Yard

The yard (abbreviation: yd) is an English unit of length, in both the British imperial and US customary systems of measurement, that comprises 3 feet or 36 inches. It is by international agreement in 1959 standardized as exactly 0.9144 meters. A metal yardstick originally formed the physical standard from which all other units of length were officially derived in both English systems.

In the 19th and 20th centuries, increasingly powerful microscopes and scientific measurement detected variation in these prototype yards which became significant as technology improved. In 1959, the United States, United Kingdom, Australia, New Zealand, and South Africa agreed to adopt the Canadian compromise value of 0.9144 meters per yard.

The term yard is also sometimes used for translating related lengths in other systems.

Name

The name derives from the Old English gerd, gyrd, &c., which was used for branches, staves, and measuring rods. It is first attested in the late-7th century laws of Ine of Wessex, where the "yard of land" mentioned is the yardland, an old English unit of tax assessment equal to ¹⁄₄ hide. Around the same time, the Lindisfarne Gospel's account of the messengers from John the Baptist in the Book of Matthew used it for a branch swayed by the wind. In addition to the yardland, Old and Middle English both used their forms of "yard" to denote the surveying lengths of 15 or 16 ¹⁄₂ ft used in computing acres, a distance now usually known as the "rod".

Yard (land)

A yard is an area of land immediately adjacent to a building or a group of buildings. It may be either enclosed or open. The word comes from the same linguistic root as the word garden and has many of the same meanings.

A number of derived words exist, usually tied to a particular usage or building type. Some may be archaic or in lesser use now. Examples of such words are: courtyard, barnyard, hopyard, graveyard, churchyard, brickyard, prison yard, railyard, junkyard and stableyard.

Word origin

The word "yard" came from the Anglo-Saxon geard, compare "garden" (German Garten), Old Norse garðr, Russian gorod = "town" (originally as an "enclosed fortified area"), Latin hortus = "garden" (hence horticulture and orchard), from Greek χορτος (hortos) = "farm-yard", "feeding-place", "fodder", (from which "hay" originally as grown in an enclosed field). "Girdle," and "court" are other related words from the same root.

In areas where farming is an important part of life, a yard is also a piece of enclosed land for farm animals or other agricultural purpose, often referred to as a cattleyard, sheepyard, stockyard, etc. In Australia portable or mobile yards are sets of transportable steel panels used to build temporary stockyards.

Rail yard

A rail yard, railway yard or railroad yard is the US term for a complex series of railroad tracks for storing, sorting, or loading/unloading, railroad cars and/or locomotives. Railroad yards have many tracks in parallel for keeping rolling stock stored off the mainline, so that they do not obstruct the flow of traffic. Railroad cars are moved around by specially designed yard switchers, a type of locomotive. Cars in a railroad yard may be sorted by numerous categories, including railroad company, loaded or unloaded, destination, car type, or whether they need repairs. Railroad yards are normally built where there is a need to store cars while they are not being loaded or unloaded, or are waiting to be assembled into trains. Large yards may have a tower to control operations.

Many railway yards are located at strategic points on a main line. Main line yards are often composed of an Up yard and a Down yard, linked to the associated railroad direction. There are different types of yards, and different parts within a yard, depending on how they are built.