Piggyback (transportation)
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.[1]
Etymology
Piggyback is a corruption of pickaback, which is likely to be a folk etymology alteration of pick pack (1560s), which perhaps is from pick, a dialectal variant of the verb pitch.[2]
Examples
Human locomotion
A person carrying someone else on their
Piggybacking may also feature in the context of play or sport, and evidence of this dates back to
Rail
In rail transport, the practice of carrying trailers or
The rail service provided for trucks which are carried on trains for part of their journey is referred to as a rolling road, or
A railway wagon of one track gauge can be carried on a flat wagon (transporter wagon or rollbock) 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 on the Marree railway line in South Australia between Telford Cut and Port Augusta in the mid-1950s.[8][9] Japan Railways planned a similar "Train on Train" scheme, but at much higher speeds, to operate from 2016.[10]
Marine
Small ships of all kinds can be piggybacked on larger ships. Examples include
Air transport
The 1930s British Short Mayo Composite, in which a smaller, four-engine floatplane aircraft named Mercury was carried aloft on the back of a larger four-engine flying boat 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 was carried on top of specially-modified Boeing 747 Shuttle Carrier Aircraft when the shuttle landed at places other than Kennedy Space Center.
Space
In space transportation systems, a smaller satellite 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 satellites and 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 and having to remain on a similar orbit to that of the big satellite.
Military
The metal caterpillar treads of a tank 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
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Timber wagon on rollbocks
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Trucks on board a ro-ro ship
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A South Australian Railways T class narrow-gauge locomotive on a broad-gauge crocodile car
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Youths playing a ball game, circa 500 B.C.
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Trailers on flatcars in the United States
See also
- Autorack
- Bière–Apples–Morges Railway
- Car carrier trailer
- Car float
- Double-stack rail transport
- Ferry
- Fireman's carry
- Hupac
- Konkan Railway Corporation
- Loading gauge
- Modalohr
- Motorail
- Pichi Richi Railway
- Roadrailer
- Rolling highway
- Roll-on/roll-off
- Structure gauge
- Train ferry
- Two-foot-gauge railways in South Africa
References
- ^ Pearlman, Robert Z. (7 September 2012). "Shuttle Endeavour to get one last piggyback ride across US". NBC News. Retrieved 24 October 2012.
- ^ Harper, Douglas. "piggyback". Online Etymology Dictionary. Retrieved 24 October 2012.
- ^ Gardiner, E. Norman, 'Athletics of the Ancient World', Oxford: OUP, 1967, illustration 209 / facing p. 230
- ^ "The Geography of Transport Systems". Archived from the original on 24 March 2012. Retrieved 11 July 2011.
- ^ "The Train Book" by DK, p23
- ^ Piggback: The Trailer Train story Railway Age May 25, 1964 page 44
- ISBN 978-0-300-15109-1.
- Adelaide Advertiser
- ^ Complete narrow-gauge trains on standard-gauge wagons Railway Gazette International September 9, 1955 pages 305-308
- ^ 独自の研究開発 人と物流 高速化に活路 [Own R&D leading to increased speed]. Hokkaido Shimbun (in Japanese). Japan: The Hokkaido Shimbun Press. 20 December 2008. Retrieved 30 September 2009.
- ^ "Mine-Sweepers By "Piggyback"", The Mercury (Hobart): 5, 5 June 1951