Excavators where the digging action is an upward motion are called front shovels or just shovels. The front shovel perform excavation by crowding the material away from the machine.They are mainly used for digging above the track level and loading the material into hauling units. Thus they are suitable for use in quarries for loading of blasted or short rocks. A typical modern shovel is depicted in the diagram below.

A Front Shovel Diagram

A front shovel has the capacity to develop high breaking force. This is required as the material being excavated should be such that it will stand on its own almost at a vertical face. And normally such material are rocky in nature. Usually the front shovel are mounted on track base and have a slow traveling speed. The other basic parts of a shovel consist of the mount, cab, boom, stick and the bucket as shown in the figure below. The size of a shovel is indicated by the weight and bucket size.

A front shovel has to be close to the material to be excavated before it begin excavating. When this is achieved, the bucket is lowered to just above the track level with the bucket teethes pointing into the material face. A crowding force is applied by hydraulic pressure to the stick cylinder and at the same time the bucket cylinder rotates the bucket through the face.

The bucket will be fully filled if the height of the of the excavated material is right. If the material height is too low a second pass will be required. Then once the bucket is full it just tipped over to load the material into hauling units. Finally the material left on the pit floor will be excavated after the upper material is excavated.

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