Excavator

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A typical modern excavator:
a CAT 325C, fitted with quick coupler and tilting bucket

An excavator is an engineering vehicle consisting of an articulated arm (boom, stick), bucket and cab mounted on a pivot (a rotating platform, like a Lazy Susan) atop an undercarriage with tracks or wheels. Their design is a natural progression from the steam shovel.

1 Usage
2 Configurations
3 Terminology
4 Education
5 Gallery
6 Major manufacturers
7 See also
- 7.1 Types of excavator
- 7.2 Other
8 External links

[edit] Usage

Excavator demolishing a house. Note the hydraulic thumb

Excavators are used in many roles:

Digging of trenches, holes, foundations
Material handling
Brush cutting with hydraulic attachments
Demolition
General grading/landscaping
Heavy lift, e.g. lifting and placing of pipes
Mining, especially, but not only open-pit mining
River dredging

[edit] Configurations

An excavator with sheeps foot compactor attachment

Excavators come in a wide variety of sizes. The smaller ones are called a mini-excavator or compact excavator. One manufacturer's largest model weighs 84,980 kg (187,360 lb) and has a maximum bucket size of 4.5 m³ (5.9 yd³). The same manufacturer's smallest mini-excavator weighs 1470 kg (3240 lb), has a maximum bucket size of 0.036 m³ (0.048 yd³) and the width of its tracks can be adjusted to 89 cm (35 inches). Another company makes a mini excavator that will fit through a doorway with tracks that can be adjusted to only 70 cm (28 inches) wide.

In recent years, hydraulic excavator capabilities have expanded far beyond excavation tasks. With the advent of hydraulic powered attachments such as a breaker, a grapple or an auger, the excavator is frequently used in many applications other than excavation. Many excavators feature quick-attach mounting systems for simplified attachment mounting, dramatically increasing the machine's utilization on the jobsite. Excavators are usually employed together with loaders and bulldozers. Most wheeled versions, and smaller, compact excavators have a small backfill (or dozer-) blade. This is a horizontal bulldozer-like blade attached to the undercarriage and is used for pushing removed material back into a hole.

[edit] Terminology

Excavators are also called diggers and 360-degree excavators, sometimes abbreviated simply to a 360. Tracked excavators are sometimes called trackhoes by analogy to the backhoe. Even though the 'back' in backhoe refers to the action of the bucket (which pulls "back" toward the machine) and not the location of the shovel, excavators are also occasionally referred to as fronthoes or even just "hoes" .

[edit] Education

The National Association of Heavy Equipment Training Schools (NAHETS), established 2002, uses excavator training schools and circuilum as a method to test and train users in the ability of excavator use.