The excavator is a machine designed to move earth and stone materials, primarily in the construction and mining industries. Excavators have been around since the mid-1800s, with the invention of the Steam Shovel, and have evolved and expanded into a large class of demolition and digging machines powered now mostly by hydraulics. Today, engineers are developing hybrid and biofuel powered excavators with numerous amenities for the comfort of the operator.
The first digging machine not powered by man is believed to be the Steam Shovel, which arrived around 1839 courtesy of inventor William Smith Otis. The Steam Shovel used pulleys to operate the bucket and arm of the machine, and "revolutionised the construction and civil engineering industries." Modern excavators, though powered generally by diesel fuel and systems of hydraulics, perform operations very similarly to their predecessors, moving material by lifting it away in a bucket or pushing it towards or away from the machine with a large scoop.
Excavators are designed to dig into the earth and lift it away through a series of motions by the boom (the long arm of the machine connected to a large scoop), and the bucket (the scoop, shovel, or mechanical "claw" attached to the end of the boom). The operations are performed from the cab (enclosed or open seat area for the operator), and use both mechanical and electronic systems for completing tasks. The operator sits in the cab of the vehicle and manipulates the machine's motions through an electronic panel and various hand controls.
Today, significant advancements have been made to excavators with regard to operator comfort and assistance. Electronic instruments provide diagnostics and increase an operator's productivity through "variable hydraulics, integrated power controls, and optional modes of operation matching power supply to demand." The machines feature HVAC environments in the cabs, utilise "bio-friendly oils," and "reduced emissions complying with tough standards in countries around the world," according to CNH Construction Equipment Division President Harold Boyanovsky.
There are several common types of excavators, and an excavator can adapt to different needs by the implementation of various kinds of scoops, claws, and buckets on the arm of the machine. The backhoe pulls material toward the machine via a large scoop with teeth. The front loader performs the same action in the opposite direction, pushing material away and containing it in front of the machine. Other types of excavators include varying sizes to accommodate different situations and sites. Mini and small excavators work well for smaller jobs, and ultra high demolition (UHD) excavators are designed to be durable and powerful for heavy-duty material moving, according to Caterpillar's website.
There are many uses for excavators, and improvements in capability and operation are continually being explored. According to CNH's Boyanovsky, engineers are working on improving air quality and climate control in excavator cabs, and developing solutions for noise and emissions reduction. The use of alternative materials to create more powerful, lighter excavators is being realised, and hybrid diesel/electric vehicles and machines that are 100 per cent recyclable are also in the works.