Big Pit EarthCache

Big Pit

Given coordinates bring you to the front of Big Pit National Mining Museum of Wales. It is imposing place where you can see a lot of interests about mining history in South Wales, coal mining and the coal itself. I highly recommend to visit Big Pit FREE ENTRY Museum (opening hours 9.30 - 17.00 daily). Parking is available close to the Big Pit entrance.

Big Pit

Big Pit

History of the working pit

The pit was first worked in 1860, called "Big Pit" because it was the first shaft in Wales large enough to allow two tramways. In the late 1870s the shaft was deepened to 293 feet. By 1908, Big Pit provided employment for 1,122 people, but this number gradually decreased until by 1970 the workforce only numbered 494. It closed on February 2, 1980.

History of the National Coal Museum

The mine reopened for visitors in 1983. On 1 February 2001 it became incorporated into the National Museum Wales, and was initially known as the National Mining Museum of Wales, it has since been renamed to become Big Pit: National Coal Museum. The site was redeveloped in 2003, with design work from TACP/Brooke Millar Partnership, Powell Dobson Partnership and Haley Sharpe, with Davis Langdon providing cost and project management services.

Blaenavon Industrial Landscape World Heritage Site

The area around Blaenavon and Big Pit is on the World Heritage list (date of Inscription: 2000). It is evidence of the pre-eminence of South Wales as the world's major producer of iron and coal in the 19th century. All the necessary elements can still be seen - coal and ore mines, quarries, a primitive railway system, furnaces, workers' homes, and the social infrastructure of their community.

Coal

Anthracite Coal

Coal is a readily combustible black or brownish-black sedimentary rock normally occurring in rock strata in layers or veins called coal beds. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure. It is composed primarily of carbon along with variable quantities of other elements, chiefly sulfur, hydrogen, oxygen and nitrogen.

Coal starts as layer upon layer of annual plant remains accumulating slowly that were protected from biodegradation by usually acidic covering waters that gave a natural antiseptic effect combating microorganisms and then later mud deposits protecting against oxidization in the widespread shallow seas — mainly during the Carboniferous period — thus trapping atmospheric carbon in the ground in immense peat bogs that eventually were covered over and deeply buried by sediments under which they metamorphosed into coal. Over time, the chemical and physical properties of the plant remains (believed to mainly have been fern-like species antedating more modern plant and tree species) were changed by geological action to create a solid material.

Coal, a fossil fuel, is the largest source of energy for the generation of electricity worldwide, as well as one of the largest worldwide anthropogenic sources of carbon dioxide emissions. Gross carbon dioxide emissions from coal usage are slightly more than those from petroleum and about double the amount from natural gas. Coal is extracted from the ground by mining, either underground or in open pits.

Types of coal

As geological processes apply pressure to dead biotic matter over time, under suitable conditions it is transformed successively into

• Peat, considered to be a precursor of coal, has industrial importance as a fuel in some regions, for example, Ireland and Finland.
• Lignite, also referred to as brown coal, is the lowest rank of coal and used almost exclusively as fuel for electric power generation. Jet is a compact form of lignite that is sometimes polished and has been used as an ornamental stone since the Iron Age.
• Sub-bituminous coal, whose properties range from those of lignite to those of bituminous coal are used primarily as fuel for steam-electric power generation. Additionally, it is an important source of light aromatic hydrocarbons for the chemical synthesis industry.
• Bituminous coal, dense mineral, black but sometimes dark brown, often with well-defined bands of bright and dull material, used primarily as fuel in steam-electric power generation, with substantial quantities also used for heat and power applications in manufacturing and to make coke.
• Anthracite, the highest rank; a harder, glossy, black coal used primarily for residential and commercial space heating. It may be divided further into metamorphically altered bituminous coal and petrified oil, as from the deposits in Pennsylvania.
• Graphite, technically the highest rank, but difficult to ignite and is not so commonly used as fuel: it is mostly used in pencils and, when powdered, as a lubricant.

The classification of coal is generally based on the content of volatiles. However, the exact classification varies between countries.

Environmental effects

There are a number of adverse environmental effects of coal mining and burning, specially in power stations.
These effects include:

• Release of carbon dioxide, a greenhouse gas, which causes climate change and global warming according to the IPCC. Coal is the largest contributor to the human-made increase of CO2 in the air.
• Generation of hundred of millions of tons of waste products, including fly ash, bottom ash, flue gas desulfurization sludge, that contain mercury, uranium, thorium, arsenic, and other heavy metals.
• Acid rain from high sulfur coal
• Interference with groundwater and water table levels
• Contamination of land and waterways and destruction of homes from fly ash spills such as Kingston Fossil Plant coal fly ash slurry spill
• Impact of water use on flows of rivers and consequential impact on other land-uses
• Dust nuisance
• Subsidence above tunnels, sometimes damaging infrastructure
• Coal-fired power plants without effective fly ash capture are one of the largest sources of human-caused background radiation exposure
• Coal-fired power plants shorten nearly 24,000 lives a year in the United States, including 2,800 from lung cancer.
• Coal-fired power plant releases emissions including mercury, selenium, and arsenic which are harmful to human health and the environment.

Source: http://en.wikipedia.org/