Excavators- An Overview
Excavators are vehicles used to aid engineering projects. They are essentially made up of an articulated arm- also called a boom or stick, a cab for the crew person or personnel, and a bucket mounted on a rotating platform- also called a pivot, which in turn is mounted on an under carriage. Excavators can either have tracks or wheels attached to their undercarriage as a means of locomotion. Excavators evolved from steam shovels, the design of which dates back to the 19th century.
Excavators are quite versatile and are used for many engineering purposes, more than just mere excavation. These include of course, the digging of holes or trenches, handling material that can be put in an excavator bucket, clearing areas, cutting vegetation with special modifications or attachments, demolition of buildings and other structures, grading of surfaces such as roads, large scale landscaping, heavy lifting of certain materials, placing heavy objects and materials, mining- especially and most notably open pit mining and strip mining, river dredging, and on occasion, soil aeration.
Different roles for excavators are possible given different attachments and modifications. There are also many makes and sizes of these machines. The larger ones can weigh in excess of 188,360 lbs (around 86,000 kg) and have buckets with the maximum size of around 6 square yards (around 4.5 meters). Smaller models can weigh a lot less than that at perhaps 3,300 lbs (around 1,500 kg) with bucket sizes of maybe a third or half of a single yard or meter. There are occasionally special purpose models that have bigger or smaller dimensions. For example, a company has designed a very small excavator that will that will fit through a doorway around 28 inches (around 70 cm) wide. That is quite remarkably less than three feet or a meter wide.
Due to advances in technology, the abilities of excavators have become a lot more varied and versatile. The capabilities of these machines nowadays are more than just mere excavation. Such attachments as the sheep foot, grapples, breakers, augers, among others, they are used in many roles besides excavation. Some have modular designs or feature systems that allow different attachments to be used on the machines that can greatly increase their utility on jobsites and project areas. Loaders and bulldozers are usually teamed up with an excavator on project sites and there have been hybrid models of these machines. Many of the smaller models of excavator typically have bulldozer blades attached, typically for use in pushing back material into a hole. There quite a number of terms related to excavators. Those with tracks are sometimes called trackhoes. They are sometimes called fronthoes or mistakenly called backhoes. They are occasionally called diggers. Some companies market them as 360-degree excavators, leading some to refer to them simply as 360s. As heavy equipment, specialized training is often needed to get the most utility out of these remarkable machines. Generally, only a very select group of people are allowed to use excavators in many countries. Recently, there also are school and institutions that train people in the use of an excavator. Before this, training was a hit-or-miss affair conducted by construction companies and manufacturers. In the United States, the National Association of Heavy Equipment Training Schools or NAHETS is body that governs the training curriculum regarding the usage of excavators as well as that of other heavy machinery.
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