Forklift History

A forklift truck (also called a lift truck, a fork truck, or a forklift) is a powered industrial truck used to lift and move materials short distances. The forklift was developed in the early 20th century by various companies including the transmission manufacturing company Clark and the hoist company Yale & Towne Manufacturing. Following World War II the use and development of the forklift truck has greatly expanded worldwide. Forklifts have become an indispensable piece of equipment in manufacturing and warehousing operations. In 2013 alone the top 20 manufacturers worldwide posted sales of $30.4 billion dollars with 944,405 machines sold.

History

he middle nineteenth century through the early twentieth century saw the developments that led to today’s modern forklifts. The forerunner of the modern forklift were manually powered hoists that were used to lift loads. In 1906 the Pennsylvania Railroad introduced battery powered platform trucks for moving luggage at their Altoona, Pennsylvania train station. World War I saw the development of different types of material handling equipment in the United Kingdom by Ransomes, Sims and Jeffries of Ipswich. This was in part due to the labor shortages caused by the war. In 1917 Clark in the United States began developing and using powered tractor and powered lift tractors in their factories. In 1919 the Towmotor Company and Yale & Towne Manufacturing in 1920 entered the lift truck market in the United States. Continuing development and expanded use of the forklift continued through the 1920s and 1930s. The introduction of hydraulic power and the development of the first electric power forklifts, along with the use of standardized pallets in the late 1930s, helped to increase the popularity of forklift trucks.

The start of World War II, like World War I before, spurred the use of forklift trucks in the war effort. Following the war, more efficient methods for storing products in warehouses were being implemented. Warehouses needed more maneuverable forklift trucks that could reach greater heights and new forklift models were made that filled this need. For example, in 1954 a British company named Lansing Bagnall, now part of Linde Material Handling, developed what was claimed to be the first narrow aisle electric reach truck. The development changed the design of warehouses leading to narrower aisles and higher load stacking that increased storage capability. During the 1950s and 1960s operator safety became a concern due to the increasing lifting heights and capacities. Safety features such as load back rests and operator cages, called overhead guards, began to be added to forklifts produced in this era.[4] In the late 1980s ergonomic design began to be incorporated in new forklift designs to improve operator comfort, reduce injuries and increase productivity. During the 1990s exhaust emissions from forklift operations began to be addressed which led to emission standards being implemented for forklift manufacturers in various countries. The introduction of alternating current, or AC power, forklifts along with fuel cell technology are also refinements in continuing forklift development. In 2011, the size of the forklift manufacturing industry was nearly $27 billion.

General Operations

Forklifts are rated for loads at a specified maximum weight and a specified forward center of gravity. This information is located on a nameplate provided by the manufacturer, and loads must not exceed these specifications. In many jurisdictions it is illegal to remove or tamper with the nameplate without the permission of the forklift manufacturer.

An important aspect of forklift operation is that most have rear-wheel steering. While this increases maneuverability in tight cornering situations, it differs from a driver’s traditional experience with other wheeled vehicles. While steering, as there is no caster action, it is unnecessary to apply steering force to maintain a constant rate of turn.

Another critical characteristic of the forklift is its instability. The forklift and load must be considered a unit with a continually varying center of gravity with every movement of the load. A forklift must never negotiate a turn at speed with a raised load, where centrifugal and gravitational forces may combine to cause a disastrous tip-over accident. The forklift are designed with a load limit for the forks which is decreased with fork elevation and undercutting of the load (i.e., when a load does not butt against the fork “L”). A loading plate for loading reference is usually located on the forklift. A forklift should not be used as a personnel lift without the fitting of specific safety equipment, such as a “cherry picker” or “cage”.

Forklifts are a critical element of warehouses and distribution centers. It’s imperative that these structures be designed to accommodate their efficient and safe movement. In the case of Drive-In/Drive-Thru Racking, a forklift needs to travel inside a storage bay that is multiple pallet positions deep to place or retrieve a pallet. Often, forklift drivers are guided into the bay through guide rails on the floor and the pallet is placed on cantilevered arms or rails. These maneuvers require well-trained operators. Since every pallet requires the truck to enter the storage structure, damage is more common than with other types of storage. In designing a drive-in system, dimensions of the fork truck, including overall width and mast width, must be carefully considered.

Forklift Control and Capabilities

Forklift hydraulics are controlled with either levers directly manipulating the hydraulic valves, or by electrically controlled actuators, using smaller “finger” levers for control. The latter allows forklift designers more freedom in ergonomical design.

Forklift trucks are available in many variations and load capacities. In a typical warehouse setting most forklifts have load capacities between one to five tons. Larger machines, up to 50 tons lift capacity, are used for lifting heavier loads, including loaded shipping containers.

In addition to a control to raise and lower the forks (also known as blades or tines), the operator can tilt the mast to compensate for a load’s tendency to angle the blades toward the ground and risk slipping off the forks. Tilt also provides a limited ability to operate on non-level ground. Skilled forklift operators annually compete in obstacle and timed challenges at regional forklift rodeo.

Design types

The following is a list, in no particular order, of the more common lift truck types:

Hand pallet truck – no power system of any kind
Walkie low lift truck[14] – powered pallet truck, usually Electrically Powered[citation needed] Rider low lift truck[14] – usually Electrically Powered
Towing tractor[14] – may be Internal Combustion Engine or Electric Powered
Walkie stacker[14] – usually Electrically Powered
Rider stacker[14] – usually Electrically Powered
Reach truck [14]- variant on a Rider Stacker forklift, designed for small aisles, usually Electrically Powered, named because the forks can extend to reach the load. There are two variants, moving carriage, which are common in North America, and moving mast which are common in the rest of the world, and generally regarded as safer[citation needed] Electric Counterbalanced truck[14]- comes in Stand on End Control, Stand on Center Control, and Sit Down Center Control, which is the most numerous[citation needed] Internal Combustion Engine Powered Counterbalanced Forklift[14]- comes in Stand on End Control, Stand on Center Control, and Sit Down Center Control, which is the most numerous. Engines may be diesel, kerosene, gasoline, natural gas, butane, or propane fueled, and may be either Two Stroke Spark Ignition, Four Stroke Spark Ignition (common), Two Stroke Compression Ignition, and Four Stroke Compression Ignition (common). North American Engines come with advanced emission control systems. Forklifts built in countries like Iran or Russia will typically have no emission control systems.[citation needed] Electric Forklifts – powered by lead-acid batteries, several types of forklifts are electric: cushion tire forklifts, scissor lifts, order pickers, stackers, reach trucks and pallet jacks. Electric forklifts are primarily used indoors on flat, even surfaces. Electric forklift batteries last 6 consecutive hours or throughout an 8-hour shift with 2-3 breaks. Batteries prevent the emission of harmful fumes and are recommended for facilities in food-processing and healthcare sectors.
Fuel cell forklifts produce no local emissions, can work for a full 8-hour shift on a single tank of hydrogen, can be refueled in 3 minutes and have a lifetime of 8–10 years. Fuel-cell-powered forklifts are often used in refrigerated warehouses as their performance is not degraded by lower temperatures.
Sideloader[14] – comes in Stand on End Control, and Sit Down End Control, which is the most numerous. It may be Electrically Powered, or have an Internal Combustion Engine. Engines may be diesel, kerosene, gasoline, natural gas, butane, or propane fueled, and may be either Two Stroke Spark Ignition, Four Stroke Spark Ignition (common), Two Stroke Compression Ignition, and Four Stroke Compression Ignition (common). North American Engines come with advanced emission control systems. Forklifts built in countries like Iran or Russia will typically have no emission control systems. Some Sideloaders have Hybrid drivetrains.[citation needed] Telescopic handler – comes in Stand on Center Control, and Sit Down Center Control, which is the most numerous. Usually has an Internal Combustion Engine. Engines are almost always diesel, but sometimes operate on kerosene, and sometimes use propane injection as a power boost. Some old units are Two Stroke Compression Ignition, most are Four Stroke Compression Ignition (common). North American Engines come with advanced emission control systems. Forklifts built in countries like Iran or Russia will typically have no emission control systems. Some Telescopic handlers have Hybrid drivetrains.[citation needed] Walkie Order Picking truck[14] – usually Electrically Powered
Rider Order Picking truck[14] – commonly called an “Order Picker”; like a small Reach Truck, except the operator rides in a cage welded to the fork carriage, while wearing a specially designed safety harness to prevent falls. A special toothed grab holds the pallet to the forks. The operator hand transfers the load onto the pallet one article at a time. This is an efficient way of picking less than pallet load shipments, and is popular for use in large distribution centers.

A Raymond reach truck. Note the pantograph allowing the extension of the forks in tight aisles.

Articulated Very Narrow Aisle Counterbalanced trucks – sometimes called “Flexi or Bendi Trucks” after two of the largest manufacturers. Comes in Stand on Center Control, and Sit Down Center Control, which is the most numerous. May have an Internal Combustion Engine or an Electric Motor. Electric Motors are most common. Engines may be diesel, kerosene, gasoline, natural gas, butane, or propane fueled, and may be either Two Stroke Spark Ignition, Four Stroke Spark Ignition (common), Two Stroke Compression Ignition, and Four Stroke Compression Ignition (common). North American Engines come with advanced emission control systems. Forklifts built in countries like Iran or Russia will typically have no emission control systems. Some units have Hybrid drivetrains.[citation needed] Guided Very Narrow Aisle truck – A counterbalance type Sit Down Rider Electric Forklift fitted with a specialized mast assembly. The Mast is capable of rotating 90 degrees, and the forks can then advance like on a reach mechanism, to pick full pallets. Because the forklift does not have to turn, the aisles can be exceptionally narrow, and if wire guidance is fitted in the floor of the building the machine can almost work on its own. Masts on this type of machine tend to be very high. The higher the racking that can be installed, the higher the density the storage can reach. This sort of storage system is popular in cities where land prices are really high, as by building the racking up to three times higher than normal and using these machines, it is possible to stock an incredible amount of material in what appears to be a small space.[citation needed] Guided Very Narrow Aisle Order Picking truck – counterbalance type Order Picking Truck similar to the Guided Very Narrow Aisle truck, except that the operator and the controls which operate the machine are in a cage welded to the mast. The operator of course wears a restraint system to protect him against falls. Otherwise the description is the same as Guided Very Narrow Aisle truck.[citation needed] Truck Mounted Forklift / Sod Loader – comes in Sit Down Center Control. Usually has an Internal Combustion Engine. Engines are almost always diesel, but sometimes operate on kerosene, and sometimes use propane injection as a power boost. Some old units are Two Stroke Compression Ignition, most are Four Stroke Compression Ignition (common). North American Engines come with advanced emission control systems. Forklifts built in countries like Iran or Russia will typically have no emission control systems.