An articulated vehicle is a vehicle which has a permanent or semi-permanent coupling in its construction. This coupling works as a large
pivot joint
In animal anatomy, a pivot joint (trochoid joint, rotary joint or lateral ginglymus) is a type of synovial joint whose movement axis is parallel to the long axis of the proximal bone, which typically has a convex articular surface.
According ...
, allowing it to bend and turn more sharply. There are many kinds, from
heavy equipment
Heavy equipment, heavy machinery, earthmovers, construction vehicles, or construction equipment, refers to heavy-duty vehicles specially designed to execute construction tasks, most frequently involving earthwork operations or other large con ...
to
buses
A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a motor vehicle that carries significantly more passengers than an average car or van, but fewer than the average rail transport. It is most commonly used ...
,
tram
A tram (also known as a streetcar or trolley in Canada and the United States) is an urban rail transit in which Rolling stock, vehicles, whether individual railcars or multiple-unit trains, run on tramway tracks on urban public streets; some ...
s and
trains
A train (from Old French , from Latin">-4; we might wonder whether there's a point at which it's appropriate to talk of the beginnings of French, that is, when it wa ... , from Latin , "to pull, to draw") is a series of connected vehicles th ...
.
Steam locomotives were sometimes articulated so the driving wheels could pivot around corners.
In a broader sense, any vehicle towing a
trailer (including a
semi-trailer
A semi-trailer is a trailer (vehicle), trailer without a front axle. The combination of a semi-trailer and a tractor truck is called a ''semi-trailer truck'' (also known simply as a "semi-trailer", "tractor trailer", or "semi" in the United Sta ...
) could be described as articulated (which comes from the
Latin
Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
word ''articulus'', "small joint"). In the UK, an ''articulated lorry'' is the combination of a
tractor
A tractor is an engineering vehicle specifically designed to deliver a high tractive effort (or torque) at slow speeds, for the purposes of hauling a Trailer (vehicle), trailer or machinery such as that used in agriculture, mining or constructio ...
and a trailer, abbreviated to "artic". In the US, it is called a
semi-trailer truck
A semi-trailer truck (also known by a wide variety of other terms – see below) is the combination of a tractor unit and one or more semi-trailers to carry freight. A semi-trailer attaches to the tractor with a type of hitch called ...
, tractor-trailer or semi-truck and is not necessarily considered articulated.
Types
Buses
Buses are articulated to allow for a much longer bus that can still navigate within the
turning radius of a normal bus. Most buses have one articulation, but some
have two.
Trucks
In the UK,
tractor unit
A tractor unit, also known as a truck unit, lorry unit, power unit, prime mover, ten-wheeler, semi-tractor, semi-truck, semi-lorry, tractor cab, truck cab, lorry cab, big rig tractor, big rig truck or big rig lorry or simply a tractor, truck, ...
and trailer combinations are referred to as
articulated lorries, or "artics".
Trains and rail
Many train cars are made with articulated connections, sharing a common
truck
A truck or lorry is a motor vehicle designed to transport freight, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construct ...
between two cars. This reduces costs, weight, vibration and noise; and also enables higher speed running. One of the first examples of articulated railway carriages were used by the
London & North Eastern Railway (LNER) in
Great Britain
Great Britain is an island in the North Atlantic Ocean off the north-west coast of continental Europe, consisting of the countries England, Scotland, and Wales. With an area of , it is the largest of the British Isles, the List of European ...
on its London Suburban Trains in the mid-1920s; this rolling stock was designed by
Nigel Gresley
Sir Herbert Nigel Gresley (19 June 1876 – 5 April 1941) was a British railway engineer. He was one of Britain's most famous steam locomotive engineers, who rose to become Chief Mechanical Engineer (CME) of the London and North Eastern Rail ...
and built at the LNER's
Doncaster Works
Doncaster Railway Works is a railway workshop located in Doncaster, England.
Also referred to as ''The Plant'', it was established by the Great Northern Railway (England), Great Northern Railway in 1853, replacing the previous works in Boston, ...
. The four set "Quad-arts" were one of the very earliest articulated trains, this innovation was to save space. Although not the same as modern high speed trains where all the carriages share common
bogie
A bogie ( ) (or truck in North American English) comprises two or more Wheelset (rail transport), wheelsets (two Railroad wheel, wheels on an axle), in a frame, attached under a vehicle by a pivot. Bogies take various forms in various modes ...
s, they are an early form of the now more common design.
Tram
A tram (also known as a streetcar or trolley in Canada and the United States) is an urban rail transit in which Rolling stock, vehicles, whether individual railcars or multiple-unit trains, run on tramway tracks on urban public streets; some ...
s and
light rail
Light rail (or light rail transit, abbreviated to LRT) is a form of passenger urban rail transit that uses rolling stock derived from tram technology National Conference of the Transportation Research Board while also having some features from ...
vehicles have been made with articulated designs since the 1950s. Articulated trams, were invented and first used by the
Boston Elevated Railway
The Boston Elevated Railway (BERy) was a Tram, streetcar and rapid transit railroad operated on, above, and below, the streets of Boston, Massachusetts and surrounding communities. Founded in 1894, it eventually acquired the West End Street R ...
in 1912–13.
This was instead of using trailers or multiple units, which had been attempted in the early 1900s. The articulated design allows passengers (and fare inspectors) to move the entire length of the vehicle, whether stopped or in motion.
File:DTTX 724681 20050529 IL Rochelle.jpg, Articulated well cars with containers
File:Gresley Quad Art Set at Sheringham station - geograph.org.uk - 1386710.jpg, London and North Eastern Railway
The London and North Eastern Railway (LNER) was the second largest (after London, Midland and Scottish Railway, LMS) of the "Big Four (British railway companies), Big Four" railway companies created by the Railways Act 1921 in Britain. It ope ...
articulated train from 1924
Heavy equipment
Front loaders,
grader
A grader, also commonly referred to as a road grader, motor grader, or simply blade, is a form of heavy equipment with a long blade used to create a flat surface during Grading (engineering), grading. Although the earliest models were towed b ...
s,
dump truck
A dump truck, known also as a dumping truck, dump lorry or dumper lorry or a dumper for short, is used for transporting materials (such as dirt, gravel, or demolition waste) for construction as well as coal. A typical dump truck is equipped ...
s and other vehicles have been made with articulated joints to greatly reduce their
turning radius and make a single track when making a turn in a soft surface like mud or sand. (the rear wheels follow the front wheel trajectory)
The most common models of
articulated haulers are
Caterpillar
Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths).
As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder ...
,
Volvo
The Volvo Group (; legally Aktiebolaget Volvo, shortened to AB Volvo, stylized as VOLVO) is a Swedish multinational manufacturing corporation headquartered in Gothenburg. While its core activity is the production, distribution and sale of truck ...
, and
Terex trucks ranging in tonnage from 25 to 40 ton.
Military vehicles
Some military vehicles, including the
United States Armed Forces
The United States Armed Forces are the Military, military forces of the United States. U.S. United States Code, federal law names six armed forces: the United States Army, Army, United States Marine Corps, Marine Corps, United States Navy, Na ...
'
M561 Gama Goat and the Swedish
Bandvagn 206 were engineered with an articulated body for rough terrain capability.
Watercraft
The "integral unit", or
"Integrated Tug and Barge" (ITB), comprises specially designed vessels that lock together in such a rigid and strong method as to be certified as such by authorities (classification societies) such as the
American Bureau of Shipping
The American Bureau of Shipping (ABS) is an American maritime classification society established in 1862. Its stated mission is to promote the security of life, property, and the natural environment, primarily through the development and verific ...
,
Lloyd's Register of Shipping
Lloyd's Register Group Limited, trading as Lloyd's Register (LR), is a technical and professional services organisation and a maritime classification society, wholly owned by the Lloyd’s Register Foundation, a UK charity dedicated to research ...
,
Indian Register of Shipping
Indian Register of Shipping (IRClass) is an internationally recognised, independent ship classification society, founded in India in 1975. It is a public limited company incorporated under Section 25 of the Indian Companies Act 1956 (Section 8 o ...
,
Det Norske Veritas
Det Norske Veritas (DNV), formerly DNV GL, is an international accredited registrar and classification society headquartered in Høvik, Norway. DNV provides services for several industries, including maritime, oil and gas, renewable energy, e ...
or several others. These units stay combined under virtually any sea conditions and the "tugs" usually have poor sea-keeping designs for navigation without their "barges" attached. Vessels in this category are legally considered to be ships rather than tugboats and barges must be staffed accordingly. These vessels must show navigation lights compliant with those required of ships rather than those required of tugboats and vessels under tow.
"Articulated Tug and Barge" (ATB) units also utilize mechanical means to connect to their barges. ATBs generally utilize Intercon and
Bludworth
{{unreferenced, date=March 2011
The Bludworth articulated tug and barge (ATB) ocean tug barge connection system was developed by Richard and Robert Bludworth during the 1960s.
The first Bludworth articulated tug barge unit was the ocean Liquef ...
connecting systems. ATBs are generally staffed as a large tugboat, with between seven and nine crew members. The typical American ATB operating on the east coast, per custom, displays navigational lights of a towing vessel pushing ahead, as described in the '72 COLREGS.
See also
*
Dolly (trailer)
A dolly is an unpowered vehicle designed for tow hitch, connection to a tractor unit, truck or prime mover vehicle with strong traction power.
United States Classification by axle configuration
There are several types of dolly Bogie#Articu ...
*
Fifth wheel coupling
*
Jackknifing
*
Road train
A road train, also known as a land train or long combination vehicle (LCV) is a semi-trailer used to move road freight more efficiently than single-trailer semi-trailers. It consists of one semi-trailer or more connected together with or wit ...
*
Semi-trailer
A semi-trailer is a trailer (vehicle), trailer without a front axle. The combination of a semi-trailer and a tractor truck is called a ''semi-trailer truck'' (also known simply as a "semi-trailer", "tractor trailer", or "semi" in the United Sta ...
*
Semi-trailer truck
A semi-trailer truck (also known by a wide variety of other terms – see below) is the combination of a tractor unit and one or more semi-trailers to carry freight. A semi-trailer attaches to the tractor with a type of hitch called ...
*
Slack action
In railroading, slack action is the amount of free movement of one car before it transmits its motion to an adjoining coupled car. This free movement results from the fact that in railroad practice, cars are loosely coupled, and the coupling is o ...
*
Trackless train
*
Trailer arrangements
*
Trailer bus
References
{{Authority control
Automotive technologies
Trucks