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A dragline bucket system consists of a large bucket which is suspended from a boom (A large truss like structure). The bucket is maneuvered by means of a number of ropes and chains. The hoistrope, powered by large diesel or electric motors, supports the bucket and hoist-coupler assembly from the boom. The dragrope is used to draw the bucket assembly horizontally. By skillful maneuver of the hoist and the dragropes the bucket is controlled for various operations. A schematic of a large dragline bucket system is shown below.
In a typical cycle of excavation, the bucket is positioned above the material overburden to be excavated. The bucket is then lowered and the dragrope is then drawn so that the bucket is dragged along the surface of the material. The bucket is then lifted by using the hoist rope. A swing operation is then performed to move the bucket to the place where the material is to be dumped. The dragrope is then released causing the bucket to tilt making the material in the bucket to fall down. This is called a dump operation.
A large dragline system used in the open pit mining industry costs approximately US$20-50 million. A typical bucket has a volume ranging from 30 to 60 cubic metres (Extremely large buckets range up to 120 cubic metres). The length of the boom ranges from 45 to 100 metres. In a single cycle it can move up to 450 metric tonnes of material.
A notable feature of mining draglines is that they are not fuelFuel is material with potential energy which can be transferred into kinetic energy, or as heat or mechanical work. In most cases this is just something that will burn. There are many different types of fuel. Solid fuels include coal, wood and peat. All t powered like most other mining equipment. Their power consumption is so great that they have a direct connection to the high voltageThe difference between high voltage and low voltage depends on the situation and on the field of science or industry involved. Laypeople generally consider mains to be high voltage largely because it is the highest voltage they normally encounter. The UK' grid at 11 kV. Many (possibly anecdotal) stories have been told about the blackout-causing effects of mining draglines. For instance, there is a long-lived story that, back in the 1970sMillennia: 1st millennium 2nd millennium 3rd millennium Centuries: 19th century 20th century 21st century Decades: 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s 2010s 2020s Years: 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 Events and trends, if all 7 of Peak Downs (a very large coal mine in central QueenslandQueensland State flag ( In detail) Coat of Arms ( In detail) Capital Brisbane Governor HE Ms Quentin Bryce Premier Peter Beattie Area — Land — Marine — Total 1 730 648 km˛ 121 994 km˛ 1 852 642 km˛ Population (2002) Density 3 729 000 2. 15/km˛ Time zone U, AustraliaAustralia is the sixth-largest country in the world (geographically), the only one to occupy an entire continent, and the largest in the region of Australasia. Australia includes the island of Tasmania, which is an Australian State. Its neighbouring count) draglines turned simultaneously, they would black-out all of North Queensland.
In all but the smallest of draglines, movement is accomplised by 'walking' using pontoonA pontoon is a buoyant device, either of solid lightweight material or constructed as a watertight chamber, used to support objects above or below water. Pontoons may be simply constructed from closed cylinders such as pipes or barrels or fabricated as bos, as caterpillar trackCaterpillar tracks are large (modular) tracks used on tanks, construction equipment and certain other off-road vehicles. The tracks help the vehicle to distribute its weight more evenly over a larger surface area than wheels can, keeping it from sinking is place too much pressure on the ground, and have great difficultly under the immense weight of the dragline. Maximum speed is only up to a few hundred metres per hour. If travelling medium distances, (about 30-100 km), a special dragline carrier can be brought in to transport the dragline. Above this distance, disassembly is generally required.