Assessing Fire Risk Management Your management policy should reflect the highest level of safety . The ultimate goal is to minimize bus fire risks , monitor the effectiveness of safety risk controls , and to meet or exceed safety objectives . The maintenance team should be aware of the root causes of fires , conducting risk assessments , and formulating best practices for safety . Manufacturers should ensure new products and manufacturing methods reduce the risks to the best extent possible . Performing a fire risk assessments outlines the level of risk posed by a fire hazard and the assessment of the likelihood of harm , firstly to people , but also to property and business continuity .
Identify Fire Hazard Areas A fire hazard area is any compartment or space that contains both an ignition source and flammable / combustible material . Engine compartments and battery compartments are known hazards in which fire have occurred .
Identifying Fire Risks Within the Hazards Within the fire hazard an assessment is made by identifying the likelihood of flammable fluids or combustible igniting on a hot surface and arching / shorting of electrical cables . The risk is determined based on the known failure modes which have been shown to result in fires .
• Heat Degradation of combustible materials in close proximity to high heat sources
• Components that are operated at or near their maximum specified duty cycles , temperatures etc .
• Abrasion or other mechanical damage
• Maintenance issues
• Risks introduced during manufacturing of the bus It is crucial to understand the risks in terms of flame spread , smoke , and toxic gas generation . Plastics – Plastic material is a compound of polymer plus additives which has the capabilities of being shaped or molded into a valuable product . Common plastics found on transit buses include air cleaners , reservoirs for flammable liquids , fan cowling , wheelwell liners , insulation for components like battery cables ., and in the vehicle ’ s trim itself . There are two types of plastics : Thermoplastics tend to soften and flow at high temperatures , often before ignition takes place . Thermosetting materials do not soften but undergo localized surface charring
( sometimes with flaming ), and the charred residue can either fall off or remain in place to form an insulating layer . Plastics containing carbon and hydrogen monomers can be highly flammable and , once they ignite , they produce flammable gases that can fuel a fire further . Plastics which are composed of carbon , hydrogen , and oxygen burn slower than the others mentioned . For plastics which contain halogens ( less combustible than other plastics ), a flame must be continuous or the plastic will self-extinguish . Plastics as a group generally have higher ignition temperatures than wood . However , almost all plastics can be made flame- or smoke-retardant by adding other chemicals during manufacturing . Plastics have been reported to have very high flame spread characteristics , as high as 2 feet per second , or 10 times that of wood on the surface . Because of their ability to melt and run , plastics can spread fires in ways that could mislead fire investigators . Heated / burning plastics may produce large quantities of thick , black smoke – or even toxic gas .
Mitigation / Control Methods Training – Increase awareness of fires at your operation and increase the general concern level of your employees . This is a matter of creating a well-informed interest in fire risks and making sure everyone has the knowledge needed to assess these risks . Operators should have knowledge of early fire indicators . There should be briefings for passengers on bus fires , and on emergency evacuation procedures . Dispatchers should practice procedures related to fire responses , using 911-style flipcards if necessary .
Fire Detection and Suppression Fire suppression technology should focus on fast detection with minimal nuisance alarms . The system should have a sufficient quantity of extinguishing agent and nozzles . Furthermore , it should protect against re-ignition ( a deadly concern in the case of electric vehicle fires ) and be effective during all operation modes . Componentry should withstand harsh environments in a bus application , and techs should be cognizant of required preventive maintenance . The goal of any fire suppression system is to provide as much evacuation time for the driver and passengers – not to fully extinguish a major vehicle fire . Keep the fire contained , keep it from spreading , and get everyone off the bus so the fire department can arrive and do their job .
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