A forklift truck is a motorized, self-propelled vehicle equipped with a forklift. While these vehicles are often simply called forklifts, the forklift itself is the lifting device mounted on the vehicle and not the vehicle itself. A forklift is a mechanism for lifting that uses two heavy metal rails, called forks, to pick up a load. These machines are designed to be used with palletized loads, so that the forks slide under the pallet in such a way that when the forks are raised, the forklift will lift the pallet in a balanced and stable manner.
In the early 20th century, the first forklift vehicle, a tractor with a forklift attachment was introduced. A few years later, the first purpose-built forklift truck was developed. With the rapid increase of worldwide industrialization came a need for vehicles capable of quickly and efficiently moving freight and other loads. A lack of manpower during the First World War increased this need. As pallets became more and more common as a standard unit of freight and the primary way to hold, move, and store loads, forklift trucks became important machines in all fields of industry, including warehouses, docks and shipping operations.
The basic design of the forklift truck has changed little since its introduction in the early 20th century, with improvements mostly revolving around design efficiency and safety. A modern forklift truck consists of a self-propelled chassis with an integral forklift device and a cockpit and seat for the operator. Modern forklifts may have electric motors or internal combustion engines which run on standard gasoline, liquefied petroleum (LP) gas, or diesel fuel.
Most forklifts have enclosed cabs with reinforced cages for safety, although some lack this feature. Mounted at the rear of the forklift is a large counterweight, usually made of iron, to offset the heavy loads. Without a counterweight, a forklift would tip forward when lifting a large load.
The forklift device has two large, heavy forks, usually made from steel, that extend outward from the front of the vehicle. They are linked together and can be raised and lowered by the operator who can also control their angle relative to the ground. This allows the operator to tilt a load backward slightly for increased stability. A carriage, which has a reinforced backrest to hold loads stable, and a mast complete the forklift device. The carriage is the portion of the device that moves up and down and to which the forks or other attachments are mounted, and the mast is the frame on which the carriage moves.