Crawler excavator An excavator is a construction vehicle used to dig or move large objects. The excavator is comprised of two parts, a driving base (usually called under carriage) and a powerful boom arm with an attached bucket designed for digging and cutting. The operator sits inside a small cab attached to the base and controls the arm.

The undercarriage of an excavator is made up of two sets of articulating tracks that are attached to the side of the excavator. The tracks operate like wheels to move the unit, but provide a larger surface area that creates in a more stable base and lower ground pressure for the excavator. On top of the base is a platform (usually called superstructure) that rotates between 180 and 360 degrees, operator is able turn the superstructure of excavator to any degree by moving the level in the cabin.

The operator sits inside the excavator cab and has two sets of controls. One set moves the actual unit forward and backwards. The other set of controls moves the unit on the horizontal plan and controls the arm of excavator. These controls determine the angle and speed of the movements of the arm and bucket along the vertical axis.

A crawler excavator is designed for use on construction sites and is quite expensive to purchase owing to the complicated structure and mostly with hydraulic driving systems. Many smaller construction companies lease or rent these excavators to avoid the expensive overhead costs.

All excavator operators are required to obtain a license for the safe operation of an excavator. Failure to obtain this qualification can result in a construction site being closed by the workplace health and safety inspector. The site is typically closed until a valid certificate holder is available to operate the excavator. In addition, many insurance policies are void if the excavator is not operated by a properly licensed operator.

Excavators come in a wide range of sizes and capacities. The heavier the unit, the greater the lift capacity will be, and the larger the bucket will be. Some excavators are small enough to fit through a standard doorway, while others are much larger, say hundreds tons of operating weight. The most important factor to consider when looking at smaller excavators is the amount of workgroup movement. The greater the degree of movement, the more flexibility you will have to work.

In recent years, hydraulic excavator capabilities have expanded far beyond excavation or digging tasks with buckets. With the advantage of hydraulic powered attachments such as a hydraulic breaker, a grapple or an auger, the excavator is frequently used in many applications other than excavation. Many excavators feature a quick coupler or quick hitch for simplified attachment mounting, increasing the machine's utilization on the jobsite. Excavators are usually employed together with loaders and bulldozers.

When selecting an excavator for purchase or rental, carefully consider the work that you plan to do with it. Make sure that the weight capability or the bucket is large enough to safely accommodate your requirements. Explore the different accessories and hydraulic systems in place to find one that will work best for you.