An echelon formation () is a (usually

military A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. It is typically authorized and maintained by a sovereign state, with its members identifiable by their distin ...

) formation in which its units are arranged diagonally. Each unit is stationed behind and to the right (a "right echelon"), or behind and to the left ("left echelon"), of the unit ahead. The name of the formation comes from the French word échelon, meaning a rung of a ladder, which describes the shape that this formation has when viewed from above or below.

Military formation

Use of the formation dates back to ancient

infantry Infantry is a military specialization which engages in ground combat on foot. Infantry generally consists of light infantry, mountain infantry, motorized infantry & mechanized infantry, airborne infantry, air assault infantry, and mari ...

and

cavalry Historically, cavalry (from the French word ''cavalerie'', itself derived from "cheval" meaning "horse") are soldiers or warriors who fight mounted on horseback. Cavalry were the most mobile of the combat arms, operating as light cavalry in ...

warfare, as an alternative to

column A column or pillar in architecture and structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below. In other words, a column is a compression member. ...

, line-abreast, or

phalanx The phalanx ( grc, φάλαγξ; plural phalanxes or phalanges, , ) was a rectangular mass military formation, usually composed entirely of heavy infantry armed with spears, pikes, sarissas, or similar pole weapons. The term is particularly ...

(box) formations. One of its earliest uses was at the

Battle of Leuctra The Battle of Leuctra ( grc-gre, Λεῦκτρα, ) was a battle fought on 6 July 371 BC between the Boeotians led by the Thebans, and the Spartans along with their allies amidst the post-Corinthian War conflict. The battle took place in the vicin ...

, when the

Thebans Thebes (; ell, Θήβα, ''Thíva'' ; grc, Θῆβαι, ''Thêbai'' .) is a city in Boeotia, Central Greece. It played an important role in Greek myths, as the site of the stories of Cadmus, Oedipus, Dionysus, Heracles and others. Archaeologic ...

attacked the Spartan right with a column 48 men deep while their weaker center and right were repelled. The echelon formation may have been used by

Hannibal Hannibal (; xpu, 𐤇𐤍𐤁𐤏𐤋, ''Ḥannibaʿl''; 247 – between 183 and 181 BC) was a Carthaginian general and statesman who commanded the forces of Carthage in their battle against the Roman Republic during the Second Pun ...

at the Battle of Cannae,

Alexander the Great Alexander III of Macedon ( grc, Ἀλέξανδρος, Alexandros; 20/21 July 356 BC – 10/11 June 323 BC), commonly known as Alexander the Great, was a king of the ancient Greek kingdom of Macedon. He succeeded his father Philip II to t ...

at the

Battle of Gaugamela The Battle of Gaugamela (; grc, Γαυγάμηλα, translit=Gaugámela), also called the Battle of Arbela ( grc, Ἄρβηλα, translit=Árbela), took place in 331 BC between the forces of the Army of Macedon under Alexander the Great ...

Frederick II of Prussia Frederick II (german: Friedrich II.; 24 January 171217 August 1786) was King in Prussia from 1740 until 1772, and King of Prussia from 1772 until his death in 1786. His most significant accomplishments include his military successes in the Sil ...

, and the Confederate army at the

Battle of Gettysburg The Battle of Gettysburg () was fought July 1–3, 1863, in and around the town of Gettysburg, Pennsylvania, Gettysburg, Pennsylvania, by Union Army, Union and Confederate States Army, Confederate forces during the American Civil War. In t ...

The tactic still persists and is regularly employed by all branches of the modern armed forces. Tactically, echelon formations are used because of the excellent range of vision offered to each participant in the formation. In particular, it is commonly employed by armored cavalry because of the large, overlapping fields of fire that it gives to each

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 engi ...

in the formation, and by combat aircraft, allowing them to communicate visually and maneuver as a single unit. USAF_Fighter_School_Acrojets_demonstration_team_-_1950

USAF_Fighter_School_Acrojets_demonstration_team_-_1950

"Echeloning" is the name of a tactic in use by the United Kingdom's armed forces, mainly the

. It consists of using a

company A company, abbreviated as co., is a legal entity representing an association of people, whether natural, legal or a mixture of both, with a specific objective. Company members share a common purpose and unite to achieve specific, declared go ...

to attack a set of positions. Once the first platoon in the company has reached its limit of advance (ammunition has been expended,

fatigue Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...

has become high, or casualties are mounting) another

platoon A platoon is a military unit typically composed of two or more squads, sections, or patrols. Platoon organization varies depending on the country and the branch, but a platoon can be composed of 50 people, although specific platoons may range ...

"echelons through" it to continue onto the next position. The tactic is similar to

leapfrogging Leapfrogging is a concept used in many domains of the economics and business fields, and was originally developed in the area of industrial organization and economic growth. The main idea behind the concept of leapfrogging is that small and incre ...

. Echelon formations are also commonly used by civic or

riot police Riot police are police who are organized, deployed, trained or equipped to confront crowds, protests or riots. Riot police may be regular police who act in the role of riot police in particular situations or they may be separate units organized ...

to move crowds either to the left or right. ''En echelon'' is also used for a type of arrangement of gun turrets on ships: see .

Derived meanings

The name has been adopted by the

birdwatching Birdwatching, or birding, is the observing of birds, either as a recreational activity or as a form of citizen science. A birdwatcher may observe by using their naked eye, by using a visual enhancement device like binoculars or a telescope, by ...

community to describe the familiar V-shaped formations of flights of

geese A goose ( : geese) is a bird of any of several waterfowl species in the family Anatidae. This group comprises the genera '' Anser'' (the grey geese and white geese) and '' Branta'' (the black geese). Some other birds, mostly related to the sh ...

duck Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a form ...

s and other

migratory birds Bird migration is the regular seasonal movement, often north and south along a flyway, between breeding and wintering grounds. Many species of bird migrate. Migration carries high costs in predation and mortality, including from hunting b ...

, though this more symmetric formation is more strictly defined as a

V formation A V formation is the symmetric V-shaped flight formation of flights of geese, swans, ducks, and other migratory birds, improving their energy efficiency. Usually, large birds fly in this formation since smaller birds create more complex wind cu ...

. In geology, ''en echelon'' describes an arrangement where a set of short linear features overlap or are staggered in a line that runs obliquely to the strike of the individual features.

Echelon faults ECHELON, originally a secret government code name, is a surveillance program (signals intelligence/SIGINT collection and analysis network) operated by the five signatory states to the UKUSA Security Agreement:Given the 5 dialects that use ...

and

en echelon veins In structural geology, en échelon veins, "en échelon gash fractures" or "Tiger Stripes" are structures within rock caused by noncoaxial shear. En echelon veins can be parallel or subparallel, closely-spaced, overlapping or step-like minor st ...

are examples. In sheet material response to shear stress it is typical for a series of echelon cracks to form. This is commonly seen in asphalt roads subject to shear stress imposed by aseismic fault creep. In mathematics, the term

row echelon form In linear algebra, a matrix is in echelon form if it has the shape resulting from a Gaussian elimination. A matrix being in row echelon form means that Gaussian elimination has operated on the rows, and column echelon form means that Gaussian el ...

refers to a kind of

matrix Matrix most commonly refers to: * ''The Matrix'' (franchise), an American media franchise ** ''The Matrix'', a 1999 science-fiction action film ** "The Matrix", a fictional setting, a virtual reality environment, within ''The Matrix'' (franchis ...

where the non-zero elements are shaped in an echelon-like manner. In

road bicycle racing Road bicycle racing is the cycle sport discipline of road cycling, held primarily on paved roads. Road racing is the most popular professional form of bicycle racing, in terms of numbers of competitors, events and spectators. The two most common ...

, an echelon formation is a diagonal line of racers, which allows cooperative drafting in crosswinds.

References

{{reflist Tactical formations Ornithology Structural geology