- Dragline – In a dragline , a bucket is connected to a cable , which is attached to a long -___________ crane . The soil is excavated by dragging this bucket against the soil to be excavated . In dragline , bucket falls under the gravity load which loosens the soil . It is used for excavation as well as loading the material in the truck . Dragline can also be used for underwater excavation .
- Clamshell – Like dragline , clamshell bucket is designed to excavate the soil in vertical direction . The bucked is like an inverted jaw , having a biting motion . Generally it is used for excavating soft soil and stockpiling it . The bucket can be opened and closed with the help of a cable or by hydraulic control . It is designed in such away that it is half opened when dropped and gets closed when the bucket is filled . it can stock pile the soil up to 20-30m of height and at a diameter up to 60m . It is often used in mining industry .
- Backhoe – Backhoe is hydraulic excavator with a bucked attached to hydraulic controlled boom and stick . In backhoe , the excavation bucket moves in downward and backward direction during excavation . The difference between power shovel and backhoe is the movement of bucket . Backhoe may be crawler or rubber wheel mounted . Backhoe is more suited for the excavation below the ground , such as excavation for basements in building construction or trenches for laying sewer lines . The learning requirements for backhoe is same as power shovel .
Transportation
We have seen that some of the equipments used for excavation are also used for transporting for a distance , depending upon ground conditions . Many a time , the soil needs to be transported to other places which are not adjacent to the excavation site. The equipment used for transportation is also called haulers . |