A Caterpillar excavator with backhoe with "thumb" attachment. The bucket is raked toward the machine to create a trench or pit. The lower jaw "thumb" enables large objects to be moved and 'grabbing' building components during demolition. Most excavators have the bucket fitted without the thumb attachment.

Heavy equipment refers to heavy-duty vehicles, specially designed for executing construction tasks, most frequently, ones involving earth moving. They are also known as construction equipment, earth movers, engineering vehicles, or just plain equipment. They usually comprise five equipment systems: implement, traction, structure, power train, control and information.^[1] Through the mechanical advantage of a simple machine, the ratio between input force applied and force exerted is multiplied.^[2] Currently most equipment use hydraulics as a primary source of transferring power. The use of heavy equipment has a long history. The ancient Roman engineer Vitruvius (1st century BCE) gave detailed descriptions of heavy equipment and cranes in ancient Rome in his treatise De architectura.^{[citation needed]}

[edit] Types

[edit] Images

Wheel loader	Grader (plowing snow here)	Military scraper	Landfill compactor (tamping tip)
Combat engineering vehicle	A wheeled front loader at work. This wheeled tractor is equipped with a large bucket, which can be raised or lowered by hydraulic arms.	Reconditioned Caterpillar 825G Soil Compactor

[edit] Implements and Hydromechanical Work Tools

[edit] Traction: Off-the-road tires^[3] and Tracks

Caterpillar D9 armoured bulldozer. Heavy bulldozers are powerful tools, equipped with a hollow steel blade, making them highly suitable for military applications and large earthmoving projects.

• see caterpillar tracks

Heavy equipment requires specialized tires for various construction applications. While many types of equipment have continuous tracks applicable to more severe service requirements, tires are used where greater speed or mobility is required. An understanding of what equipment will be used for during the life of the tires is required for proper selection. Tire selection can have a significant impact on production and unit cost. There are three types of off-the-road tires, transport for earthmoving machines, work for slow moving earth moving machines, and load and carry for transporting as well as digging. Off-highway tires have six categories of service C compactor, E earthmover, G grader, L loader, LS log-skidder and ML mining and logging. Within these service categories are various tread types designed for use on hard-packed surface, soft surface and rock. Tires are a large expense on any construction project, careful consideration should be given to prevent excessive wear or damage.

[edit] Structure

"This system connects components, transmits loads, provides attachment points for implements, and allows the machine to travel over uneven ground. The machine’s frame, articulation, and steering for wheeled equipment are the major parts of this system."^[4]

[edit] Powertrain

[edit] Control and Information

"The control and information systems. These systems enable the operator to direct and control all the other systems and provide information to guide operations or to monitor the performance and health of the equipment."^[5]

[edit] Equipment operators

* see Heavy equipment operator

operator training

The International Union of Operating Engineers has equipment schools where apprentice operators are trained.

The Association of Equipment Manufacturers provides effective safety training materials for operators of rough terrain forklifts and operators of industrial and agricultural mowers.

The National Association of Heavy Equipment Training Schools provides American national certification for heavy equipment operator

Interior Heavy Equipment School (www.iheschool.com) provides Canadian certification for heavy equipment operators

Currently there is not an international association of heavy equipment schools.

[edit] Equipment Cost

^[6]

Depreciation can be calculated several ways, the simplest is the straight-line method. The annual depreciation is constant, reducing the equipment value annually. The following are simple equations paraphrased from the Peurifoy & Schexnayder text:

[edit] Operating cost

For an expense to be classified as an operating cost, it must be incurred through use of the equipment. These costs are as follows^[7]:

The biggest distinction from a cost standpoint is if a repair is classified as a major repair or a minor repair. A major repair can change the depreciable equipment value due to an extension in service life, while a minor repair is normal maintenance. Major repairs are charged to the equipment, and minor repairs are charged to the job. It is advantageous for projects to classify all repairs as major, while the equipment department will desire to classify all repairs as "minor" and charge the work to a job.

A drilling machine at a construction site with a concrete pump and a barely visible concrete mixer-truck. The tops of foundation piles with re-inforcing iron rods sticking out, are visible at the bottom of the photo. This is an image of a very specialized auger which has a pipe all the way down its axis, permitting concrete to be pumped down while the auger is withdrawn.

[edit] Models

Die-cast metal promotional scale models of heavy equipment are often produced for each vehicle to give to prospective customers. These are typically in 1:50 scale. The popular manufacturers of these models are Conrad and NZG in Germany, even for US vehicles.

[edit] Manufacturers

The leading global manufacturers of construction equipment (in order):^{[citation needed]}

1. Caterpillar Inc.
2. Komatsu
3. Terex
4. CNH Global (CASE, New Holland, Kobelco)
5. Volvo Construction Equipment^{[citation needed]}
6. Deere & Company
7. Doosan Group (Bobcat Company)
8. Hitachi Construction Machinery (a subsidiary of Hitachi, Ltd.; inc: Euclid Trucks)
9. Bell Equipment
10. Hitachi Construction Machinery (Europe)
11. Bharath Earth Movers Ltd(India)

Other manufacturers

[edit] References