Excavator systems and work principles

An excavator uses a boom, arm and attachment to perform digging, trenching and material-handling tasks. Theory includes machine configuration, swing radius, undercarriage, hydraulic systems, ground bearing conditions and work-zone planning. Key components include the boom, arm, bucket, cab, upper structure, tracks, slew ring and hydraulic cylinders. Safe work principles: establish an exclusion zone around the swing radius; check underground services and overhead hazards; assess ground stability; use approved attachments; never allow people beneath suspended loads. Knowledge check: What is the swing radius? Why must underground services be identified before work?