are heavy construction equipment consisting
of a boom, stick, bucket and cab on
a rotating platform (known as the "house").
The house sits atop an undercarriage
with tracks or wheels. A cable-operated
excavator uses winches and steel ropes
to accomplish the movements. They are
a natural progression from the steam
shovels and often called power shovels.
movement and functions of a hydraulic
excavator are accomplished through
the use of hydraulic fluid, with hydraulic
cylinders and hydraulic motors. Due
to the linear actuation of hydraulic
cylinders, their mode of operation
is fundamentally different from cable-operated