chapter  11
25 Pages

SHOVEL LOADING

Inmedium to large-scale surfacemines, the principal piece of production loading equipment is the shovel. Although several different varieties exist and are used, this short section will only deal with electric rope shovels. One such shovel is shown diagrammatically in Figure 11.1 with some of the major points labeled. Although the figure is somewhat dated, in general it still applies. For P&H shovels, the

shipper shaft and pinion crowd are still used in rock but a dipper handle replaces the dipper stick. Caterpillar shovels have a dipper stick but no shipper shaft. The digging element of a power shovel is a dipper attached to a handle. The dipper lip,

the principal cutting edge, is attached to the dipper front and is equipped with replaceable teeth. The handle is connected to the back side of the dipper. The dipper bottom is a hinged door and has a latch for dumping the contents (Sargent, 1990). Shovel dippers are sized to match the unit material weights to be handled with ruggedness

increasing with the severity of the expected digging conditions. The dipper represents a dead weight load that subtracts from the load that can be raised by the machine (payload) and hence its weight must be kept to a minimum. The angle between the handle axis and the bottom surface of the dipper with teeth is generally about 65◦. The dipper is tapered to

Figure 11.1. Shovel nomenclature (Martin, 1982).