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Excavators: What You Need To Know

February 20, 2023

This article discusses key features and capabilities, uses, types, sizes, and applications for excavators. Also, advantages and limitations, plus some common attachments.

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What is an Excavator?

An excavator is a heavy construction machine that is used to dig and move large quantities of earth, rock, or other materials. It is equipped with a large bucket attached to a hydraulic arm, which can be used to scoop up and move soil or other materials.

Excavators are used in construction, mining, and other industries where large-scale excavation work is required. They come in various sizes, from small machines used for digging trenches or landscaping, to larger ones used for major construction projects.

In this article we discuss:

  • Anatomy and components
  • What an excavator is used for
  • Types, sizes, and applications
  • Attachments
  • Advantages
  • Limitations

Anatomy and components 

An excavator can be broken down into several main components, each serving a specific purpose in its operation:

  • Cab: The operator's compartment where the controls and steering wheel are located. It is designed to be comfortable and safe for the operator, with features like air conditioning, adjustable seating, and a soundproofed interior.
  • Boom: The long, hydraulic arm that extends from the front of the excavator. It is used to lift and move heavy objects and can be adjusted to different lengths and angles.
  • Arm: The section of the excavator that connects the boom to the bucket or other attachment. It can also be adjusted to different lengths and angles.
  • Bucket: The most common attachment, used for digging and moving materials such as soil, gravel, and debris. It is attached to the arm and can be tilted or rotated to dump its contents.
  • Undercarriage: The bottom part of the excavator, consisting of tracks or wheels that allow the machine to move over rough terrain. It also includes the hydraulic system, engine, and other components that power the excavator.
  • Counterweight: A heavy component attached to the rear of the excavator, which helps to balance the weight of the boom and arm and prevent it from tipping over.
  • Hydraulic System: Powers the movement of the boom, arm, and bucket, as well as attachments. It uses hydraulic fluid to create pressure, which is then used to move the various components.
  • Engine: Provides power to the hydraulic system and other components of the excavator, such as the tracks or wheels. It is typically located in the rear of the machine.

Each of these plays a vital role in the excavator’s operation, allowing it to dig, lift, and move heavy objects with precision and efficiency.

What an excavator is used for

Excavators are used for a variety of tasks in construction, mining, and other industries. Some common applications include:

  • Digging of foundations, trenches, and holes for pipes or cables
  • Demolition of buildings, bridges, and other structures
  • Material handling, moving heavy materials such as rocks, dirt, and debris
  • Mining operations to extract minerals and other resources from the ground
  • Landscaping to move soil and shape the terrain
  • Snow removal, but will need attachments, such as a snow bucket or snow blade
  • Forestry to clear land, remove trees, and prepare the ground for planting
  • Road construction to grade and level the ground, as well dig ditches for drainage

Excavators can be used from small residential projects to large-scale commercial and industrial operations.

2018 Komatsu PC170 LC-11

Excavator types, sizes, and applications

Excavators come in a range of sizes from mini that weigh less than 6 tons to large that can weigh over 90 tons. Each type and size of excavator is designed for specific tasks and operating conditions:

  • Mini excavators: Small excavators typically used for tasks in tight spaces and low impact jobs. They typically weigh less than 6 tons.
  • Standard excavators: Larger excavators, typically used for heavy-duty excavation, demolition and construction jobs. They can weigh anywhere from 6 to 90 tons.
  • Long reach excavators: Used for reaching long distances, such as when working in water, deep trenches or for demolition.
  • Crawler excavators: They move on tracks and are designed to operate on uneven or unstable terrain. They are often used for heavy-duty tasks like mining and construction.
  • Wheeled excavators: They move on wheels and are designed for mobility, speed, and maneuverability. They are often used for road and highway construction jobs.
  • Amphibious: Specifically designed to work in wet conditions such as swamps and marshes.

The size of an excavator is determined by its weight, with smaller machines being used for light-duty work and larger machines used for heavier jobs. The size of an excavator also affects its digging depth, reach, and lifting capacity.


Excavators can be fitted with a variety of attachments to carry out specific tasks and are designed to be easily interchangeable:  

  • Bucket: The most common attachment for excavators, to dig and move materials such as soil, gravel, and debris.
  • Auger: Used to drill holes in the ground for foundations, poles, and other structures.
  • Grapple: Picks up and moves large, bulky objects such as tree trunks and rocks.
  • Hammer: Breaks up concrete, asphalt, and other hard materials.
  • Shears: Cuts and demolishes steel and other metals.
  • Ripper: Breaks up hard soil and rock.
  • Rake: Used to grade and level the ground.
  • Compactor: For compacting soil, gravel, and other materials.
  • Thumb: Grips and moves objects such as logs and pipes.
  • Trencher: Digs narrow, deep trenches for pipes and cables.

Excavator attachments can be swapped out quickly, enabling it to be used for different tasks without the need for an additional piece of equipment.

Six advantages of an excavator

Excavators offer several advantages in construction, mining, and other industries:

  1. Versatility: They can be used for a wide range of tasks. With different attachments, they can be used for digging, demolition, material handling, forestry, landscaping, and more.
  2. Power: These powerful machines have large hydraulic systems that allow them to lift and move heavy materials with ease.
  3. Efficiency: Designed to work quickly and efficiently, leads to increased productivity and reduced labor costs.
  4. Mobility: Excavators move easily over rough terrain, making them suitable for use in remote or difficult-to-access locations.
  5. Precision: Being equipped with advanced technology, such as GPS and laser guidance systems, allows them to perform tasks with a high degree of precision.
  6. Safety: Features such as cab guards, seat belts, and backup cameras help to protect the operator and other workers on a job site.

Excavators are an essential piece of equipment for many industries, allowing tasks to be performed that would be difficult or impossible to complete otherwise.

Six limitations of an excavator

While excavators offer many advantages, they also have some limitations: 

  1. Limited reach: They may not be able to reach certain areas or heights.
  2. Limited mobility: Even though excavators are designed to move over rough terrain, they may still have limitations on mobility in certain conditions, for example, steep slopes or unstable ground.
  3. Limited maneuverability: The large machines may not be able to access certain areas or work in tight spaces.
  4. Cost: Excavators can be expensive to purchase or rent, especially the larger models.
  5. Environmental impact: Excavators can have a significant environmental impact, particularly on sensitive ecosystems such as wetlands or forests.
  6. Noise pollution: They can be noisy machines and cause disruption.

Although excavators are powerful and versatile, they may not be the best option for every job or situation. Other equipment or methods may be more suitable for tasks that require more precision or less environmental impact.

Buy a Used Excavator with Black Star

View the excavators we have available for sale now. If you don’t see one here, there might be one listed in an upcoming auction that could meet your needs. Check back often with us, excavators sell quickly!

But, if you don’t find the equipment you’re looking for we may know someone who is selling. With our extended network of contacts, it won’t be difficult for us to find any type of equipment for you.  

Please email/text/call us with any specific questions regarding excavators.
Phone: 309-361-5101.

This article is our representation of useful information and is not intended to be a complete guide for making the right decision for your company. Ask our experts - or your own - for specific advice based on your unique circumstances.

Excavators: What You Need To Know
Susan Hyde

Susan’s 25+ years’ experience includes technical content on heavy construction equipment and large-scale, mass-production machinery. She has developed and written technical manuals, industry-specific articles, instructional material and more, and writes for Black Star’s technical and non-technical audiences.

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