Piggyback transportation refers to the transportation of goods where one transportation unit is carried on the back of something else. It is a specialised form of intermodal transportation and

combined transport Combined transport is a form of Intermodal freight transport, intermodal transport, which is the movement of goods in one and the same loading unit or road vehicle, using successively two or more modes of transport without handling the goods thems ...

Etymology

''Piggyback'' is a corruption of ''pickaback'', which is likely to be a folk

etymology Etymology ()The New Oxford Dictionary of English (1998) – p. 633 "Etymology /ˌɛtɪˈmɒlədʒi/ the study of the class in words and the way their meanings have changed throughout time". is the study of the history of the Phonological chan ...

alteration of ''pick pack'' (1560s), which perhaps is from ''pick'', a dialectal variant of the verb ''pitch''.

Examples

Rail

In rail transport, the practice of carrying trailers or

semi-trailer A semi-trailer is a trailer without a front axle. In the United States, the term is also used to refer to the combination of a truck and a semi-trailer; a tractor-trailer. A large proportion of a semi-trailer's weight is supported by a tracto ...

s in a train atop a

flatcar A flatcar (US) (also flat car, or flatbed) is a piece of rolling stock that consists of an open, flat deck mounted on a pair of trucks (US) or bogies (UK), one at each end containing four or six wheels. Occasionally, flat cars designed to carry ...

is referred to as "piggybacking". Early drawings of the

Liverpool & Manchester Railway The Liverpool and Manchester Railway (L&MR) was the first inter-city railway in the world. It opened on 15 September 1830 between the Lancashire towns of Liverpool and Manchester in England. It was also the first railway to rely exclusively ...

c1830 show road coaches being piggybacked on railway flat wagons. The rail service provided for trucks which are carried on trains for part of their journey is referred to as a rolling road, or

rolling highway In rail transportation, a rolling highway or rolling road is a form of combined transport involving the conveying of road trucks by rail, referred to as Ro-La trains. The concept is a form of piggyback transportation. The technical challeng ...

. A related transportation method is the rail transport of

s, without road tractors, sometimes referred to as "trailer on flatcar (TOFC)". In the United States, TOFC traffic grew from 1% of freight in 1957 to 5% in 1964 and 15% in 1986. A railway wagon of one

track gauge In rail transport, track gauge (in American English, alternatively track gage) is the distance between the two rails of a railway track. All vehicles on a rail network must have wheelsets that are compatible with the track gauge. Since many d ...

can be carried on a flat wagon (

transporter wagon A transporter wagon, in railway terminology, is a wagon ( UIC) or railroad car (US) designed to carry other railway equipment. Normally, it is used to transport equipment of a different rail gauge. In most cases, a transporter wagon is a n ...

rollbock ''Rollbocks'', sometimes called transporter trailers, are narrow gauge railway trucks or bogies that allow a standard gauge wagon to 'piggyback' on a narrow-gauge line. The Vevey system enables a coupled train of standard gauge wagons to be autom ...

) of another gauge. In addition, an entire train of coupled wagons of one gauge can be carried on continuous rails on a train of flat wagons of another gauge. This was achieved by the

Commonwealth Railways The Commonwealth Railways were established in 1917 by the Government of Australia with the Commonwealth Railways Act to administer the Trans-Australia and Port Augusta to Darwin railways. It was absorbed into Australian National in 1975. O ...

on the

Marree railway line The Marree railway line is located in the Australian state of South Australia. History As a result of the opening up of the Leigh Creek Coalfield in the late 1940s and capacity restrictions on the existing narrow gauge Central Australia Railwa ...

in South Australia between

Telford Cut Telford Cut was an open-cut coal mine, now closed, in the Leigh Creek Coalfield in South Australia. For the 72 years between its opening in 1943 and its closure, the mine supplied sub-bituminous coal to fire power stations first in Adelaide the ...

and

Port Augusta Port Augusta is a small city in South Australia. Formerly a port, seaport, it is now a road traffic and Junction (rail), railway junction city mainly located on the east coast of the Spencer Gulf immediately south of the gulf's head and about ...

in the mid-1950s. Japan Railways planned a similar "

Train on Train __NOTOC__ is a concept for piggybacking (that is, carrying narrow-gauge wagons on broader-gauge flatwagons) by the trainload rather than one wagon at a time. The need arose when Japan's Hokkaido Railway Company (JR Hokkaido) was planning f ...

" scheme, but at much higher speeds, to operate from 2016.

Marine

Small ships of all kinds can be piggybacked on larger ships. Examples include

lifeboat Lifeboat may refer to: Rescue vessels * Lifeboat (shipboard), a small craft aboard a ship to allow for emergency escape * Lifeboat (rescue), a boat designed for sea rescues * Airborne lifeboat, an air-dropped boat used to save downed airmen ...

landing craft Landing craft are small and medium seagoing watercraft, such as boats and barges, used to convey a landing force (infantry and vehicles) from the sea to the shore during an amphibious assault. The term excludes landing ships, which are larger. Pr ...

, and

minesweepers A minesweeper is a small warship designed to remove or detonate naval mines. Using various mechanisms intended to counter the threat posed by naval mines, minesweepers keep waterways clear for safe shipping. History The earliest known usage of ...

mothership A mother ship, mothership or mother-ship is a large vehicle that leads, serves, or carries other smaller vehicles. A mother ship may be a maritime ship, aircraft, or spacecraft. Examples include bombers converted to carry experimental airc ...

s, as well as

midget submarine A midget submarine (also called a mini submarine) is any submarine under 150 tons, typically operated by a crew of one or two but sometimes up to six or nine, with little or no on-board living accommodation. They normally work with mother ships, ...

s on larger

submarine A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...

s, such as those used for the 1942 Japanese submarine attack on Sydney.

Air transport

The 1930s British

Short Mayo Composite The Short Mayo Composite was a piggy-back long-range seaplane/flying boat combination produced by Short Brothers to provide a reliable long-range air transport service to North America and, potentially, to other distant places in the Britis ...

, in which a smaller, four-engine

floatplane A floatplane is a type of seaplane with one or more slender floats mounted under the fuselage to provide buoyancy. By contrast, a flying boat uses its fuselage for buoyancy. Either type of seaplane may also have landing gear suitable for land, ...

aircraft named Mercury was carried aloft on the back of a larger four-engine

flying boat A flying boat is a type of fixed-winged seaplane with a hull, allowing it to land on water. It differs from a floatplane in that a flying boat's fuselage is purpose-designed for floatation and contains a hull, while floatplanes rely on fusela ...

named Maia, enabled the Mercury to achieve a greater range than would have been possible had it taken off under its own power. The American

Space Shuttle The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program na ...

was carried on top of specially-modified

Boeing 747 The Boeing 747 is a large, long-range wide-body airliner designed and manufactured by Boeing Commercial Airplanes in the United States between 1968 and 2022. After introducing the 707 in October 1958, Pan Am wanted a jet times its size, t ...

Shuttle Carrier Aircraft The Shuttle Carrier Aircraft (SCA) are two extensively modified Boeing 747 airliners that NASA used to transport Space Shuttle orbiters. One (N905NA) is a 747-100 model, while the other (N911NA) is a short range 747-100SR. The SCAs were used t ...

when the shuttle landed at places other than Kennedy Space Center.

Space

In space transportation systems, a smaller

satellite A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope ...

that is carried as a secondary payload on a launch is said to be "piggybacked" on the main launch. It is often the case of

small satellite A small satellite, miniaturized satellite, or smallsat is a satellite of low mass and size, usually under . While all such satellites can be referred to as "small", different classifications are used to categorize them based on mass. Satellites ca ...

s and

cubesats A CubeSat is a class of miniaturized satellite based around a form factor consisting of cubes. CubeSats have a mass of no more than per unit, and often use commercial off-the-shelf (COTS) components for their electronics and structure. CubeSats ...

, since they can not usually afford accessing space on a dedicated launch and they choose instead to take profit of the remaining payload capacity in a big satellite launch. However, this is usually at the cost of not being able to fly to their desired

orbit In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as a p ...

and having to remain on a similar orbit to that of the big satellite.

Military

The metal caterpillar treads of a

tank A tank is an armoured fighting vehicle intended as a primary offensive weapon in front-line ground combat. Tank designs are a balance of heavy firepower, strong armour, and good battlefield mobility provided by tracks and a powerful engin ...

wear out quickly when travelling long distances on ordinary roads. Also, tracked vehicles seriously damage the tarmac layer of ordinary roads (unless the caterpillar treads are specially fitted with rubber pads to avoid this). It is therefore necessary to provide

tank transporter A tank transporter is a combination of a heavy tractor unit and a mating full trailer or semi-trailer (typically of the "lowboy" type), used for transporting tanks and other armoured fighting vehicles. Some also function as tank recovery vehi ...

s, which have rubber tires, to the battlefield.

Human locomotion

A person carrying someone else on their

back The human back, also called the dorsum, is the large posterior area of the human body, rising from the top of the buttocks to the back of the neck. It is the surface of the body opposite from the chest and the abdomen. The vertebral column runs ...

is most commonly seen in the modern day in the form of a parent carrying a child. It may also feature in the context of play or sport, and evidence of this dates back to

ancient Greece Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity ( AD 600), that comprised a loose collection of cult ...

where games involving piggyback riding were combined with the requirement of catching or throwing a ball.Gardiner, E. Norman, 'Athletics of the Ancient World', Oxford: OUP, 1967, illustration 209 / facing p. 230

Gallery

File:001015 gauge buster.jpg,

Transporter wagon A transporter wagon, in railway terminology, is a wagon ( UIC) or railroad car (US) designed to carry other railway equipment. Normally, it is used to transport equipment of a different rail gauge. In most cases, a transporter wagon is a n ...

File:MBC Ua 235A.JPG, Timber wagon on

s File:Crocodile Waggon transports locomotive bodily.gif, "Crocodile Waggon" of GNR 1907 File:South Australian Railways narrow gauge locomotive T232 on broad gauge crocodile car.jpg, A

South Australian Railways South Australian Railways (SAR) was the statutory corporation through which the Government of South Australia built and operated railways in South Australia from 1854 until March 1978, when its non-urban railways were incorporated into Austr ...

T class narrow-gauge locomotive on a broad-gauge crocodile car File:Atlantis on Shuttle Carrier Aircraft.jpg, The Space Shuttle ''Atlantis'' atop a

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

File:Trajekt im Strom.jpg,

Bonn–Oberkassel train ferry The Bonn–Oberkassel train ferry was a German train ferry operated by the Rhenish Railway Company from 1870 to connect its East Rhine Railway, right and West Rhine Railway, left Rhine railways. It was the last of six train ferries to begin operat ...

File:ROLA Kelenfold.JPG,

Rolling road Maryland Route 166 (MD 166) is a state highway in the U.S. state of Maryland. The state highway runs from Interstate 195 (I-195) in Arbutus north to MD 144 in Catonsville. MD 166 consists of two sections: a short freeway section that serves ...

File:Maia and Mercury, August 1938 (Our Generation, 1938).jpg,

just before the first trans-Atlantic flight, August 1938 File:Handball pick-a-back Ancient Greece.jpg, Youths playing a ball game, circa 500 B.C. File:Tsukioka Yoshitoshi, Japanese - The Demon Omatsu Murders Shirosaburō in the Ford - Google Art Project.jpg, A man killed by a woman when carrying her piggyback in the river. File:Piggyback by the trainload rather than one wagon at a time is more efficient.gif, Piggyback by trainload concept File:The End (for now) (6265367138).jpg, Trailers on flatcars in the United States

References

External links

Double Piggyback p120

{{DEFAULTSORT:Piggy-Back (Transportation) Transport operations Intermodal transport