How do you select equipment for earthwork? What are the different types of excavators? Explain any one in detail. Distinguish between dipper shovel and drag shovel. Explain a clamshell along with its...

How do you select equipment for earthwork? What are the different types of excavators? Explain any one in detail. Distinguish between dipper shovel and drag shovel. Explain a clamshell along with its applications. How a dragline works? In what situation can they be used?