Tandem, or in tandem, is an arrangement in which a team of machines, animals or people are lined up one behind another, all facing in the same direction. The original use of the term in English was in ''tandem harness'', which is used for two or more

draft horse A draft horse (US), draught horse (UK) or dray horse (from the Old English ''dragan'' meaning "to draw or haul"; compare Dutch ''dragen'' and German ''tragen'' meaning "to carry" and Danish ''drage'' meaning "to draw" or "to fare"), less o ...

s, or other

draft animal A working animal is an animal, usually domesticated, that is kept by humans and trained to perform tasks instead of being slaughtered to harvest animal products. Some are used for their physical strength (e.g. oxen and draft horses) or fo ...

s, harnessed in a single line one behind another, as opposed to a pair, harnessed side by side, or a team of several pairs. The tandem harness allows additional animals to provide pulling power for a vehicle designed for a single animal. The English word ''tandem'' derives from the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power ...

adverb An adverb is a word or an expression that generally modifies a verb, adjective, another adverb, determiner, clause, preposition, or sentence. Adverbs typically express manner, place, time, frequency, degree, level of certainty, etc., answering q ...

, meaning ''at length'' or ''finally''. It is a

word play Word play or wordplay (also: play-on-words) is a literary technique and a form of wit in which words used become the main subject of the work, primarily for the purpose of intended effect or amusement. Examples of word play include puns, pho ...

, using the Latin phrase (referring to time, not position) for English "at length, lengthwise". Tandem bicycles are named for their tandem seating, a more common arrangement than side-by-side " sociable" seating. ''Tandem'' can also be used more generally to refer to any group of persons or objects working together, not necessarily in line.

Automobiles

The Messerschmitt KR200 was an example of a very small automobile that used tandem seating. A tandem arrangement may also be used for cars

parked ''Parked'' is a 2011 Irish drama film written by Ciaran Creagh and directed by Darragh Byrne about homelessness, friendship, and the will to survive adversity, whilst still retaining poise. It premiered at the 2010 Torino Film Festival Plot Having ...

in a residential garage.

Trucks

In heavy trucks tandem refers to two closely spaced axles. Legally defined by the distance between the axles (up to in the European Union, in the United States), mechanically there are many configurations. Either or both axles may be powered, and often interact with each other. In the United States, both axles are typically powered and equalized; in the European Union, one axle is typically unpowered, and can often be adjusted to load, and even raised off the ground, turning a tandem into a single-

axle An axle or axletree is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, beari ...

Aviation

The two seating configurations for trainer, night and all-weather interceptor or attack aircraft are pilot and instructor side by side or in tandem. Usually, the pilot is in front and the instructor behind. In attack helicopters, sometimes the pilot sits in back with the weapons operator in front for better view to aim weapons, as the Bell AH-1 Cobra was a tandem cockpit redesign which produced a much slimmer profile than the

Bell UH-1 Iroquois The Bell UH-1 Iroquois (nicknamed "Huey") is a utility military helicopter designed and produced by the American aerospace company Bell Helicopter. It is the first member of the prolific Huey family, as well as the first turbine-powered hel ...

on which it was based. Attack aircraft and all-weather interceptors often use a second crew member to operate avionics such as radar, or as a second pilot. Bombers such as the

Convair B-58 Hustler The Convair B-58 Hustler, designed and produced by American aircraft manufacturer Convair, was the first operational bomber capable of Mach 2 flight. The B-58 was developed during the 1950s for the United States Air Force (USAF) Strategic Air ...

seated three crew members in tandem. A common engineering adaptation is to lengthen the cockpit or fuselage to create a trainer with tandem seating from a single-seater aircraft.

Side-by-side seating

An alternative configuration is side-by-side seating, which is common in civil aircraft of all sizes,

trainers Sneakers (also called trainers, athletic shoes, tennis shoes, gym shoes, kicks, sport shoes, flats, running shoes, or runners) are shoes primarily designed for sports or other forms of physical exercise, but which are now also widely used fo ...

and large military aircraft, but less so in high performance jets and gliders where drag reduction is paramount. The

Boeing B-47 Stratojet The Boeing B-47 Stratojet (Boeing company designation Model 450) is a retired American long- range, six-engined, turbojet-powered strategic bomber designed to fly at high subsonic speed and at high altitude to avoid enemy interceptor aircraf ...

and Boeing XB-52 bombers used fighter-style tandem seating, but the final

B-52 The Boeing B-52 Stratofortress is an American long-range, subsonic aircraft, subsonic, jet-powered strategic bomber. The B-52 was designed and built by Boeing, which has continued to provide support and upgrades. It has been operated by the ...

bomber series used a conventional side-by-side cockpit. The

Grumman A-6 Intruder The Grumman A-6 Intruder is an American twinjet all-weather attack aircraft developed and manufactured by American aircraft company Grumman Aerospace and operated by the U.S. Navy and U.S. Marine Corps. It was designed in response to a 195 ...

General Dynamics F-111 Aardvark The General Dynamics F-111 Aardvark is a retired supersonic, medium-range, Multirole combat aircraft, multirole combat aircraft. Production variants of the F-111 had roles that included attack aircraft, ground attack (e.g. Air interdiction, i ...

Sukhoi Su-24 The Sukhoi Su-24 ( NATO reporting name: Fencer) is a supersonic, all-weather attack aircraft developed in the Soviet Union. The aircraft has a variable-sweep wing, twin-engines and a side-by-side seating arrangement for its crew of two. It ...

or the

Sukhoi Su-34 The Sukhoi Su-34 (russian: Сухой Су-34; NATO reporting name: Fullback) is a Soviet-origin Russian twin-engine, twin-seat, all-weather supersonic medium-range fighter-bomber/ strike aircraft. It first flew in 1990, intended for the Sov ...

are examples of combat aircraft that use this configuration. For training aircraft, it has the advantage that pilot and instructor can see each other's actions, allowing the pilot to learn from the instructor and the instructor to correct the student pilot. The tandem configuration has the advantage of being closer to the normal working environment that a fast jet pilot is likely to encounter. In some cases, such as the

Northrop Grumman EA-6B Prowler The Northrop Grumman (formerly Grumman) EA-6B Prowler is a twin-engine, four-seat, mid-wing electronic-warfare aircraft derived from the A-6 Intruder airframe. The EA-6A was the initial electronic warfare version of the A-6 used by the United ...

, a two-place aircraft can be lengthened into a four-place aircraft. Also, a single seat cockpit can be redesigned into a side-by-side arrangement in the case of the

Douglas A-1 Skyraider The Douglas A-1 Skyraider (formerly known as the AD Skyraider) is an American single-seat attack aircraft in service from 1946 to the early 1980s. The Skyraider had an unusually long career, remaining in front-line service well into the Jet Age ...

, TF-102 trainer or the

Hawker Hunter The Hawker Hunter is a transonic British jet propulsion, jet-powered fighter aircraft that was developed by Hawker Aircraft for the Royal Air Force (RAF) during the late 1940s and early 1950s. It was designed to take advantage of the newly dev ...

training versions.

Animals

During mating among

odonata Odonata is an order of flying insects that includes the dragonflies and damselflies. Members of the group first appeared during the Triassic, though members of their total group, Odonatoptera, first appeared in Late Carboniferous. The two co ...

( dragonflies and damselflies), a male uses claspers at the end of his

abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the tors ...

to grab a female between the

head A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may no ...

and

thorax The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the ...

, forming a tandem. The pair may take flight while in tandem. Argia moesta-tandem.jpg, Powdered Dancers in tandem Tramea lacerata-flying tandem flight.jpg, Black saddlebags tandem flight

References

External links

{{wiktionary
Clipart.com Closeup , Royalty-Free Image of tandem carriage horses harness coach driver whip
Illustration.

Museum Victoria (Australia) official site; illustration. Carriages Horse driving

Animal-powered vehicles {{Cat main, Horse-drawn vehicle This category is to list all animal-powered vehicles. Animal-powered transport Vehicles by fuel ...

Real object ordering Seating