What an Excavator Does and Where It Works

An excavator is a machine that digs, lifts and moves material with an arm and a bucket mounted on a body that can turn all the way round. You see excavators on building sites, road works, pipeline routes, quarries, farms, demolition jobs and oil and gas sites. On many sites it is the busiest and most powerful machine people work beside.

The key feature of an excavator is that the top part of the machine, called the upper structure or house, sits on a large bearing and can turn through a full circle (360°) on the tracks or wheels below. This turning is called slewing or swinging. It lets the operator dig on one side and drop the material on the other side without moving the tracks. It is also the source of one of the biggest dangers: anything inside the circle the machine can swing through can be struck or crushed.

Typical jobs

• Digging trenches for pipes and cables, and digging foundations.
• Loading soil, rock or rubble into trucks.
• Grading and shaping slopes, ditches and banks.
• Lifting loads such as pipes or drainage chambers, but only when the machine is set up and allowed for lifting.
• Breaking, crushing or sorting material with other attachments, such as a hydraulic breaker or a grab.

Each job brings its own hazards. This course takes them one by one: the machine and its parts, the people around it, the daily inspection, the controls, the main tasks, and parking, transport and emergencies.