Excavators are a common piece of equipment used in construction from day-to-day, thanks to their heavy duty digging which gives the ability to move earth quickly and without too much effort.
It is very important to choose the right excavator for your project as it will determine how long the job will take and how easily you will be able to complete it. However, with so many options available and many factors to consider such as the size, type of tail swing, load capacity, track configuration, and more, it can become quite confusing and time consuming. Once you find the right excavator, you can operate at maximum efficiency to meet your project requirements.
Excavator sizing terms
Before we look at the variety of excavator sizes, its important to define what we mean by size.
When we use the term weight, we are referring to the excavators operating weight. This is the excavator’s total weight, including a driver and fuel. With all different size machines, the operating weight can change significantly. It is important to be aware of the operating weight as it can impact the machines capabilities, how it will impact the terrain, and how it should be transported.
The physical space that an excavator takes up in length, width and height is another way to understand size. This is called the dimensions, which determines the amount of space it may take on a job site or for transportation.
The tail-swing design of an excavator is another feature that can affect the amount of space an excavator will take up. Zero tail-swing models are great for tight spaces, as their house won’t extend much or at all beyond the tracks. On the other hand, the house will extend beyond the tracks when rotating with excavators that have the conventional tail-swing.
Types of excavators
A standard excavator also known as a crawler excavator, has a boom, stick and bucket attached at the front of the machine. To dig soil or other materials the bucket arm extends and lowers, then retracts towards the machine to lift the materials. Thanks to the excavator cab which can rotate 360 degrees, the operator can easily dig, move, and dump materials while the machine remains stationary. They run on two parallel tracks which offers low ground pressure and provides traction on unstable or sloped landscapes.
You can find standard excavators in a variety of sizes, from mini excavators right up to the largest excavators you can get. Depending on what task you are tackling, you can also choose different size buckets and lengths of booms. Standard excavators are useful for nearly any jobs that requires excavation, such as construction, trenching, landscaping, mining, farming, and forestry.
A wheeled excavator can accomplish the same tasks as a standard excavator, the difference being that it runs on wheels instead of tracks. These excavators are best for job sites with hard terrain such as asphalt or concrete. They offer easy manoeuvrability and greater speed for transporting materials to dump trucks when working on a flat construction site. However, wheeled excavators are not well suited for muddy or hilly terrain due to their higher ground pressure and decreased traction. Wheeled excavators can be used for a variety of tasks, including road work, material handling, scrapyard work, and more.
Long-reach excavators are another variation of the standard excavator, but with an extended boom and arm to reach further than a normal excavator would. With a range of 12 to 40 metres, it makes it possible to reach construction zones that are more than 30 metres away horizontally. These types of excavators are great for excavation in hard-to-reach areas, such as dams or rivers. They are also popular for demolition projects that require accuracy with speed and efficiency.
Sizes of excavators
There are four main size categories of excavators: mini, midi, medium, and large. In order to pick the right excavator, you will need to know the options are and what size would best cater to your job.
Mini Excavator (<6 tons)
Even though mini excavators are small, they certainly do not lack the power to perform tough jobs. In fact, their power might surprise you. They are generally better for projects that take place within a tight space, as their compact size makes it easier to manoeuvre into small areas. For jobs that need precision, the mini excavators are the desired choice. Most of the mini excavators have zero tail swing, which is a great advantage for operators that work around buildings and fences etc to help avoid hitting into them. Having the ability to swing the machine 360 degrees means you can dump material wherever you want to while stationary. Mini excavators also cause less ground damage because of their small and light size. This means they can operate on soft terrain or finished sites without tearing up the ground. These small machines are popular for landscapers as they do not leave as many track marks that larger, heavier excavators would. Another benefit of the mini excavators is that they can be easily transported with a trailer or class 2 truck efficiently around multiple sites, giving the operator more time to excavate.
However, depending on the dig depth, life capacity and project in general, these small machines will not cater to every job. They are great for light earthmoving jobs, indoor projects, drainage, landscaping, and more projects that do not require the size, power, and reach of a larger machine.
Midi Excavators (7-10t)
You may have heard the term midi excavators, these are the smaller of the medium sized excavators, weighing between 7 and 10 ton. There small and compact size allows them to complete many tasks that a mini excavator would, but with more power, reach and dig depth. If you require performance of a bigger machine but in a limited space, the midi excavators are the way to go.
Medium Excavators (10–45t)
Medium excavators also known as standard excavators, are great for larger jobs that require increased force and power. Being the most common excavator size for commercial construction projects due to their manoeuvrability and versatile functions, they offer great mobility, larger load capacity, reach, lift height and dig depth. Medium machines can carry out a wide variety of heavy-duty applications, such as demolition, road and civil construction, trench digging, utility work and more.
However, their heavier weight can cause damage to finished sites or soft soil. They can also bring challenges if operating in tight spaces due to their larger size, reach and tail swing.
Large Excavator (>45 tons)
Ideal for primary excavation, mining and large-scale demolition, the largest class of excavators are suited for heavy duty projects that require maximum power and capability. They are also useful for other projects such as moving large amounts of earth for civil engineering, or digging foundations for shopping centres, parking lots, apartments and more. If you need to tackle major excavation projects efficiently, a large excavator will perform with ease.
Transportation of large excavators can be a challenge as they require oversized trucks and speed transport permits, but once you get them onto your project they will be worth the effort. Another disadvantage of these huge machines is that their heavy weight can tear up the ground easier and cause ground damage. They also take up a lot of space which is why you probably have not seen them a lot in urban environments.
Understanding your project requirements
It all comes down to the type of project you are working on when trying to find the type of excavator you need. Consider the tasks the excavator will be completing on your work site, and whether it can handle your digging, lifting, and hauling needs easily and efficiently. It is good to imagine yourself through the process, step by step, to give you more of an idea of what you will require at the beginning, middle, and end of the job. Here are some project requirements you will need to investigate when finding the excavator for your job:
Boom reach: The boom reach of an excavator determines how far away the arm can dig whilst in a fixed place. A longer reach is great for jobs where there is restricted accessibility but note it can make excavation slower.
Lift height: If you are transporting material onto trucks or dumpers, or reaching up doing demolition work, you will need to be aware of the lift/dump height. It would be almost a complete waste of time if you had a machine that catered to every factor on your project apart from the actual dumping of the materials to do the job!
Dig Depth: You will need to consider the maximum digging depth for your job to ensure that your excavator can achieve this. And if it cannot, there are a range of attachments you can get to make extend the boom and dig with ease.
Load capacity: It is very important to understand how much earth you will be moving and how fast you want the job done, as this determines what load capacity you require. For example, you would not want to use a mini excavator with a small bucket to move a massive amount of dirt. This would take you a lot longer to do the job, therefore decreasing productivity and wasting valuable time. It is a good idea to have a range of bucket sizes available at your worksite just in case you need to alternate.
Load Weight: You will need to be aware of the load weight the excavator will need to be lifting. This is so that you do not choose an excavator that won’t withstand the necessary load weight needed. If you are lifting bigger and heavier materials, large excavators are a better option giving you better stability, and less chance of toppling.
Terrain: The terrain that you will be working on will help determine what type of machine you will need to complete the job efficiently and safely. If you are going to excavating in rough sloped terrain you would be thinking of a bigger steel tracked machine. Whereas if you would be carrying out the final touches on a project where you cannot make too much of a mess, you would require a lighter rubber tracked machine. It all comes down to your own requirements and what is best for your project.
The types of excavators available from Pronto Hire
If you are unsure what excavator you are supposed to be for your project, get in touch with the Pronto Hire team and we would be more than happy to help you out. At Pronto Hire we have a range of excavators to suit almost any project. Check out our full range from 1.7t right up to 30t with both rubber tracks or steel tracks here, and reach out to our team if you need more expert advice on the perfect excavator for your job.