Көмір шахталарындағы қауіпсіздік шамдары және газ түрлері

Any of several types of lamp that provides illumination in coal mines

A safety lamp is any of several types of lamp that provides illumination in places such as coal mines where the air may carry coal dust or a build up of inflammable gases, which may explode if ignited, possibly by an electric spark. Until the development of effective electric lamps in the early 1900s, miners used flame lamps to provide illumination. Open flame lamps could ignite flammable gases which collected in mines, causing explosions; safety lamps were developed to enclose the flame to prevent it from igniting the explosive gases. Flame safety lamps have been replaced for lighting in mining with sealed explosion proof electric lights, but continue to be used to detect gases.

Miners have traditionally referred to the various gases encountered during mining as damps, from the Middle Low German word dampf (meaning "vapour"). Damps are variable mixtures and are historic terms. Firedamp Naturally occurring flammable mixtures, principally methane. Blackdamp or Chokedamp Nitrogen and carbon dioxide with no oxygen. Formed by complete combustion of firedamp or occurring naturally. Coal in contact with air will oxidize slowly and, if unused workings are not ventilated, pockets of blackdamp may develop. Also referred to as azotic air in some 19th century papers. Whitedamp Formed by the incomplete combustion of coal, or firedamp. The mixture may contain significant amounts of carbon monoxide, which is toxic and potentially explosive. Stinkdamp Naturally occurring hydrogen sulphide and other gases. The hydrogen sulphide is highly toxic, but easily detected by smell. The other gases with it may be firedamp or blackdamp. Afterdamp The gas from an explosion of firedamp or coal dust. Contains varying proportions of blackdamp and whitedamp and is therefore suffocating, toxic, or explosive, or any combination of these. Afterdamp may also contain stinkdamp. Afterdamp may be a bigger killer following an explosion than the explosion itself.

Before the invention of safety lamps, miners used candles with open flames. This gave rise to frequent explosions. For example, at one colliery (Killingworth) in the north east of England, 10 miners were killed in 1806 and 12 in 1809. In 1812, 90 men and boys were suffocated or burnt to death in the Felling Pit near Gateshead and 22 in the following year. describes the testing of a mine for firedamp. A candle is prepared by being trimmed and excess fat removed. It is held at arm's length at floor level in one hand, the other hand shielding out all except the tip of the flame. As the candle is raised the tip is observed and if unchanged the atmosphere is safe. If however the tip turns bluish gray increasing in height to a thin extended point becoming a deeper blue, then firedamp is present. Upon detecting firedamp the candle is lowered and arrangements made for the ventilating of the area or the deliberate firing of the firedamp after the end of a shift. To fire the gas, a man edged forward with a lit candle on the end of a stick. He kept his head down to allow the explosion to pass over him, but as soon as the explosion had occurred stood as upright as possible to avoid the afterdamp. Officially known as a fireman, he was also referred to as a penitent or monk from the hooded garb he wore as protection. The protective clothing was made of well dampened wool or leather. This was a job with risk of injury, or to life. This straining led first to temporary nystagmus and then to a permanent disability. Mild nystagmus would self correct if a miner ceased to perform this work, but if left untreated would force a man to give up mining. The lower levels of light emitted by safety lamps caused an increase in the incidence of nystagmus.

In Europe and Britain dried fish skins which emitted a faint bioluminescence (often called phosphorescence) were used. Another safe source of illumination in mines was bottles containing fireflies. Flint and steel mills introduced by Carlisle Spedding (1696–1755) before 1733 had been tried with limited success. A steel disk was rotated at high speed by a crank mechanism. Pressing a flint against the disk produced a shower of sparks and dim illumination.

timeline item||Miners Lamp Committee reported and made recommendations, after carrying out tests. At Wallsend in 1818 lamps were burning red hot (indicating significant firedamp). A boy (Thomas Elliott) was employed to carry hot lamps to the fresh air and bring cool lamps back. For some reason he stumbled; the gauze was damaged and the damaged lamp triggered the explosion. At Trimdon Grange (1882) a roof fall caused a sudden blast of air and the flame passed through the gauze with fatal results (69 killed). The lamp becomes unsafe in a current of from 8 to 12 feet per second, about twice that of the Davy. The pin could only be released by applying a vacuum to a captive hollow screw; not something that a nicotine starved miner could do at the coal face .

Clanny abandoned his pumps and candles and developed a safety lamp which combined features of both the Davy and Geordie. The oil lamp was surrounded by a glass chimney with no ventilation from below. Above the chimney is a wire gauze cylinder with a double top. Air enters from the side and spent gases exit from the top. In the presence of firedamp the flame intensifies. The flame must be kept fairly high in normal use, a small flame permits the enclosed space to fill with firedamp/air mixture and the subsequent detonation may pass through the gauze. A larger flame will keep the upper part full of burnt gas. The Clanny gives more light than the Davy and can be carried more easily in a draught. Lupton notes however it is superior in no other respect, particularly as a test instrument. Some Mueseler lamps were fitted with a mechanism which locked the base of the lamp. Turning down the wick eventually released the base, but by then the flame was extinguished and therefore safe. The lamp was patented in 1840, and in 1864 the Belgian government made this type of lamp compulsory. A shielded Marsaut lamp can resist a current of 30 feet per second. is similar to a shielded Clanny, but there is a brass cylinder outside the gauze above the glass. It resists draughts well, but illumination is poor.

The Morgan is a cross between the Mueseler and the Marsaut. It is a shielded lamp with a series of disks at the top to allow spent fumes out and a series of holes lower down the shield to allow air in. There is an inner and outer shield so that air cannot blow directly on the wire gauze but must first find its way through a slim chamber. There are multiple gauzes, like the Mersaut, and there is an internal chimney like the Mueseler. There is no "shelf" supporting the chimney, instead it hangs from an inverted gauze cone. The Morgan will resist air up to 53 feet per second and is "sufficiently safe for every practical purpose". The lamp has been tested and according to Lupton "successfully resisted every effort to explode it up to a velocity of more than 100 feet per second". This turned out not to be the case and progress was slow in attaining reliability and economy. The Sussmann lamp was introduced into Britain in 1893 and following trials at Murton Colliery in Durham it became a widely used electric lamp with 3000 or so reported by the company in use in 1900 However, by 1910 there were only 2055 electric lamps of all types in use about 0.25% of all safety lamps. In 1911, an anonymous colliery owner, through the British government, offered a prize of £1000 (1000.0 in 1911 is equivalent to about <calculated amount> in recent years) for the best lamp to specified requirements. There were 195 entries. It was won by a German engineer with the CEAG lamp, which was hand held and delivered twice the illumination of oil lamps, with a battery life of 16 hours. Awards were made to 8 other lamps that met the judges' criteria. Clearly this stimulated development and over the next few years there was a marked increase in the use of electric lamps, especially the CEAG, Gray Sussmann, and Oldham, so by 1922 there were 294,593 in use in Britain. In 1913, Thomas Edison won the Ratheman medal for inventing a lightweight storage battery that could be carried on the back, powering a parabolic reflector that could be mounted on the miner's helmet. After extensive testing, 70,000 robust designs were in use in the US by 1916. Early electric lamps in Britain were hand held as miners were used to this and helmet lamps became common much later than in countries like the US where helmet (cap) lamps had been the norm. Nowadays, safety lamps are mainly electric, and traditionally mounted on miners' helmets (such as the Wheat lamp or the Oldham headlamp), sealed to prevent gas penetrating the casing where it might be ignited by an electrical spark. Although its use as a light source was superseded by electric lighting, the flame safety lamp has continued to be used in mines to detect methane and blackdamp, although many modern mines now use sophisticated electronic gas detectors for this purpose. A newer light source, the light emitting diode (LED), has advantages for safety lamps, mainly higher efficiency providing much longer illumination time from the same battery. Batteries too have improved and provide more energy per unit weight; LEDs in conjunction with batteries such as rechargeable lithium units provide much better performance in safety lamp applications. The Office of Mine Safety and Health (OMSHR), a part of the National Institute for Occupational Safety and Health (NIOSH) (itself part of Centers for Disease Control and Prevention) in the United States has been investigating the benefits of LED headlamps. A problem in mining is that the average age of miners is increasing (43.3 years in the US in 2013), and vision deteriorates with ages. LED technology is physically robust compared to a filament light bulb, and has a longer life: 50,000 hours compared to 1,000 – 3,000. Extended life reduces light maintenance and failures; according to OMSHR an average of 28 accidents per year occur in US mines involving lighting. NIOSH has sponsored the development of cap lamp systems which they say improve the "ability of older subjects to detect moving hazards by 15% and trip hazards by 23.7%, and discomfort glare was reduced by 45%". Conventional lights illuminate a narrow beam; NIOSH LED lamps are designed to produce a wider more diffuse beam which is claimed to improve the perception of objects by 79.5%.