A power shovel is a bucket equipped machine, usually electrically powered, used for digging and loading earth or fragmented rock material[1].
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Shovels normally consist of a revolving deck with a power plant, driving and controlling mechanisms, usually a counterweight, and a front attachment, such as a boom or crane which supports a handle with a digger at the end. The machinery is mounted on a base platform with tracks or wheels[2]. The bucket is also known as the dipper. Modern bucket capacities range from 8 m3 to nearly 80 m3 [3].
Power shovels are used principally for excavation and removal of overburden in open-cut mining operations, though it may include loading of minerals, such as coal. Overburden is the term used in Mining to describe material that lies above the area of economic interest e Open-pit mining, also known as opencast mining and open-cut mining and strip mining, refers to a method of extracting rock or Minerals They are the modern equivalent of steam shovels, and operate in a similar fashion. A steam shovel is a large steam-powered excavating machine designed for lifting and moving material such as rock and Soil.
The shovel operates using several main motions:
A shovel's work cycle, or digging cycle, consists of four phases:
The digging phase consists of crowding the dipper into the bank, hoisting the dipper to fill it, then retracting the full dipper from the bank. The swinging phase occurs once the dipper is clear of the bank both vertically and horizontally. The operator controls the dipper through a planned swing path and dump height until it is suitably positioned over the haul unit (e. g. truck). Dumping involves opening the dipper door to dump the load, while maintaining the correct dump height. Returning is when the dipper swings back to the bank, and involves lowering the dipper into the tuck position to close the dipper door.
| Bucket Capacity (m3) | Type | Year | Name |
|---|---|---|---|
| 69 | Bucyrus Erie 1850B | 1962 | Big Brutus |
| 140 | Marion 6360 | 1965 | The Captain |