Mechanical devices, including tractors and implements, used in farming to save labour. The great variety of farming devices covers a wide range of complexity, from simple hand-held implements used since prehistoric times to the complex harvesters of modern mechanized agriculture. From the early 19th century to the present, the chief source of power in farming has changed from animals to steam power, then to gasoline, and finally to diesel. In developed countries, the number of farmworkers has steadily declined in the 20th century, while farm production has increased because of the use of machinery.
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A loader is a type of construction equipment (engineering vehicle) machinery that is primarily used to "load" material (asphalt, demolition debris, dirt, feed, gravel, logs, raw minerals, recycled material, rock, sand, wood chips, etc.) into or onto another type of machinery (dump truck, conveyor belt, feed-hooper, rail-car, etc.).
The loader assembly may be a removable attachment or permanently mounted. Often the bucket can be replaced with other devices or tools--for example, many can mount forks to lift heavy pallets or shipping containers, and a hydraulically-opening "clamshell" bucket allows a loader to act as a light dozer or scraper. The bucket can also be augmented with devices like a bale grappler for handling large bales of hay or straw.
Large loaders, such as the John Deere 844J, Caterpillar 950H, Volvo L120E, Case 921E, Caterpillar 966H, or Hitachi ZW310 usually have only a front bucket and are called Front Loaders, whereas small loader tractors are often also equipped with a small backhoe and are called backhoe loaders or loader backhoes.
The largest loader in the world is LeTourneau L-2350. Currently these large loaders are in production in the Longview, Texas facility. The L-2350 uses a diesel electric propulsion system simlilar to that used in a locomotive. Each rubber tired wheel is driven by its own independent electric motor.
Loaders are used mainly for uploading materials into trucks, laying pipe, clearing rubble, and digging. A loader is not the most efficient machine for digging as it cannot dig very deep below the level of its wheels, like a backhoe can. Their deep bucket can usually store about 3-6 cubic meters (exact number varies with the model) of earth. The front loader's bucket capacity is much bigger than a bucket capacity of a backhoe loader. Loaders are not classified as earthmoving machinery, as their primary purpose is other than earthmoving.
Unlike most bulldozers, most loaders are wheeled and not tracked, although track loaders are common. They are successful where sharp edged materials in construction debris would damage rubber wheels, or where the ground is soft and muddy. Wheels provide better mobility and speed and do not damage paved roads as much as tracks, but provide less traction.
In construction areas loaders are also used to transport building materials - such as bricks, pipe, metal bars, and digging tools - over short distances.
Loaders are also used for snow removal, using their bucket or a snowbasket, but usually using a snowplow attachment. They clear snow from streets, highways and parking lots. They sometimes load snow into dump trucks for transport.
High-tip buckets are suitable for light materials such as chip, peat and light gravel and when the bucket is emptied from a height.
Unlike backhoes or standard tractors fitted with a front bucket, many large loaders do not use automotive steering mechanisms. Instead, they steer by a hydraulically actuated pivot point set exactly between the front and rear axles. This is referred to as "articulated steering" and allows the front axle to be solid, allowing it to carry greater weight. Articulated steering provides better maneuverability for a given wheelbase. Since the front wheels and attachment rotate on the same axis, the operator is able to "steer" his load in an arc after positioning the machine, which can be useful. The tradeoff is that when the machine is "twisted" to one side and a heavy load is lifted high, it has a greater risk of turning over to the "wide" side.
Front loaders gained popularity during the last two decades, especially in urban engineering projects and small earthmoving works. Many engineering vehicle manufacturers offer a wide range of loaders, the most notable are those of John Deere, Caterpillar, Case, Volvo, Komatsu and Liebherr.
The term "loader" is also used in the debris removal field to describe the boom on a.
Popular additions to compact utility tractors and farm tractors are Front End Loaders, also referred to as a FEL. Compact utility tractors, also called CUTs are small tractors, typically with 18 to 50 horsepower and used primarily for grounds maintenance and landscape chores. There are 2 primary designs of compact tractor FELs, the traditional dogleg designed style and the curved arm style.
John Deere Tractor manufactures a semi-curved loader design that does not feature the one piece curved arm, but also is not of the traditional two piece design. New Holland Ag introduced a compact loader with a one piece curved arm on its compact utility tractors, similar one piece curved arm loaders are now available on compact tractors on many brands including Case/Farmall, and some Montana and Kioti tractors. Kubota markets traditional loader designs on most of its compact tractors but now features a semi-curved loader design similar to the John Deere loader design on several of its small tractors.
While the Front End Loaders on CUT size tractors are capable of many tasks, given their relatively small size and low capacities when compared to commercial loaders, the compact loaders can be made more useful with some simple options. A Toothbar is commonly added to the front edge of a loader bucket to aid with digging. Some loaders are equipped with a Quick Attach (QA) system, the QA system allows the bucket to be removed easily and other tools to be added in its place. Common additions would include a set of Pallet Forks for lifting pallets of goods or a Bale Spear for lifting hay bales.