Excavator is the machine that can excavate the soil of various types forcefully and then using hydraulic system a hydraulic force is generated and utilizing this force bucket is pull back towards the machine. Bucket of excavator is replaceable. If front bucket is exchange with some other attachments then excavator can be used for multi-purpose. For example: pile diver, hydraulic jack hammer etc…
Excavator comes in numerous sizes depending on bucket size, length of boom, length of arm, and operation speed. Performance of excavator can be measured from the production cycle. Production cycle is the time that an excavator took to load the bucket from source, swing, dump, return back and then dig again. Therefore, faster the operation speed, the faster will be the one complete cycle and hence production cycle will increase.
Excavators are mostly used for digging of soils and for loading dump trucks. It is either of;
- Crawler excavator
Crawler excavator runs on two endless tracks (chain wheel system). These types of excavators are used in hilly areas where risks of sliding of machinery are on the verge. Crawler type excavator has low ground pressure because of spreading of load on large area. Therefore, it is also used where soil support is weak.
- Wheel excavator
Wheel excavator runs on wheels and are used for excavation and loading of dump trucks and most of the time it is only used for plain ground operations. Because of wheel, it is not suitable for hilly areas due to low grip value to the ground.
Excavators are used for;
- Excavating under water (amphibious type excavators are used for this kind of excavation)
- Breaking previous layers of highways and loading.