Firedamp
Encyclopedia
Firedamp is a flammable gas
found in coal mines
. It is the name given to a number of flammable gases, especially methane
. It is particularly commonly found in areas where the coal is bituminous
. The gas accumulates in pockets in the coal and adjacent strata, and when they are penetrated, the release can trigger explosions.
. The invention was prompted by the Felling mine disaster
near Newcastle upon Tyne
claiming 92 lives on 25 May 1812. Davy experimented with iron
gauze
, determining the minimum size of the gaps and the optimum wire
thickness to prevent a flame
passing through the gauze. If a naked flame was thus enclosed totally by such a gauze, then methane could pass into the lamp and burn safely above the flame. He did not patent his invention.
Even after the safety lamps were brought into common use, firedamp explosions could still occur from sparks produced when coal contaminated with pyrite
s was struck with metal tools. The presence of coal dust
in the air increased the risk of explosion with firedamp, and indeed could cause explosions itself.
The Tyneside
coal mines in England had the deadly combination of bituminous coal contaminated with pyrites, and a great number of lives were lost in accidents due to firedamp explosions, including 102 dead at Wallsend
in 1835. A continuous flame was produced at Whitehaven
sometime before 1733, described as being "a yard wide and two yards long." The miners dealt with it by piping it to the outside.
Rather than the Davy lamp, Tyneside miners used a Geordie lamp
, a similar safety lamp designed by George Stephenson
. After the widespread introduction of the safety lamp, explosions continued because the early Davy lamps were fragile and easily damaged. The iron gauze for example only needed to lose one wire to become unsafe. The light was also very poor, and there were continuous attempts to improve the basic design. The height of the cone of burning methane in a flame safety lamp can be used to estimate the concentration of the gas in the local atmosphere. It was not until the 1890s that safe and reliable electric lamps became available in collieries.
". This comes from the German word Dampf (meaning "vapour"), and was probably introduced when German miners and mine engineers were brought to England in the 17th century to help in the development of deep mining. This is not certain, however, as the technical term for gases (air and others) among German miners is Wetter (literally "weather").
Other damps included blackdamp
(carbon dioxide
and other gases), and the insidiously lethal afterdamp
(carbon monoxide
and other gases) produced following explosions of firedamp or coal dust.
Gas
Gas is one of the three classical states of matter . Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point , boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons...
found in coal mines
Coal mining
The goal of coal mining is to obtain coal from the ground. Coal is valued for its energy content, and since the 1880s has been widely used to generate electricity. Steel and cement industries use coal as a fuel for extraction of iron from iron ore and for cement production. In the United States,...
. It is the name given to a number of flammable gases, especially methane
Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...
. It is particularly commonly found in areas where the coal is bituminous
Bituminous coal
Bituminous coal or black coal is a relatively soft coal containing a tarlike substance called bitumen. It is of higher quality than lignite coal but of poorer quality than Anthracite...
. The gas accumulates in pockets in the coal and adjacent strata, and when they are penetrated, the release can trigger explosions.
Mine accidents
Firedamp is explosive at concentrations between 4% and 16%, with most violence at around 10%, and caused much loss of life in coal mines before the invention of the Davy lampDavy lamp
The Davy lamp is a safety lamp with a wick and oil vessel burning originally a heavy vegetable oil, devised in 1815 by Sir Humphry Davy. It was created for use in coal mines, allowing deep seams to be mined despite the presence of methane and other flammable gases, called firedamp or minedamp.Sir...
. The invention was prompted by the Felling mine disaster
Felling mine disaster
Felling mine disaster was a major mining accident in Britain, claiming 92 lives on 25 May 1812.The colliery was situated in Felling, Tyne and Wear, part of Gateshead, in what used to be County Durham, and had two shafts about 600 feet deep. It was extended in 1810 by the opening up of a new coal...
near Newcastle upon Tyne
Newcastle upon Tyne
Newcastle upon Tyne is a city and metropolitan borough of Tyne and Wear, in North East England. Historically a part of Northumberland, it is situated on the north bank of the River Tyne...
claiming 92 lives on 25 May 1812. Davy experimented with iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
gauze
Gauze
Gauze is a thin, translucent fabric with a loose open weave.-Uses and types:Gauze was originally made of silk and was used for clothing. It is now used for many different things, including gauze sponges for medical purposes. When used as a medical dressing, gauze is generally made of cotton...
, determining the minimum size of the gaps and the optimum wire
Wire
A wire is a single, usually cylindrical, flexible strand or rod of metal. Wires are used to bear mechanical loads and to carry electricity and telecommunications signals. Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Standard sizes are determined by various...
thickness to prevent a flame
Flame
A flame is the visible , gaseous part of a fire. It is caused by a highly exothermic reaction taking place in a thin zone...
passing through the gauze. If a naked flame was thus enclosed totally by such a gauze, then methane could pass into the lamp and burn safely above the flame. He did not patent his invention.
Even after the safety lamps were brought into common use, firedamp explosions could still occur from sparks produced when coal contaminated with pyrite
Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...
s was struck with metal tools. The presence of coal dust
Coal dust
Coal dust is a fine powdered form of coal, which is created by the crushing, grinding, or pulverizing of coal. Because of the brittle nature of coal, coal dust can be created during mining, transportation, or by mechanically handling coal.-Explosions:...
in the air increased the risk of explosion with firedamp, and indeed could cause explosions itself.
Tyneside
Tyneside is a conurbation in North East England, defined by the Office of National Statistics, which is home to over 80% of the population of Tyne and Wear. It includes the city of Newcastle upon Tyne and the Metropolitan Boroughs of Gateshead, North Tyneside and South Tyneside — all settlements on...
coal mines in England had the deadly combination of bituminous coal contaminated with pyrites, and a great number of lives were lost in accidents due to firedamp explosions, including 102 dead at Wallsend
Wallsend
Wallsend is an area in North Tyneside, Tyne and Wear, England. Wallsend derives its name as the location of the end of Hadrian's Wall. It has a population of 42,842.-Romans:...
in 1835. A continuous flame was produced at Whitehaven
Whitehaven
Whitehaven is a small town and port on the coast of Cumbria, England, which lies equidistant between the county's two largest settlements, Carlisle and Barrow-in-Furness, and is served by the Cumbrian Coast Line and the A595 road...
sometime before 1733, described as being "a yard wide and two yards long." The miners dealt with it by piping it to the outside.
Rather than the Davy lamp, Tyneside miners used a Geordie lamp
Geordie lamp
The Geordie lamp was invented by George Stephenson in 1815 as a solution to explosions due to firedamp in coal mines.Although controversy arose between Stephenson's design and the Davy lamp, , Stephenson's original design worked on significantly different principles...
, a similar safety lamp designed by George Stephenson
George Stephenson
George Stephenson was an English civil engineer and mechanical engineer who built the first public railway line in the world to use steam locomotives...
. After the widespread introduction of the safety lamp, explosions continued because the early Davy lamps were fragile and easily damaged. The iron gauze for example only needed to lose one wire to become unsafe. The light was also very poor, and there were continuous attempts to improve the basic design. The height of the cone of burning methane in a flame safety lamp can be used to estimate the concentration of the gas in the local atmosphere. It was not until the 1890s that safe and reliable electric lamps became available in collieries.
Damps
Gases (other than air) in coal mines in England were collectively known as "dampsDamp (mining)
Historically, gases in coal mines in Britain were collectively known as "damps". This comes from the Middle Low German word dampf , and was in use by 1480 .Damps included:...
". This comes from the German word Dampf (meaning "vapour"), and was probably introduced when German miners and mine engineers were brought to England in the 17th century to help in the development of deep mining. This is not certain, however, as the technical term for gases (air and others) among German miners is Wetter (literally "weather").
Other damps included blackdamp
Blackdamp
Blackdamp is an asphyxiant, reducing the available oxygen content of air to a level incapable of sustaining human or animal life. It is not a single gas but a mixture of unbreathable gasses left after oxygen is removed from the air and typically consists of nitrogen, argon, carbon dioxide and...
(carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
and other gases), and the insidiously lethal afterdamp
Afterdamp
Afterdamp is the toxic mixture of gases left in a mine following an explosion caused by firedamp, which itself can initiate a much larger explosion of coal dust. It consists of carbon dioxide, carbon monoxide and nitrogen. Hydrogen sulfide, another highly toxic gas, may also be present...
(carbon monoxide
Carbon monoxide
Carbon monoxide , also called carbonous oxide, is a colorless, odorless, and tasteless gas that is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal...
and other gases) produced following explosions of firedamp or coal dust.