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rail,common name for some members of the large family Rallidae, marsh and tropical forest birds that include the gallinule and the cootcoot,
common name for a migratory marsh bird related to rails and gallinules and found in North America and Europe. The American coot (Fulica americana), or mud hen, is slate gray with a white bill, black head and neck, and white wing edgings and tail patch.
..... Click the link for more information. , two specialized rails. Rails are cosmopolitan in distribution, except in polar regions. Although migratory, they have small wings and are weak fliers, escaping danger by concealment rather than flight. They are protectively colored in drab browns and reds and have extremely slender bodies (whence the expression "thin as a rail") and strong legs, enabling them to dart through thick marsh vegetation undetected. Rails, also called mud hens or marsh hens, are omnivorous, hunting their food at nightfall. They may be divided into two major types: the long-billed rails, which include the Virginia (Rallus limicola), king, clapper, and water rails; and those with short, conical bills, including the sora (Porzana carolina), yellow, and black rails (called crakes in Europe.) Gallinules are rails that have webbed toes; they are more aquatic and less timid than those members of the family specifically called rails. They have bright forehead shields and are widespread in temperate and tropical regions. The common American gallinule, Gallinula chloropus, and the similar Eurasian moorhen are drab in color; the gaudier purple gallinule, Porphyrula martinica, found from Texas to Ecuador, has blue-green plumage and yellow legs. Fifteen species of extinct flightless rails are known, and a number of flightless rails and gallinules still exist. The rails are all considered good game birds and are perhaps the most widely distributed of all the avian families. Rails are classified in the phylum ChordataChordata
, phylum of animals having a notochord, or dorsal stiffening rod, as the chief internal skeletal support at some stage of their development. Most chordates are vertebrates (animals with backbones), but the phylum also includes some small marine invertebrate animals.
..... Click the link for more information. , subphylum Vertebrata, class Aves, order Gruiformes, family Rallidae.
a wooden or metal plank mounted above the bulwarks or stanchions and lifelines of a vessel.
a bar of grooved and rolled steel that is used for the movement of railroad and subway rolling stock, streetcars, locomotives, pit cars, monorail cars, crane trolleys, and other structures that are capable of locomotion, turning, or revolving.
Metal rails were first produced in 1767 in Great Britain. In Russia cast-iron rails were used in mine and factory lines in 1788 at the Alexander Cannon Factory in Petrozavodsk. Rolled-steel rails were widely used in the second half of the 19th century—in Russia they were manufactured in, for example, the Putilov Factory. Rails are now produced by means of rolling production and are made of special rail steel, which has a chemical composition that is determined by government standards.
Railroad rails are part of a track superstructure and are laid on supports and are attached to the supports and to each other, forming a track. Railroad rails receive the load stress of the rolling-stock wheels. In the USSR there are four types of rails—R43, R50, R65, and R75—each classified according to a rounded-off weight of 1 m. The cross section of the rails is similar to that of an I-beam, and its dimensions are regulated by government standards. The selection of a rail type depends on the freight-traffic density of the line. In the mid-1950’s rails 12.5 m long were produced. Since the early 1970’s there has been a transition to rails 25 m long. Short rails are produced for laying track in curved sections. The basic information about the rail is registered on each rolled bar. Railroad rails produced outside the USSR differ somewhat from those produced within the country, although their cross section is also shaped like an I-beam.
Streetcar rails are made in the same way as railroad rails, but they have a depression and are usually higher and have a greater cross section area. These rails are 15–18 m long and are usually welded together upon laying the track.
Rails lighter than railroad rails are used for pit cars, mobile hoisting cranes and their mechanisms, and turning and rotary units; in some cases, these rails have a special cross section.
REFERENCESShakhuniants, G. M. Zheleznodorozhnyi put’. Moscow, 1969.
Chernyshev, M. A. Zheleznodorozhnyi put’. Moscow, 1974.
V. I. TIKHOMIROV
rail(1) See The Rail and Ruby.
(2) A DC voltage in a power supply. A computer's power supply converts AC power into several DC voltages (typically plus and minus 3.3v, 5v and 12v), each of which is known as a rail. The term comes from the power lines on motherboards. Power must be available throughout a motherboard; hence, voltage lines tend to run in long strips like railroad tracks.