Flashover (electrical)
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Flashover (electrical)
A flashover is the near-simultaneous ignition of most of the directly exposed combustible material in an enclosed area. When certain organic materials are heated, they undergo thermal decomposition and release flammable gases. Flashover occurs when the majority of the exposed surfaces in a space are heated to their autoignition temperature and emit flammable gases (see also flash point). Flashover normally occurs at or for ordinary combustibles and an incident heat flux at floor level of . An example of flashover is the ignition of a piece of furniture in a domestic room. The fire involving the initial piece of furniture can produce a layer of hot smoke, which spreads across the ceiling in the room. The hot buoyant smoke layer grows in depth, as it is bounded by the walls of the room. The radiated heat from this layer heats the surfaces of the directly exposed combustible materials in the room, causing them to give off flammable gases, via pyrolysis. When the temperatures ...
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Combustible
A combustible material is something that can burn (i.e., ''combust'') in air. A combustible material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort and a flammable material catches fire immediately on exposure to flame. The degree of flammability or combustibility in air depends largely upon the volatility of the material - this is related to its composition-specific vapour pressure, which is temperature dependent. The quantity of vapour produced can be enhanced by increasing the surface area of the material forming a mist or dust. Take wood as an example. Finely divided wood dust can undergo explosive combustion and produce a blast wave. A piece of paper (made from wood) catches on fire quite easily. A heavy oak desk is much harder to ignite, even though the wood fibre is the same in all three materials. Common sense (and indeed scientific consensus until the mid-1700s) would seem to suggest that ma ...
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Glossary Of Firefighting
: ''Note: This list does not include firefighting equipment, i.e., tools and apparatus used by firefighters. Please refer to Glossary of firefighting equipment for such terms. Similarly, although there is much overlap, you may also want to refer to the Glossary of wildfire terms for terminology particular to that type of firefighting.'' : ''Note: Many of the terms defined here, particularly relating to systems of work, team names, procedures, careers and policies, seem to originate in the U.S. and are not necessarily applicable to other English-speaking countries' fire and rescue services. For example, ''Call Firefighter'' (U.S.) and ''Retained Firefighter'' (UK). Firefighting jargon includes a diverse lexicon of both common and idiosyncratic terms. One problem that exists in trying to create a list such as this is that much of the terminology used by a particular department is specifically defined in their particular standing operating procedures, such that two departments may ha ...
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Ufa Train Disaster
The Ufa train disaster was a railway accident that occurred on 4 June 1989, in Iglinsky District, Bashkir ASSR, Soviet Union, when an explosion killed 575 people and injured 800 more. It is the deadliest rail disaster during peacetime in Soviet/Russian history. The accident was named after Ufa, the largest city in the Bashkir ASSR, although it occurred about east of the city. An annual commemoration is usually held at the , near the disaster site; there is a memorial at the site. Background The pipeline had originally been designed for the transportation of oil but had been reformatted to transport natural gas liquids for the Soviet petrochemical industry. In May 1984 the Soviet Ministry of Petroleum had canceled the installation of an automatic real time leak detection system. In 1985 an excavator caused severe mechanical damage to the pipe in the form of a crack during bypass construction. Additionally on the night of the explosion there was increased pressure in the syste ...
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King's Cross Fire
The King's Cross fire was a 1987 fire in a London Underground station with 31 fatalities, after a fire under a wooden escalator suddenly spread into the underground ticket hall in a flashover. The fire began at approximately 19:30 on 18 November 1987 at King's Cross St Pancras tube station, a major interchange on the London Underground. As well as the mainline railway stations above ground and subsurface platforms for the Metropolitan, Circle and Hammersmith & City lines, there were platforms deeper underground for the Northern, Piccadilly, and Victoria lines. The fire started under a wooden escalator serving the Piccadilly line and, at 19:45, erupted in a flashover into the underground ticket hall, killing 31 people and injuring 100. A public inquiry was conducted from February to June 1988. Investigators reproduced the fire twice, once to determine whether grease under the escalator was ignitable, and the other to determine whether a computer simulation of the fire—which w ...
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Kilbirnie Street Fire
The Kilbirnie Street fire, on Friday 25 August 1972, was a warehouse fire in the Port Eglinton area, on the south side of Glasgow, Scotland, which killed seven Glasgow Fire Service firemen in a flashover while they were trying to rescue a trapped colleague. What started as a routine industrial premises fire resulted in one of the highest losses of life for the UK Fire Service at a single incident in peacetime. The Sher Brothers warehouse The warehouse premises at 70–72 Kilbirnie Street was used as a cash and carry warehouse by the Sher Brothers company, selling textiles, clothing and household goods. It was built as a stables in 1899, but in common with much of Glasgow's industrial premises at that time, had seen numerous uses over the years. It was a brick built construction of ground, first and attic floors, connected by internal stairs and a goods lift. The first floor was of concrete construction, and the attic floor of composite steel and timber, supported on cast iron co ...
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Firestorm
A firestorm is a conflagration which attains such intensity that it creates and sustains its own wind system. It is most commonly a natural phenomenon, created during some of the largest bushfires and wildfires. Although the term has been used to describe certain large fires, the phenomenon's determining characteristic is a fire with its own storm-force winds from every point of the compass towards the storm's center, where the air is heated and then ascends. The Black Saturday bushfires and the Great Peshtigo Fire are possible examples of forest fires with some portion of combustion due to a firestorm, as is the Great Hinckley Fire. Firestorms have also occurred in cities, usually due to targeted explosives, such as in the aerial firebombings of London, Hamburg, Dresden, and Tokyo, and the atomic bombing of Hiroshima. Mechanism A firestorm is created as a result of the stack effect as the heat of the original fire draws in more and more of the surrounding air. This dr ...
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Charleston Sofa Super Store Fire
The Charleston Sofa Super Store fire occurred on the evening of June 18, 2007, in Charleston, South Carolina, and killed nine firefighters. This was the deadliest firefighter disaster in the US since the September 11 attacks. The fire was believed to have started in some discarded furniture in the loading dock area, and though the source of ignition remains undetermined, there is reason to believe it may have been a discarded cigarette. Fire and collapse The fire occurred at the Sofa Super Store, composed of a 42,000 ft² (3,902 m²) single-story steel trussed showroom building with a 17,000 ft² (1,579 m²) warehouse building located behind the retail space, located at 1807 Savannah Highway in Charleston. The building had no fire sprinkler system. The fire started at approximately 7:00 p.m. in a covered loading dock area built between the showroom and warehouse buildings which was attached to both buildings. At the time, the business was open and employees were ...
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Backdraft
A backdraft (North American English) or backdraught (British English) is the abrupt burning of superheated gasses in a fire, caused when oxygen rapidly enters a hot, oxygen-depleted environment; for example, when a window or door to an enclosed space is opened or broken. Backdrafts present a serious threat to firefighters. There is some debate concerning whether backdrafts should be considered a type of flashover (see below). Burning When material is heated enough, it begins to break down into smaller compounds, including hydrogen. This is called pyrolysis, and does not require oxygen. If oxygen is also provided, then the hydrogen can combust, starting a fire. If material undergoing pyrolysis is later given sufficient oxygen, the hydrogen gas will ignite, and therefore, combustion takes place. Cause A backdraft can occur when a compartment fire has little or no ventilation. Due to this, little or no oxygen can flow into the compartment. Then, because fires reduce oxygen, the ...
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Air Canada Flight 797
Air Canada Flight 797 was an international passenger flight operating from Dallas/Fort Worth International Airport to Montréal–Dorval International Airport, with an intermediate stop at Toronto Pearson International Airport. On 2 June 1983, the McDonnell Douglas DC-9-32 operating the service developed an in-flight fire in air around the rear lavatory that spread between the outer skin and the inner decor panels, filling the plane with toxic smoke. The spreading fire also burned through crucial electrical cables that disabled most of the instrumentation in the cockpit, forcing the plane to divert to Cincinnati/Northern Kentucky International Airport. Ninety seconds after the plane landed and the doors were opened, the heat of the fire and fresh oxygen from the open exit doors created flashover conditions, and the plane's interior immediately became engulfed in flames, killing 23 passengers who were unable to evacuate the aircraft. The accident became a watershed for global av ...
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Ventilation (firefighting)
Ventilation is a part of structural firefighting tactics, and involves the expulsion of heat and smoke from a burning building, permitting the firefighters to more easily and safely find trapped individuals and attack the fire. If a large fire is not properly ventilated, it is much harder to fight, and can build up enough poorly burned smoke to create a smoke explosion or enough heat to create a flashover. Poorly placed or timed ventilation can increase the fire's air supply, causing it to grow and spread rapidly. Flashover from inadequate ventilation can cause the temperature inside the building to peak at over . Types of ventilation In general, there are two types of ventilation; vertical and horizontal. Their names refer to the general locations of the intended exit points of the heat and smoke to be ventilated. Vertical ventilation takes place through holes cut in the roof, typically by truck companies during the early stages of a fire in a process known collectively as roo ...
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London
London is the capital and largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary down to the North Sea, and has been a major settlement for two millennia. The City of London, its ancient core and financial centre, was founded by the Romans as '' Londinium'' and retains its medieval boundaries.See also: Independent city § National capitals The City of Westminster, to the west of the City of London, has for centuries hosted the national government and parliament. Since the 19th century, the name "London" has also referred to the metropolis around this core, historically split between the counties of Middlesex, Essex, Surrey, Kent, and Hertfordshire, which largely comprises Greater London, governed by the Greater London Authority.The Greater London Authority consists of the Mayor of London and the London Assembly. The London Mayor is distinguished fr ...
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Factory
A factory, manufacturing plant or a production plant is an industrial facility, often a complex consisting of several buildings filled with machinery, where workers manufacture items or operate machines which process each item into another. They are a critical part of modern economic production, with the majority of the world's goods being created or processed within factories. Factories arose with the introduction of machinery during the Industrial Revolution, when the capital and space requirements became too great for cottage industry or workshops. Early factories that contained small amounts of machinery, such as one or two spinning mules, and fewer than a dozen workers have been called "glorified workshops". Most modern factories have large warehouses or warehouse-like facilities that contain heavy equipment used for assembly line production. Large factories tend to be located with access to multiple modes of transportation, some having rail, highway and water loading ...
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