Types of Excavators
Excavating machines make difficult building projects possible, and offer a much higher level of efficiency compared to moving dirt and rocks by hand. These machines can be used during building construction, road and bridge work or even simple landscaping projects.
The right excavator can not only help you maximize productivity, but can also help you maintain your project budget and schedule.
Backhoes represent one of the most common forms of excavators. These machines feature a wheeled or track base, and a large bucket extended from a boom arm above the ground. On a backhoe, this bucket faces toward the operator cab, allowing the driver to scoop earth towards the machine. These excavating machines range in size from compact residential units that fit in a backyard to heavy-duty versions designed for river dredging and bridge building. Compact models allow drivers to work in small spaces, and often offer 360-degree swiveling motion for digging anywhere around the unit.
Steam shovels represent the classic excavating machine, and are one of the oldest types of excavators. Traditional steam shovels relied on steam energy, while modern units typically operate using an electric or diesel motor. These machines share many features with backhoes, but feature a shovel or bucket that faces away from the machine, rather than towards it. This allows the user to push dirt away from the machine rather than pulling the earth towards the unit. The position of the steam shovel bucket makes this machine useful for working next to walls, or for digging around objects that may interfere with a standard backhoe.
Dragline excavators feature a design similar to that of a backhoe, but also include a series of cables and lines to support the pulling motion of the bucket. According to the University of Arizona Department of Mining and Geological Engineering, the design of the dragline excavator allows users to dig deeper and utilize a longer reach than what is possible with a standard backhoe. The cables and long boom also help users operate a dragline excavator successfully over wet or unstable ground, where excavating with a backhoe would not be possible.
Bucket Wheel Excavator
Bucket wheel excavators feature a large front wheel equipped with built-in shovels and buckets. As the wheel rotates, the buckets scoop up dirt and rocks and transfer them to a conveyor belt built into the machine. The belt then carries the earth into a bin, which may be built into the machine or used separately.
Suction excavators resemble a modern dump truck. Operators use a large diameter hose to suck earth and rocks out of the ground using vacuum technology, then transfer it into the truck. This type of excavator makes it safe to dig around pipes and other underground objects with a reduced risk of damage compared to standard backhoes.
- University of Arizona Department of Mining and Geological Engineering: Equipment Operations Technology
- Montana State University Bozeman: Ecosystem Restoration
- Carnegie Mellon University Department of Civil and Environmental Engineering: Labor, Material and Equipment Utilization
- Bobcat: Selecting the Right Compact Excavator