Sometimes, you may wonder; what do those numbers on the side of an excavator mean? Other times, you may get confused by the different names for the same excavator type or part. A guide on all you need to know about excavator nomenclature can come in handy.
How Are Excavators Classified?
The different OEMs use different ways to categorize their equipment. These categories include classification based on carriers and classification based on working mechanisms. Others still may classify excavators based on size.
Classification of Excavators Based On Carriers
There are 4 types of excavators in this category. They include crawler-mounted, truck-mounted, self-propelled, and rail-mounted excavators.
1. Crawler-mounted Excavator
Crawler excavators are used in digging.
Also called crawling digger, it is designed to dig, grade, or move large objects. When you need to perform heavy work on difficult terrains, you can use this. It adds mobility to the crawler-mounted excavators.
Moreover, they are effective on different materials. These include sharp rocks, wet soil, and soft soil. The turning radius is quite small and the speed is slow.
2. Truck-mounted Excavator
A truck-mounted excavator is mounted on a truck chassis. Equipped with two engines and cabs, it is no wonder it moves easily at high speed. However, it needs operating space and firm ground.
3. Self-propelled Excavator
On the other hand, this excavator has only one engine and a cab. As the name implies, it is self-propelled. Furthermore, it has rubber tires and moves at a speed between 10 and 30 km per hour.
4. Rail-mounted Excavator
These excavators are mounted either on a barge or rail. It is used close to railway lines for excavation works. It can also be used in water.
Classification Based on the working mechanism
Based on its technological functions, an excavator can be classified as either hydraulic or mechanical. A hydraulic excavator is more commonly used than a mechanical excavator. This is due to its efficient mobility and productivity.
1. Hydraulic Excavator
A hydraulic excavator is characterized by a rotating superstructure and a slightly bigger engine. It is appropriate for digging operations. The hydraulic pumps or valves control the cylinders and the system is powered by hydraulic motors.
However, oil filtration needs to be done occasionally. This is because soil and dirt could cause erosion of the pumps or valves. Furthermore, the hydraulic excavator can hold multiple attachments.
2. Mechanical Excavator
It can also be referred to as cable-operated excavators. Here, you can have two types. First, the hoe-type excavator which has the bucket digging towards the machine while facing it. Second, the shovel-type excavator has the bucket digging away from the excavator.
Excavator terms you should know
Excavators are known by different names. They are called diggers, 360s, and track hoes. Other names for it are JCBs, or rubber ducks.
The following are some excavator nomenclature you should be familiar with :
1. The boom
It has an angled arm also called the dipper or stick. The boom is attached to the excavator while the arm is pinned to the boom. While the standard booms only move up and down, a knuckle boom moves either left or right.
2. The bucket
You can find the bucket at the end of the arm. It has various designs to suit different purposes. For example, there are general-purpose buckets, rock buckets, mud buckets, and hard-pan buckets.
3. The backfill blade
This is also referred to as the dozer blade. The blade is located between the treads or wheels. It can be used to move unneeded materials away or anchor the excavator in place.
4. Ground clearance
Ground clearance describes the distance from the base of the undercarriage between the treads or wheels to the ground.
4. Ground clearance
However, ground pressure measures the weight of the excavator that is spread out by the undercarriage.
6. Grousers
Grousers are similar to tire treads. You find them as protruding rib-like structures on the tracks of an excavator. They help increase traction.
7. House
This interesting nomenclature describes the group including the cab, counterweights, hydraulic tank, fuel tank, and engine. You can find the cab just above the undercarriage
8. Hydraulic rams
This part of the excavator is used to control the movements of the boom, arm, and bucket.
9. The maximum bucket force
The amount of force you apply during excavation using the largest boom/stick configuration available is called the maximum bucket force.
10. The maximum digging depth
It measures how far down the excavator is able to dig with the boom, stick, and bucket all extended downwards.
11. The operating weight
The excavator’s operating weight comprises the weight of the operator and the weight of fluids in the usual construction settings. The fluids include fuel and hydraulic acid.
12. Reach
The term Reach describes how far the arm of an excavator can be extended.
13. Swamp pad
When the ground is soft, the tracks can sink into it. The swamp bad prevents this by distributing the weight of the excavator. The pad is therefore used beneath the tracks.
14. Swing
The space needed for the excavator to rotate is called a swing.
15. Zero tail swing model
These are models that do not need extra space for rotation. This is because the house is within the width of the tracks. There are swing gears and a swing motor to facilitate and power the swing.
16. The track drive
You can call this the propel motor, track motor, or final drive. It propels the excavator by providing the necessary torque.
17. The undercarriage
This includes the final drive motors, the track frame, the tracks, and sometimes, the blade if added.
18. Wheel excavators
These replace the wheels for excavators that do not use wheels. They are also called rubber ducks.
What are the parts of the excavators?
The parts of the excavator can be grouped as follows :
Front Attachment
Here, you can find 3 parts. They include the following:
- Bucket
The bucket is used for Digging.
- Arm/Dipper-
This is used to move the bucket and apply force on the ground.
- Boom
The boom acts as the main lever to operate the arm. It moves materials up and down.
Under Carriage
In turn, the undercarriage has 3 parts.
- X-Frame–
The x-frame forms the main structure and the base on which the excavator is mounted.
- Track
It is made up of the Track shoe and the Track-link.
- Final Drive
Here, you find the track motor and the speed reduction gear.
Upper Structure
The upper structure comprises of the base frame, engine, rotary coupling, and control valve. It also has the operator cabin, ROC, fuel tank, hydraulic tank, and hydraulic pump.
- Cabin
The cabin is where all mechanical / Electrical controls are housed. The operator controls the excavator from this location.
- Engine
People sometimes call this the prime mover. It converts fuel energy to mechanical energy.
- Hydraulic pump
On the other hand, the hydraulic pump converts mechanical energy to fluid energy. It is the heart of the machine.
- Main Control Valve
This controls the operation of the excavator.
- Slew Bearing
The slew bearing is a joint piece of the upper and lower structure.
Excavator Types & Sizes
Excavator Types
The configuration of an excavator is designed to meet specific applications or project needs. Consequently, we have different types of excavators. Some are preferred for heavy-duty jobs. Others are used for more precise digging and trenching.
The common types of excavators are mentioned below :
1. Standard/Crawler Excavator
You will find three attachments at the front. They are a boom, a stick, and a bucket. Furthermore, the bucket arm stretches and goes down to dig materials.
Thereafter, it retracts and lifts the materials. You can rotate the excavator cab up to 360 degrees. Consequently, you have the mobility to move materials while the machine is stationary.
Typically, these excavators run on tracks and work easily with soft terrain. It also has a variety of sizes ranging from mini excavators to heavy-duty excavators.
2. Wheeled Excavator
Instead of tracks, this excavator runs on wheels. Thus, it is suited for work with hard terrains like asphalt or concrete. Furthermore, it has a higher ground pressure and decreased traction.
As such, it does not work well with soft soil, hilly landscapes, or sloped landscapes. However, wheeled excavators are quite useful for several applications. They include road work, material handling, and waste handling.
3. Long-Reach Excavator
This is similar to the standard excavator. However, it has an extended boom and arm. The reach of the arm can be over 100 feet horizontally. This enables it to tackle large jobs easily and with precision.
For example, with it, you can work across a body of water. The high-reach excavator – a variant of the long-reach excavator – is mainly used for the demolition of tall buildings. Likewise, the ultra-high reach demolition excavator (UHD) has several tens of meters of reach.
4. Backhoe Excavator
The backhoe excavator is sometimes confused with standard excavators. It has an excavator boom attachment on its rear. The excavator’s arm only rotates 200 degrees rather than the full 360 degrees of the standard excavator.
A large bucket or blade for moving soil and materials is at the front. The ubiquitous backhoe excavator can perform digging tasks, grade soil, and move large materials.
5. Dragline Excavator
When you think of this excavator, think of heavy-duty machines used in strip–mining, or canal dredging. It uses wire ropes and chains to drag a bucket. The bucket, in turn, is used to excavate materials.
After lifting the bucket using the hoist rope, the excavator rotates to the dump location to dump the contents.
6. Amphibious Excavator (Dredger)
Unlike the dragline excavator, amphibious excavators can perform dredging operations while standing on one bank. They are used for excavation in lakes, riverbeds, and the sea. Examples of this type of excavator include ladder dredger, dipper dredger, and suction dredger.
Dredger excavators are used in the sea
7. Hydraulic or Power Shovel
Similarly, the hydraulic shovel excavator is a heavy-duty machine used for heavy lifting, mining, and digging. It has a lifting arm with a large bucket. The bucket can face toward the excavator’s cab like that of the standard excavator. Alternatively, the bucket can face away from the cab
8. Suction Excavator
As the name implies, a suction excavator works by blasting materials loose using high-pressure water. Thereafter, it uses a suction pipe to remove the materials. Thus, it is ideally used to precisely loosen and remove soil materials without damaging underground components.
9. Skid steer excavator
Interestingly, you can use the small engine-powered skid steer to transport raw materials in a site. Additionally, you can use it in rough grading. The lift arms can have various attachments.
The left-side wheel drive is independent from that of the right side. Furthermore, you use differential steering to turn the four wheels. This means that the left and right wheel pairs can have different speeds.
Excavator Size Classes
What project do you want to perform? It could be a large-scale construction or simple landscaping. There is an excavator size to suit it.
The following are the classifications of the major excavator sizes according to their operating weight and uses.
Excavator class sizes chart :
| Operating Weight | Common Name | Features and uses |
| < 1 tonne < 2,204 lbs | Micro Excavator | It is used for small jobs, in construction, and in agriculture. Furthermore, it is ideal for use in narrow spaces such as within a building. |
| < 6 tonnes< 13,227 lbs | Mini Excavator | Another name for it is compact excavator. The mini excavator is ideal for foundation digging, earthwork for housing, building a swimming pool, digging trenches for pipes, and holes for trees. Usually, it has a standard backfill blade, and an independent boom swing. There is also a heavy-duty arm with a wide range of attachments. |
| < 10 tonnes < 22,046 lbs |
Medium Excavator | Some manufacturers also class this as mini excavators. They are also called mid-sized excavators. Some of them offer greater precision than larger equipment. They may also have zero or near-zero/minimum tail swing. While offering digging and lifting capabilities, they can be used in transportation. You can use them to do more work. It is not too cumbersome. |
| < 30 tonnes < 66,138 lbs |
Standard Excavator | Standard-sized excavators are commonly used for construction projects. The standard excavator is used to move earth and does demolition work. Hydraulic standard excavators can have different work tool attachments . |
| < 100 tonnes < 220,462 lbs |
Large Excavator | These excavators are appropriate for heavy lifting and heavy earthworks. They are used in civil construction projects where large volumes of soil are moved. |
| > 100 tonnes > 220,462 lb |
Mining excavator , Production Excavator | You can find this excavator in use in quarries during ore extraction. |
Standard excavators are useful for demolition work.
How do you specify an Excavator?
Clearly, based on your digging or mining objectives, you would always want to increase productivity and reduce cost. It is therefore important to choose the right excavator for the right job. Read on to know how to specify an excavator.
Identify intended tasks
You need to know what tasks need to be performed or materials that need to be moved. Also, think long term. Will the excavator continue to be relevant?
For example, you may go for an excavator that can take multiple attachments to increase utilization rate. Furthermore, you may need a long-reach excavator rather than a standard one.
Match the excavator to the optimal bucket size and material :
Common metrics for defining excavator productivity include machine hydraulics, horsepower, and digging and lifting capacity. As such, you need to determine your daily production targets and the density of the material.
Certainly, this involves going for machines that offer good quality, and reliability, are stable, and operate smoothly. It should also have reduced fuel and maintenance costs. Thereafter, match the target and material density to the size of the excavator bucket you need. In turn, this will clue you in as to the size of the machine you need. Remember to base your specifications of the bucket on the heaviest material it can take.
Match the excavator to the right hauling equipment :
Certainly, you want to reduce loading cycles. One way to ensure efficient production is to match the excavator to the right hauling equipment. This will ensure the excavator operator and the hauling truck operator do not wait long between loading cycles.
For instance, if the number of passes to fill a dump truck is more than five, production is likely to suffer .
Match the excavator to the right hauling equipment
Certainly, you want to reduce loading cycles. One way to ensure efficient production is to match the excavator to the right hauling equipment. This will ensure the excavator operator and the hauling truck operator do not wait long between loading cycles.
For instance, if the number of passes to fill a dump truck is more than five, production is likely to suffer.
Go for long life and durability
With heavy digging and lifting operations, sturdy frames, plate thickness, and reinforced upper structures are important. This is because they will ensure maximum rigidity. In the same vein, the pin-up points, and hard wear discs can determine the overall durability of the bucket area.
The undercarriage too should have guards and shields.
Go for excavators with long life and durability.
Opt for dealers with good warranties and dealership support
Dealers who provide good warranties and offer pertinent after-sales support should be preferred. There are dealers who can help you meet deadlines and minimize downtime by providing parts. More so, they provide invaluable maintenance services when needed.
Job location and size considerations
If your job site is along the roadside, for example, you should go for excavators with lower tail swing/zero tail swing. Clearly, using standard tail swing excavators could lead to shutting off an extra lane of traffic. Similarly, larger machines may be restricted in small job sites.
Match the excavator to the right attachments needed
Is the excavator matching just one bucket or it has room for multiple attachments? Will you be able to attach a quick coupler that allows you to remove the bucket and do lifting operations?
Again, there are hydraulic excavators that have auxiliary hydraulic systems. This allows you to handle chosen attachments.
Match your excavator to the right attachment
Features in the excavator cab
The operator in the cab of an excavator that operates for long hours needs to be comfortable. What are the air conditioner and heater capacity? They can mean much in hot and cold conditions.
In addition, the design should reduce vibration and provide good ergonomics.
Available technology for optimal efficiency
Clearly, you would be interested in increasing efficiency and uptime. Certain technologies like telematics offer machine status monitoring. You can schedule preventive maintenance when necessary.
Technology can also improve automation and precision in digging operations.
What are the notable brands of Excavators?
There are quite a number of brands or manufacturers of excavators all over the world. The following are some notable brands.
1. Volvo CE
Volvo Construction Equipment specializes in the manufacture of equipment for construction and mining. It is a subsidiary of Swedish carmaker Volvo.
It has operations in over 140 countries. It is notable for manufacturing excavators with responsive advanced hydraulics.
2. Caterpillar Inc
The world’s largest excavator – the Bucyrus RH400 – is owned by Carterpillar Inc. Their excavators are known for durability, ease of maintenance, high-tech safety features, and the latest technology.
The company has its headquarters in Illinois, United States.
3. Komatsu
A Japanese multinational company, Komatsu manufactures construction and mining equipment. It has headquarters in Minato, Tokyo, and Japan, its excavators.
Komatsu excavators are characterized by advanced technology such as 3D GPS systems. They manufacture mini excavators and other large, powerful mining excavators.
4. Doosan
Doosan Infracore Company is a Korean multinational company. It manufactures heavy construction equipment such as dump trucks, wheel loaders, compact loaders, and mini-diggers. They also manufacture crawler excavators.
5. Hitachi
Hitachi Construction Machinery Company specializes in manufacturing a wide range of transportation and construction equipment.
It manufactures mini excavators, large excavators, wheel loaders, dump trucks, crawler cranes, and light compaction equipment.
6. JCB
Joseph Cyril Bamford Excavators Ltd manufactures construction, demolition, and waste handling equipment. The headquarters is in Rocester, Staffordshire. The US branch is reputed for manufacturing telehandlers and backhoes. JCB compact excavators are used for a variety of applications.
7. Liebherr Group
Headquartered in Germany, the Liebherr Group is known to manufacture a wide range of excavators. The company produced the longest telescopic boom in the world.
It has a reach of up to 100 meters and is fixed on a double cab truck.
8. Deere & Company
The headquarters of Deere & Company is in Moline, Illinois in the United States. It manufactures equipment used in agriculture, construction, mining, and forestry. The largest John Deere excavator is the 188,716-lb. John Deere 870G LC. It has a digging depth of 31 ft. 5 in.
9. Hyundai Heavy Industries
Hyundai Heavy Industries is based in South Korea. They manufacture powerful excavators used for digging, lifting, and loading operations. In addition, they are known for manufacturing compact (mini) excavators, crawler excavators, and wheeled excavators.
10. Case CE
Commonly called Case, this company specializes in manufacturing heavy construction equipment. These include excavators, wheel loaders, compact track loaders, crawler loaders, and motor graders.
What do Letters and Numbers on the excavator mean?
When you understand what the letters and numbers on an excavator mean, you understand relevant information about it.
Generally, the numbers and letters on an excavator will progress in this fashion.
The numbers or letters of the excavator Followed by the tonnage of the excavator and the series or generations of the excavator .
Example 1: Caterpillar excavator CAT 336D model
3 – Represents the excavator/ product type.
For Caterpillar excavators, 1 is a grader, 7 is an articulated truck, and 9 is a loader.
36 – Indicates the tonnage of the excavator as 36 tons. D indicates which series of products. In this case, the D series is a newer machine compared to B and C
Example 2 : PC200-8
PC – for Komatsu
200 represent 20 tons.
-8 represents the 8th generation product. However, some manufacturers begin from -7.
What is the meaning of 210 in Volvo EC 210 LC Excavator?
First, EC Stands for Excavator Crawler.
Second, the number 210 specifies the Machine weight. Machine weight describes the weight of the excavator. In turn, this weight includes the fuel tank, oil, water, an operator, and a standard bucket at the maximum loaded weight.
Therefore, 210 represents the weight of the Volvo excavator as 21 tonnes.
What does LC stand for?
LC is used to indicate that the model uses a widened and lengthened crawler.
This means that the contact area with the ground is increased. Such crawlers are usually used in soft ground conditions.
What is the difference between a CAT 312 and CAT 325 Excavator?
The first difference is in the weight class. The CAT 325 Excavator is larger and heavier. It is also more capable.
Differences in specifications and features of CAT 325 and CAT 312 Excavators
| SN | Specification/Feature | CAT 325 Hydraulic Excavator | CAT 312C Hydraulic Excavator |
| 1. | Engine | Cat C4.4 engine with 174hp/129kw | Turbo-charged CAT 3064T Engine with 94hp/70kw |
| 2. | Operating Weight | 22,800kg , 50300 lb | 13,140kg , 28,970lb |
| 3. | Swing Speed | 11.1 RPM | 12.9 RPM |
| 4. | Hydraulic System | 6 Cylinders | 4 Cylinders |
| 5. | Hydraulics | It has advanced hydraulic system, a new electro-hydraulic pump, and a main control valve Auxiliary hydraulic option with the versatility of a wide range of Cat attachments. |
Open centre 2-pump, with pump flow control |
| 6. | Maximum Travel Speed | 5.7 km/h 3.5mph | 5.5km/h 3.4mph |
| 7. | Fuel tank capacity | 313 L 82.7 gal | 250L 66gal |
| 8. | Operator Station | Simple-to-use technologies: Cat GRADE with 2D, Grade Assist, Lift Assist, and Payload –to boost operator efficiencies up to 45%. | Large, quiet, climate-controlled cab, good sightlines to the work area. |
| 9. | Applications | Perfect for medium to heavy duty | This falls in the category of medium excavators used for construction digging and lifting materials. |
| 10. | Fuel Consumption | A power system that reduces fuel consumption by up to 25% | The 3064 T engine has the best fuel consumption in this class of diesel engines. The thermal efficiency is improved. Furthermore, the friction resistance between the liners and the piston is reduced. |
| 11. | Swing Torque | 82 kN·m 60,300 lbf-ft. It has a 10% improved swing torque for easy work on slopes. | 30 500 N•m 22,496 lb ft |
In addition, the CAT 325 excavator has improved features as follows:
A compact radius design for working in tight spaces
Longer maintenance interval that reduces maintenance costs up to 20%.
There is an optional blade to aid faster job site cleaning, leveling, and better lifting capabilities.
There is a SmartBoom mode available. It allows the boom to move up and down freely. More so, it does not use any pump flow. This leaves the operator free to focus on the stick and bucket work.
Conclusion
Before you go ahead and purchase an excavator for that project, you have to pause. First, you should learn all you need to know about excavator nomenclature.
This includes the classifications, types, sizes, brands, and how to specify the excavator. This will build your confidence in getting the right excavator for the right application.
