as it moves away. When the gas cools it becomes denser (Charles law); thus, it also reduces the mobility of smoke and avoids the "boomerang" of water vapor. Also, spreading sprays create an "inert water vapor", which prevents "roll-over" (fire rolls on the ceiling made by hot combustion gases).
Only short-circuits of water need to be sprayed, otherwise spraying modifies the balance, and the gas mixture instead of remaining stilts: the hot gas (initially in the ceiling) moves around the room, and the temperature rises in the ground, which is dangerous for firefighters.
The alternative is to cool the entire atmosphere by spraying the entire atmosphere as if drawing a letter in the air ("penciling").
Modern methods for extinguishing urban fire dictate the use of massive initial water flows, eg. 500Ã, L/min for each fire hose. The goal is to absorb as much heat as possible in the beginning to stop the expansion of the fire and reduce the smoke. If the flow is too low, the cooling is insufficient, and the resulting steam can burn the firefighter (the pressure is too small and the steam is pushed back toward it).
Although it may seem paradoxical, the use of a strong flow with an efficient fire hose and efficient strategy (diffuse spray, small droplets) requires less water. This is because once the temperature is lowered, only a small amount of water is required to press the fire chair with a straight spray. For living room 50 m 2 (60 m²), the required amount of water is estimated at 60 L (15 gal).
French firefighters used an alternative method in the 1970s: spraying water onto a hot wall to create a vapor atmosphere and turn off the fire. This method is no longer used because it is risky; the pressure created pushes the hot gas and steam toward the firemen, causing severe burns, and pushing the hot gas into another room where they can start another fire.
Asphyxiating fire
In some cases, water use is undesirable. This is because some chemical products react with water to produce toxic gases, or they can even burn when they come into contact with water (for example, sodium). Another problem is that some products float in water, such as hydrocarbons (gasoline, oil, and alcohol, etc.); the burning layer can then be spread by fire. If the pressurized fuel tank is threatened by fire, it is necessary to avoid heat shocks which may damage the tank if sprayed with cooling water; the resulting decompression can produce BLEVE (a steamy liquid bubble explosion).
Electric fires can not be extinguished with water because water can act as a conductor.
In such a case, it is necessary to forge a fire. This can be done in many ways. Chemical products that react with the fuel can be used to stop combustion. A waterproof flame retardant coating can be applied by a fire hose to separate the oxygen in the air from the fuel. carbon dioxide, halon, or sodium bicarbonate may be used. In the case of very small fires and in the absence of other fire-extinguishing agents, closing fire with fire blankets can eliminate the flow of oxygen to the fire. A simple and usually effective way to extinguish the fire on the stove is to place the lid on the pan and leave it there.
Tactical vent or fire insulation
One of the major risks of fire is smoke; because, it brings heat and poison gas, and obscures the vision. In case of fire in a closed location (building), the following two different strategies may be used: fire insulation or ventilation.
Paul Grimwood introduced the concept of tactical ventilation in the 1980s to encourage a better thinking approach to this aspect of firefighting. After working with Warrington Fire Research Consultants (FRDG 6/94) the terminology and concepts were formally adopted by the UK fire service, and are now referred to throughout the revised Office of Training guide (1996-1997). Grimwood's original definition of its 1991 unified strategy states that, "tactical ventilation is the act of emptying, or detaining (isolation) by on-site firefighters, used to take control of the beginning of a fire-burning regime , in an attempt to gain tactical advantage during internal structural blackout operations. "
When used properly, ventilation improves the safety of life, fire fighting, and conservation of property by 'pulling' fire from occupants and trapped objects.
In most cases of structural blackouts, the 4x4 foot opening is cut into the roof directly above the fire chamber. This allows the smoke and hot gas to come out through the gap, restoring the conditions in the room to normal. It is important to coordinate ventilation with an interior fire attack because the opening of ventilation holes supplies more air, and thus oxygen, to the fire. Ventilation can also "limit the spread of fire by channeling flames toward nearby openings and allowing firefighters to safely attack fire" and limiting smoke, heat, and water damage.
Positive pressure ventilation (PPV) consists of using a fan to create excess pressure in the building. This pressure pushes smoke and heat out of the building, thereby facilitating rescue and fire fighting operations. Needed to get out of the smoke, to know the layout of the building well to predict where the smoke will go, and to ensure that the door ensures the ventilation remains open by propping or supporting them. The main risk of this method is to speed up the fire, or even create a flash-over; for example, if smoke and heat build up in a dead end.
Hydraulic ventilation is the process of directing the flow of water from the inside of the structure out the window using a fog pattern. This will effectively pull the smoke out of the room. The smoke ejector can also be used for this purpose.
Categorize fires in the US
In the US, fires are sometimes categorized as "one alarm", "all hand", "two alarm", "three alarm" (or higher) alarms. There is no standard definition for what this means quantitatively; though, always refers to the level of response by local authorities. In some cities, numerical ratings refer to the number of fire stations that have been summoned to fire. On the other hand, it reflects the number of "submissions" requesting additional personnel and equipment.
Alarm levels are generally used to determine the level of response to what resources will be used. For example, the structure fire response draws the following equipment: four engine companies/pumper, one truck/ladder/air/quint company, and one battalion head unit. This is referred to as the Initial Alarm or Box Alarm. A request for a working fire (for the same incident) will call the air/light unit and the commander/commander of a large army (if not provided in the original dispatch). This summarizes the response to the First Alarm fire. The second alarm and subsequently called two engine companies and one trucking company.
The reasoning behind the "Alarm" is that once Commander Inc does not need to register every necessary tool. He can only say, "Give me a second alarm here", rather than "Give me a trucking company and two machine companies" along with asking where they should come from. Fire categorization varies among fire departments. One alarm for one department may be the second alarm for another. The response always depends on the size of the fire and the department.
See also
- Glossary of the term firefighter - a list of terms and acronyms of firefighting, with a description
- List of fire fighting equipment - expansion Glossary of firefighters
- Glossary of fire - expansion Glossary of firefighters
- Index of firefighting articles - alphabetical list of firefighting articles
- List of fire departments
- Outline of firefighters - list of structured firefighting topics, organized by subject area
References
External links
- CDC - NIOSH Program for Investigation and Prevention of Fatality of Fire Brigade
Source of the article : Wikipedia
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