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120-405: On30 (also called On2 1 ⁄ 2 , O16.5 and Oe ) gauge is the modelling of narrow gauge railways in O scale on HO ( 16.5 mm  / 0.65 in ) gauge track in 1:48 scale ratio by American and Australian model railroaders, in 1:43.5 scale ratio by British and French model railroaders and 1:45 by Continental European model railroaders (excluding France). On30 uses

240-644: A future connection to other lines, and the choice of track gauge was still a pragmatic decision based on local requirements and prejudices, and probably determined by existing local designs of (road) vehicles. Thus, the Monkland and Kirkintilloch Railway (1826) in the West of Scotland used 4 ft 6 in ( 1,372 mm ); the Dundee and Newtyle Railway (1831) in the north-east of Scotland adopted 4 ft  6 + 1 ⁄ 2  in ( 1,384 mm );

360-636: A hopper and a shaking screen or trommel which frees the desired minerals from the waste gravel. The minerals are then concentrated using sluices or jigs. Large drills are used to sink shafts, excavate stopes, and obtain samples for analysis. Trams are used to transport miners, minerals and waste. Lifts carry miners into and out of mines, and move rock and ore out, and machinery in and out, of underground mines. Huge trucks, shovels and cranes are employed in surface mining to move large quantities of overburden and ore. Processing plants use large crushers, mills, reactors, roasters and other equipment to consolidate

480-518: A huge preponderance of standard gauge . When Bristol promoters planned a line from London, they employed the innovative engineer Isambard Kingdom Brunel . He decided on a wider gauge, to give greater stability, and the Great Western Railway adopted a gauge of 7 ft ( 2,134 mm ), later eased to 7 ft  1 ⁄ 4  in ( 2,140 mm ). This became known as broad gauge . The Great Western Railway (GWR)

600-883: A mass of actual rock. Both types of ore deposit, placer or lode, are mined by both surface and underground methods. Some mining, including much of the rare earth elements and uranium mining , is done by less-common methods, such as in-situ leaching : this technique involves digging neither at the surface nor underground. The extraction of target minerals by this technique requires that they be soluble, e.g., potash , potassium chloride , sodium chloride , sodium sulfate , which dissolve in water. Some minerals, such as copper minerals and uranium oxide , require acid or carbonate solutions to dissolve. Explosives in Mining Explosives have been used in surface mining and sub-surface mining to blast out rock and ore intended for processing. The most common explosive used in mining

720-426: A mining operation. Once the analysis determines a given ore body is worth recovering, development begins to create access to the ore body. The mine buildings and processing plants are built, and any necessary equipment is obtained. The operation of the mine to recover the ore begins and continues as long as the company operating the mine finds it economical to do so. Once all the ore that the mine can produce profitably

840-503: A more sustainable future, the demand for metals is set to skyrocket. Between 2022 and 2050, an estimated 7 billion metric tons of metals will need to be extracted. Steel will account for the largest portion of this total at 5 billion tons, followed by aluminum at 950 million tons, copper at 650 million tons, graphite at 170 million tons, nickel at 100 million tons, and other metals. Notably, the energy expenditure required to extract these metals will soon surpass that of coal mining, highlighting

960-763: A negative environmental impact, both during the mining activity and after the mine has closed. Hence, most of the world's nations have passed regulations to decrease the impact; however, the outsized role of mining in generating business for often rural, remote or economically depressed communities means that governments often fail to fully enforce such regulations. Work safety has long been a concern as well, and where enforced, modern practices have significantly improved safety in mines. Unregulated, poorly regulated or illegal mining , especially in developing economies , frequently contributes to local human rights violations and environmental conflicts . Mining can also perpetuate political instability through resource conflicts . Since

1080-503: A new independent line was proposed to open up an unconnected area, the gauge was crucial in determining the allegiance that the line would adopt: if it was broad gauge, it must be friendly to the Great Western railway; if narrow (standard) gauge, it must favour the other companies. The battle to persuade or coerce that choice became very intense, and became referred to as "the gauge wars" . As passenger and freight transport between

1200-580: A novelty in the shape of a mixed-gauge goods train was introduced between Truro and Penzance. It was worked by a narrow-gauge engine, and behind the narrow-gauge trucks came a broad-gauge match-truck with wide buffers and sliding shackles, followed by the broad-gauge trucks. Such trains continued to run in West Cornwall until the abolition of the Broad Gauge; they had to stop or come down to walking pace at all stations where fixed points existed and

1320-1000: A number of other models. On30 is now regarded as the fastest growing segment of the model railroading market in the United States. Several other companies have produced mass market models for the USA market including Mountain Model Imports (MMI) who produced die-cast K series DRGW models (also available in 0n3), Broadway Limited who produced a 2-8-0 and a "galloping goose", San Juan Car company produce kits and RTR plastic wagons, Accucraft/AMS produce brass engines and plastic rolling stock. Many US modellers can be broadly cast into one of two groups: The first group are freelance modelers, not modelling any specific prototype. These modelers are adept at taking H0 gauge models and modifying them with new cabs and other features into models without prototypes. A common saying in this group of modelers

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1440-421: A plateway, spaced these at 4 ft 4 in ( 1,321 mm ) over the outside of the upstands. The Penydarren Tramroad probably carried the first journey by a locomotive, in 1804, and it was successful for the locomotive, but unsuccessful for the track: the plates were not strong enough to carry its weight. A considerable progressive step was made when cast iron edge rails were first employed; these had

1560-406: A proposed mine, extraction of the desired materials, and final reclamation or restoration of the land after the mine is closed. Mining materials are often obtained from ore bodies, lodes , veins , seams , reefs , or placer deposits . The exploitation of these deposits for raw materials is dependent on investment, labor, energy, refining, and transportation cost. Mining operations can create

1680-520: A ratio of 1:43.5. In Germany and many other European countries 0 scale uses a ratio of 1:45. The prototypes represented as example the German 750 mm ( 2 ft  5 + 1 ⁄ 2  in ) gauge, Austrian 760 mm ( 2 ft  5 + 15 ⁄ 16  in ) gauge, and 800 mm ( 2 ft  7 + 1 ⁄ 2  in ) gauge rack railways in Switzerland . In

1800-405: A relatively static disposition of infantry, requiring considerable logistics to bring them support staff and supplies (food, ammunition, earthworks materials, etc.). Dense light railway networks using temporary narrow gauge track sections were established by both sides for this purpose. Mining Modern mining processes involve prospecting for ore bodies, analysis of the profit potential of

1920-429: A required standard. A loading gauge is a two-dimensional profile that encompasses a cross-section of the track, a rail vehicle and a maximum-sized load: all rail vehicles and their loads must be contained in the corresponding envelope. A structure gauge specifies the outline into which structures (bridges, platforms, lineside equipment etc.) must not encroach. The most common use of the term "track gauge" refers to

2040-657: A slight variation from the nominal gauge for pragmatic reasons. The gauge is defined in imperial units , metric units or SI units. Imperial units were established in the United Kingdom by the Weights and Measures Act 1824 . The United States customary units for length did not agree with the imperial system until 1959, when one international yard was defined as 0.9144 meters and, as derived units, 1 foot (= 1 ⁄ 3  yd) as 0.3048 meter and 1 inch (= 1 ⁄ 36  yd) as 25.4 mm. The list shows

2160-408: A strong inducement to extract these metals or to lease the deposits and collect royalties from mine operators. English, German , and Dutch capital combined to finance extraction and refining . Hundreds of German technicians and skilled workers were brought over; in 1642 a colony of 4,000 foreigners was mining and smelting copper at Keswick in the northwestern mountains. Use of water power in

2280-663: A successful locomotive on the Killingworth Wagonway , where he worked. His designs were successful, and when the Stockton and Darlington Railway was opened in 1825, it used his locomotives, with the same gauge as the Killingworth line , 4 ft 8 in ( 1,422 mm ). The Stockton and Darlington line was very successful, and when the Liverpool and Manchester Railway , the first intercity line,

2400-588: Is ammonium nitrate . Between 1870 and 1920, in Queensland Australia, an increase in mining accidents lead to more safety measures surrounding the use of explosives for mining. In the United States of America, between 1990 and 1999, about 22.3 billion kilograms of explosives were used in mining quarrying and other industries; Moreover " coal mining used 66.4%, nonmetal mining and quarrying 13.5%, metal mining 10.4%, construction 7.1%, and all other users 2.6%". Artisanal and small-scale mining (ASM)

2520-811: Is a blanket term for a type of subsistence mining involving a miner who may or may not be officially employed by a mining company but works independently, mining minerals using their own resources, usually by hand. While there is no completely coherent definition for ASM, artisanal mining generally includes miners who are not officially employed by a mining company and use their own resources to mine. As such, they are part of an informal economy . ASM also includes, in small-scale mining, enterprises or individuals that employ workers for mining, but who generally still use similar manually-intensive methods as artisanal miners (such as working with hand tools). In addition, ASM can be characterized as distinct from large-scale mining (LSM) by less efficient extraction of pure minerals from

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2640-581: Is also modeled in Japan, where it is used to represent the 2 ft 6 in ( 762 mm ) narrow gauge railways, such as the Kiso Forest Railway , that were once quite common in that country. Several brass locomotive kits have been produced. The following table lists the most popular narrow gauges in O scale: 5 Model railroaders with layouts and rolling stocks by American standard and usually by British standard, use for designation of

2760-484: Is also used for the suburban railway systems in South Australia , and Victoria , Australia . The term "medium gauge" had different meanings throughout history, depending on the local dominant gauge in use. In 1840s, the 1,600 mm ( 5 ft 3 in ) Irish gauge was considered a medium gauge compared to Brunel's 7 ft  1 ⁄ 4  in ( 2,140 mm ) broad gauge and

2880-476: Is done by removing surface vegetation, dirt, and bedrock to reach buried ore deposits. Techniques of surface mining include: open-pit mining , which is the recovery of materials from an open pit in the ground; quarrying , identical to open-pit mining except that it refers to sand, stone and clay; strip mining , which consists of stripping surface layers off to reveal ore underneath; and mountaintop removal , commonly associated with coal mining, which involves taking

3000-613: Is mining upward, creating a sloping underground room, long wall mining , which is grinding a long ore surface underground, and room and pillar mining, which is removing ore from rooms while leaving pillars in place to support the roof of the room. Room and pillar mining often leads to retreat mining , in which supporting pillars are removed as miners retreat, allowing the room to cave in, thereby loosening more ore. Additional sub-surface mining methods include hard rock mining , bore hole mining, drift and fill mining, long hole slope mining, sub level caving, and block caving . Heavy machinery

3120-484: Is much more common, and produces, for example, 85% of minerals (excluding petroleum and natural gas) in the United States, including 98% of metallic ores. Targets are divided into two general categories of materials: placer deposits , consisting of valuable minerals contained within river gravels, beach sands, and other unconsolidated materials ; and lode deposits , where valuable minerals are found in veins, in layers, or in mineral grains generally distributed throughout

3240-413: Is not of immediate interest to the miner. The total movement of ore and waste constitutes the mining process. Often more waste than ore is mined during the life of a mine, depending on the nature and location of the ore body. Waste removal and placement is a major cost to the mining operator, so a detailed characterization of the waste material forms an essential part of the geological exploration program for

3360-833: Is probably the rack railway of the Basel Model Railway Club (MCB), german: Modelleisenbahnclub Basel , in Switzerland can be traced back to 1938. Just a few years after Trix and Märklin independently launched 00 gauge products with a model gauge of 16.5 mm. In 1957, an early gauge 0e modell railroad line according to the Mariazell Railway was built on the club layout of the St. Pölten Railway Model Club, german: Eisenbahnmodellbauklub St. Pölten , in Austria, based on experience with 0e gauge railway models built in

3480-584: Is recovered, reclamation can begin, to make the land used by the mine suitable for future use. Technical and economic challenges notwithstanding, successful mine development must also address human factors. Working conditions are paramount to success, especially with regard to exposures to dusts, radiation, noise, explosives hazards, and vibration, as well as illumination standards. Mining today increasingly must address environmental and community impacts, including psychological and sociological dimensions. Thus, mining educator Frank T. M. White (1909–1971), broadened

3600-497: Is sometimes referred to as On2 1 ⁄ 2 . O16.5 (sometimes O-16.5) in the United Kingdom is a model railway scale/gauge combination of 7 mm to the foot . This is the same scale as British O scale (1:43.5 ratio) running on 16.5 mm ( 0.65 in ) gauge track, which is also used by OO gauge model railways. It thus represents the prototype gauge of just over 2 ft 4 in ( 711 mm ) (e.g.

3720-511: Is that they model with "no standards", a reaction to the highly accurate modelling known as "rivet counting" found in some other sections of the hobby. The second group model prototype American narrow gauge railroads ranging from mining and logging companies through to large shortline railways such as the 2 ft ( 610 mm ) Sandy River and Rangeley Lakes and the 3 ft ( 914 mm ) Denver and Rio Grande Western Railroad . Modelers following these prototypes often choose On30 over

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3840-656: Is the largest producer of diamonds in Africa, with an estimated 12 million carats in 2019. Other types of mining reserves in Africa include cobalt , bauxite , iron ore , coal, and copper . Gold and coal mining started in Australia and New Zealand in the 19th century. Nickel has become important in the economy of New Caledonia . In Fiji , in 1934, the Emperor Gold Mining Company Ltd. established operations at Vatukoula , followed in 1935 by

3960-423: Is to conduct a feasibility study to evaluate the financial viability, the technical and financial risks, and the robustness of the project. This is when the mining company makes the decision whether to develop the mine or to walk away from the project. This includes mine planning to evaluate the economically recoverable portion of the deposit, the metallurgy and ore recoverability, marketability and payability of

4080-506: Is typically greater for track limited to slower speeds, and tighter for track where higher speeds are expected (as an example, in the US the gauge is allowed to vary between 4 ft 8 in (1,420 mm) to 4 ft 10 in (1,470 mm) for track limited to 10 mph (16 km/h), while 70 mph (110 km/h) track is allowed only 4 ft 8 in (1,420 mm) to 4 ft 9 + 1 ⁄ 2  in (1,460 mm). Given

4200-410: Is undertaken when no other alternative is available. The nominal track gauge is the distance between the inner faces of the rails. In current practice, it is specified at a certain distance below the rail head as the inner faces of the rail head (the gauge faces ) are not necessarily vertical. Some amount of tolerance is necessarily allowed from the nominal gauge to allow for wear, etc.; this tolerance

4320-550: Is used between China and Central Asia, and between Poland and Ukraine, using the SUW 2000 and INTERGAUGE variable axle systems. China and Poland use standard gauge, while Central Asia and Ukraine use 1,520 mm ( 4 ft  11 + 27 ⁄ 32  in ). When individual railway companies have chosen different gauges and have needed to share a route where space on the ground is limited, mixed gauge (or dual gauge) track, in which three (sometimes four) rails are supported in

4440-419: Is used in mining to explore and develop sites, to remove and stockpile overburden, to break and remove rocks of various hardness and toughness, to process the ore, and to carry out reclamation projects after the mine is closed. Bulldozers, drills, explosives and trucks are all necessary for excavating the land. In the case of placer mining , unconsolidated gravel, or alluvium , is fed into machinery consisting of

4560-494: The 1,435 mm ( 4 ft  8 + 1 ⁄ 2  in ) narrow gauge, which became the modern standard gauge . In modern usage, the term "narrow gauge" generally refers to track spaced significantly narrower than 1,435 mm ( 4 ft  8 + 1 ⁄ 2  in ). Narrow gauge is the dominant or second dominant gauge in countries of Southern, Central Africa, East Africa, Southeast Asia, Japan, Taiwan, Philippines, Central America and South America, During

4680-486: The American O scale of 1 ⁄ 4 inch to the foot, (ratio 1:48) to operate trains on HO gauge ( 16.5 mm  / 0.65 in ) track. The 30 indicates the scale/gauge combination is used to model 2 ft 6 in ( 762 mm ) narrow gauge prototypes, although it is often used to model 2 ft ( 610 mm ) and 3 ft ( 914 mm ) gauge prototypes as well. This scale/gauge combination

4800-599: The Bratislava – Lviv train, and the Romania/Moldova border on the Chișinău – Bucharest train. A system developed by Talgo and Construcciones y Auxiliar de Ferrocarriles (CAF) of Spain uses variable gauge wheelsets ; at the border between France and Spain, through passenger trains are drawn slowly through an apparatus that alters the gauge of the wheels, which slide laterally on the axles. A similar system

4920-521: The Greek author Diodorus Siculus , who mentions fire-setting as one method used to break down the hard rock holding the gold . One of the complexes is shown in one of the earliest known mining maps. The miners crushed the ore and ground it to a fine powder before washing the powder for the gold dust known as the dry and wet attachment processes. Mining in Europe has a very long history. Examples include

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5040-601: The Redruth and Chasewater Railway (1825) in Cornwall chose 4 ft ( 1,219 mm ). The Arbroath and Forfar Railway opened in 1838 with a gauge of 5 ft 6 in ( 1,676 mm ), and the Ulster Railway of 1839 used 6 ft 2 in ( 1,880 mm ). Locomotives were being developed in the first decades of the 19th century; they took various forms, but George Stephenson developed

5160-690: The Snailbeach District Railways ), although also widely used to model 2 ft ( 610 mm ) (e.g. the Ffestiniog Railway ) and 2 ft 3 in ( 686 mm ) (e.g. the Tal-y-llyn Railway ) gauge UK prototypes. 0e (sometimes Oe) is the Continental European notation for 0 scale using 16.5 mm ( 0.65 in ) track. In France and a few other countries 0 scale uses

5280-496: The Transmongolian Railway , Russia and Mongolia use 1,520 mm ( 4 ft  11 + 27 ⁄ 32  in ) while China uses the standard gauge of 1,435 mm. At the border, each carriage is lifted and its bogies are changed . The operation can take several hours for a whole train of many carriages. Other examples include crossings into or out of the former Soviet Union: Ukraine/Slovakia border on

5400-517: The argentiferous galena in the mines of Cartagena ( Cartago Nova ), Linares ( Castulo ), Plasenzuela and Azuaga , among many others. Spain was one of the most important mining regions, but all regions of the Roman Empire were exploited. In Great Britain the natives had mined minerals for millennia , but after the Roman conquest , the scale of the operations increased dramatically, as

5520-836: The greenstone of the Langdale axe industry based in the English Lake District . The oldest-known mine on archaeological record is the Ngwenya Mine in Eswatini (Swaziland) , which radiocarbon dating shows to be about 43,000 years old. At this site Paleolithic humans mined hematite to make the red pigment ochre . Mines of a similar age in Hungary are believed to be sites where Neanderthals may have mined flint for weapons and tools. Ancient Egyptians mined malachite at Maadi . At first, Egyptians used

5640-509: The 21st century begins, a globalized mining industry of large multinational corporations has arisen. Peak minerals and environmental impacts have also become a concern. Different elements, particularly rare-earth minerals , have begun to increase in demand as a result of new technologies. In 2023, 8.5 billion metric tons of coal were extracted from the Earth's crust. However, as the global economy transitions away from fossil fuels and toward

5760-680: The 7th century to the 14th century. Gold was often traded to Mediterranean economies that demanded gold and could supply salt , even though much of Africa was abundant with salt due to the mines and resources in the Sahara desert . The trading of gold for salt was mostly used to promote trade between the different economies. Since the Great Trek in the 19th century, after, gold and diamond mining in Southern Africa has had major political and economic impacts. The Democratic Republic of Congo

5880-675: The French crown to operate mines in 1733, becoming "the first practical miner on Lake Superior"; seven years later, mining was halted by an outbreak between Sioux and Chippewa tribes. Mining in the United States became widespread in the 19th century, and the United States Congress passed the General Mining Act of 1872 to encourage mining of federal lands. As with the California Gold Rush in

6000-454: The GWR, there was an extended period between political intervention in 1846 that prevented major expansion of its 7 ft  1 ⁄ 4  in ( 2,140 mm ) broad gauge and the final gauge conversion to standard gauge in 1892. During this period, many locations practicality required mixed gauge operation, and in station areas the track configuration was extremely complex. This

6120-661: The German firm Fleischmann produced ready-to-run models until a few years ago of small German and Austrian locomotives and associated rolling stock in Oe gauge on a scale of about 1:40. The line was called "Magic Train". "Billerbahn" was already producing its field railway from 1948 to 1977. Märklin also produced a small range of 3 rail 0e gauge models between 1970 and 1972 under the "MINEX" range name. All three ranges were aimed at children but had appeal to serious modelers too. Surveys at modelling conventions in Australia have found that

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6240-643: The Loloma Gold Mines, N.L., and then by Fiji Mines Development Ltd. (aka Dolphin Mines Ltd.). These developments ushered in a “mining boom”, with gold production rising more than a hundred-fold, from 931.4 oz in 1934 to 107,788.5 oz in 1939, an order of magnitude then comparable to the combined output of New Zealand and Australia's eastern states. During prehistoric times, early Americans mined large amounts of copper along Lake Superior 's Keweenaw Peninsula and in nearby Isle Royale ; metallic copper

6360-579: The Middle East, and China. In modern usage, the term "broad gauge" generally refers to track spaced significantly wider than 1,435 mm ( 4 ft  8 + 1 ⁄ 2  in ). Broad gauge is the dominant gauge in countries in Indian subcontinent, the former Soviet Union ( CIS states, Baltic states, Georgia and Ukraine), Mongolia, Finland (which still uses the original Soviet Gauge of 1524mm), Spain, Portugal, Argentina, Chile and Ireland. It

6480-592: The NA Puffing Billy locomotive was released by Haskell in 2014 and they have subsequently also released NQR openwagons. The scale is also popular for modelers of timber logging tramways and the Queensland sugar cane tramways, as well as freelance modelers. Ixion produced a "Coffee Pot" (a 3-foot 6 gauge prototype) for this market. A small number of models have also been produced in 7 mm:1 ft scale, mostly of New South Wales prototypes. On30

6600-581: The PECO O-16.5 range of track, and rolling stock kits appeared early in 1978, with other items released over the next 2-3 years to become a large part of the range that we have today. For accurate modelling of two-foot gauge railways, such as the Ffestiniog or Lynton and Barnstaple O14 has been employed, although there is some limited commercial support for this scale/gauge, it is mostly of industrial prototypes. The first known 0e gauge model railway

6720-481: The Romans needed Britannia 's resources, especially gold , silver , tin , and lead . Roman techniques were not limited to surface mining. They followed the ore veins underground once opencast mining was no longer feasible. At Dolaucothi they stoped out the veins and drove adits through bare rock to drain the stopes. The same adits were also used to ventilate the workings, especially important when fire-setting

6840-545: The Spanish to pulverize ore after being mined. This device was powered by animals and used the same principles used for grain threshing . Much of the knowledge of medieval mining techniques comes from books such as Biringuccio 's De la pirotechnia and probably most importantly from Georg Agricola 's De re metallica (1556). These books detail many different mining methods used in German and Saxon mines. A prime issue in medieval mines, which Agricola explains in detail,

6960-756: The Umm el-Sawwan site; gypsum was used to make funerary items for private tombs. Other minerals mined in Egypt from the Old Kingdom (2649-2134 BC) until the Roman Period (30 BC-AD 395) including granite , sandstone , limestone , basalt , travertine , gneiss , galena , and amethyst . Mining in Egypt occurred in the earliest dynasties. The gold mines of Nubia were among the largest and most extensive of any in Ancient Egypt. These mines are described by

7080-630: The United States modelling in On30 dates back to the 1950s, using HO gauge wheels and locomotive chassis. The scale was popularised to some extent in the 1960s and 1970s by the writings of modellers such as Gordon North . An On30 layout, the Venago Valley (built by Bill Livingston) was featured in the June 1971 issue of Railroad Model Craftsman magazine. However, as there are very few prototype 2 ft 6 in ( 762 mm ) gauge railways in

7200-516: The United States, it remained very much a minority modelling area, especially when compared with modelling in On2 and On3 . In 1998 Bachmann Industries introduced a model of a 2-6-0 steam locomotive in this scale for the Christmas village market. This model, being very inexpensive, was quickly adopted by modellers. Other manufacturers followed Bachmann into this market, and Bachmann also introduced

7320-404: The actual distance between the rails lies within tolerances of a prescribed standard: on curves, for example, the spacing is wider than normal. Deriving from the name of the bar, the distance between these rails is also referred to as the track gauge. The earliest form of railway was a wooden wagonway, along which single wagons were manhandled, almost always in or from a mine or quarry. Initially

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7440-556: The advantage of Peco flexible track and turnouts, which have become popular throughout the On30 modelling world. The 7mm Narrow Gauge Association supports the hobby, and publishes a magazine, "Narrow Lines". Most modellers attempt to accurately model one of the many 2 ft ( 610 mm ), 2 ft 3 in ( 686 mm ) and 2 ft 6 in ( 762 mm ) gauge railways that were found throughout Britain, although European, American and even railways from Britain's colonial empire have become popular. First items in

7560-402: The allowed tolerance, it is a common practice to widen the gauge slightly in curves, particularly those of shorter radius (which are inherently slower speed curves). Rolling stock on the network must have running gear ( wheelsets ) that are compatible with the gauge, and therefore the gauge is a key parameter in determining interoperability, but there are many others – see below. In some cases in

7680-624: The beginning of civilization, people have used stone , clay and, later, metals found close to the Earth's surface. These were used to make early tools and weapons; for example, high quality flint found in northern France , southern England and Poland was used to create flint tools . Flint mines have been found in chalk areas where seams of the stone were followed underground by shafts and galleries. The mines at Grimes Graves and Krzemionki are especially famous, and like most other flint mines, are Neolithic in origin (c. 4000–3000 BC). Other hard rocks mined or collected for axes included

7800-528: The bright green malachite stones for ornamentations and pottery . Later, between 2613 and 2494 BC, large building projects required expeditions abroad to the area of Wadi Maghareh in order to secure minerals and other resources not available in Egypt itself. Quarries for turquoise and copper were also found at Wadi Hammamat , Tura , Aswan and various other Nubian sites on the Sinai Peninsula and at Timna . Quarries for gypsum were found at

7920-561: The convenience in laying it and changing its location over unimproved ground. In restricted spaces such as tunnels, the temporary way might be double track even though the tunnel will ultimately be single track. The Airport Rail Link in Sydney had construction trains of 900 mm ( 2 ft  11 + 7 ⁄ 16  in ) gauge, which were replaced by permanent tracks of 1,435 mm ( 4 ft  8 + 1 ⁄ 2  in ) gauge. During World War I, trench warfare led to

8040-417: The cutter-head is progressively launched further into the coal seam. High wall mining can produce thousands of tons of coal in contour-strip operations with narrow benches, previously mined areas, trench mine applications and steep-dip seams. Sub-surface mining consists of digging tunnels or shafts into the earth to reach buried ore deposits. Ore, for processing, and waste rock, for disposal, are brought to

8160-448: The earliest days of railways, the railway company saw itself as an infrastructure provider only, and independent hauliers provided wagons suited to the gauge. Colloquially the wagons might be referred to as "four-foot gauge wagons", say, if the track had a gauge of four feet. This nominal value does not equate to the flange spacing, as some freedom is allowed for. An infrastructure manager might specify new or replacement track components at

8280-698: The focus to the “total environment of mining”, including reference to community development around mining, and how mining is portrayed to an urban society, which depends on the industry, although seemingly unaware of this dependency. He stated, “[I]n the past, mining engineers have not been called upon to study the psychological, sociological and personal problems of their own industry – aspects that nowadays are assuming tremendous importance. The mining engineer must rapidly expand his knowledge and his influence into these newer fields.” Mining techniques can be divided into two common excavation types: surface mining and sub-surface (underground) mining . Today, surface mining

8400-487: The form of water mills was extensive. The water mills were employed in crushing ore, raising ore from shafts, and ventilating galleries by powering giant bellows . Black powder was first used in mining in Selmecbánya , Kingdom of Hungary (now Banská Štiavnica , Slovakia) in 1627. Black powder allowed blasting of rock and earth to loosen and reveal ore veins. Blasting was much faster than fire-setting and allowed

8520-400: The growing importance of sustainable metal extraction practices. The process of mining from discovery of an ore body through extraction of minerals and finally to returning the land to its natural state consists of several distinct steps. The first is discovery of the ore body, which is carried out through prospecting or exploration to find and then define the extent, location and value of

8640-423: The imperial and other units that have been used for track gauge definitions: A temporary way is the temporary track often used for construction, to be replaced by the permanent way (the structure consisting of the rails, fasteners, sleepers/ties and ballast (or slab track), plus the underlying subgrade) when construction nears completion. In many cases narrow-gauge track is used for a temporary way because of

8760-402: The major axis of the rail section configured vertically, giving a much stronger section to resist bending forces, and this was further improved when fish-belly rails were introduced. Edge rails required a close match between rail spacing and the configuration of the wheelsets, and the importance of the gauge was reinforced. Railways were still seen as local concerns: there was no appreciation of

8880-687: The majority of all narrow gauge modellers in that country model in On30, 1:48 scale. An early pioneer was Rick Richardson, with his Vulcan Vale model railway. Recent examples include 'Steam in the Bush' who are based in the Blue Mountains and produce a range of On30 'craftsman' style kits. Many modelers choose to model the 2ft6in gauge railways in Victoria , such as Puffing Billy , and a number of kits and ready to run models have been produced for that prototype. A ready to run die-cast and plastic model of

9000-535: The metals due to the difficulties of transporting them, but the copper was eventually traded throughout the continent along major river routes. In the early colonial history of the Americas, "native gold and silver was quickly expropriated and sent back to Spain in fleets of gold- and silver-laden galleons", the gold and silver originating mostly from mines in Central and South America. Turquoise dated at 700 AD

9120-717: The mid-19th century, mining for minerals and precious metals, along with ranching , became a driving factor in the U.S. Westward Expansion to the Pacific coast. With the exploration of the West, mining camps sprang up and "expressed a distinctive spirit, an enduring legacy to the new nation"; Gold Rushers would experience the same problems as the Land Rushers of the transient West that preceded them. Aided by railroads, many people traveled West for work opportunities in mining. Western cities such as Denver and Sacramento originated as mining towns. When new areas were explored, it

9240-497: The mid-sixteenth century. On the continent, mineral deposits belonged to the crown, and this regalian right was stoutly maintained. But in England, royal mining rights were restricted to gold and silver (of which England had virtually no deposits) by a judicial decision of 1568 and a law in 1688. England had iron , zinc , copper , lead , and tin ores. Landlords who owned the base metals and coal under their estates then had

9360-432: The minehead, where the water was stored in large reservoirs and tanks. When a full tank was opened, the flood of water sluiced away the overburden to expose the bedrock underneath and any gold-bearing veins. The rock was then worked by fire-setting to heat the rock, which would be quenched with a stream of water. The resulting thermal shock cracked the rock, enabling it to be removed by further streams of water from

9480-431: The mining of previously impenetrable metals and ores. In 1762, one of the world's first mining academies was established in the same town there. The widespread adoption of agricultural innovations such as the iron plowshare , as well as the growing use of metal as a building material, was also a driving force in the tremendous growth of the iron industry during this period. Inventions like the arrastra were often used by

9600-615: The more accurate On2 and On3 gauges citing the lower cost of models and the ready availability of 'ready-to-run' models by Bachmann, Accucraft Trains and Broadway Limited. Detail parts and kits for specific models can be adapted easily from models manufactured for On3 modellers and others. In Britain O16.5 modelling also began in the 1950s, using modified proprietary OO scale models. A number of small companies now supply kits for locomotives made of materials such as brass and white metal, as well as rolling stock kits. British modellers have also had

9720-404: The narrow portion side-stepped to right or left. In rare situations, three different gauges may converge on to a rail yard and triple-gauge track is needed to meet the operational needs of the break-of-gauge station – most commonly where there is insufficient space to do otherwise. Construction and operation of triple-gauge track and its signalling, however, involves immense cost and disruption, and

9840-405: The ore body. This leads to a mathematical resource estimation to estimate the size and grade of the deposit. This estimation is used to conduct a pre-feasibility study to determine the theoretical economics of the ore deposit. This identifies, early on, whether further investment in estimation and engineering studies is warranted and identifies key risks and areas for further work. The next step

9960-462: The ore concentrates, engineering concerns, milling and infrastructure costs, finance and equity requirements, and an analysis of the proposed mine from the initial excavation all the way through to reclamation. The proportion of a deposit that is economically recoverable is dependent on the enrichment factor of the ore in the area. To gain access to the mineral deposit within an area it is often necessary to mine through or remove waste material which

10080-442: The ore, lower wages, decreased occupational safety, benefits, and health standards for miners, and a lack of environmental protection measures. Artisanal miners often undertake the activity of mining seasonally. For example, crops are planted in the rainy season , and mining is pursued in the dry season . However, they also frequently travel to mining areas and work year-round. There are four broad types of ASM: Surface mining

10200-570: The overhead tanks. The Roman miners used similar methods to work cassiterite deposits in Cornwall and lead ore in the Pennines . Sluicing methods were developed by the Romans in Spain in 25 AD to exploit large alluvial gold deposits, the largest site being at Las Medulas , where seven long aqueducts tapped local rivers and sluiced the deposits. The Romans also exploited the silver present in

10320-555: The period known as " the Battle of the gauges ", Stephenson's standard gauge was commonly known as "narrow gauge", while Brunel's railway's 7 ft  1 ⁄ 4  in ( 2,140 mm ) gauge was termed " broad gauge ". Many narrow gauge railways were built in mountainous regions such as Wales , the Rocky Mountains of North America, Central Europe and South America. Industrial railways and mine railways across

10440-431: The remaining part of a coal seam previously exploited by other surface-mining techniques has too much overburden to be removed but can still be profitably exploited from the side of the artificial cliff made by previous mining. A typical cycle alternates sumping, which undercuts the seam, and shearing, which raises and lowers the cutter-head boom to cut the entire height of the coal seam. As the coal recovery cycle continues,

10560-416: The same track structure, can be necessary. The most frequent need for such track was at the approaches to city terminals or at break-of-gauge stations. Tracks of multiple gauges involve considerable costs in construction (including signalling work) and complexities in track maintenance, and may require some speed restrictions. They are therefore built only when absolutely necessary. If the difference between

10680-590: The scale in English language publications the letter O and not the number 0 . In British and sometimes in French-speaking countries, for narrow gauge it is written after designation of the scale the model gauge in mm. As examples OO9 or OO6.5 in United Kingdom and H09 at the place of H0e or H06,5 at the place of H0f in France. Track gauge In rail transport , track gauge is the distance between

10800-446: The shafts could no longer be pumped dry with the available technology. Although an increased use of banknotes , credit and copper coins during this period did decrease the value of, and dependence on, precious metals , gold and silver still remained vital to the story of medieval mining. Due to differences in the social structure of society, the increasing extraction of mineral deposits spread from central Europe to England in

10920-567: The silver mines of Laurium , which helped support the Greek city state of Athens . Although they had over 20,000 slaves working them, their technology was essentially identical to their Bronze Age predecessors. At other mines, such as on the island of Thassos , marble was quarried by the Parians after they arrived in the 7th century BC. The marble was shipped away and was later found by archaeologists to have been used in buildings including

11040-497: The space between the rails of a track is colloquially referred to as the "four-foot", and the space between two tracks the "six-foot", descriptions relating to the respective dimensions. In modern usage the term "standard gauge" refers to 1,435 mm ( 4 ft  8 + 1 ⁄ 2  in ). Standard gauge is dominant in a majority of countries, including those in North America, most of western Europe, North Africa,

11160-474: The surface through the tunnels and shafts. Sub-surface mining can be classified by the type of access shafts used, and the extraction method or the technique used to reach the mineral deposit. Drift mining uses horizontal access tunnels, slope mining uses diagonally sloping access shafts, and shaft mining uses vertical access shafts. Mining in hard and soft rock formations requires different techniques. Other methods include shrinkage stope mining , which

11280-602: The tomb of Amphipolis. Philip II of Macedon , the father of Alexander the Great , captured the gold mines of Mount Pangeo in 357 BC to fund his military campaigns. He also captured gold mines in Thrace for minting coinage, eventually producing 26 tons per year. However, it was the Romans who developed large-scale mining methods, especially the use of large volumes of water brought to the minehead by numerous aqueducts . The water

11400-448: The top of a mountain off to reach ore deposits at depth. Most placer deposits, because they are shallowly buried, are mined by surface methods. Finally, landfill mining involves sites where landfills are excavated and processed. Landfill mining has been thought of as a long-term solution to methane emissions and local pollution. High wall mining, which evolved from auger mining, is another form of surface mining. In high wall mining,

11520-628: The top slats. Many examples of such devices have been found in old Roman mines and some examples are now preserved in the British Museum and the National Museum of Wales . Mining as an industry underwent dramatic changes in medieval Europe . The mining industry in the early Middle Ages was mainly focused on the extraction of copper and iron . Other precious metals were also used, mainly for gilding or coinage. Initially, many metals were obtained through open-pit mining , and ore

11640-420: The transverse distance between the inside surfaces of the two load-bearing rails of a railway track , usually measured at 12.7 millimetres (0.50 inches) to 15.9 millimetres (0.63 inches) below the top of the rail head in order to clear worn corners and allow for rail heads having sloping sides. The term derives from the "gauge", a metal bar with a precisely positioned lug at each end that track crews use to ensure

11760-553: The two areas became increasingly important, the difficulty of moving from one gauge to the other—the break of gauge —became more prominent and more objectionable. In 1845 a Royal Commission on Railway Gauges was created to look into the growing problem, and this led to the Regulating the Gauge of Railways Act 1846 , which forbade the construction of broad gauge lines unconnected with the broad gauge network. The broad gauge network

11880-617: The two gauges is large enough – for example between 1,435 mm ( 4 ft  8 + 1 ⁄ 2  in ) standard gauge and 3 ft 6 in ( 1,067 mm ) – three-rail dual-gauge is possible, but if not – for example between 3 ft 6 in ( 1,067 mm ) and 1,000 mm ( 3 ft  3 + 3 ⁄ 8  in ) metre gauge – four rails must be used. Dual-gauge rail lines occur (or have occurred) in Argentina, Australia, Brazil, Japan, North Korea, Spain, Switzerland, Tunisia and Vietnam. On

12000-444: The two rails of a railway track . All vehicles on a rail network must have wheelsets that are compatible with the track gauge. Since many different track gauges exist worldwide, gauge differences often present a barrier to wider operation on railway networks. The term derives from the metal bar, or gauge, that is used to ensure the distance between the rails is correct. Railways also deploy two other gauges to ensure compliance with

12120-513: The wagon wheels. As the guidance of the wagons was improved, short strings of wagons could be connected and pulled by teams of horses, and the track could be extended from the immediate vicinity of the mine or quarry, typically to a navigable waterway. The wagons were built to a consistent pattern and the track would be made to suit the needs of the horses and wagons: the gauge was more critical. The Penydarren Tramroad of 1802 in South Wales,

12240-441: The wagons were guided by human muscle power; subsequently by various mechanical methods. Timber rails wore rapidly: later, flat cast-iron plates were provided to limit the wear. In some localities, the plates were made L-shaped, with the vertical part of the L guiding the wheels; this is generally referred to as a "plateway". Flanged wheels eventually became universal, and the spacing between the rails had to be compatible with that of

12360-826: The world are often narrow gauge. Sugar cane and banana plantations are mostly served by narrow gauges. Very narrow gauges of under 2 feet (610 mm) were used for some industrial railways in space-restricted environments such as mines or farms. The French company Decauville developed 500 mm ( 19 + 3 ⁄ 4  in ) and 400 mm ( 15 + 3 ⁄ 4  in ) tracks, mainly for mines; Heywood developed 15 in ( 381 mm ) gauge for estate railways . The most common minimum gauges were 15 in ( 381 mm ), 400 mm ( 15 + 3 ⁄ 4  in ), 16 in ( 406 mm ), 18 in ( 457 mm ), 500 mm ( 19 + 3 ⁄ 4  in ) or 20 in ( 508 mm ). Through operation between railway networks with different gauges

12480-469: The world's gold, followed by the establishment of large mines such as the Mount Morgan Mine , which ran for nearly a hundred years, Broken Hill ore deposit (one of the largest zinc-lead ore deposits), and the iron ore mines at Iron Knob . After declines in production, another boom in mining occurred in the 1960s. In the early 21st century, Australia remains a major world mineral producer. As

12600-474: The world, which was increasingly demanding copper for electrical and household goods. Canada's mining industry grew more slowly than did the United States due to limitations in transportation, capital, and U.S. competition; Ontario was the major producer of the early 20th century with nickel, copper, and gold. Meanwhile, Australia experienced the Australian gold rushes and by the 1850s was producing 40% of

12720-529: The years after 1948. The narrow gauge rack railway in Basel, the narrow gauge railway in St. Pölten, as well as the following Billerbahn were initially assigned to gauge 00. This, as far as Billerbahn is concerned, even in 1956. The term '0 scale' as well as the term 'gauge 0e' did not exist at that time. A similar pattern of small manufacturers producing kits is followed in Continental Europe. However

12840-443: Was adopted, but many countries or companies chose a different gauge as their national gauge, either by governmental policy, or as a matter of individual choice. Standard gauge is generally known world-wide as being 1,435 mm ( 4 ft  8 + 1 ⁄ 2  in ). Terms such as broad gauge and narrow gauge do not have any fixed meaning beyond being materially wider or narrower than standard. In British practice,

12960-441: Was compounded by the common rail having to be at the platform side in stations; therefore, in many cases, standard-gauge trains needed to be switched from one side of the track to the other at the approach. A special fixed point arrangement was devised for the purpose, where the track layout was simple enough. In some cases, mixed gauge trains were operated with wagons of both gauges. For example, MacDermot wrote: In November 1871

13080-519: Was eventually converted—a progressive process completed in 1892, called gauge conversion . The same Act mandated the gauge of 5 ft 3 in ( 1,600 mm ) for use in Ireland. As railways were built in other countries, the gauge selection was pragmatic: the track would have to fit the rolling stock. If locomotives were imported from elsewhere, especially in the early days, the track would be built to fit them. In some cases standard gauge

13200-628: Was mined in pre-Columbian America; in the Cerillos Mining District in New Mexico , an estimate of "about 15,000 tons of rock had been removed from Mt. Chalchihuitl using stone tools before 1700." In 1727 Louis Denys (Denis) (1675–1741), sieur de La Ronde – brother of Simon-Pierre Denys de Bonaventure and the son-in-law of René Chartier – took command of Fort La Pointe at Chequamegon Bay ; where natives informed him of an island of copper. La Ronde obtained permission from

13320-533: Was opened in 1830, it used the same gauge. It too was very successful, and the gauge, widened to 4 ft  8 + 1 ⁄ 2  in or 1,435 mm and named " standard gauge ", was well on its way to becoming the established norm. The Liverpool and Manchester was quickly followed by other trunk railways, with the Grand Junction Railway and the London and Birmingham Railway forming

13440-532: Was originally impossible; goods had to be transshipped and passengers had to change trains. This was obviously a major obstacle to convenient transport, and in Great Britain, led to political intervention. On narrow gauge lines, rollbocks or transporter wagons are used: standard gauge wagons are carried on narrow gauge lines on these special vehicles, generally with rails of the wider gauge to enable those vehicles to roll on and off at transfer points. On

13560-576: Was primarily extracted from shallow depths, rather than through deep mine shafts. Around the 14th century , the growing use of weapons , armour , stirrups , and horseshoes greatly increased the demand for iron. Medieval knights , for example, were often laden with up to 100 pounds (45 kg) of plate or chain link armour in addition to swords , lances and other weapons. The overwhelming dependency on iron for military purposes spurred iron production and extraction processes. The silver crisis of 1465 occurred when all mines had reached depths at which

13680-497: Was referred to as "narrow gauge" to indicate the contrast. Some smaller concerns selected other non-standard gauges: the Eastern Counties Railway adopted 5 ft ( 1,524 mm ). Most of them converted to standard gauge at an early date, but the GWR's broad gauge continued to grow. The larger railway companies wished to expand geographically, and large areas were considered to be under their control. When

13800-406: Was still present near the surface in colonial times. Indigenous peoples used Lake Superior copper from at least 5,000 years ago; copper tools, arrowheads, and other artifacts that were part of an extensive native trade-network have been discovered. In addition, obsidian , flint , and other minerals were mined, worked, and traded. Early French explorers who encountered the sites made no use of

13920-449: Was successful and was greatly expanded, directly and through friendly associated companies, widening the scope of broad gauge. At the same time, other parts of Britain built railways to standard gauge, and British technology was exported to European countries and parts of North America, also using standard gauge. Britain polarised into two areas: those that used broad gauge and those that used standard gauge. In this context, standard gauge

14040-411: Was the removal of water from mining shafts. As miners dug deeper to access new veins, flooding became a very real obstacle. The mining industry became dramatically more efficient and prosperous with the invention of mechanically- and animal-driven pumps. Iron metallurgy in Africa dates back over four thousand years. Gold became an important commodity for Africa during the trans-Saharan gold trade from

14160-403: Was used for a variety of purposes, including removing overburden and rock debris, called hydraulic mining , as well as washing comminuted , or crushed, ores and driving simple machinery. The Romans used hydraulic mining methods on a large scale to prospect for the veins of ore, especially using a now-obsolete form of mining known as hushing . They built numerous aqueducts to supply water to

14280-465: Was used. At other parts of the site, they penetrated the water table and dewatered the mines using several kinds of machines, especially reverse overshot water-wheels . These were used extensively in the copper mines at Rio Tinto in Spain, where one sequence comprised 16 such wheels arranged in pairs, and lifting water about 24 metres (79 ft). They were worked as treadmills with miners standing on

14400-539: Was usually the gold ( placer and then lode ) and then silver that were taken into possession and extracted first. Other metals would often wait for railroads or canals, as coarse gold dust and nuggets do not require smelting and are easy to identify and transport. In the early 20th century, the gold and silver rush to the western United States also stimulated mining for coal as well as base metals such as copper, lead, and iron. Areas in modern Montana, Utah, Arizona, and later Alaska became predominant suppliers of copper to

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