Firefighting Contrivance Kindling Incidents - Term Paper Example

2000 words Course name: Professor’s name: University name: City, State Date of submission: Forensic awareness and firefighting tactics are significant to the firefighters so as to avoid destruction of evidence that may be available at the fire scene. Preserving fire scene starts with first units to arrive at the scene. Awareness and attitude are two key concepts that firefighters should have. Once firefighters are aware of the research consequences and influence of the fire operations and the major role they play in the general investigative process, they make the protection of the fire scene critical. Improper preservation of the fire scenes results in the destruction, loss, contamination of evidence available at the scene. Fire is destructive; therefore the firefighting tactics needs to be employed carefully and in the right manner to avoid worsening the probability of losing the available evidence at the fire scene (GOTTSCHALK, 2012, 274). Various firefighting tactics include, use of water, foams including CAFS, use of dry agents and chemical additives, tactical ventilation, isolation of the fire and lastly is cutting away and removal (overhaul) (CHANDLER, 2009, 88). Fire squads should avoid producing excessive damage when carrying out excessive overhaul. Fire squad carrying out excessive overhaul and carrying items from one position to another at the fireplace critically affect an investigation. Under the use of water as firefighting tactic, using fire hose streams bring about ruining of physical proof at the fireplace.Valuable evidence of the fire cause, originate at the area of origin. Using of hose lines destroys evidence at the fire scene. Nozzle regulation is a vital consideration in the investigation of the fire cause. Using of more water at the fireplace dilutes flammable liquids. In this case, dilution brings about a negative test for the existence of combustible liquid in a laboratory analysis (CHANDLER, 2009, 88). Excessive water also causes wood or burned paper to float away from their source, and this prevents their discovery. Also controlling the excessive use of water in regions that cannot easily be drained, for example where the investigator wishes to look at the floor for fire patterns is vital. During the draining process of the floor of standing water, the drain hole should be positioned to a place where it will have the least influence on the fire patterns. Avoiding excessive use of water until the investigation of the fire scenes is over is crucial. The usage of water is the particular method of extinguishing thefire. The water has different roles when extinguishing fire. One of the role is that when water comes in contact with the fire it vaporizes and the vapor formed displaces the oxygen that supports the combustion hence the fire stops to continue (GOTTSCHALK, 2012, 267). The second role of the usage of water in firefighting is that the vaporization of the water used absorbs the heat from the fire cooling the smoke walls and air that could act as a fuel, and this prevents the fire from growing. The extinguishment of fire involves a combination of cutting off the oxygen source and cooling. Water for fire- fighting may be acquired from water sources like rivers or lakes through the pumping process and transported by tanker truck. Water can also get acquired from a pressurized fire hydrant. An armored firefighting tank may get used where the entrance to the area is hard (KLAENE & SANDERS, 2010, 98). Under the overhaul, most of the remaining proofs that have not been destroyed by the fire is damaged or moved. The overhaul is the method of looking for unseen fire extension on a fireplace. It is used in combination with salvage processes to decrease loss caused by fire. The overhaul is one of the latter stages of the firefighting procedure. Excessive overhaul before the investigation of the scene affects the evidence at the fireplace. The best method to ensure that evidence at the fire scene is not damaged; the investigator should assume some management of the overhaul operations. Firefighters have the second tasks of preserving fire evidence and checking for fire extension. However this two tasks clashes but looking for hidden fire is vital than the other. When an overhaul get approached in a systematic way, the two tasks can be accomplished at a go. Under the isolation of fire, firefighters should avoid resetting switches or turning the knobs on any equipment at the fireplace until they investigate and get documented. The position of switches and knobs may be vital to the investigation, particularly in coming up with eruption fire scenarios. The materials that make the knobs are plastics and they are very brittle when subjected to heat. So any movement may cause them to get destroyed, thus losing the critical value. Under speed and weight of response, the fire in its early phases normally grows fast, following an exponential development rate curve. In this case, an early response ensures that the resources needed to fight the fire at the scene are relatively small. If the firefighters wait for new resources to make a severe attack, the fire may run out of control hence making it impossible to put it off. Under the use of foam including CAFS as a tactical method for fighting the fire, there are different types of foam existing for firefighting reasons: high-expansion foam and low-medium expansion foam. Low- and medium expansion foam is used in fire-fighting operations, to extinguish the fire. Low expansion foam is very useful especially in the fire involving chemical warehouses since the firefighters require reaching the fire at a distance because of the heat radiation (KLAENE & SANDERS, 2010, 78). The extinguishing influence of foam is because of the feedback breaking from flames to the fuel surface and hence causing pyrolysis to stop. High-expansion foam gets used by filling a house when an internal attack is difficult for safety reasons. Foam filling is used in combination with properly placed ventilation to decrease the overpressure in the house produced by the foam filling procedure. In this case, it implies that all openings below the foam filling distance should get closed. Under the use of dry agents and chemical additives, there are different dry powders available which include potassium chloride, sodium hydroxide, and potassium hydroxide. Most dry powders do not have the same absorption capacity. The heat concentration capacity of dry powder appears to beat heat absorption capacity of other media that extinguishes the fire, although there is one weakness of the dry powder. The weakness of the dry powders is that some powders, for example, class BC is operative only in the gas stage. When a BC powder gets used in a building fire, the fire will quickly re-ignite as heat get collected and as the pyrolysis remains (LAYMAN, 2011, 87). To stop the re-ignition of the fire foam or water in an attack should run parallel with the powder. Class ABC powders inhibit re-ignition to some level, but in this case, foam or water backup is paramount. It is also worth knowing that, the dry powder may react with stored chemicals. Hence, it is very crucial to know the type of dry powder available for the stored chemical. In this case, it assists for a clear assessment of what reactions that are likely to occur and when and make a decision when to use or not use the powder. One of the major dangers of fire is the smoke: it conveys poisonous gasses and heat; this makes it difficult to see. In the case of a fire in a closed room, two different methods to extinguish fire may be used: the first one is the isolation of the fire, and the second one is ventilation. Ventilation is a process of any firefighting activity. Ventilation is a crucial part of building firefighting methods that involve the removal of smoke and heat from a building, allowing the firefighters to move safely and find trapped individuals. The capability to eliminate heat, smoke and fire gasses from a building greatly assist in finding victims in the building. Ventilation creates an atmosphere more survivable for fire victims and decreases the environmental influence that firefighters operate. Ventilation also hastens the ability to enable fire control (LAYMAN, 2011, 67). However, improper ventilation greatly increases the extent of work needed to complete ground fire chores by spreading fire. Poor ventilation also increases the level of heat, and this contributes to injuries of the firefighter. Under the tactical ventilation, heated fire gasses moves towards the low-pressure parts based on changing building designs and the existing ventilation openings. In this case, the fire's energy pulls in additional oxygen from the low-pressure parts. Operations that get done in an independent flow pathway without an effort to limit the velocity of the flow path makes people available at a major risk since there is an increased movement of the fire. There are various types of ventilation that include natural ventilation, mechanical ventilation and positive pressure ventilation (DUNN, 2007, 65). Under natural ventilation, there is nothing that controls the flow of smoke and firefighters. Natural ventilation can get attained when time and conditions permit. Windows should get opened and not broken out this relieves heat and smoke and enhance positive pressure ventilation. Windows on several floors should get opened; beginning on top and working downwards because opening windows from below first causes smoke and fire spread. Under Positive pressure, it acts on the principle of the venture. When air gets forced into a building through an opening, it seeks the path of smallest resistance to find its path out of the building. When the opening that get used as an exit is less than the size of the first opening, there remains a lasting positive pressure in the building. This positive pressure pulls the heat and smoke inside a building and drives it out of the organized ventilation exit. Contaminating the fire scene results in a mixing with a foreign substance. This contamination leads to an invalid investigation of the fire scene. Contamination happens when firefighters use gasoline-powered tools in regions that investigator will use to test for the presence of a liquid accelerant. Firefighters can also unknowingly pollute the fire scene when they walk through the affected area with combustible liquid remains on their boots. Rescue operations also have a great influence on fire scene investigation since they involve removing fire debris from the fire scene (LAYMAN, 2011, 109). Movement of the fire debris from the fireplace greatly affects the investigation of the fire scene. Altering the fire scene adversely influences the examination of fire arrangements. However, the serious concerns happen when firefighters totally remove the fire debris (DUNN, 2007, 78). When the investigator does not observe a fire destroyed room, the entire analysis becomes jeopardized. Carefully controlling the usage of diesel-powered or gasoline equipment helps preserve evidence at the fireplace. In this case, the usage of diesel and gasoline powered equipment near the suspected area of origin is disallowed. Refueling any diesel or gasoline powered equipment should happen outside the perimeter of the fire scene. Firefighters need to be conscious about the introduction of fuel from the equipment impacts the evidence value of any samples taken and could result in erroneous conclusions concerning the investigation. Limiting access to the fire scene to many people and emergence people helps preserve evidence at the fire scene. Limiting people to the fireplace is a genuine concern when there is a probability of contaminating evidence. It is, therefore, advisable to postpone the activity of fire operation to protect evidence. When conditions dictate, such as a proved fire involving a fatality, all fire squad entering the scene should be registered in with their name and reason for being at the scene get recorded. In conclusion, the responsibilities of protecting the fire scene lie with all the individuals on the scene and not firefighters and investigators only. However, the firefighters should make every effort to preserve the whole fire scene, undisturbed and intact. It is through a logical inspection and examination of the fireplace that the investigator finds the fire's origin, ignition circumstances and cause. The fire investigator should secure the fireplace to avoid unauthorized people at the scene who can limit the firefighting operations. Also, the investigators should not only think of proofs at the fireplace in the context of criminality but should consider everything at the fireplace as evidence. References CHANDLER, R. K. (2009). Fire investigation. Australia, Delmar Cengage Learning. DUNN, V. (2007). The strategy of firefighting. Tulsa, Okla, PenWell. GOTTSCHALK, J. (2012). Firefighting. London, DK Pub. KLAENE, B. J., & SANDERS, R. E. (2010). Structural firefighting. Quincy, Mass, NFPA, National Fire Protection Association. LAYMAN, L. (2011). Fundamentals of firefighting tactics. Parkersburg, W. Va, Magruder Pub. Co. Read More