A Basic Guide to Choosing an Excavator for Your Project

Selecting the right machine for an earthmoving or civils project can be time hungry. Pick one that is too small and it won’t have the dig, lift or power capacity you need for the task. Too big and it may not fit on the site and be difficult to maneuver.

While you can spend time agonizing over brand or model, the size will be the most important thing. Excavator sizing can be broken into a few, easy-to-navigate categories:

The mini digger – 1T to 1.7T and <6T

These fellas can move with ease around landscaping, buildings and tight spaces, and on footpaths. They can also avoid obstructions like trees and hanging lines. Mini diggers are easy to transport. They be very versatile with attachments and the actions they can perform. The downfall of these smaller machines is the lift, reach and depth compared to the bigger excavators

8t to 25T

The most common size in commercial construction. These boys are large enough to handle a lot of attachments and offer power and capacity.

30T+

Useful for major construction, bulk earthworks and demolition projects. They have massive power in terms of both lifting and digging capacity.

The drawback here is that it’ll be a bit of a mission to transport, requiring a pilot vehicle. Site constraints also mean that an excavator this size sometimes simply wont fit.

Once you have a general idea of the size you will need, you can then look into more specifics. Evaluate your project and consider the following:

• Site conditions
  Consider the worksite: What is the layout and terrain like? Is there enough room for the excavator you are wanting to use and is it safe to maneuver? Are there any roads you will need to cross or walkways you will block? Are there overhead lines?
  
  
• Transport
  What transport will you need for the excavator size? Will you need the excavator at multiple locations?
  
  
• Task
  The power you will need for lifting, digging, towing or loading

• Lifting capacity
  Generally larger excavators are better at lifting, with more power and counterweight.
  
  Here’s an example a Cat 308E CR

• Digging depth
  How deep and far will you need the reach?
  An example showing the range of a Kubota U55-4

• Bucket capacity
  While excavators are significantly determined by their size, it is important to know what you are lifting or digging and if the buckets are the right size. You may need to request a specific bucket when hiring. This is especially important for trenching where over dig can cost a lot of time and money on backfill materials.

• Attachments
  Will you require any attachments, such as breakers, augers, grab buckets? Is the excavator a sufficient size and power to manage the kind of attachment you need? Are the machine and the attachment compatible?

Finally, a few extra tips to keep in mind:

Loading out

Loading out into a 6-wheeler truck can be done with a 5T excavator, but an 8T would be able to manage this easier due to the reach.

Lifting

A basic rule to follow is that an excavator can lift 1/3 of its weight
i.e. a 20T excavator could lift approximately 8T

Other machines?

It is also possible that an excavator may not be the best machine for the job. If you’re moving dirt or metal around, you might also consider a skid steer. It’s maneuverable, compact and can be a little quicker than an excavator.

Now that you know what you’re after, check out the different excavator sizes and brands Equipt has available here.

Want to know more about excavators? Get in touch here.

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