A forklift (also called a lift truck, a high/low, a stacker-truck, trailer loader, sideloader, fork truck, tow-motor or a fork hoist) is a powered industrial truck used to lift and transport materials. The modern forklift was developed in the 1920s by various companies including the transmission manufacturing company Clark and the hoist company Yale & Towne Manufacturing.[1] The forklift has since become an indispensable piece of equipment in manufacturing and warehousing operations.
Contents |
The middle 19th century through the early 20th century saw the developments that led to today's modern forklifts. The Pennsylvania Railroad in 1906 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.[2]
Continuing development and expanded use of the forklift continued through the 1920s and 1930s. 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. New forklift models were made that filled this need.[3] In 1956 Toyota introduced its first lift truck model, the Model LA, in Japan and sold its first forklift in the United States in 1967. [4]
The following is a list of the more common lift truck types. It is arranged from the smallest type of lift to largest:
At the other end of the spectrum from the counterbalanced forklift trucks are more 'high end' specialty trucks:
These are, unlike most lift trucks, front wheel steer, and are a hybrid VNA (Very Narrow Aisle) truck designed to be both able to offload trailers and place the load in narrow aisle racking. Increasingly these trucks are able to compete in terms of pallet storage density, lift heights and pallet throughput with Guided Very Narrow Aisle trucks.
These are rail or wire guided and available with lift heights up to 40' non top-tied and 98' top-tied. Two forms are available; 'man-down' and 'man-riser' where the operator elevates with the load for increased visibility or for multilevel 'break bulk' order picking. This type of truck, unlike Articulated Narrow Aisle Trucks, requires a high standard of floor flatness.
These are for operation in potentially explosive atmospheres found in chemical, petrochemical, pharmaceutical, food and drink, logistics or other industries handling flammable material. Commonly referred to as Pyroban trucks, in Europe they must meet the requirements of the ATEX 94/9/EC Directive if used in Zone 1, 2, 21 or 22 areas and be maintained accordingly.
In North America, internal combustion powered industrial vehicles carry Underwriters Laboratories ratings that are part of UL 558. Industrial trucks that are considered "explosion proof" carry the designations GS for gasoline powered, DS for diesel powered, LPS for liquified propane or GS/LPS for a dual fuel gasoline/liquified propane powered truck.[5]
In order to decrease work wages, reduce operational cost and improve productivity, automated forklifts have also been developed.[6][7] Automated forklifts are also called forked automated guided vehicles and are already available from a growing number of suppliers.[8]
A typical counterbalanced forklift contains the following components:[9]
Below is a list of common forklift attachments:[10]
Any attachment on a forklift will reduce its nominal load rating, which is computed with a stock fork carriage and forks. The actual load rating may be significantly lower.
Forklift trucks are available in many variations and load capacities. In a typical warehouse setting most forklifts used 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.[12]
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 rodeos.
Forklifts are rated for loads at a specified maximum weight and a specified forward centre 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 centre 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. 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. Oftentimes, 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.[13]
There are many national as well as continental associations related to the industrial truck industry. Some of the major organizations are listed as:
There are many significant contacts among these organizations and they have established joint statistical and engineering programs. One program is the World Industrial Trucks Statistics (WITS) which is published every month to the association memberships. The statistics are separated by area (continent), country and class of machine. While the statistics are generic, and do not count production from most of the smaller manufacturers, the information is significant for its depth. These contacts have brought to a common definition of a Class System which all the major manufacturers adhere to.
Forklift safety is subject to a variety of standards world wide. The most important standard is the ANSI B56—of which stewardship has now been passed from the American National Standards Institute (ANSI) to the Industrial Truck Standards Development Foundation after multi-year negotiations. ITSDF is a non-profit organization whose only purpose is the promulgation and modernization of the B56 standard.[20]
Other standards have been implemented in the United States by the Occupational Safety and Health Administration (OSHA) and in the United Kingdom by the Health and Safety Executive.[21] In many countries forklift truck operators must be trained and certified to operate forklift trucks. Certification may be required for each individual class of lift that an operator would use.
In the UK, the Provision and Use of Work Equipment Regulations (PUWER) state that operators of fork lift trucks must be adequately trained in their operation, but the nature of this training is not specified. Third party organisations have developed de-facto 'best practice' standards for forklift training, commonly referred to in the UK as a 'forklift license', but such training is not a legal requirement as is commonly believed.[22] Organised training however helps to demonstrate that an employer has taken steps to ensure its 'duty of care' in the unfortunate event of an accident. The details below represent the de-facto standards proscribed by training organisations.
In the UK, Forklift Training is carried out by a number of different organisations, which all Forklift Instructors must be registered with at least one of them. Although R.T.I.T.B. operators are registered on a database which has to be renewed a 3 yearly basis, the amount of time determined between refresher courses is subject to the H&S Executive, Insurance companies or company policies. The H&S Executive (HSG136 Workplace Transport Safety) does recommend re-training/testing every 3 to 5 years.
United Kingdom Forklift Instructors must be registered to one of the following;
RTITB
Independent Training Standards Scheme and Register (ITSSAR)
Association of Industrial Truck Trainers (AITT)
National Plant Operators Registration Scheme (NPORS)
CITB-ConstructionSkills
Lantra - Sector Skills Council for the environmental and land-based sector
There are various different training companies across the UK that can provide training on-site and off-site, these can be independent instructors or part of a training company. There are also various training centre's across the United Kingdom that can provide individuals not already trained to use a Forklift Truck to help gain a certificate of competence.
In the United Kingdom training falls into four different categories;
REFRESHER - People who have gained a Forklift Training Certificate and need to be brought up to date with new laws and/or regulations.
CONVERSION - People who have been trained on a type of truck recently, and need to start using a different type.
SEMI-EXPERIENCED - People who are competent on a forklift truck, but have never been certificated.
NOVICE - Never been on a Forklift Truck before and never been certificated.
The courses can last for 1 day for a Refresher or a Conversion course, to 5 days for a Novice course. United Kingdom Forklift Instructors are allowed to train a maximum of Three People per day, this does not include classroom work.
In the UK, there are a number of publications dedicated to forklift trucks as well as the materials handling and logistics markets[23].
Some of the most popular are:
Below are the top six manufacturers of the Powered Industrial Trucks market in terms of worldwide sales as of 2008[update].[24]