since B-C ratio is 0.34 which is greater than, challenger should be selected. An upper carriage with a hydraulically rotating top deck (revolving 360 degrees) and attachment make up a hydraulic excavator.
directly attached to a crawler or wheeled undercarriage. A bucket, grapple, scrap shear, or similar tool may be found on the front end of an excavator attachment. Through a hydraulic swivel at the pin's axis, high-pressure oil is sent to the tracks' hydraulic motors, enabling the machine to slew 360° without being obstructed and providing the left- and right-moving action. The closer-and-further (or digging action) motions are performed by the arm. An excavator is mostly used for trenching, drilling holes, and laying foundations since it has the strength to carry out these jobs far more quickly and efficiently than any other piece of heavy machinery available today.
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