An Introduction to Excavators for Beginners in Construction

Written by Staff Writer

An excavator can make a tough job look easy. One minute it is digging a trench and the next it is loading a dump truck, all while turning in place. Whether the task is digging, lifting, demolition or trenching, the excavator is built to stay productive without a lot of repositioning.

This beginner-friendly guide walks you through the basics, including what an excavator is, how it works, where it is used, operator safety training and how to choose the right type for your job.

What Is an Excavator?

An excavator is a heavy machine that digs, lifts and moves material using hydraulic power. It consists of a lower base equipped with tracks or wheels and an upper cab that can rotate in a full circle. That rotation lets you dig in one spot, swing the load and place it where you need it without constantly moving the machine.

The digging apparatus is made up of three primary components.

• Boom: This is the large first arm that connects directly to the machine.
• Stick: The second section connected to the boom that extends outward to control how far you dig and how you pull material toward you. This is sometimes called the arm or the dipper.
• Attachment: The default tool is a bucket, but you can change it for another tool, like a breaker, grapple or auger.

From the cab, the operator controls the boom, stick and attachment separately with joysticks and pedals. The hydraulic system pushes pressurized fluid through cylinders, which creates the force that lifts the arm, curls the bucket and powers any attachments.

Backhoe vs. Excavator

People mix these up all the time, and it is understandable. After all, they both can dig and often show up on construction sites. The differences are in the design and stability.

A backhoe is a tractor-like machine with a front loader bucket and a rear digging arm. It is a strong all-around option for smaller jobs and sites that need both loading and light trenching.

An excavator focuses on digging and lifting and differs in key areas.

• Rotation: A backhoe’s rear arm swings in a limited arc from side to side. An excavator’s cab and upper body rotate a full 360 degrees, which makes it better for jobs that require a larger range of motion.
• Stability and reach: Due to a lower center of gravity, wider base, and heavier counterweights, excavators are more stable for heavy lifting and deeper digging, especially when you are working on rough terrain or uneven ground.
• Attachment flexibility: Excavators can handle a wider range of attachments with easier changeovers compared to the semi-fixed tools of a backhoe.

Excavators may also have a dozer blade on the front that you can drop for extra stability while digging or use it for backfill or light grading. That blade is different from a backhoe bucket. A dozer blade pushes and levels material from the front, while the backhoe’s powerful bucket is built to scoop and carry material.

Uses and Industries

These machines can be used anywhere you need to move earth, shape ground or handle heavy materials. On a typical jobsite , you might see one complete several different tasks in the same day.

Common uses include:

• Trenching. Digging trenches for ditches, water lines, gas lines or conduit. Using a narrower trenching bucket helps when you need cleaner cuts.
• Foundations and site prep. Cutting building pads, shaping slopes, removing unsuitable material and backfilling.
• Loading and material handling. Moving material into trucks, placing pipe and handling large materials with a grapple or rigging.
• Demolition and breaking. Using a hydraulic breaker to smash concrete, asphalt or rock.
• Land clearing and cleanup. Removing brush, pulling debris, loading out waste and supporting grading work.

An excavator is an irreplaceable piece of equipment anywhere crews need reach, rotation and hydraulic power to work quickly with fewer moves. Numerous industries rely on excavators, including construction, utilities, landscaping, mining, logging, rail and municipal public works.

Types of Excavators

Because these machines work in so many industries, there is no single standard design. You may choose multiple sizes and boom setups depending on the job and the site conditions.

Crawler

These are the workhorses you see on most big jobsites. They move on tracks, which spread weight over a larger area and allow them to work on soft or uneven soil without getting bogged down. While they excel in power and stability, they are not designed for quick travel.

Wheeled

Where crawlers are too slow, wheeled designs excel at jobsites that require greater mobility for frequent trips from point to point. Since they roll on tires, they can travel across pavement without causing damage, making them a common sight on city streets and road projects.

Mini

Mini excavators are the go-to choice when space is tight. Their smaller size allows them to operate between buildings or along tight utility corridors where a full-size rig cannot maneuver easily.

Many models also have reduced tail swing, which means the back of the machine does not extend beyond the tracks as it rotates. That makes it easier to work near obstacles like walls and fences with less risk of bumping into something.

Long-Reach

As the name suggests, long-reach models have longer booms and sticks. That extra reach helps clear obstacles, dig into deeper areas and work from further away instead of driving onto a soft bank or unstable surface.

A longer arm means giving up some digging force and lifting capacity, and the machine can feel less stable at full extension. These rely on lighter bucket loads and require you to pay close attention to swing speed and positioning to keep the excavator from tipping.

Dragline

These depart significantly from traditional designs. Instead of pushing a bucket into the ground, these machines operate by dropping a bucket and dragging it back with cables, then lifting and dumping the load. This setup works well for big excavation jobs, especially when the ground is wet or the digging area is deep. You will mainly see draglines in mining and large dredging projects.

Suction

Suction or vacuum attachments remove soil and debris by pulling it through a large hose into an onboard debris tank. Instead of digging with a bucket, they loosen the ground with either compressed air or high-pressure water, then use a vacuum attachment to lift the material out.

Suction excavation is mainly used for daylighting or potholing, which allows you to expose buried utilities while minimizing surface damage and the risk of striking a line.

Dig Into Safe Operation

Excavators are large machines with powerful hydraulics, large blind spots and a wide swing radius that can quickly put property and people at risk if you are careless. One wrong movement can injure a worker, damage a client’s property, shut down a lane or trigger a widespread utility outage.

Implementing strong safety practices and training from the start helps you complete work with fewer interruptions and consistent results. It also protects your crew’s confidence, your company’s reputation and your ability to win future jobs.

If you are new to excavator operation, OSHA Education Center’s Excavator Operator Training course helps you build good habits early, from pre-use inspections and stable positioning to safe digging around buried utilities. Build confidence instead of bad habits with your early experience by enrolling today.