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 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 themselves in changing modes. Com ...

Etymology

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

etymology Etymology ( ) is the study of the origin and evolution of words—including their constituent units of sound and meaning—across time. In the 21st century a subfield within linguistics, etymology has become a more rigorously scientific study. ...

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

Examples

Human locomotion

A person carrying someone else on their

back The human back, also called the dorsum (: dorsa), 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 c ...

is most commonly seen in the modern day in the form of a

parent A parent is either the progenitor of a child or, in humans, it can refer to a caregiver or legal guardian, generally called an adoptive parent or step-parent. Parents who are progenitors are First-degree relative, first-degree relatives and have ...

carrying an underage

child A child () is a human being between the stages of childbirth, birth and puberty, or between the Development of the human body, developmental period of infancy and puberty. The term may also refer to an unborn human being. In English-speaking ...

, either for travelling or for

children's game This is a list of games that are played by children. Traditional children's games do not include commercial products such as board games but do include games which require props such as hopscotch or marbles (toys go in List of toys unless the t ...

s. It can involve the carrier crawling on hands and knees with the child straddling over the back like riding a horse, or with the carrier standing upright with the child

hug A hug is a form of Affection, endearment, found in virtually all Communities, human communities, in which two or more people put their arms around the neck, back, under the armpits or waists of one another and hold each other closely. If more th ...

ging or cradled behind the back, often with the child's arms leaning over the carrier's

shoulder The human shoulder is made up of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone) as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder m ...

s and legs wrapping around the flanks. Piggybacking may also feature in the context of play or sport, and evidence of this dates back to

Ancient Greece Ancient Greece () was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity (), that comprised a loose collection of culturally and linguistically r ...

where games involving piggyback riding were combined with the requirement of catching or throwing a ball. In the modern era, wife carrying competitions, where the female participants ride on the back of their male partners running the race, are popular in some countries.

Rail

In rail transport, the practice of carrying trailers or

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 ...

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 trucks (US) or bogies (UK) at each end. Occasionally, flat cars designed to carry extra heavy or extra large loads are mounted ...

is referred to as "piggybacking". Early drawings of the Liverpool & Manchester Railway 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. 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 rail vehicle of one

track gauge In rail transport, track gauge is the distance between the two rails of a railway track. All vehicles on a rail network must have Wheelset (rail transport), wheelsets that are compatible with the track gauge. Since many different track gauges ...

can be carried on a flatcar (

transporter wagon A transporter wagon, in railway terminology, is a goods wagon, wagon (International Union of Railways, UIC) or railroad car (US) designed to carry other railway equipment. Normally, it is used to transport equipment of a different rail gauge. ...

or rollbock) of another gauge. In addition, an entire train of coupled cars of one gauge can be carried on continuous rails on a train of flatcars of another gauge. This was achieved, as a temporary expedient, by the Commonwealth Railways on the Marree railway line in South Australia between Telford Cut and

Port Augusta Port Augusta (''Goordnada'' in the revived indigenous Barngarla language) is a coastal city in South Australia about by road from the state capital, Adelaide. Most of the city is on the eastern shores of Spencer Gulf, immediately south of the ...

in the mid-1950s. Japan Railways planned a similar " Train on Train" scheme, but at much higher speeds, to operate from 2016.

Trucking

For semi trucks the trucks can be stacked 4 deep if it is just a day-cab truck and only 3 deep if it has a sleeper-cab. The trucks drive up a ramp or are lifted into place by a tow hook on the front bumper, from a heavy-duty

tow truck A tow truck (also called a wrecker, a breakdown truck, recovery vehicle or a breakdown lorry) is a truck used to move disabled, improperly parked, Vehicle impoundment, impounded, or otherwise indisposed motor vehicles. This may involve recoverin ...

overhead crane An overhead crane, commonly called a bridge crane, is a type of crane found in industrial environments. An overhead crane consists of two parallel rails seated on longitudinal I-beams attached to opposite steel columns by means of brackets. ...

. A saddle is placed on the fifth-wheel, that the front axel of the next truck is attached to, which is called decking. The mirrors are folded in on the trucks being hauled for width requirements and safety. For undecking the trucks, a tow truck or overhead crane is used again. It is typically used to transport newly built or purchased trucks.

Marine

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

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. ...

, 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 bomber aircraft, bombers converted to carry exp ...

s, as well as

midget submarine A midget 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, from which they are launched an ...

s on larger

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

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

Air transport

The 1930s British Short Mayo Composite, 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 seaplane with a hull, allowing it to land on water. It differs from a floatplane in having a fuselage that is purpose-designed for flotation, while floatplanes rely on fuselage-mounted floats for buoyancy. Though ...

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 launch system, 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. ...

was carried on top of specially-modified

Boeing 747 The Boeing 747 is a long-range wide-body aircraft, wide-body airliner designed and manufactured by Boeing Commercial Airplanes in the United States between 1968 and 2023. After the introduction of the Boeing 707, 707 in October 1958, Pan Am ...

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. Both are now retired. ...

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

Space

In space transportation systems, a smaller

satellite A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...

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 c ...

s and

cubesats A CubeSat is a class of small satellite with a form factor of cubes. CubeSats have a mass of no more than per unit,, url=https://static1.squarespace.com/static/5418c831e4b0fa4ecac1bacd/t/5f24997b6deea10cc52bb016/1596234122437/CDS+REV14+2020-07-3 ...

, 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 (also known as orbital revolution) 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 ...

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 battlefield mobility provided by tracks and a powerful engine; ...

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 transporters, which have rubber tires, to the battlefield.

Gallery

File:MBC Ua 235A.JPG, Timber wagon on rollbocks File:20090803 hellenic spirit25.jpg, Trucks on board a ro-ro ship File:South Australian Railways narrow gauge locomotive T232 on broad gauge crocodile car.jpg, A

South Australian Railways South Australian Railways (SAR) was the organisation 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 Australian Natio ...

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 agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

File:Trajekt im Strom.jpg, Bonn–Oberkassel train ferry File:ROLA Kelenfold.JPG, Rolling road File:The Queen Mary's Army Auxiliary Corps during the First World War, France Q11512.jpg, A person being carried piggy-back at the beach (1918) 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