Excavators are indispensable equipment pieces in the earthmoving business. They’re also invaluable for general construction and utility work, demolition and scrap businesses, quarry and aggregate operations as well as handling waste and recycling products. If there’s material to move, no doubt you’ll find an excavator nearby.
It’s not just a question of using an excavator to dig, load or spread. It’s additional questions like what excavator types, what sizes, what power and what attachments you’ll find around excavation jobs. There’s no such thing as a one-size-fits-all application when it comes to excavators.
It’s easy to get confused when researching excavators. You’ll find several the different types of excavators available, such as mini-excavators, backhoe excavators, extended-reach excavators and even excavators built to use suction rather than teeth. Excavators also have complex parts and a surprising array of attachments available.
If you're considering renting or using an excavator, get the full story on these dependable digging tools.
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Mechanized excavators have been around for over two hundred years. The first steam shovel appeared in 1796. William Otis assembled a highly functional system of gears, chains, pulleys and cables to excavate dry earth. He patented the design in 1839. By the mid-1800s, his steam shovel invention was the backbone of railway construction. It could move 300 yards of material per day. A team of men with picks and shovels could only dig 12.
Hydraulic excavators, which also use steam power, date to 1882. Early prototypes built by Sir W.G. Armstrong & Co. featured steam-driven cylinders moving cables. By 1897, the Kilgore Machine Company introduced the Direct Acting Excavator. It was the first truly hydraulic excavator without chains or cables.
The Caterpillar Tractor Company entered the heavy equipment scene in 1925. Cat® machines were the first to use steel-linked tracks, which propelled their first bulldozers. It wasn’t long before Cat engineers put tracks under their hydraulic excavators, revolutionizing the earthmoving world.
Over the years, some excavators have set world records. The world record for the largest excavator goes to the Bucyrus RH400. The behemoth Bucyrus is 32 feet tall, 24 feet wide and weighs 980 tons. Its twin 4,500 horsepower engines drive a 65-yard bucket that moves 9,000 tons of material per hour.
The world’s largest land vehicle title also goes to an excavator. It’s the Bagger 293 mining machine, which tips the scale at 14,200 tons. It has a bucket wheel feature that handles 8.5 million cubic feet per working day. The machine is big enough to see in satellite photos.
On the small-scale end, there's the Cat 300.9D. It measures 28 inches wide and has a retractable undercarriage. It can sneak through a doorway to take on interior demolition challenges. Don’t think that small size means low power, though. The Cat 300.9D has a 13 horsepower engine running its tracks, bucket and blade.
Some excavators are designed with the future in mind. The Regolith Advanced Surface Systems Operations Robot (RASSOR) Excavator is a mini-mover that works in low-gravity environments such as those on the Moon, Mars, asteroids and comets. "Regolith" is the industry term for loose mineral material covering bedrock.
Excavators become more technically advanced each year. New generation machines have better fuel consumption, lower emissions, produce less noise and provide more power than earlier models. Advanced computer systems monitor the excavator’s health and assess operator performance.
Excavators are also much safer today than they were in early steam shovel years. Modern excavators have climate-controlled cabs with ergonomic controls. Advances such as zero-swing designs make them safer for nearby workers, too. And then there’s the wide assortment of work tools you can attach to your choice of an excavator.
Although a wide range of machine types and equipment sizes are available, most hydraulic excavators operate on the same principle. They use an engine, usually diesel-powered, to drive hydraulic pumps that pressurize oil and move drive and dig components. The main difference is the capacity and magnitude of the parts.
You’ll find three main component groups in hydraulic excavators. One is the drive system or undercarriage. The second area is called the house. It contains the engine, hydraulic pumps, counterbalance and control grouping. The third part is the excavating arm or the business end of the machine.
An excavator is truly a system where each component contributes to the machine’s overall operation. Excavators are a prime example of the whole being greater than its parts. No part of a hydraulic excavator is more important than the other. The components work as an excavating team, and without an individual player, the digging game would be lost.
An excavator’s undercarriage is its stabilization and propulsion unit. It contains the drive mechanism that lets the machine move forward, backward and sideways. The undercarriage is a complex system on its own with many interconnecting pieces that cooperate to drive the excavator around its workplace.
You might assume that all excavators have tracks. While most hydraulic excavators use steel or rubber tracks in their undercarriage, wheeled excavators do exist.
Here are the main parts in a track-equipped excavator undercarriage:
The brilliance of a true hydraulic excavator is its ability to revolve in a complete circle. Excavators differ from backhoes and their digger cousins because they can rotate 360-degrees without restriction. Backhoes can dig like excavators, but they’re limited to a 200-degree side-to-side movement.
An excavator’s house sits on a turntable joining the cab and engine to the undercarriage. The house also connects to the excavating arm, making it the central command and control center. It’s also the powerhouse where fuel energy gets converted to excavating force.
Here are the main components you’ll find in an excavator’s house:
Without the excavating arm, the machine would be an undercarriage-mounted house with only the ability to move its self about. But add an arm and the machine goes to work.
Excavator arms are ingenious inventions that work as a series of hinges. The arm component can raise and lower, open and close, and extend and retreat. Combined, the hinged arm components let the machine dig, bail, load, throw and place material. Here are the main parts you’ll find on an excavator's arm:
It’s the combination of house, arm and undercarriage that put an excavator to work. The reach, lift and load capacity depends on a blend of the parts. It’s usually true that the larger the excavator undercarriage, arm and house, the more performance it has within a fixed time.
These marvelous machines have come a long way in design, power and capability since the 1800s. Today, excavators offer operators convenience and safety.
There’s no one type of excavator. You’ll see an array of earthmoving and material handling equipment labeled “excavator." The type of excavator you need has to match how you'll use it. For most excavator operators, that function can change rather quickly.
There are seven separate excavator types. Some cross categories and serve dual purposes, but these different types had specific purposes when the design and engineering teams thought them out. Here are the general excavator types you’ll find serving many industries:
Each excavator type has its purpose. Whether you perform regular construction, build roads, demolish buildings or mine material in a commercial capacity, there is a suitable excavator available.
There are many excavator sizes and types available for sale and rent, and there are plenty of situations when you’d use your machine. Demand opened the door for invention and innovation, leading to exceptionally well-designed excavator types. Now there are more excavator models on the market than most other pieces of construction equipment.
It's useful to sort excavators by use category than list all the specific jobs and roles the machines can handle. You’ll find excavators in narrow specialties like forestry works and river dredging as well as pile-driving and pole-setting. However, the majority of excavation use falls into these four categories:
There are a lot of excavator designs, sizes and shapes on the market, and an equal or greater choice of excavator attachments. Excavators are limited to digging, loading, backfilling or spreading material for graded job sites. With the right work tool attachments, you can turn your machine into a versatile ally that can perform many roles.
Work tool attachments are what really brought excavators into the modern construction world. Where excavators were once limited to earthworks, they’re now cross-industry equipment with tools that transform your job site performance. Here are just a few of the excavator-friendly attachments available:
There are other attachments available as work tools for your excavator. The use you have in mind for your attachment and the type of excavator you’re operating determines what tool you’ll source.
In many cases, it makes sense to rent your equipment to give you the versatility and flexibility you need without the commitment. That’s where The Cat Rental Store can help.
The Cat Rental Store is a nationwide network of dealers who specialize in top-end Cat equipment. We rent all types of excavators and tool attachments as well as a comprehensive inventory of related construction equipment. We’re here to help you source the most suitable machines for whatever task you’re tackling.
Let The Cat Rental Store specialists walk you through our excavator line and demonstrate how attachments can turn your basic machine into a value-added profit center. Call The Cat Rental Store today at 1-800-RENT-CAT or find a location near you.Find The Cat Rental Store Near You